These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

11 files changed, 7328 insertions, 0 deletions

diff --git a/kernel/drivers/scsi/cxlflash/Kconfig b/kernel/drivers/scsi/cxlflash/Kconfig
new file mode 100644
index 000000000..c052104e5
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/Kconfig
@@ -0,0 +1,11 @@
+#
+# IBM CXL-attached Flash Accelerator SCSI Driver
+#
+
+config CXLFLASH
+	tristate "Support for IBM CAPI Flash"
+	depends on PCI && SCSI && CXL && EEH
+	default m
+	help
+	  Allows CAPI Accelerated IO to Flash
+	  If unsure, say N.
diff --git a/kernel/drivers/scsi/cxlflash/Makefile b/kernel/drivers/scsi/cxlflash/Makefile
new file mode 100644
index 000000000..9e39866d4
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_CXLFLASH) += cxlflash.o
+cxlflash-y += main.o superpipe.o lunmgt.o vlun.o
diff --git a/kernel/drivers/scsi/cxlflash/common.h b/kernel/drivers/scsi/cxlflash/common.h
new file mode 100644
index 000000000..c11cd193f
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/common.h
@@ -0,0 +1,204 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXLFLASH_COMMON_H
+#define _CXLFLASH_COMMON_H
+
+#include <linux/list.h>
+#include <linux/rwsem.h>
+#include <linux/types.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_device.h>
+
+extern const struct file_operations cxlflash_cxl_fops;
+
+#define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
+
+#define CXLFLASH_BLOCK_SIZE	4096	/* 4K blocks */
+#define CXLFLASH_MAX_XFER_SIZE	16777216	/* 16MB transfer */
+#define CXLFLASH_MAX_SECTORS	(CXLFLASH_MAX_XFER_SIZE/512)	/* SCSI wants
+								   max_sectors
+								   in units of
+								   512 byte
+								   sectors
+								*/
+
+#define NUM_RRQ_ENTRY    16     /* for master issued cmds */
+#define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
+
+/* AFU command retry limit */
+#define MC_RETRY_CNT         5	/* sufficient for SCSI check and
+				   certain AFU errors */
+
+/* Command management definitions */
+#define CXLFLASH_NUM_CMDS	(2 * CXLFLASH_MAX_CMDS)	/* Must be a pow2 for
+							   alignment and more
+							   efficient array
+							   index derivation
+							 */
+
+#define CXLFLASH_MAX_CMDS               16
+#define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
+
+
+static inline void check_sizes(void)
+{
+	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
+}
+
+/* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
+#define CMD_BUFSIZE     SIZE_4K
+
+/* flags in IOA status area for host use */
+#define B_DONE       0x01
+#define B_ERROR      0x02	/* set with B_DONE */
+#define B_TIMEOUT    0x04	/* set with B_DONE & B_ERROR */
+
+enum cxlflash_lr_state {
+	LINK_RESET_INVALID,
+	LINK_RESET_REQUIRED,
+	LINK_RESET_COMPLETE
+};
+
+enum cxlflash_init_state {
+	INIT_STATE_NONE,
+	INIT_STATE_PCI,
+	INIT_STATE_AFU,
+	INIT_STATE_SCSI
+};
+
+enum cxlflash_state {
+	STATE_NORMAL,	/* Normal running state, everything good */
+	STATE_RESET,	/* Reset state, trying to reset/recover */
+	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
+};
+
+/*
+ * Each context has its own set of resource handles that is visible
+ * only from that context.
+ */
+
+struct cxlflash_cfg {
+	struct afu *afu;
+	struct cxl_context *mcctx;
+
+	struct pci_dev *dev;
+	struct pci_device_id *dev_id;
+	struct Scsi_Host *host;
+
+	ulong cxlflash_regs_pci;
+
+	struct work_struct work_q;
+	enum cxlflash_init_state init_state;
+	enum cxlflash_lr_state lr_state;
+	int lr_port;
+	atomic_t scan_host_needed;
+
+	struct cxl_afu *cxl_afu;
+	struct pci_dev *parent_dev;
+
+	atomic_t recovery_threads;
+	struct mutex ctx_recovery_mutex;
+	struct mutex ctx_tbl_list_mutex;
+	struct rw_semaphore ioctl_rwsem;
+	struct ctx_info *ctx_tbl[MAX_CONTEXT];
+	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
+	struct file_operations cxl_fops;
+
+	/* Parameters that are LUN table related */
+	int last_lun_index[CXLFLASH_NUM_FC_PORTS];
+	int promote_lun_index;
+	struct list_head lluns; /* list of llun_info structs */
+
+	wait_queue_head_t tmf_waitq;
+	spinlock_t tmf_slock;
+	bool tmf_active;
+	wait_queue_head_t reset_waitq;
+	enum cxlflash_state state;
+};
+
+struct afu_cmd {
+	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
+	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
+	spinlock_t slock;
+	struct completion cevent;
+	char *buf;		/* per command buffer */
+	struct afu *parent;
+	int slot;
+	atomic_t free;
+
+	u8 cmd_tmf:1;
+
+	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
+	 * However for performance reasons the IOARCB/IOASA should be
+	 * cache line aligned.
+	 */
+} __aligned(cache_line_size());
+
+struct afu {
+	/* Stuff requiring alignment go first. */
+
+	u64 rrq_entry[NUM_RRQ_ENTRY];	/* 128B RRQ */
+	/*
+	 * Command & data for AFU commands.
+	 */
+	struct afu_cmd cmd[CXLFLASH_NUM_CMDS];
+
+	/* Beware of alignment till here. Preferably introduce new
+	 * fields after this point
+	 */
+
+	/* AFU HW */
+	struct cxl_ioctl_start_work work;
+	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
+	struct sisl_host_map __iomem *host_map;		/* MC host map */
+	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
+
+	ctx_hndl_t ctx_hndl;	/* master's context handle */
+	u64 *hrrq_start;
+	u64 *hrrq_end;
+	u64 *hrrq_curr;
+	bool toggle;
+	bool read_room;
+	atomic64_t room;
+	u64 hb;
+	u32 cmd_couts;		/* Number of command checkouts */
+	u32 internal_lun;	/* User-desired LUN mode for this AFU */
+
+	char version[16];
+	u64 interface_version;
+
+	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
+
+};
+
+static inline u64 lun_to_lunid(u64 lun)
+{
+	__be64 lun_id;
+
+	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
+	return be64_to_cpu(lun_id);
+}
+
+int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
+void cxlflash_list_init(void);
+void cxlflash_term_global_luns(void);
+void cxlflash_free_errpage(void);
+int cxlflash_ioctl(struct scsi_device *, int, void __user *);
+void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
+int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
+void cxlflash_term_local_luns(struct cxlflash_cfg *);
+void cxlflash_restore_luntable(struct cxlflash_cfg *);
+
+#endif /* ifndef _CXLFLASH_COMMON_H */
diff --git a/kernel/drivers/scsi/cxlflash/lunmgt.c b/kernel/drivers/scsi/cxlflash/lunmgt.c
new file mode 100644
index 000000000..a0923cade
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/lunmgt.c
@@ -0,0 +1,269 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <misc/cxl.h>
+#include <asm/unaligned.h>
+
+#include <scsi/scsi_host.h>
+#include <uapi/scsi/cxlflash_ioctl.h>
+
+#include "sislite.h"
+#include "common.h"
+#include "vlun.h"
+#include "superpipe.h"
+
+/**
+ * create_local() - allocate and initialize a local LUN information structure
+ * @sdev:	SCSI device associated with LUN.
+ * @wwid:	World Wide Node Name for LUN.
+ *
+ * Return: Allocated local llun_info structure on success, NULL on failure
+ */
+static struct llun_info *create_local(struct scsi_device *sdev, u8 *wwid)
+{
+	struct llun_info *lli = NULL;
+
+	lli = kzalloc(sizeof(*lli), GFP_KERNEL);
+	if (unlikely(!lli)) {
+		pr_err("%s: could not allocate lli\n", __func__);
+		goto out;
+	}
+
+	lli->sdev = sdev;
+	lli->host_no = sdev->host->host_no;
+	lli->in_table = false;
+
+	memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
+out:
+	return lli;
+}
+
+/**
+ * create_global() - allocate and initialize a global LUN information structure
+ * @sdev:	SCSI device associated with LUN.
+ * @wwid:	World Wide Node Name for LUN.
+ *
+ * Return: Allocated global glun_info structure on success, NULL on failure
+ */
+static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid)
+{
+	struct glun_info *gli = NULL;
+
+	gli = kzalloc(sizeof(*gli), GFP_KERNEL);
+	if (unlikely(!gli)) {
+		pr_err("%s: could not allocate gli\n", __func__);
+		goto out;
+	}
+
+	mutex_init(&gli->mutex);
+	memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
+out:
+	return gli;
+}
+
+/**
+ * lookup_local() - find a local LUN information structure by WWID
+ * @cfg:	Internal structure associated with the host.
+ * @wwid:	WWID associated with LUN.
+ *
+ * Return: Found local lun_info structure on success, NULL on failure
+ */
+static struct llun_info *lookup_local(struct cxlflash_cfg *cfg, u8 *wwid)
+{
+	struct llun_info *lli, *temp;
+
+	list_for_each_entry_safe(lli, temp, &cfg->lluns, list)
+		if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
+			return lli;
+
+	return NULL;
+}
+
+/**
+ * lookup_global() - find a global LUN information structure by WWID
+ * @wwid:	WWID associated with LUN.
+ *
+ * Return: Found global lun_info structure on success, NULL on failure
+ */
+static struct glun_info *lookup_global(u8 *wwid)
+{
+	struct glun_info *gli, *temp;
+
+	list_for_each_entry_safe(gli, temp, &global.gluns, list)
+		if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
+			return gli;
+
+	return NULL;
+}
+
+/**
+ * find_and_create_lun() - find or create a local LUN information structure
+ * @sdev:	SCSI device associated with LUN.
+ * @wwid:	WWID associated with LUN.
+ *
+ * The LUN is kept both in a local list (per adapter) and in a global list
+ * (across all adapters). Certain attributes of the LUN are local to the
+ * adapter (such as index, port selection mask, etc.).
+ *
+ * The block allocation map is shared across all adapters (i.e. associated
+ * wih the global list). Since different attributes are associated with
+ * the per adapter and global entries, allocate two separate structures for each
+ * LUN (one local, one global).
+ *
+ * Keep a pointer back from the local to the global entry.
+ *
+ * This routine assumes the caller holds the global mutex.
+ *
+ * Return: Found/Allocated local lun_info structure on success, NULL on failure
+ */
+static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
+{
+	struct llun_info *lli = NULL;
+	struct glun_info *gli = NULL;
+	struct Scsi_Host *shost = sdev->host;
+	struct cxlflash_cfg *cfg = shost_priv(shost);
+
+	if (unlikely(!wwid))
+		goto out;
+
+	lli = lookup_local(cfg, wwid);
+	if (lli)
+		goto out;
+
+	lli = create_local(sdev, wwid);
+	if (unlikely(!lli))
+		goto out;
+
+	gli = lookup_global(wwid);
+	if (gli) {
+		lli->parent = gli;
+		list_add(&lli->list, &cfg->lluns);
+		goto out;
+	}
+
+	gli = create_global(sdev, wwid);
+	if (unlikely(!gli)) {
+		kfree(lli);
+		lli = NULL;
+		goto out;
+	}
+
+	lli->parent = gli;
+	list_add(&lli->list, &cfg->lluns);
+
+	list_add(&gli->list, &global.gluns);
+
+out:
+	pr_debug("%s: returning %p\n", __func__, lli);
+	return lli;
+}
+
+/**
+ * cxlflash_term_local_luns() - Delete all entries from local LUN list, free.
+ * @cfg:	Internal structure associated with the host.
+ */
+void cxlflash_term_local_luns(struct cxlflash_cfg *cfg)
+{
+	struct llun_info *lli, *temp;
+
+	mutex_lock(&global.mutex);
+	list_for_each_entry_safe(lli, temp, &cfg->lluns, list) {
+		list_del(&lli->list);
+		kfree(lli);
+	}
+	mutex_unlock(&global.mutex);
+}
+
+/**
+ * cxlflash_list_init() - initializes the global LUN list
+ */
+void cxlflash_list_init(void)
+{
+	INIT_LIST_HEAD(&global.gluns);
+	mutex_init(&global.mutex);
+	global.err_page = NULL;
+}
+
+/**
+ * cxlflash_term_global_luns() - frees resources associated with global LUN list
+ */
+void cxlflash_term_global_luns(void)
+{
+	struct glun_info *gli, *temp;
+
+	mutex_lock(&global.mutex);
+	list_for_each_entry_safe(gli, temp, &global.gluns, list) {
+		list_del(&gli->list);
+		cxlflash_ba_terminate(&gli->blka.ba_lun);
+		kfree(gli);
+	}
+	mutex_unlock(&global.mutex);
+}
+
+/**
+ * cxlflash_manage_lun() - handles LUN management activities
+ * @sdev:	SCSI device associated with LUN.
+ * @manage:	Manage ioctl data structure.
+ *
+ * This routine is used to notify the driver about a LUN's WWID and associate
+ * SCSI devices (sdev) with a global LUN instance. Additionally it serves to
+ * change a LUN's operating mode: legacy or superpipe.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_manage_lun(struct scsi_device *sdev,
+			struct dk_cxlflash_manage_lun *manage)
+{
+	int rc = 0;
+	struct llun_info *lli = NULL;
+	u64 flags = manage->hdr.flags;
+	u32 chan = sdev->channel;
+
+	mutex_lock(&global.mutex);
+	lli = find_and_create_lun(sdev, manage->wwid);
+	pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n",
+		 __func__, get_unaligned_be64(&manage->wwid[0]),
+		 get_unaligned_be64(&manage->wwid[8]),
+		 manage->hdr.flags, lli);
+	if (unlikely(!lli)) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) {
+		/*
+		 * Update port selection mask based upon channel, store off LUN
+		 * in unpacked, AFU-friendly format, and hang LUN reference in
+		 * the sdev.
+		 */
+		lli->port_sel |= CHAN2PORT(chan);
+		lli->lun_id[chan] = lun_to_lunid(sdev->lun);
+		sdev->hostdata = lli;
+	} else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) {
+		if (lli->parent->mode != MODE_NONE)
+			rc = -EBUSY;
+		else {
+			sdev->hostdata = NULL;
+			lli->port_sel &= ~CHAN2PORT(chan);
+		}
+	}
+
+	pr_debug("%s: port_sel = %08X chan = %u lun_id = %016llX\n", __func__,
+		 lli->port_sel, chan, lli->lun_id[chan]);
+
+out:
+	mutex_unlock(&global.mutex);
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
diff --git a/kernel/drivers/scsi/cxlflash/main.c b/kernel/drivers/scsi/cxlflash/main.c
new file mode 100644
index 000000000..1e5bf0ca8
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/main.c
@@ -0,0 +1,2608 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <asm/unaligned.h>
+
+#include <misc/cxl.h>
+
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <uapi/scsi/cxlflash_ioctl.h>
+
+#include "main.h"
+#include "sislite.h"
+#include "common.h"
+
+MODULE_DESCRIPTION(CXLFLASH_ADAPTER_NAME);
+MODULE_AUTHOR("Manoj N. Kumar <manoj@linux.vnet.ibm.com>");
+MODULE_AUTHOR("Matthew R. Ochs <mrochs@linux.vnet.ibm.com>");
+MODULE_LICENSE("GPL");
+
+/**
+ * cmd_checkout() - checks out an AFU command
+ * @afu:	AFU to checkout from.
+ *
+ * Commands are checked out in a round-robin fashion. Note that since
+ * the command pool is larger than the hardware queue, the majority of
+ * times we will only loop once or twice before getting a command. The
+ * buffer and CDB within the command are initialized (zeroed) prior to
+ * returning.
+ *
+ * Return: The checked out command or NULL when command pool is empty.
+ */
+static struct afu_cmd *cmd_checkout(struct afu *afu)
+{
+	int k, dec = CXLFLASH_NUM_CMDS;
+	struct afu_cmd *cmd;
+
+	while (dec--) {
+		k = (afu->cmd_couts++ & (CXLFLASH_NUM_CMDS - 1));
+
+		cmd = &afu->cmd[k];
+
+		if (!atomic_dec_if_positive(&cmd->free)) {
+			pr_devel("%s: returning found index=%d cmd=%p\n",
+				 __func__, cmd->slot, cmd);
+			memset(cmd->buf, 0, CMD_BUFSIZE);
+			memset(cmd->rcb.cdb, 0, sizeof(cmd->rcb.cdb));
+			return cmd;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * cmd_checkin() - checks in an AFU command
+ * @cmd:	AFU command to checkin.
+ *
+ * Safe to pass commands that have already been checked in. Several
+ * internal tracking fields are reset as part of the checkin. Note
+ * that these are intentionally reset prior to toggling the free bit
+ * to avoid clobbering values in the event that the command is checked
+ * out right away.
+ */
+static void cmd_checkin(struct afu_cmd *cmd)
+{
+	cmd->rcb.scp = NULL;
+	cmd->rcb.timeout = 0;
+	cmd->sa.ioasc = 0;
+	cmd->cmd_tmf = false;
+	cmd->sa.host_use[0] = 0; /* clears both completion and retry bytes */
+
+	if (unlikely(atomic_inc_return(&cmd->free) != 1)) {
+		pr_err("%s: Freeing cmd (%d) that is not in use!\n",
+		       __func__, cmd->slot);
+		return;
+	}
+
+	pr_devel("%s: released cmd %p index=%d\n", __func__, cmd, cmd->slot);
+}
+
+/**
+ * process_cmd_err() - command error handler
+ * @cmd:	AFU command that experienced the error.
+ * @scp:	SCSI command associated with the AFU command in error.
+ *
+ * Translates error bits from AFU command to SCSI command results.
+ */
+static void process_cmd_err(struct afu_cmd *cmd, struct scsi_cmnd *scp)
+{
+	struct sisl_ioarcb *ioarcb;
+	struct sisl_ioasa *ioasa;
+	u32 resid;
+
+	if (unlikely(!cmd))
+		return;
+
+	ioarcb = &(cmd->rcb);
+	ioasa = &(cmd->sa);
+
+	if (ioasa->rc.flags & SISL_RC_FLAGS_UNDERRUN) {
+		resid = ioasa->resid;
+		scsi_set_resid(scp, resid);
+		pr_debug("%s: cmd underrun cmd = %p scp = %p, resid = %d\n",
+			 __func__, cmd, scp, resid);
+	}
+
+	if (ioasa->rc.flags & SISL_RC_FLAGS_OVERRUN) {
+		pr_debug("%s: cmd underrun cmd = %p scp = %p\n",
+			 __func__, cmd, scp);
+		scp->result = (DID_ERROR << 16);
+	}
+
+	pr_debug("%s: cmd failed afu_rc=%d scsi_rc=%d fc_rc=%d "
+		 "afu_extra=0x%X, scsi_extra=0x%X, fc_extra=0x%X\n",
+		 __func__, ioasa->rc.afu_rc, ioasa->rc.scsi_rc,
+		 ioasa->rc.fc_rc, ioasa->afu_extra, ioasa->scsi_extra,
+		 ioasa->fc_extra);
+
+	if (ioasa->rc.scsi_rc) {
+		/* We have a SCSI status */
+		if (ioasa->rc.flags & SISL_RC_FLAGS_SENSE_VALID) {
+			memcpy(scp->sense_buffer, ioasa->sense_data,
+			       SISL_SENSE_DATA_LEN);
+			scp->result = ioasa->rc.scsi_rc;
+		} else
+			scp->result = ioasa->rc.scsi_rc | (DID_ERROR << 16);
+	}
+
+	/*
+	 * We encountered an error. Set scp->result based on nature
+	 * of error.
+	 */
+	if (ioasa->rc.fc_rc) {
+		/* We have an FC status */
+		switch (ioasa->rc.fc_rc) {
+		case SISL_FC_RC_LINKDOWN:
+			scp->result = (DID_REQUEUE << 16);
+			break;
+		case SISL_FC_RC_RESID:
+			/* This indicates an FCP resid underrun */
+			if (!(ioasa->rc.flags & SISL_RC_FLAGS_OVERRUN)) {
+				/* If the SISL_RC_FLAGS_OVERRUN flag was set,
+				 * then we will handle this error else where.
+				 * If not then we must handle it here.
+				 * This is probably an AFU bug.
+				 */
+				scp->result = (DID_ERROR << 16);
+			}
+			break;
+		case SISL_FC_RC_RESIDERR:
+			/* Resid mismatch between adapter and device */
+		case SISL_FC_RC_TGTABORT:
+		case SISL_FC_RC_ABORTOK:
+		case SISL_FC_RC_ABORTFAIL:
+		case SISL_FC_RC_NOLOGI:
+		case SISL_FC_RC_ABORTPEND:
+		case SISL_FC_RC_WRABORTPEND:
+		case SISL_FC_RC_NOEXP:
+		case SISL_FC_RC_INUSE:
+			scp->result = (DID_ERROR << 16);
+			break;
+		}
+	}
+
+	if (ioasa->rc.afu_rc) {
+		/* We have an AFU error */
+		switch (ioasa->rc.afu_rc) {
+		case SISL_AFU_RC_NO_CHANNELS:
+			scp->result = (DID_NO_CONNECT << 16);
+			break;
+		case SISL_AFU_RC_DATA_DMA_ERR:
+			switch (ioasa->afu_extra) {
+			case SISL_AFU_DMA_ERR_PAGE_IN:
+				/* Retry */
+				scp->result = (DID_IMM_RETRY << 16);
+				break;
+			case SISL_AFU_DMA_ERR_INVALID_EA:
+			default:
+				scp->result = (DID_ERROR << 16);
+			}
+			break;
+		case SISL_AFU_RC_OUT_OF_DATA_BUFS:
+			/* Retry */
+			scp->result = (DID_ALLOC_FAILURE << 16);
+			break;
+		default:
+			scp->result = (DID_ERROR << 16);
+		}
+	}
+}
+
+/**
+ * cmd_complete() - command completion handler
+ * @cmd:	AFU command that has completed.
+ *
+ * Prepares and submits command that has either completed or timed out to
+ * the SCSI stack. Checks AFU command back into command pool for non-internal
+ * (rcb.scp populated) commands.
+ */
+static void cmd_complete(struct afu_cmd *cmd)
+{
+	struct scsi_cmnd *scp;
+	ulong lock_flags;
+	struct afu *afu = cmd->parent;
+	struct cxlflash_cfg *cfg = afu->parent;
+	bool cmd_is_tmf;
+
+	spin_lock_irqsave(&cmd->slock, lock_flags);
+	cmd->sa.host_use_b[0] |= B_DONE;
+	spin_unlock_irqrestore(&cmd->slock, lock_flags);
+
+	if (cmd->rcb.scp) {
+		scp = cmd->rcb.scp;
+		if (unlikely(cmd->sa.ioasc))
+			process_cmd_err(cmd, scp);
+		else
+			scp->result = (DID_OK << 16);
+
+		cmd_is_tmf = cmd->cmd_tmf;
+		cmd_checkin(cmd); /* Don't use cmd after here */
+
+		pr_debug_ratelimited("%s: calling scsi_done scp=%p result=%X "
+				     "ioasc=%d\n", __func__, scp, scp->result,
+				     cmd->sa.ioasc);
+
+		scsi_dma_unmap(scp);
+		scp->scsi_done(scp);
+
+		if (cmd_is_tmf) {
+			spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+			cfg->tmf_active = false;
+			wake_up_all_locked(&cfg->tmf_waitq);
+			spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+		}
+	} else
+		complete(&cmd->cevent);
+}
+
+/**
+ * context_reset() - timeout handler for AFU commands
+ * @cmd:	AFU command that timed out.
+ *
+ * Sends a reset to the AFU.
+ */
+static void context_reset(struct afu_cmd *cmd)
+{
+	int nretry = 0;
+	u64 rrin = 0x1;
+	u64 room = 0;
+	struct afu *afu = cmd->parent;
+	ulong lock_flags;
+
+	pr_debug("%s: cmd=%p\n", __func__, cmd);
+
+	spin_lock_irqsave(&cmd->slock, lock_flags);
+
+	/* Already completed? */
+	if (cmd->sa.host_use_b[0] & B_DONE) {
+		spin_unlock_irqrestore(&cmd->slock, lock_flags);
+		return;
+	}
+
+	cmd->sa.host_use_b[0] |= (B_DONE | B_ERROR | B_TIMEOUT);
+	spin_unlock_irqrestore(&cmd->slock, lock_flags);
+
+	/*
+	 * We really want to send this reset at all costs, so spread
+	 * out wait time on successive retries for available room.
+	 */
+	do {
+		room = readq_be(&afu->host_map->cmd_room);
+		atomic64_set(&afu->room, room);
+		if (room)
+			goto write_rrin;
+		udelay(nretry);
+	} while (nretry++ < MC_ROOM_RETRY_CNT);
+
+	pr_err("%s: no cmd_room to send reset\n", __func__);
+	return;
+
+write_rrin:
+	nretry = 0;
+	writeq_be(rrin, &afu->host_map->ioarrin);
+	do {
+		rrin = readq_be(&afu->host_map->ioarrin);
+		if (rrin != 0x1)
+			break;
+		/* Double delay each time */
+		udelay(2 << nretry);
+	} while (nretry++ < MC_ROOM_RETRY_CNT);
+}
+
+/**
+ * send_cmd() - sends an AFU command
+ * @afu:	AFU associated with the host.
+ * @cmd:	AFU command to send.
+ *
+ * Return:
+ *	0 on success, SCSI_MLQUEUE_HOST_BUSY on failure
+ */
+static int send_cmd(struct afu *afu, struct afu_cmd *cmd)
+{
+	struct cxlflash_cfg *cfg = afu->parent;
+	struct device *dev = &cfg->dev->dev;
+	int nretry = 0;
+	int rc = 0;
+	u64 room;
+	long newval;
+
+	/*
+	 * This routine is used by critical users such an AFU sync and to
+	 * send a task management function (TMF). Thus we want to retry a
+	 * bit before returning an error. To avoid the performance penalty
+	 * of MMIO, we spread the update of 'room' over multiple commands.
+	 */
+retry:
+	newval = atomic64_dec_if_positive(&afu->room);
+	if (!newval) {
+		do {
+			room = readq_be(&afu->host_map->cmd_room);
+			atomic64_set(&afu->room, room);
+			if (room)
+				goto write_ioarrin;
+			udelay(nretry);
+		} while (nretry++ < MC_ROOM_RETRY_CNT);
+
+		dev_err(dev, "%s: no cmd_room to send 0x%X\n",
+		       __func__, cmd->rcb.cdb[0]);
+
+		goto no_room;
+	} else if (unlikely(newval < 0)) {
+		/* This should be rare. i.e. Only if two threads race and
+		 * decrement before the MMIO read is done. In this case
+		 * just benefit from the other thread having updated
+		 * afu->room.
+		 */
+		if (nretry++ < MC_ROOM_RETRY_CNT) {
+			udelay(nretry);
+			goto retry;
+		}
+
+		goto no_room;
+	}
+
+write_ioarrin:
+	writeq_be((u64)&cmd->rcb, &afu->host_map->ioarrin);
+out:
+	pr_devel("%s: cmd=%p len=%d ea=%p rc=%d\n", __func__, cmd,
+		 cmd->rcb.data_len, (void *)cmd->rcb.data_ea, rc);
+	return rc;
+
+no_room:
+	afu->read_room = true;
+	schedule_work(&cfg->work_q);
+	rc = SCSI_MLQUEUE_HOST_BUSY;
+	goto out;
+}
+
+/**
+ * wait_resp() - polls for a response or timeout to a sent AFU command
+ * @afu:	AFU associated with the host.
+ * @cmd:	AFU command that was sent.
+ */
+static void wait_resp(struct afu *afu, struct afu_cmd *cmd)
+{
+	ulong timeout = msecs_to_jiffies(cmd->rcb.timeout * 2 * 1000);
+
+	timeout = wait_for_completion_timeout(&cmd->cevent, timeout);
+	if (!timeout)
+		context_reset(cmd);
+
+	if (unlikely(cmd->sa.ioasc != 0))
+		pr_err("%s: CMD 0x%X failed, IOASC: flags 0x%X, afu_rc 0x%X, "
+		       "scsi_rc 0x%X, fc_rc 0x%X\n", __func__, cmd->rcb.cdb[0],
+		       cmd->sa.rc.flags, cmd->sa.rc.afu_rc, cmd->sa.rc.scsi_rc,
+		       cmd->sa.rc.fc_rc);
+}
+
+/**
+ * send_tmf() - sends a Task Management Function (TMF)
+ * @afu:	AFU to checkout from.
+ * @scp:	SCSI command from stack.
+ * @tmfcmd:	TMF command to send.
+ *
+ * Return:
+ *	0 on success, SCSI_MLQUEUE_HOST_BUSY on failure
+ */
+static int send_tmf(struct afu *afu, struct scsi_cmnd *scp, u64 tmfcmd)
+{
+	struct afu_cmd *cmd;
+
+	u32 port_sel = scp->device->channel + 1;
+	short lflag = 0;
+	struct Scsi_Host *host = scp->device->host;
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	ulong lock_flags;
+	int rc = 0;
+	ulong to;
+
+	cmd = cmd_checkout(afu);
+	if (unlikely(!cmd)) {
+		dev_err(dev, "%s: could not get a free command\n", __func__);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	/* When Task Management Function is active do not send another */
+	spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+	if (cfg->tmf_active)
+		wait_event_interruptible_lock_irq(cfg->tmf_waitq,
+						  !cfg->tmf_active,
+						  cfg->tmf_slock);
+	cfg->tmf_active = true;
+	cmd->cmd_tmf = true;
+	spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+
+	cmd->rcb.ctx_id = afu->ctx_hndl;
+	cmd->rcb.port_sel = port_sel;
+	cmd->rcb.lun_id = lun_to_lunid(scp->device->lun);
+
+	lflag = SISL_REQ_FLAGS_TMF_CMD;
+
+	cmd->rcb.req_flags = (SISL_REQ_FLAGS_PORT_LUN_ID |
+			      SISL_REQ_FLAGS_SUP_UNDERRUN | lflag);
+
+	/* Stash the scp in the reserved field, for reuse during interrupt */
+	cmd->rcb.scp = scp;
+
+	/* Copy the CDB from the cmd passed in */
+	memcpy(cmd->rcb.cdb, &tmfcmd, sizeof(tmfcmd));
+
+	/* Send the command */
+	rc = send_cmd(afu, cmd);
+	if (unlikely(rc)) {
+		cmd_checkin(cmd);
+		spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+		cfg->tmf_active = false;
+		spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+		goto out;
+	}
+
+	spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+	to = msecs_to_jiffies(5000);
+	to = wait_event_interruptible_lock_irq_timeout(cfg->tmf_waitq,
+						       !cfg->tmf_active,
+						       cfg->tmf_slock,
+						       to);
+	if (!to) {
+		cfg->tmf_active = false;
+		dev_err(dev, "%s: TMF timed out!\n", __func__);
+		rc = -1;
+	}
+	spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+out:
+	return rc;
+}
+
+/**
+ * cxlflash_driver_info() - information handler for this host driver
+ * @host:	SCSI host associated with device.
+ *
+ * Return: A string describing the device.
+ */
+static const char *cxlflash_driver_info(struct Scsi_Host *host)
+{
+	return CXLFLASH_ADAPTER_NAME;
+}
+
+/**
+ * cxlflash_queuecommand() - sends a mid-layer request
+ * @host:	SCSI host associated with device.
+ * @scp:	SCSI command to send.
+ *
+ * Return: 0 on success, SCSI_MLQUEUE_HOST_BUSY on failure
+ */
+static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)host->hostdata;
+	struct afu *afu = cfg->afu;
+	struct device *dev = &cfg->dev->dev;
+	struct afu_cmd *cmd;
+	u32 port_sel = scp->device->channel + 1;
+	int nseg, i, ncount;
+	struct scatterlist *sg;
+	ulong lock_flags;
+	short lflag = 0;
+	int rc = 0;
+
+	dev_dbg_ratelimited(dev, "%s: (scp=%p) %d/%d/%d/%llu "
+			    "cdb=(%08X-%08X-%08X-%08X)\n",
+			    __func__, scp, host->host_no, scp->device->channel,
+			    scp->device->id, scp->device->lun,
+			    get_unaligned_be32(&((u32 *)scp->cmnd)[0]),
+			    get_unaligned_be32(&((u32 *)scp->cmnd)[1]),
+			    get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
+			    get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
+
+	/*
+	 * If a Task Management Function is active, wait for it to complete
+	 * before continuing with regular commands.
+	 */
+	spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+	if (cfg->tmf_active) {
+		spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+	spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+
+	switch (cfg->state) {
+	case STATE_RESET:
+		dev_dbg_ratelimited(dev, "%s: device is in reset!\n", __func__);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	case STATE_FAILTERM:
+		dev_dbg_ratelimited(dev, "%s: device has failed!\n", __func__);
+		scp->result = (DID_NO_CONNECT << 16);
+		scp->scsi_done(scp);
+		rc = 0;
+		goto out;
+	default:
+		break;
+	}
+
+	cmd = cmd_checkout(afu);
+	if (unlikely(!cmd)) {
+		dev_err(dev, "%s: could not get a free command\n", __func__);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	cmd->rcb.ctx_id = afu->ctx_hndl;
+	cmd->rcb.port_sel = port_sel;
+	cmd->rcb.lun_id = lun_to_lunid(scp->device->lun);
+
+	if (scp->sc_data_direction == DMA_TO_DEVICE)
+		lflag = SISL_REQ_FLAGS_HOST_WRITE;
+	else
+		lflag = SISL_REQ_FLAGS_HOST_READ;
+
+	cmd->rcb.req_flags = (SISL_REQ_FLAGS_PORT_LUN_ID |
+			      SISL_REQ_FLAGS_SUP_UNDERRUN | lflag);
+
+	/* Stash the scp in the reserved field, for reuse during interrupt */
+	cmd->rcb.scp = scp;
+
+	nseg = scsi_dma_map(scp);
+	if (unlikely(nseg < 0)) {
+		dev_err(dev, "%s: Fail DMA map! nseg=%d\n",
+			__func__, nseg);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	ncount = scsi_sg_count(scp);
+	scsi_for_each_sg(scp, sg, ncount, i) {
+		cmd->rcb.data_len = sg_dma_len(sg);
+		cmd->rcb.data_ea = sg_dma_address(sg);
+	}
+
+	/* Copy the CDB from the scsi_cmnd passed in */
+	memcpy(cmd->rcb.cdb, scp->cmnd, sizeof(cmd->rcb.cdb));
+
+	/* Send the command */
+	rc = send_cmd(afu, cmd);
+	if (unlikely(rc)) {
+		cmd_checkin(cmd);
+		scsi_dma_unmap(scp);
+	}
+
+out:
+	pr_devel("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_wait_for_pci_err_recovery() - wait for error recovery during probe
+ * @cfg:	Internal structure associated with the host.
+ */
+static void cxlflash_wait_for_pci_err_recovery(struct cxlflash_cfg *cfg)
+{
+	struct pci_dev *pdev = cfg->dev;
+
+	if (pci_channel_offline(pdev))
+		wait_event_timeout(cfg->reset_waitq,
+				   !pci_channel_offline(pdev),
+				   CXLFLASH_PCI_ERROR_RECOVERY_TIMEOUT);
+}
+
+/**
+ * free_mem() - free memory associated with the AFU
+ * @cfg:	Internal structure associated with the host.
+ */
+static void free_mem(struct cxlflash_cfg *cfg)
+{
+	int i;
+	char *buf = NULL;
+	struct afu *afu = cfg->afu;
+
+	if (cfg->afu) {
+		for (i = 0; i < CXLFLASH_NUM_CMDS; i++) {
+			buf = afu->cmd[i].buf;
+			if (!((u64)buf & (PAGE_SIZE - 1)))
+				free_page((ulong)buf);
+		}
+
+		free_pages((ulong)afu, get_order(sizeof(struct afu)));
+		cfg->afu = NULL;
+	}
+}
+
+/**
+ * stop_afu() - stops the AFU command timers and unmaps the MMIO space
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Safe to call with AFU in a partially allocated/initialized state.
+ */
+static void stop_afu(struct cxlflash_cfg *cfg)
+{
+	int i;
+	struct afu *afu = cfg->afu;
+
+	if (likely(afu)) {
+		for (i = 0; i < CXLFLASH_NUM_CMDS; i++)
+			complete(&afu->cmd[i].cevent);
+
+		if (likely(afu->afu_map)) {
+			cxl_psa_unmap((void __iomem *)afu->afu_map);
+			afu->afu_map = NULL;
+		}
+	}
+}
+
+/**
+ * term_mc() - terminates the master context
+ * @cfg:	Internal structure associated with the host.
+ * @level:	Depth of allocation, where to begin waterfall tear down.
+ *
+ * Safe to call with AFU/MC in partially allocated/initialized state.
+ */
+static void term_mc(struct cxlflash_cfg *cfg, enum undo_level level)
+{
+	int rc = 0;
+	struct afu *afu = cfg->afu;
+	struct device *dev = &cfg->dev->dev;
+
+	if (!afu || !cfg->mcctx) {
+		dev_err(dev, "%s: returning from term_mc with NULL afu or MC\n",
+		       __func__);
+		return;
+	}
+
+	switch (level) {
+	case UNDO_START:
+		rc = cxl_stop_context(cfg->mcctx);
+		BUG_ON(rc);
+	case UNMAP_THREE:
+		cxl_unmap_afu_irq(cfg->mcctx, 3, afu);
+	case UNMAP_TWO:
+		cxl_unmap_afu_irq(cfg->mcctx, 2, afu);
+	case UNMAP_ONE:
+		cxl_unmap_afu_irq(cfg->mcctx, 1, afu);
+	case FREE_IRQ:
+		cxl_free_afu_irqs(cfg->mcctx);
+	case RELEASE_CONTEXT:
+		cfg->mcctx = NULL;
+	}
+}
+
+/**
+ * term_afu() - terminates the AFU
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Safe to call with AFU/MC in partially allocated/initialized state.
+ */
+static void term_afu(struct cxlflash_cfg *cfg)
+{
+	term_mc(cfg, UNDO_START);
+
+	if (cfg->afu)
+		stop_afu(cfg);
+
+	pr_debug("%s: returning\n", __func__);
+}
+
+/**
+ * cxlflash_remove() - PCI entry point to tear down host
+ * @pdev:	PCI device associated with the host.
+ *
+ * Safe to use as a cleanup in partially allocated/initialized state.
+ */
+static void cxlflash_remove(struct pci_dev *pdev)
+{
+	struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+	ulong lock_flags;
+
+	/* If a Task Management Function is active, wait for it to complete
+	 * before continuing with remove.
+	 */
+	spin_lock_irqsave(&cfg->tmf_slock, lock_flags);
+	if (cfg->tmf_active)
+		wait_event_interruptible_lock_irq(cfg->tmf_waitq,
+						  !cfg->tmf_active,
+						  cfg->tmf_slock);
+	spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
+
+	cfg->state = STATE_FAILTERM;
+	cxlflash_stop_term_user_contexts(cfg);
+
+	switch (cfg->init_state) {
+	case INIT_STATE_SCSI:
+		cxlflash_term_local_luns(cfg);
+		scsi_remove_host(cfg->host);
+		/* fall through */
+	case INIT_STATE_AFU:
+		term_afu(cfg);
+		cancel_work_sync(&cfg->work_q);
+	case INIT_STATE_PCI:
+		pci_release_regions(cfg->dev);
+		pci_disable_device(pdev);
+	case INIT_STATE_NONE:
+		free_mem(cfg);
+		scsi_host_put(cfg->host);
+		break;
+	}
+
+	pr_debug("%s: returning\n", __func__);
+}
+
+/**
+ * alloc_mem() - allocates the AFU and its command pool
+ * @cfg:	Internal structure associated with the host.
+ *
+ * A partially allocated state remains on failure.
+ *
+ * Return:
+ *	0 on success
+ *	-ENOMEM on failure to allocate memory
+ */
+static int alloc_mem(struct cxlflash_cfg *cfg)
+{
+	int rc = 0;
+	int i;
+	char *buf = NULL;
+	struct device *dev = &cfg->dev->dev;
+
+	/* AFU is ~12k, i.e. only one 64k page or up to four 4k pages */
+	cfg->afu = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					    get_order(sizeof(struct afu)));
+	if (unlikely(!cfg->afu)) {
+		dev_err(dev, "%s: cannot get %d free pages\n",
+			__func__, get_order(sizeof(struct afu)));
+		rc = -ENOMEM;
+		goto out;
+	}
+	cfg->afu->parent = cfg;
+	cfg->afu->afu_map = NULL;
+
+	for (i = 0; i < CXLFLASH_NUM_CMDS; buf += CMD_BUFSIZE, i++) {
+		if (!((u64)buf & (PAGE_SIZE - 1))) {
+			buf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+			if (unlikely(!buf)) {
+				dev_err(dev,
+					"%s: Allocate command buffers fail!\n",
+				       __func__);
+				rc = -ENOMEM;
+				free_mem(cfg);
+				goto out;
+			}
+		}
+
+		cfg->afu->cmd[i].buf = buf;
+		atomic_set(&cfg->afu->cmd[i].free, 1);
+		cfg->afu->cmd[i].slot = i;
+	}
+
+out:
+	return rc;
+}
+
+/**
+ * init_pci() - initializes the host as a PCI device
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_pci(struct cxlflash_cfg *cfg)
+{
+	struct pci_dev *pdev = cfg->dev;
+	int rc = 0;
+
+	cfg->cxlflash_regs_pci = pci_resource_start(pdev, 0);
+	rc = pci_request_regions(pdev, CXLFLASH_NAME);
+	if (rc < 0) {
+		dev_err(&pdev->dev,
+			"%s: Couldn't register memory range of registers\n",
+			__func__);
+		goto out;
+	}
+
+	rc = pci_enable_device(pdev);
+	if (rc || pci_channel_offline(pdev)) {
+		if (pci_channel_offline(pdev)) {
+			cxlflash_wait_for_pci_err_recovery(cfg);
+			rc = pci_enable_device(pdev);
+		}
+
+		if (rc) {
+			dev_err(&pdev->dev, "%s: Cannot enable adapter\n",
+				__func__);
+			cxlflash_wait_for_pci_err_recovery(cfg);
+			goto out_release_regions;
+		}
+	}
+
+	rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+	if (rc < 0) {
+		dev_dbg(&pdev->dev, "%s: Failed to set 64 bit PCI DMA mask\n",
+			__func__);
+		rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+	}
+
+	if (rc < 0) {
+		dev_err(&pdev->dev, "%s: Failed to set PCI DMA mask\n",
+			__func__);
+		goto out_disable;
+	}
+
+	pci_set_master(pdev);
+
+	if (pci_channel_offline(pdev)) {
+		cxlflash_wait_for_pci_err_recovery(cfg);
+		if (pci_channel_offline(pdev)) {
+			rc = -EIO;
+			goto out_msi_disable;
+		}
+	}
+
+	rc = pci_save_state(pdev);
+
+	if (rc != PCIBIOS_SUCCESSFUL) {
+		dev_err(&pdev->dev, "%s: Failed to save PCI config space\n",
+			__func__);
+		rc = -EIO;
+		goto cleanup_nolog;
+	}
+
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+
+cleanup_nolog:
+out_msi_disable:
+	cxlflash_wait_for_pci_err_recovery(cfg);
+out_disable:
+	pci_disable_device(pdev);
+out_release_regions:
+	pci_release_regions(pdev);
+	goto out;
+
+}
+
+/**
+ * init_scsi() - adds the host to the SCSI stack and kicks off host scan
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_scsi(struct cxlflash_cfg *cfg)
+{
+	struct pci_dev *pdev = cfg->dev;
+	int rc = 0;
+
+	rc = scsi_add_host(cfg->host, &pdev->dev);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: scsi_add_host failed (rc=%d)\n",
+			__func__, rc);
+		goto out;
+	}
+
+	scsi_scan_host(cfg->host);
+
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * set_port_online() - transitions the specified host FC port to online state
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ *
+ * The provided MMIO region must be mapped prior to call. Online state means
+ * that the FC link layer has synced, completed the handshaking process, and
+ * is ready for login to start.
+ */
+static void set_port_online(__be64 __iomem *fc_regs)
+{
+	u64 cmdcfg;
+
+	cmdcfg = readq_be(&fc_regs[FC_MTIP_CMDCONFIG / 8]);
+	cmdcfg &= (~FC_MTIP_CMDCONFIG_OFFLINE);	/* clear OFF_LINE */
+	cmdcfg |= (FC_MTIP_CMDCONFIG_ONLINE);	/* set ON_LINE */
+	writeq_be(cmdcfg, &fc_regs[FC_MTIP_CMDCONFIG / 8]);
+}
+
+/**
+ * set_port_offline() - transitions the specified host FC port to offline state
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ *
+ * The provided MMIO region must be mapped prior to call.
+ */
+static void set_port_offline(__be64 __iomem *fc_regs)
+{
+	u64 cmdcfg;
+
+	cmdcfg = readq_be(&fc_regs[FC_MTIP_CMDCONFIG / 8]);
+	cmdcfg &= (~FC_MTIP_CMDCONFIG_ONLINE);	/* clear ON_LINE */
+	cmdcfg |= (FC_MTIP_CMDCONFIG_OFFLINE);	/* set OFF_LINE */
+	writeq_be(cmdcfg, &fc_regs[FC_MTIP_CMDCONFIG / 8]);
+}
+
+/**
+ * wait_port_online() - waits for the specified host FC port come online
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ * @delay_us:	Number of microseconds to delay between reading port status.
+ * @nretry:	Number of cycles to retry reading port status.
+ *
+ * The provided MMIO region must be mapped prior to call. This will timeout
+ * when the cable is not plugged in.
+ *
+ * Return:
+ *	TRUE (1) when the specified port is online
+ *	FALSE (0) when the specified port fails to come online after timeout
+ *	-EINVAL when @delay_us is less than 1000
+ */
+static int wait_port_online(__be64 __iomem *fc_regs, u32 delay_us, u32 nretry)
+{
+	u64 status;
+
+	if (delay_us < 1000) {
+		pr_err("%s: invalid delay specified %d\n", __func__, delay_us);
+		return -EINVAL;
+	}
+
+	do {
+		msleep(delay_us / 1000);
+		status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+	} while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_ONLINE &&
+		 nretry--);
+
+	return ((status & FC_MTIP_STATUS_MASK) == FC_MTIP_STATUS_ONLINE);
+}
+
+/**
+ * wait_port_offline() - waits for the specified host FC port go offline
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ * @delay_us:	Number of microseconds to delay between reading port status.
+ * @nretry:	Number of cycles to retry reading port status.
+ *
+ * The provided MMIO region must be mapped prior to call.
+ *
+ * Return:
+ *	TRUE (1) when the specified port is offline
+ *	FALSE (0) when the specified port fails to go offline after timeout
+ *	-EINVAL when @delay_us is less than 1000
+ */
+static int wait_port_offline(__be64 __iomem *fc_regs, u32 delay_us, u32 nretry)
+{
+	u64 status;
+
+	if (delay_us < 1000) {
+		pr_err("%s: invalid delay specified %d\n", __func__, delay_us);
+		return -EINVAL;
+	}
+
+	do {
+		msleep(delay_us / 1000);
+		status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+	} while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_OFFLINE &&
+		 nretry--);
+
+	return ((status & FC_MTIP_STATUS_MASK) == FC_MTIP_STATUS_OFFLINE);
+}
+
+/**
+ * afu_set_wwpn() - configures the WWPN for the specified host FC port
+ * @afu:	AFU associated with the host that owns the specified FC port.
+ * @port:	Port number being configured.
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ * @wwpn:	The world-wide-port-number previously discovered for port.
+ *
+ * The provided MMIO region must be mapped prior to call. As part of the
+ * sequence to configure the WWPN, the port is toggled offline and then back
+ * online. This toggling action can cause this routine to delay up to a few
+ * seconds. When configured to use the internal LUN feature of the AFU, a
+ * failure to come online is overridden.
+ *
+ * Return:
+ *	0 when the WWPN is successfully written and the port comes back online
+ *	-1 when the port fails to go offline or come back up online
+ */
+static int afu_set_wwpn(struct afu *afu, int port, __be64 __iomem *fc_regs,
+			u64 wwpn)
+{
+	int rc = 0;
+
+	set_port_offline(fc_regs);
+
+	if (!wait_port_offline(fc_regs, FC_PORT_STATUS_RETRY_INTERVAL_US,
+			       FC_PORT_STATUS_RETRY_CNT)) {
+		pr_debug("%s: wait on port %d to go offline timed out\n",
+			 __func__, port);
+		rc = -1; /* but continue on to leave the port back online */
+	}
+
+	if (rc == 0)
+		writeq_be(wwpn, &fc_regs[FC_PNAME / 8]);
+
+	/* Always return success after programming WWPN */
+	rc = 0;
+
+	set_port_online(fc_regs);
+
+	if (!wait_port_online(fc_regs, FC_PORT_STATUS_RETRY_INTERVAL_US,
+			      FC_PORT_STATUS_RETRY_CNT)) {
+		pr_err("%s: wait on port %d to go online timed out\n",
+		       __func__, port);
+	}
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+
+	return rc;
+}
+
+/**
+ * afu_link_reset() - resets the specified host FC port
+ * @afu:	AFU associated with the host that owns the specified FC port.
+ * @port:	Port number being configured.
+ * @fc_regs:	Top of MMIO region defined for specified port.
+ *
+ * The provided MMIO region must be mapped prior to call. The sequence to
+ * reset the port involves toggling it offline and then back online. This
+ * action can cause this routine to delay up to a few seconds. An effort
+ * is made to maintain link with the device by switching to host to use
+ * the alternate port exclusively while the reset takes place.
+ * failure to come online is overridden.
+ */
+static void afu_link_reset(struct afu *afu, int port, __be64 __iomem *fc_regs)
+{
+	u64 port_sel;
+
+	/* first switch the AFU to the other links, if any */
+	port_sel = readq_be(&afu->afu_map->global.regs.afu_port_sel);
+	port_sel &= ~(1ULL << port);
+	writeq_be(port_sel, &afu->afu_map->global.regs.afu_port_sel);
+	cxlflash_afu_sync(afu, 0, 0, AFU_GSYNC);
+
+	set_port_offline(fc_regs);
+	if (!wait_port_offline(fc_regs, FC_PORT_STATUS_RETRY_INTERVAL_US,
+			       FC_PORT_STATUS_RETRY_CNT))
+		pr_err("%s: wait on port %d to go offline timed out\n",
+		       __func__, port);
+
+	set_port_online(fc_regs);
+	if (!wait_port_online(fc_regs, FC_PORT_STATUS_RETRY_INTERVAL_US,
+			      FC_PORT_STATUS_RETRY_CNT))
+		pr_err("%s: wait on port %d to go online timed out\n",
+		       __func__, port);
+
+	/* switch back to include this port */
+	port_sel |= (1ULL << port);
+	writeq_be(port_sel, &afu->afu_map->global.regs.afu_port_sel);
+	cxlflash_afu_sync(afu, 0, 0, AFU_GSYNC);
+
+	pr_debug("%s: returning port_sel=%lld\n", __func__, port_sel);
+}
+
+/*
+ * Asynchronous interrupt information table
+ */
+static const struct asyc_intr_info ainfo[] = {
+	{SISL_ASTATUS_FC0_OTHER, "other error", 0, CLR_FC_ERROR | LINK_RESET},
+	{SISL_ASTATUS_FC0_LOGO, "target initiated LOGO", 0, 0},
+	{SISL_ASTATUS_FC0_CRC_T, "CRC threshold exceeded", 0, LINK_RESET},
+	{SISL_ASTATUS_FC0_LOGI_R, "login timed out, retrying", 0, LINK_RESET},
+	{SISL_ASTATUS_FC0_LOGI_F, "login failed", 0, CLR_FC_ERROR},
+	{SISL_ASTATUS_FC0_LOGI_S, "login succeeded", 0, SCAN_HOST},
+	{SISL_ASTATUS_FC0_LINK_DN, "link down", 0, 0},
+	{SISL_ASTATUS_FC0_LINK_UP, "link up", 0, SCAN_HOST},
+	{SISL_ASTATUS_FC1_OTHER, "other error", 1, CLR_FC_ERROR | LINK_RESET},
+	{SISL_ASTATUS_FC1_LOGO, "target initiated LOGO", 1, 0},
+	{SISL_ASTATUS_FC1_CRC_T, "CRC threshold exceeded", 1, LINK_RESET},
+	{SISL_ASTATUS_FC1_LOGI_R, "login timed out, retrying", 1, 0},
+	{SISL_ASTATUS_FC1_LOGI_F, "login failed", 1, CLR_FC_ERROR},
+	{SISL_ASTATUS_FC1_LOGI_S, "login succeeded", 1, SCAN_HOST},
+	{SISL_ASTATUS_FC1_LINK_DN, "link down", 1, 0},
+	{SISL_ASTATUS_FC1_LINK_UP, "link up", 1, SCAN_HOST},
+	{0x0, "", 0, 0}		/* terminator */
+};
+
+/**
+ * find_ainfo() - locates and returns asynchronous interrupt information
+ * @status:	Status code set by AFU on error.
+ *
+ * Return: The located information or NULL when the status code is invalid.
+ */
+static const struct asyc_intr_info *find_ainfo(u64 status)
+{
+	const struct asyc_intr_info *info;
+
+	for (info = &ainfo[0]; info->status; info++)
+		if (info->status == status)
+			return info;
+
+	return NULL;
+}
+
+/**
+ * afu_err_intr_init() - clears and initializes the AFU for error interrupts
+ * @afu:	AFU associated with the host.
+ */
+static void afu_err_intr_init(struct afu *afu)
+{
+	int i;
+	u64 reg;
+
+	/* global async interrupts: AFU clears afu_ctrl on context exit
+	 * if async interrupts were sent to that context. This prevents
+	 * the AFU form sending further async interrupts when
+	 * there is
+	 * nobody to receive them.
+	 */
+
+	/* mask all */
+	writeq_be(-1ULL, &afu->afu_map->global.regs.aintr_mask);
+	/* set LISN# to send and point to master context */
+	reg = ((u64) (((afu->ctx_hndl << 8) | SISL_MSI_ASYNC_ERROR)) << 40);
+
+	if (afu->internal_lun)
+		reg |= 1;	/* Bit 63 indicates local lun */
+	writeq_be(reg, &afu->afu_map->global.regs.afu_ctrl);
+	/* clear all */
+	writeq_be(-1ULL, &afu->afu_map->global.regs.aintr_clear);
+	/* unmask bits that are of interest */
+	/* note: afu can send an interrupt after this step */
+	writeq_be(SISL_ASTATUS_MASK, &afu->afu_map->global.regs.aintr_mask);
+	/* clear again in case a bit came on after previous clear but before */
+	/* unmask */
+	writeq_be(-1ULL, &afu->afu_map->global.regs.aintr_clear);
+
+	/* Clear/Set internal lun bits */
+	reg = readq_be(&afu->afu_map->global.fc_regs[0][FC_CONFIG2 / 8]);
+	reg &= SISL_FC_INTERNAL_MASK;
+	if (afu->internal_lun)
+		reg |= ((u64)(afu->internal_lun - 1) << SISL_FC_INTERNAL_SHIFT);
+	writeq_be(reg, &afu->afu_map->global.fc_regs[0][FC_CONFIG2 / 8]);
+
+	/* now clear FC errors */
+	for (i = 0; i < NUM_FC_PORTS; i++) {
+		writeq_be(0xFFFFFFFFU,
+			  &afu->afu_map->global.fc_regs[i][FC_ERROR / 8]);
+		writeq_be(0, &afu->afu_map->global.fc_regs[i][FC_ERRCAP / 8]);
+	}
+
+	/* sync interrupts for master's IOARRIN write */
+	/* note that unlike asyncs, there can be no pending sync interrupts */
+	/* at this time (this is a fresh context and master has not written */
+	/* IOARRIN yet), so there is nothing to clear. */
+
+	/* set LISN#, it is always sent to the context that wrote IOARRIN */
+	writeq_be(SISL_MSI_SYNC_ERROR, &afu->host_map->ctx_ctrl);
+	writeq_be(SISL_ISTATUS_MASK, &afu->host_map->intr_mask);
+}
+
+/**
+ * cxlflash_sync_err_irq() - interrupt handler for synchronous errors
+ * @irq:	Interrupt number.
+ * @data:	Private data provided at interrupt registration, the AFU.
+ *
+ * Return: Always return IRQ_HANDLED.
+ */
+static irqreturn_t cxlflash_sync_err_irq(int irq, void *data)
+{
+	struct afu *afu = (struct afu *)data;
+	u64 reg;
+	u64 reg_unmasked;
+
+	reg = readq_be(&afu->host_map->intr_status);
+	reg_unmasked = (reg & SISL_ISTATUS_UNMASK);
+
+	if (reg_unmasked == 0UL) {
+		pr_err("%s: %llX: spurious interrupt, intr_status %016llX\n",
+		       __func__, (u64)afu, reg);
+		goto cxlflash_sync_err_irq_exit;
+	}
+
+	pr_err("%s: %llX: unexpected interrupt, intr_status %016llX\n",
+	       __func__, (u64)afu, reg);
+
+	writeq_be(reg_unmasked, &afu->host_map->intr_clear);
+
+cxlflash_sync_err_irq_exit:
+	pr_debug("%s: returning rc=%d\n", __func__, IRQ_HANDLED);
+	return IRQ_HANDLED;
+}
+
+/**
+ * cxlflash_rrq_irq() - interrupt handler for read-response queue (normal path)
+ * @irq:	Interrupt number.
+ * @data:	Private data provided at interrupt registration, the AFU.
+ *
+ * Return: Always return IRQ_HANDLED.
+ */
+static irqreturn_t cxlflash_rrq_irq(int irq, void *data)
+{
+	struct afu *afu = (struct afu *)data;
+	struct afu_cmd *cmd;
+	bool toggle = afu->toggle;
+	u64 entry,
+	    *hrrq_start = afu->hrrq_start,
+	    *hrrq_end = afu->hrrq_end,
+	    *hrrq_curr = afu->hrrq_curr;
+
+	/* Process however many RRQ entries that are ready */
+	while (true) {
+		entry = *hrrq_curr;
+
+		if ((entry & SISL_RESP_HANDLE_T_BIT) != toggle)
+			break;
+
+		cmd = (struct afu_cmd *)(entry & ~SISL_RESP_HANDLE_T_BIT);
+		cmd_complete(cmd);
+
+		/* Advance to next entry or wrap and flip the toggle bit */
+		if (hrrq_curr < hrrq_end)
+			hrrq_curr++;
+		else {
+			hrrq_curr = hrrq_start;
+			toggle ^= SISL_RESP_HANDLE_T_BIT;
+		}
+	}
+
+	afu->hrrq_curr = hrrq_curr;
+	afu->toggle = toggle;
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * cxlflash_async_err_irq() - interrupt handler for asynchronous errors
+ * @irq:	Interrupt number.
+ * @data:	Private data provided at interrupt registration, the AFU.
+ *
+ * Return: Always return IRQ_HANDLED.
+ */
+static irqreturn_t cxlflash_async_err_irq(int irq, void *data)
+{
+	struct afu *afu = (struct afu *)data;
+	struct cxlflash_cfg *cfg = afu->parent;
+	struct device *dev = &cfg->dev->dev;
+	u64 reg_unmasked;
+	const struct asyc_intr_info *info;
+	struct sisl_global_map __iomem *global = &afu->afu_map->global;
+	u64 reg;
+	u8 port;
+	int i;
+
+	reg = readq_be(&global->regs.aintr_status);
+	reg_unmasked = (reg & SISL_ASTATUS_UNMASK);
+
+	if (reg_unmasked == 0) {
+		dev_err(dev, "%s: spurious interrupt, aintr_status 0x%016llX\n",
+			__func__, reg);
+		goto out;
+	}
+
+	/* FYI, it is 'okay' to clear AFU status before FC_ERROR */
+	writeq_be(reg_unmasked, &global->regs.aintr_clear);
+
+	/* Check each bit that is on */
+	for (i = 0; reg_unmasked; i++, reg_unmasked = (reg_unmasked >> 1)) {
+		info = find_ainfo(1ULL << i);
+		if (((reg_unmasked & 0x1) == 0) || !info)
+			continue;
+
+		port = info->port;
+
+		dev_err(dev, "%s: FC Port %d -> %s, fc_status 0x%08llX\n",
+			__func__, port, info->desc,
+		       readq_be(&global->fc_regs[port][FC_STATUS / 8]));
+
+		/*
+		 * Do link reset first, some OTHER errors will set FC_ERROR
+		 * again if cleared before or w/o a reset
+		 */
+		if (info->action & LINK_RESET) {
+			dev_err(dev, "%s: FC Port %d: resetting link\n",
+				__func__, port);
+			cfg->lr_state = LINK_RESET_REQUIRED;
+			cfg->lr_port = port;
+			schedule_work(&cfg->work_q);
+		}
+
+		if (info->action & CLR_FC_ERROR) {
+			reg = readq_be(&global->fc_regs[port][FC_ERROR / 8]);
+
+			/*
+			 * Since all errors are unmasked, FC_ERROR and FC_ERRCAP
+			 * should be the same and tracing one is sufficient.
+			 */
+
+			dev_err(dev, "%s: fc %d: clearing fc_error 0x%08llX\n",
+				__func__, port, reg);
+
+			writeq_be(reg, &global->fc_regs[port][FC_ERROR / 8]);
+			writeq_be(0, &global->fc_regs[port][FC_ERRCAP / 8]);
+		}
+
+		if (info->action & SCAN_HOST) {
+			atomic_inc(&cfg->scan_host_needed);
+			schedule_work(&cfg->work_q);
+		}
+	}
+
+out:
+	dev_dbg(dev, "%s: returning IRQ_HANDLED, afu=%p\n", __func__, afu);
+	return IRQ_HANDLED;
+}
+
+/**
+ * start_context() - starts the master context
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Return: A success or failure value from CXL services.
+ */
+static int start_context(struct cxlflash_cfg *cfg)
+{
+	int rc = 0;
+
+	rc = cxl_start_context(cfg->mcctx,
+			       cfg->afu->work.work_element_descriptor,
+			       NULL);
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * read_vpd() - obtains the WWPNs from VPD
+ * @cfg:	Internal structure associated with the host.
+ * @wwpn:	Array of size NUM_FC_PORTS to pass back WWPNs
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int read_vpd(struct cxlflash_cfg *cfg, u64 wwpn[])
+{
+	struct pci_dev *dev = cfg->parent_dev;
+	int rc = 0;
+	int ro_start, ro_size, i, j, k;
+	ssize_t vpd_size;
+	char vpd_data[CXLFLASH_VPD_LEN];
+	char tmp_buf[WWPN_BUF_LEN] = { 0 };
+	char *wwpn_vpd_tags[NUM_FC_PORTS] = { "V5", "V6" };
+
+	/* Get the VPD data from the device */
+	vpd_size = pci_read_vpd(dev, 0, sizeof(vpd_data), vpd_data);
+	if (unlikely(vpd_size <= 0)) {
+		dev_err(&dev->dev, "%s: Unable to read VPD (size = %ld)\n",
+		       __func__, vpd_size);
+		rc = -ENODEV;
+		goto out;
+	}
+
+	/* Get the read only section offset */
+	ro_start = pci_vpd_find_tag(vpd_data, 0, vpd_size,
+				    PCI_VPD_LRDT_RO_DATA);
+	if (unlikely(ro_start < 0)) {
+		dev_err(&dev->dev, "%s: VPD Read-only data not found\n",
+			__func__);
+		rc = -ENODEV;
+		goto out;
+	}
+
+	/* Get the read only section size, cap when extends beyond read VPD */
+	ro_size = pci_vpd_lrdt_size(&vpd_data[ro_start]);
+	j = ro_size;
+	i = ro_start + PCI_VPD_LRDT_TAG_SIZE;
+	if (unlikely((i + j) > vpd_size)) {
+		pr_debug("%s: Might need to read more VPD (%d > %ld)\n",
+			 __func__, (i + j), vpd_size);
+		ro_size = vpd_size - i;
+	}
+
+	/*
+	 * Find the offset of the WWPN tag within the read only
+	 * VPD data and validate the found field (partials are
+	 * no good to us). Convert the ASCII data to an integer
+	 * value. Note that we must copy to a temporary buffer
+	 * because the conversion service requires that the ASCII
+	 * string be terminated.
+	 */
+	for (k = 0; k < NUM_FC_PORTS; k++) {
+		j = ro_size;
+		i = ro_start + PCI_VPD_LRDT_TAG_SIZE;
+
+		i = pci_vpd_find_info_keyword(vpd_data, i, j, wwpn_vpd_tags[k]);
+		if (unlikely(i < 0)) {
+			dev_err(&dev->dev, "%s: Port %d WWPN not found "
+				"in VPD\n", __func__, k);
+			rc = -ENODEV;
+			goto out;
+		}
+
+		j = pci_vpd_info_field_size(&vpd_data[i]);
+		i += PCI_VPD_INFO_FLD_HDR_SIZE;
+		if (unlikely((i + j > vpd_size) || (j != WWPN_LEN))) {
+			dev_err(&dev->dev, "%s: Port %d WWPN incomplete or "
+				"VPD corrupt\n",
+			       __func__, k);
+			rc = -ENODEV;
+			goto out;
+		}
+
+		memcpy(tmp_buf, &vpd_data[i], WWPN_LEN);
+		rc = kstrtoul(tmp_buf, WWPN_LEN, (ulong *)&wwpn[k]);
+		if (unlikely(rc)) {
+			dev_err(&dev->dev, "%s: Fail to convert port %d WWPN "
+				"to integer\n", __func__, k);
+			rc = -ENODEV;
+			goto out;
+		}
+	}
+
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * init_pcr() - initialize the provisioning and control registers
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Also sets up fast access to the mapped registers and initializes AFU
+ * command fields that never change.
+ */
+static void init_pcr(struct cxlflash_cfg *cfg)
+{
+	struct afu *afu = cfg->afu;
+	struct sisl_ctrl_map __iomem *ctrl_map;
+	int i;
+
+	for (i = 0; i < MAX_CONTEXT; i++) {
+		ctrl_map = &afu->afu_map->ctrls[i].ctrl;
+		/* Disrupt any clients that could be running */
+		/* e.g. clients that survived a master restart */
+		writeq_be(0, &ctrl_map->rht_start);
+		writeq_be(0, &ctrl_map->rht_cnt_id);
+		writeq_be(0, &ctrl_map->ctx_cap);
+	}
+
+	/* Copy frequently used fields into afu */
+	afu->ctx_hndl = (u16) cxl_process_element(cfg->mcctx);
+	afu->host_map = &afu->afu_map->hosts[afu->ctx_hndl].host;
+	afu->ctrl_map = &afu->afu_map->ctrls[afu->ctx_hndl].ctrl;
+
+	/* Program the Endian Control for the master context */
+	writeq_be(SISL_ENDIAN_CTRL, &afu->host_map->endian_ctrl);
+
+	/* Initialize cmd fields that never change */
+	for (i = 0; i < CXLFLASH_NUM_CMDS; i++) {
+		afu->cmd[i].rcb.ctx_id = afu->ctx_hndl;
+		afu->cmd[i].rcb.msi = SISL_MSI_RRQ_UPDATED;
+		afu->cmd[i].rcb.rrq = 0x0;
+	}
+}
+
+/**
+ * init_global() - initialize AFU global registers
+ * @cfg:	Internal structure associated with the host.
+ */
+static int init_global(struct cxlflash_cfg *cfg)
+{
+	struct afu *afu = cfg->afu;
+	struct device *dev = &cfg->dev->dev;
+	u64 wwpn[NUM_FC_PORTS];	/* wwpn of AFU ports */
+	int i = 0, num_ports = 0;
+	int rc = 0;
+	u64 reg;
+
+	rc = read_vpd(cfg, &wwpn[0]);
+	if (rc) {
+		dev_err(dev, "%s: could not read vpd rc=%d\n", __func__, rc);
+		goto out;
+	}
+
+	pr_debug("%s: wwpn0=0x%llX wwpn1=0x%llX\n", __func__, wwpn[0], wwpn[1]);
+
+	/* Set up RRQ in AFU for master issued cmds */
+	writeq_be((u64) afu->hrrq_start, &afu->host_map->rrq_start);
+	writeq_be((u64) afu->hrrq_end, &afu->host_map->rrq_end);
+
+	/* AFU configuration */
+	reg = readq_be(&afu->afu_map->global.regs.afu_config);
+	reg |= SISL_AFUCONF_AR_ALL|SISL_AFUCONF_ENDIAN;
+	/* enable all auto retry options and control endianness */
+	/* leave others at default: */
+	/* CTX_CAP write protected, mbox_r does not clear on read and */
+	/* checker on if dual afu */
+	writeq_be(reg, &afu->afu_map->global.regs.afu_config);
+
+	/* Global port select: select either port */
+	if (afu->internal_lun) {
+		/* Only use port 0 */
+		writeq_be(PORT0, &afu->afu_map->global.regs.afu_port_sel);
+		num_ports = NUM_FC_PORTS - 1;
+	} else {
+		writeq_be(BOTH_PORTS, &afu->afu_map->global.regs.afu_port_sel);
+		num_ports = NUM_FC_PORTS;
+	}
+
+	for (i = 0; i < num_ports; i++) {
+		/* Unmask all errors (but they are still masked at AFU) */
+		writeq_be(0, &afu->afu_map->global.fc_regs[i][FC_ERRMSK / 8]);
+		/* Clear CRC error cnt & set a threshold */
+		(void)readq_be(&afu->afu_map->global.
+			       fc_regs[i][FC_CNT_CRCERR / 8]);
+		writeq_be(MC_CRC_THRESH, &afu->afu_map->global.fc_regs[i]
+			  [FC_CRC_THRESH / 8]);
+
+		/* Set WWPNs. If already programmed, wwpn[i] is 0 */
+		if (wwpn[i] != 0 &&
+		    afu_set_wwpn(afu, i,
+				 &afu->afu_map->global.fc_regs[i][0],
+				 wwpn[i])) {
+			dev_err(dev, "%s: failed to set WWPN on port %d\n",
+			       __func__, i);
+			rc = -EIO;
+			goto out;
+		}
+		/* Programming WWPN back to back causes additional
+		 * offline/online transitions and a PLOGI
+		 */
+		msleep(100);
+	}
+
+	/* Set up master's own CTX_CAP to allow real mode, host translation */
+	/* tables, afu cmds and read/write GSCSI cmds. */
+	/* First, unlock ctx_cap write by reading mbox */
+	(void)readq_be(&afu->ctrl_map->mbox_r);	/* unlock ctx_cap */
+	writeq_be((SISL_CTX_CAP_REAL_MODE | SISL_CTX_CAP_HOST_XLATE |
+		   SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD |
+		   SISL_CTX_CAP_AFU_CMD | SISL_CTX_CAP_GSCSI_CMD),
+		  &afu->ctrl_map->ctx_cap);
+	/* Initialize heartbeat */
+	afu->hb = readq_be(&afu->afu_map->global.regs.afu_hb);
+
+out:
+	return rc;
+}
+
+/**
+ * start_afu() - initializes and starts the AFU
+ * @cfg:	Internal structure associated with the host.
+ */
+static int start_afu(struct cxlflash_cfg *cfg)
+{
+	struct afu *afu = cfg->afu;
+	struct afu_cmd *cmd;
+
+	int i = 0;
+	int rc = 0;
+
+	for (i = 0; i < CXLFLASH_NUM_CMDS; i++) {
+		cmd = &afu->cmd[i];
+
+		init_completion(&cmd->cevent);
+		spin_lock_init(&cmd->slock);
+		cmd->parent = afu;
+	}
+
+	init_pcr(cfg);
+
+	/* After an AFU reset, RRQ entries are stale, clear them */
+	memset(&afu->rrq_entry, 0, sizeof(afu->rrq_entry));
+
+	/* Initialize RRQ pointers */
+	afu->hrrq_start = &afu->rrq_entry[0];
+	afu->hrrq_end = &afu->rrq_entry[NUM_RRQ_ENTRY - 1];
+	afu->hrrq_curr = afu->hrrq_start;
+	afu->toggle = 1;
+
+	rc = init_global(cfg);
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * init_mc() - create and register as the master context
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_mc(struct cxlflash_cfg *cfg)
+{
+	struct cxl_context *ctx;
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	int rc = 0;
+	enum undo_level level;
+
+	ctx = cxl_get_context(cfg->dev);
+	if (unlikely(!ctx))
+		return -ENOMEM;
+	cfg->mcctx = ctx;
+
+	/* Set it up as a master with the CXL */
+	cxl_set_master(ctx);
+
+	/* During initialization reset the AFU to start from a clean slate */
+	rc = cxl_afu_reset(cfg->mcctx);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: initial AFU reset failed rc=%d\n",
+			__func__, rc);
+		level = RELEASE_CONTEXT;
+		goto out;
+	}
+
+	rc = cxl_allocate_afu_irqs(ctx, 3);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: call to allocate_afu_irqs failed rc=%d!\n",
+			__func__, rc);
+		level = RELEASE_CONTEXT;
+		goto out;
+	}
+
+	rc = cxl_map_afu_irq(ctx, 1, cxlflash_sync_err_irq, afu,
+			     "SISL_MSI_SYNC_ERROR");
+	if (unlikely(rc <= 0)) {
+		dev_err(dev, "%s: IRQ 1 (SISL_MSI_SYNC_ERROR) map failed!\n",
+			__func__);
+		level = FREE_IRQ;
+		goto out;
+	}
+
+	rc = cxl_map_afu_irq(ctx, 2, cxlflash_rrq_irq, afu,
+			     "SISL_MSI_RRQ_UPDATED");
+	if (unlikely(rc <= 0)) {
+		dev_err(dev, "%s: IRQ 2 (SISL_MSI_RRQ_UPDATED) map failed!\n",
+			__func__);
+		level = UNMAP_ONE;
+		goto out;
+	}
+
+	rc = cxl_map_afu_irq(ctx, 3, cxlflash_async_err_irq, afu,
+			     "SISL_MSI_ASYNC_ERROR");
+	if (unlikely(rc <= 0)) {
+		dev_err(dev, "%s: IRQ 3 (SISL_MSI_ASYNC_ERROR) map failed!\n",
+			__func__);
+		level = UNMAP_TWO;
+		goto out;
+	}
+
+	rc = 0;
+
+	/* This performs the equivalent of the CXL_IOCTL_START_WORK.
+	 * The CXL_IOCTL_GET_PROCESS_ELEMENT is implicit in the process
+	 * element (pe) that is embedded in the context (ctx)
+	 */
+	rc = start_context(cfg);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: start context failed rc=%d\n", __func__, rc);
+		level = UNMAP_THREE;
+		goto out;
+	}
+ret:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+out:
+	term_mc(cfg, level);
+	goto ret;
+}
+
+/**
+ * init_afu() - setup as master context and start AFU
+ * @cfg:	Internal structure associated with the host.
+ *
+ * This routine is a higher level of control for configuring the
+ * AFU on probe and reset paths.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_afu(struct cxlflash_cfg *cfg)
+{
+	u64 reg;
+	int rc = 0;
+	struct afu *afu = cfg->afu;
+	struct device *dev = &cfg->dev->dev;
+
+	cxl_perst_reloads_same_image(cfg->cxl_afu, true);
+
+	rc = init_mc(cfg);
+	if (rc) {
+		dev_err(dev, "%s: call to init_mc failed, rc=%d!\n",
+			__func__, rc);
+		goto out;
+	}
+
+	/* Map the entire MMIO space of the AFU */
+	afu->afu_map = cxl_psa_map(cfg->mcctx);
+	if (!afu->afu_map) {
+		dev_err(dev, "%s: call to cxl_psa_map failed!\n", __func__);
+		rc = -ENOMEM;
+		goto err1;
+	}
+
+	/* No byte reverse on reading afu_version or string will be backwards */
+	reg = readq(&afu->afu_map->global.regs.afu_version);
+	memcpy(afu->version, &reg, sizeof(reg));
+	afu->interface_version =
+	    readq_be(&afu->afu_map->global.regs.interface_version);
+	if ((afu->interface_version + 1) == 0) {
+		pr_err("Back level AFU, please upgrade. AFU version %s "
+		       "interface version 0x%llx\n", afu->version,
+		       afu->interface_version);
+		rc = -EINVAL;
+		goto err2;
+	}
+
+	pr_debug("%s: afu version %s, interface version 0x%llX\n", __func__,
+		 afu->version, afu->interface_version);
+
+	rc = start_afu(cfg);
+	if (rc) {
+		dev_err(dev, "%s: call to start_afu failed, rc=%d!\n",
+			__func__, rc);
+		goto err2;
+	}
+
+	afu_err_intr_init(cfg->afu);
+	atomic64_set(&afu->room, readq_be(&afu->host_map->cmd_room));
+
+	/* Restore the LUN mappings */
+	cxlflash_restore_luntable(cfg);
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+
+err2:
+	cxl_psa_unmap((void __iomem *)afu->afu_map);
+	afu->afu_map = NULL;
+err1:
+	term_mc(cfg, UNDO_START);
+	goto out;
+}
+
+/**
+ * cxlflash_afu_sync() - builds and sends an AFU sync command
+ * @afu:	AFU associated with the host.
+ * @ctx_hndl_u:	Identifies context requesting sync.
+ * @res_hndl_u:	Identifies resource requesting sync.
+ * @mode:	Type of sync to issue (lightweight, heavyweight, global).
+ *
+ * The AFU can only take 1 sync command at a time. This routine enforces this
+ * limitation by using a mutex to provide exclusive access to the AFU during
+ * the sync. This design point requires calling threads to not be on interrupt
+ * context due to the possibility of sleeping during concurrent sync operations.
+ *
+ * AFU sync operations are only necessary and allowed when the device is
+ * operating normally. When not operating normally, sync requests can occur as
+ * part of cleaning up resources associated with an adapter prior to removal.
+ * In this scenario, these requests are simply ignored (safe due to the AFU
+ * going away).
+ *
+ * Return:
+ *	0 on success
+ *	-1 on failure
+ */
+int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
+		      res_hndl_t res_hndl_u, u8 mode)
+{
+	struct cxlflash_cfg *cfg = afu->parent;
+	struct device *dev = &cfg->dev->dev;
+	struct afu_cmd *cmd = NULL;
+	int rc = 0;
+	int retry_cnt = 0;
+	static DEFINE_MUTEX(sync_active);
+
+	if (cfg->state != STATE_NORMAL) {
+		pr_debug("%s: Sync not required! (%u)\n", __func__, cfg->state);
+		return 0;
+	}
+
+	mutex_lock(&sync_active);
+retry:
+	cmd = cmd_checkout(afu);
+	if (unlikely(!cmd)) {
+		retry_cnt++;
+		udelay(1000 * retry_cnt);
+		if (retry_cnt < MC_RETRY_CNT)
+			goto retry;
+		dev_err(dev, "%s: could not get a free command\n", __func__);
+		rc = -1;
+		goto out;
+	}
+
+	pr_debug("%s: afu=%p cmd=%p %d\n", __func__, afu, cmd, ctx_hndl_u);
+
+	memset(cmd->rcb.cdb, 0, sizeof(cmd->rcb.cdb));
+
+	cmd->rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
+	cmd->rcb.port_sel = 0x0;	/* NA */
+	cmd->rcb.lun_id = 0x0;	/* NA */
+	cmd->rcb.data_len = 0x0;
+	cmd->rcb.data_ea = 0x0;
+	cmd->rcb.timeout = MC_AFU_SYNC_TIMEOUT;
+
+	cmd->rcb.cdb[0] = 0xC0;	/* AFU Sync */
+	cmd->rcb.cdb[1] = mode;
+
+	/* The cdb is aligned, no unaligned accessors required */
+	*((__be16 *)&cmd->rcb.cdb[2]) = cpu_to_be16(ctx_hndl_u);
+	*((__be32 *)&cmd->rcb.cdb[4]) = cpu_to_be32(res_hndl_u);
+
+	rc = send_cmd(afu, cmd);
+	if (unlikely(rc))
+		goto out;
+
+	wait_resp(afu, cmd);
+
+	/* Set on timeout */
+	if (unlikely((cmd->sa.ioasc != 0) ||
+		     (cmd->sa.host_use_b[0] & B_ERROR)))
+		rc = -1;
+out:
+	mutex_unlock(&sync_active);
+	if (cmd)
+		cmd_checkin(cmd);
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * afu_reset() - resets the AFU
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int afu_reset(struct cxlflash_cfg *cfg)
+{
+	int rc = 0;
+	/* Stop the context before the reset. Since the context is
+	 * no longer available restart it after the reset is complete
+	 */
+
+	term_afu(cfg);
+
+	rc = init_afu(cfg);
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_eh_device_reset_handler() - reset a single LUN
+ * @scp:	SCSI command to send.
+ *
+ * Return:
+ *	SUCCESS as defined in scsi/scsi.h
+ *	FAILED as defined in scsi/scsi.h
+ */
+static int cxlflash_eh_device_reset_handler(struct scsi_cmnd *scp)
+{
+	int rc = SUCCESS;
+	struct Scsi_Host *host = scp->device->host;
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)host->hostdata;
+	struct afu *afu = cfg->afu;
+	int rcr = 0;
+
+	pr_debug("%s: (scp=%p) %d/%d/%d/%llu "
+		 "cdb=(%08X-%08X-%08X-%08X)\n", __func__, scp,
+		 host->host_no, scp->device->channel,
+		 scp->device->id, scp->device->lun,
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[0]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[1]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
+
+retry:
+	switch (cfg->state) {
+	case STATE_NORMAL:
+		rcr = send_tmf(afu, scp, TMF_LUN_RESET);
+		if (unlikely(rcr))
+			rc = FAILED;
+		break;
+	case STATE_RESET:
+		wait_event(cfg->reset_waitq, cfg->state != STATE_RESET);
+		goto retry;
+	default:
+		rc = FAILED;
+		break;
+	}
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_eh_host_reset_handler() - reset the host adapter
+ * @scp:	SCSI command from stack identifying host.
+ *
+ * Return:
+ *	SUCCESS as defined in scsi/scsi.h
+ *	FAILED as defined in scsi/scsi.h
+ */
+static int cxlflash_eh_host_reset_handler(struct scsi_cmnd *scp)
+{
+	int rc = SUCCESS;
+	int rcr = 0;
+	struct Scsi_Host *host = scp->device->host;
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)host->hostdata;
+
+	pr_debug("%s: (scp=%p) %d/%d/%d/%llu "
+		 "cdb=(%08X-%08X-%08X-%08X)\n", __func__, scp,
+		 host->host_no, scp->device->channel,
+		 scp->device->id, scp->device->lun,
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[0]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[1]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
+		 get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
+
+	switch (cfg->state) {
+	case STATE_NORMAL:
+		cfg->state = STATE_RESET;
+		cxlflash_mark_contexts_error(cfg);
+		rcr = afu_reset(cfg);
+		if (rcr) {
+			rc = FAILED;
+			cfg->state = STATE_FAILTERM;
+		} else
+			cfg->state = STATE_NORMAL;
+		wake_up_all(&cfg->reset_waitq);
+		break;
+	case STATE_RESET:
+		wait_event(cfg->reset_waitq, cfg->state != STATE_RESET);
+		if (cfg->state == STATE_NORMAL)
+			break;
+		/* fall through */
+	default:
+		rc = FAILED;
+		break;
+	}
+
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_change_queue_depth() - change the queue depth for the device
+ * @sdev:	SCSI device destined for queue depth change.
+ * @qdepth:	Requested queue depth value to set.
+ *
+ * The requested queue depth is capped to the maximum supported value.
+ *
+ * Return: The actual queue depth set.
+ */
+static int cxlflash_change_queue_depth(struct scsi_device *sdev, int qdepth)
+{
+
+	if (qdepth > CXLFLASH_MAX_CMDS_PER_LUN)
+		qdepth = CXLFLASH_MAX_CMDS_PER_LUN;
+
+	scsi_change_queue_depth(sdev, qdepth);
+	return sdev->queue_depth;
+}
+
+/**
+ * cxlflash_show_port_status() - queries and presents the current port status
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t cxlflash_show_port_status(u32 port, struct afu *afu, char *buf)
+{
+	char *disp_status;
+	u64 status;
+	__be64 __iomem *fc_regs;
+
+	if (port >= NUM_FC_PORTS)
+		return 0;
+
+	fc_regs = &afu->afu_map->global.fc_regs[port][0];
+	status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]);
+	status &= FC_MTIP_STATUS_MASK;
+
+	if (status == FC_MTIP_STATUS_ONLINE)
+		disp_status = "online";
+	else if (status == FC_MTIP_STATUS_OFFLINE)
+		disp_status = "offline";
+	else
+		disp_status = "unknown";
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", disp_status);
+}
+
+/**
+ * port0_show() - queries and presents the current status of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(0, afu, buf);
+}
+
+/**
+ * port1_show() - queries and presents the current status of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_show(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_status(1, afu, buf);
+}
+
+/**
+ * lun_mode_show() - presents the current LUN mode of the host
+ * @dev:	Generic device associated with the host.
+ * @attr:	Device attribute representing the LUN mode.
+ * @buf:	Buffer of length PAGE_SIZE to report back the LUN mode in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t lun_mode_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", afu->internal_lun);
+}
+
+/**
+ * lun_mode_store() - sets the LUN mode of the host
+ * @dev:	Generic device associated with the host.
+ * @attr:	Device attribute representing the LUN mode.
+ * @buf:	Buffer of length PAGE_SIZE containing the LUN mode in ASCII.
+ * @count:	Length of data resizing in @buf.
+ *
+ * The CXL Flash AFU supports a dummy LUN mode where the external
+ * links and storage are not required. Space on the FPGA is used
+ * to create 1 or 2 small LUNs which are presented to the system
+ * as if they were a normal storage device. This feature is useful
+ * during development and also provides manufacturing with a way
+ * to test the AFU without an actual device.
+ *
+ * 0 = external LUN[s] (default)
+ * 1 = internal LUN (1 x 64K, 512B blocks, id 0)
+ * 2 = internal LUN (1 x 64K, 4K blocks, id 0)
+ * 3 = internal LUN (2 x 32K, 512B blocks, ids 0,1)
+ * 4 = internal LUN (2 x 32K, 4K blocks, ids 0,1)
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t lun_mode_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+	int rc;
+	u32 lun_mode;
+
+	rc = kstrtouint(buf, 10, &lun_mode);
+	if (!rc && (lun_mode < 5) && (lun_mode != afu->internal_lun)) {
+		afu->internal_lun = lun_mode;
+		afu_reset(cfg);
+		scsi_scan_host(cfg->host);
+	}
+
+	return count;
+}
+
+/**
+ * ioctl_version_show() - presents the current ioctl version of the host
+ * @dev:	Generic device associated with the host.
+ * @attr:	Device attribute representing the ioctl version.
+ * @buf:	Buffer of length PAGE_SIZE to report back the ioctl version.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t ioctl_version_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%u\n", DK_CXLFLASH_VERSION_0);
+}
+
+/**
+ * cxlflash_show_port_lun_table() - queries and presents the port LUN table
+ * @port:	Desired port for status reporting.
+ * @afu:	AFU owning the specified port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t cxlflash_show_port_lun_table(u32 port,
+					    struct afu *afu,
+					    char *buf)
+{
+	int i;
+	ssize_t bytes = 0;
+	__be64 __iomem *fc_port;
+
+	if (port >= NUM_FC_PORTS)
+		return 0;
+
+	fc_port = &afu->afu_map->global.fc_port[port][0];
+
+	for (i = 0; i < CXLFLASH_NUM_VLUNS; i++)
+		bytes += scnprintf(buf + bytes, PAGE_SIZE - bytes,
+				   "%03d: %016llX\n", i, readq_be(&fc_port[i]));
+	return bytes;
+}
+
+/**
+ * port0_lun_table_show() - presents the current LUN table of port 0
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port0_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(0, afu, buf);
+}
+
+/**
+ * port1_lun_table_show() - presents the current LUN table of port 1
+ * @dev:	Generic device associated with the host owning the port.
+ * @attr:	Device attribute representing the port.
+ * @buf:	Buffer of length PAGE_SIZE to report back port status in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t port1_lun_table_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)shost->hostdata;
+	struct afu *afu = cfg->afu;
+
+	return cxlflash_show_port_lun_table(1, afu, buf);
+}
+
+/**
+ * mode_show() - presents the current mode of the device
+ * @dev:	Generic device associated with the device.
+ * @attr:	Device attribute representing the device mode.
+ * @buf:	Buffer of length PAGE_SIZE to report back the dev mode in ASCII.
+ *
+ * Return: The size of the ASCII string returned in @buf.
+ */
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+			 sdev->hostdata ? "superpipe" : "legacy");
+}
+
+/*
+ * Host attributes
+ */
+static DEVICE_ATTR_RO(port0);
+static DEVICE_ATTR_RO(port1);
+static DEVICE_ATTR_RW(lun_mode);
+static DEVICE_ATTR_RO(ioctl_version);
+static DEVICE_ATTR_RO(port0_lun_table);
+static DEVICE_ATTR_RO(port1_lun_table);
+
+static struct device_attribute *cxlflash_host_attrs[] = {
+	&dev_attr_port0,
+	&dev_attr_port1,
+	&dev_attr_lun_mode,
+	&dev_attr_ioctl_version,
+	&dev_attr_port0_lun_table,
+	&dev_attr_port1_lun_table,
+	NULL
+};
+
+/*
+ * Device attributes
+ */
+static DEVICE_ATTR_RO(mode);
+
+static struct device_attribute *cxlflash_dev_attrs[] = {
+	&dev_attr_mode,
+	NULL
+};
+
+/*
+ * Host template
+ */
+static struct scsi_host_template driver_template = {
+	.module = THIS_MODULE,
+	.name = CXLFLASH_ADAPTER_NAME,
+	.info = cxlflash_driver_info,
+	.ioctl = cxlflash_ioctl,
+	.proc_name = CXLFLASH_NAME,
+	.queuecommand = cxlflash_queuecommand,
+	.eh_device_reset_handler = cxlflash_eh_device_reset_handler,
+	.eh_host_reset_handler = cxlflash_eh_host_reset_handler,
+	.change_queue_depth = cxlflash_change_queue_depth,
+	.cmd_per_lun = 16,
+	.can_queue = CXLFLASH_MAX_CMDS,
+	.this_id = -1,
+	.sg_tablesize = SG_NONE,	/* No scatter gather support */
+	.max_sectors = CXLFLASH_MAX_SECTORS,
+	.use_clustering = ENABLE_CLUSTERING,
+	.shost_attrs = cxlflash_host_attrs,
+	.sdev_attrs = cxlflash_dev_attrs,
+};
+
+/*
+ * Device dependent values
+ */
+static struct dev_dependent_vals dev_corsa_vals = { CXLFLASH_MAX_SECTORS };
+
+/*
+ * PCI device binding table
+ */
+static struct pci_device_id cxlflash_pci_table[] = {
+	{PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_CORSA,
+	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, (kernel_ulong_t)&dev_corsa_vals},
+	{}
+};
+
+MODULE_DEVICE_TABLE(pci, cxlflash_pci_table);
+
+/**
+ * cxlflash_worker_thread() - work thread handler for the AFU
+ * @work:	Work structure contained within cxlflash associated with host.
+ *
+ * Handles the following events:
+ * - Link reset which cannot be performed on interrupt context due to
+ * blocking up to a few seconds
+ * - Read AFU command room
+ * - Rescan the host
+ */
+static void cxlflash_worker_thread(struct work_struct *work)
+{
+	struct cxlflash_cfg *cfg = container_of(work, struct cxlflash_cfg,
+						work_q);
+	struct afu *afu = cfg->afu;
+	struct device *dev = &cfg->dev->dev;
+	int port;
+	ulong lock_flags;
+
+	/* Avoid MMIO if the device has failed */
+
+	if (cfg->state != STATE_NORMAL)
+		return;
+
+	spin_lock_irqsave(cfg->host->host_lock, lock_flags);
+
+	if (cfg->lr_state == LINK_RESET_REQUIRED) {
+		port = cfg->lr_port;
+		if (port < 0)
+			dev_err(dev, "%s: invalid port index %d\n",
+				__func__, port);
+		else {
+			spin_unlock_irqrestore(cfg->host->host_lock,
+					       lock_flags);
+
+			/* The reset can block... */
+			afu_link_reset(afu, port,
+				       &afu->afu_map->global.fc_regs[port][0]);
+			spin_lock_irqsave(cfg->host->host_lock, lock_flags);
+		}
+
+		cfg->lr_state = LINK_RESET_COMPLETE;
+	}
+
+	if (afu->read_room) {
+		atomic64_set(&afu->room, readq_be(&afu->host_map->cmd_room));
+		afu->read_room = false;
+	}
+
+	spin_unlock_irqrestore(cfg->host->host_lock, lock_flags);
+
+	if (atomic_dec_if_positive(&cfg->scan_host_needed) >= 0)
+		scsi_scan_host(cfg->host);
+}
+
+/**
+ * cxlflash_probe() - PCI entry point to add host
+ * @pdev:	PCI device associated with the host.
+ * @dev_id:	PCI device id associated with device.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_probe(struct pci_dev *pdev,
+			  const struct pci_device_id *dev_id)
+{
+	struct Scsi_Host *host;
+	struct cxlflash_cfg *cfg = NULL;
+	struct device *phys_dev;
+	struct dev_dependent_vals *ddv;
+	int rc = 0;
+
+	dev_dbg(&pdev->dev, "%s: Found CXLFLASH with IRQ: %d\n",
+		__func__, pdev->irq);
+
+	ddv = (struct dev_dependent_vals *)dev_id->driver_data;
+	driver_template.max_sectors = ddv->max_sectors;
+
+	host = scsi_host_alloc(&driver_template, sizeof(struct cxlflash_cfg));
+	if (!host) {
+		dev_err(&pdev->dev, "%s: call to scsi_host_alloc failed!\n",
+			__func__);
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	host->max_id = CXLFLASH_MAX_NUM_TARGETS_PER_BUS;
+	host->max_lun = CXLFLASH_MAX_NUM_LUNS_PER_TARGET;
+	host->max_channel = NUM_FC_PORTS - 1;
+	host->unique_id = host->host_no;
+	host->max_cmd_len = CXLFLASH_MAX_CDB_LEN;
+
+	cfg = (struct cxlflash_cfg *)host->hostdata;
+	cfg->host = host;
+	rc = alloc_mem(cfg);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: call to alloc_mem failed!\n",
+			__func__);
+		rc = -ENOMEM;
+		scsi_host_put(cfg->host);
+		goto out;
+	}
+
+	cfg->init_state = INIT_STATE_NONE;
+	cfg->dev = pdev;
+	cfg->cxl_fops = cxlflash_cxl_fops;
+
+	/*
+	 * The promoted LUNs move to the top of the LUN table. The rest stay
+	 * on the bottom half. The bottom half grows from the end
+	 * (index = 255), whereas the top half grows from the beginning
+	 * (index = 0).
+	 */
+	cfg->promote_lun_index  = 0;
+	cfg->last_lun_index[0] = CXLFLASH_NUM_VLUNS/2 - 1;
+	cfg->last_lun_index[1] = CXLFLASH_NUM_VLUNS/2 - 1;
+
+	cfg->dev_id = (struct pci_device_id *)dev_id;
+
+	init_waitqueue_head(&cfg->tmf_waitq);
+	init_waitqueue_head(&cfg->reset_waitq);
+
+	INIT_WORK(&cfg->work_q, cxlflash_worker_thread);
+	cfg->lr_state = LINK_RESET_INVALID;
+	cfg->lr_port = -1;
+	spin_lock_init(&cfg->tmf_slock);
+	mutex_init(&cfg->ctx_tbl_list_mutex);
+	mutex_init(&cfg->ctx_recovery_mutex);
+	init_rwsem(&cfg->ioctl_rwsem);
+	INIT_LIST_HEAD(&cfg->ctx_err_recovery);
+	INIT_LIST_HEAD(&cfg->lluns);
+
+	pci_set_drvdata(pdev, cfg);
+
+	/*
+	 * Use the special service provided to look up the physical
+	 * PCI device, since we are called on the probe of the virtual
+	 * PCI host bus (vphb)
+	 */
+	phys_dev = cxl_get_phys_dev(pdev);
+	if (!dev_is_pci(phys_dev)) {
+		dev_err(&pdev->dev, "%s: not a pci dev\n", __func__);
+		rc = -ENODEV;
+		goto out_remove;
+	}
+	cfg->parent_dev = to_pci_dev(phys_dev);
+
+	cfg->cxl_afu = cxl_pci_to_afu(pdev);
+
+	rc = init_pci(cfg);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: call to init_pci "
+			"failed rc=%d!\n", __func__, rc);
+		goto out_remove;
+	}
+	cfg->init_state = INIT_STATE_PCI;
+
+	rc = init_afu(cfg);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: call to init_afu "
+			"failed rc=%d!\n", __func__, rc);
+		goto out_remove;
+	}
+	cfg->init_state = INIT_STATE_AFU;
+
+	rc = init_scsi(cfg);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: call to init_scsi "
+			"failed rc=%d!\n", __func__, rc);
+		goto out_remove;
+	}
+	cfg->init_state = INIT_STATE_SCSI;
+
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+
+out_remove:
+	cxlflash_remove(pdev);
+	goto out;
+}
+
+/**
+ * drain_ioctls() - wait until all currently executing ioctls have completed
+ * @cfg:	Internal structure associated with the host.
+ *
+ * Obtain write access to read/write semaphore that wraps ioctl
+ * handling to 'drain' ioctls currently executing.
+ */
+static void drain_ioctls(struct cxlflash_cfg *cfg)
+{
+	down_write(&cfg->ioctl_rwsem);
+	up_write(&cfg->ioctl_rwsem);
+}
+
+/**
+ * cxlflash_pci_error_detected() - called when a PCI error is detected
+ * @pdev:	PCI device struct.
+ * @state:	PCI channel state.
+ *
+ * Return: PCI_ERS_RESULT_NEED_RESET or PCI_ERS_RESULT_DISCONNECT
+ */
+static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev,
+						    pci_channel_state_t state)
+{
+	int rc = 0;
+	struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+	struct device *dev = &cfg->dev->dev;
+
+	dev_dbg(dev, "%s: pdev=%p state=%u\n", __func__, pdev, state);
+
+	switch (state) {
+	case pci_channel_io_frozen:
+		cfg->state = STATE_RESET;
+		scsi_block_requests(cfg->host);
+		drain_ioctls(cfg);
+		rc = cxlflash_mark_contexts_error(cfg);
+		if (unlikely(rc))
+			dev_err(dev, "%s: Failed to mark user contexts!(%d)\n",
+				__func__, rc);
+		term_mc(cfg, UNDO_START);
+		stop_afu(cfg);
+		return PCI_ERS_RESULT_NEED_RESET;
+	case pci_channel_io_perm_failure:
+		cfg->state = STATE_FAILTERM;
+		wake_up_all(&cfg->reset_waitq);
+		scsi_unblock_requests(cfg->host);
+		return PCI_ERS_RESULT_DISCONNECT;
+	default:
+		break;
+	}
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+/**
+ * cxlflash_pci_slot_reset() - called when PCI slot has been reset
+ * @pdev:	PCI device struct.
+ *
+ * This routine is called by the pci error recovery code after the PCI
+ * slot has been reset, just before we should resume normal operations.
+ *
+ * Return: PCI_ERS_RESULT_RECOVERED or PCI_ERS_RESULT_DISCONNECT
+ */
+static pci_ers_result_t cxlflash_pci_slot_reset(struct pci_dev *pdev)
+{
+	int rc = 0;
+	struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+	struct device *dev = &cfg->dev->dev;
+
+	dev_dbg(dev, "%s: pdev=%p\n", __func__, pdev);
+
+	rc = init_afu(cfg);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: EEH recovery failed! (%d)\n", __func__, rc);
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+/**
+ * cxlflash_pci_resume() - called when normal operation can resume
+ * @pdev:	PCI device struct
+ */
+static void cxlflash_pci_resume(struct pci_dev *pdev)
+{
+	struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+	struct device *dev = &cfg->dev->dev;
+
+	dev_dbg(dev, "%s: pdev=%p\n", __func__, pdev);
+
+	cfg->state = STATE_NORMAL;
+	wake_up_all(&cfg->reset_waitq);
+	scsi_unblock_requests(cfg->host);
+}
+
+static const struct pci_error_handlers cxlflash_err_handler = {
+	.error_detected = cxlflash_pci_error_detected,
+	.slot_reset = cxlflash_pci_slot_reset,
+	.resume = cxlflash_pci_resume,
+};
+
+/*
+ * PCI device structure
+ */
+static struct pci_driver cxlflash_driver = {
+	.name = CXLFLASH_NAME,
+	.id_table = cxlflash_pci_table,
+	.probe = cxlflash_probe,
+	.remove = cxlflash_remove,
+	.err_handler = &cxlflash_err_handler,
+};
+
+/**
+ * init_cxlflash() - module entry point
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int __init init_cxlflash(void)
+{
+	pr_info("%s: IBM Power CXL Flash Adapter: %s\n",
+		__func__, CXLFLASH_DRIVER_DATE);
+
+	cxlflash_list_init();
+
+	return pci_register_driver(&cxlflash_driver);
+}
+
+/**
+ * exit_cxlflash() - module exit point
+ */
+static void __exit exit_cxlflash(void)
+{
+	cxlflash_term_global_luns();
+	cxlflash_free_errpage();
+
+	pci_unregister_driver(&cxlflash_driver);
+}
+
+module_init(init_cxlflash);
+module_exit(exit_cxlflash);
diff --git a/kernel/drivers/scsi/cxlflash/main.h b/kernel/drivers/scsi/cxlflash/main.h
new file mode 100644
index 000000000..60324566c
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/main.h
@@ -0,0 +1,109 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXLFLASH_MAIN_H
+#define _CXLFLASH_MAIN_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_device.h>
+
+#define CXLFLASH_NAME		"cxlflash"
+#define CXLFLASH_ADAPTER_NAME	"IBM POWER CXL Flash Adapter"
+#define CXLFLASH_DRIVER_DATE	"(August 13, 2015)"
+
+#define PCI_DEVICE_ID_IBM_CORSA	0x04F0
+#define CXLFLASH_SUBS_DEV_ID	0x04F0
+
+/* Since there is only one target, make it 0 */
+#define CXLFLASH_TARGET		0
+#define CXLFLASH_MAX_CDB_LEN	16
+
+/* Really only one target per bus since the Texan is directly attached */
+#define CXLFLASH_MAX_NUM_TARGETS_PER_BUS	1
+#define CXLFLASH_MAX_NUM_LUNS_PER_TARGET	65536
+
+#define CXLFLASH_PCI_ERROR_RECOVERY_TIMEOUT	(120 * HZ)
+
+#define NUM_FC_PORTS	CXLFLASH_NUM_FC_PORTS	/* ports per AFU */
+
+/* FC defines */
+#define FC_MTIP_CMDCONFIG 0x010
+#define FC_MTIP_STATUS 0x018
+
+#define FC_PNAME 0x300
+#define FC_CONFIG 0x320
+#define FC_CONFIG2 0x328
+#define FC_STATUS 0x330
+#define FC_ERROR 0x380
+#define FC_ERRCAP 0x388
+#define FC_ERRMSK 0x390
+#define FC_CNT_CRCERR 0x538
+#define FC_CRC_THRESH 0x580
+
+#define FC_MTIP_CMDCONFIG_ONLINE	0x20ULL
+#define FC_MTIP_CMDCONFIG_OFFLINE	0x40ULL
+
+#define FC_MTIP_STATUS_MASK		0x30ULL
+#define FC_MTIP_STATUS_ONLINE		0x20ULL
+#define FC_MTIP_STATUS_OFFLINE		0x10ULL
+
+/* TIMEOUT and RETRY definitions */
+
+/* AFU command timeout values */
+#define MC_AFU_SYNC_TIMEOUT	5	/* 5 secs */
+
+/* AFU command room retry limit */
+#define MC_ROOM_RETRY_CNT	10
+
+/* FC CRC clear periodic timer */
+#define MC_CRC_THRESH 100	/* threshold in 5 mins */
+
+#define FC_PORT_STATUS_RETRY_CNT 100	/* 100 100ms retries = 10 seconds */
+#define FC_PORT_STATUS_RETRY_INTERVAL_US 100000	/* microseconds */
+
+/* VPD defines */
+#define CXLFLASH_VPD_LEN	256
+#define WWPN_LEN	16
+#define WWPN_BUF_LEN	(WWPN_LEN + 1)
+
+enum undo_level {
+	RELEASE_CONTEXT = 0,
+	FREE_IRQ,
+	UNMAP_ONE,
+	UNMAP_TWO,
+	UNMAP_THREE,
+	UNDO_START
+};
+
+struct dev_dependent_vals {
+	u64 max_sectors;
+};
+
+struct asyc_intr_info {
+	u64 status;
+	char *desc;
+	u8 port;
+	u8 action;
+#define CLR_FC_ERROR	0x01
+#define LINK_RESET	0x02
+#define SCAN_HOST	0x04
+};
+
+#ifndef CONFIG_CXL_EEH
+#define cxl_perst_reloads_same_image(_a, _b) do { } while (0)
+#endif
+
+#endif /* _CXLFLASH_MAIN_H */
diff --git a/kernel/drivers/scsi/cxlflash/sislite.h b/kernel/drivers/scsi/cxlflash/sislite.h
new file mode 100644
index 000000000..0b3366f5e
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/sislite.h
@@ -0,0 +1,472 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _SISLITE_H
+#define _SISLITE_H
+
+#include <linux/types.h>
+
+typedef u16 ctx_hndl_t;
+typedef u32 res_hndl_t;
+
+#define SIZE_4K		4096
+#define SIZE_64K	65536
+
+/*
+ * IOARCB: 64 bytes, min 16 byte alignment required, host native endianness
+ * except for SCSI CDB which remains big endian per SCSI standards.
+ */
+struct sisl_ioarcb {
+	u16 ctx_id;		/* ctx_hndl_t */
+	u16 req_flags;
+#define SISL_REQ_FLAGS_RES_HNDL       0x8000U	/* bit 0 (MSB) */
+#define SISL_REQ_FLAGS_PORT_LUN_ID    0x0000U
+
+#define SISL_REQ_FLAGS_SUP_UNDERRUN   0x4000U	/* bit 1 */
+
+#define SISL_REQ_FLAGS_TIMEOUT_SECS   0x0000U	/* bits 8,9 */
+#define SISL_REQ_FLAGS_TIMEOUT_MSECS  0x0040U
+#define SISL_REQ_FLAGS_TIMEOUT_USECS  0x0080U
+#define SISL_REQ_FLAGS_TIMEOUT_CYCLES 0x00C0U
+
+#define SISL_REQ_FLAGS_TMF_CMD        0x0004u	/* bit 13 */
+
+#define SISL_REQ_FLAGS_AFU_CMD        0x0002U	/* bit 14 */
+
+#define SISL_REQ_FLAGS_HOST_WRITE     0x0001U	/* bit 15 (LSB) */
+#define SISL_REQ_FLAGS_HOST_READ      0x0000U
+
+	union {
+		u32 res_hndl;	/* res_hndl_t */
+		u32 port_sel;	/* this is a selection mask:
+				 * 0x1 -> port#0 can be selected,
+				 * 0x2 -> port#1 can be selected.
+				 * Can be bitwise ORed.
+				 */
+	};
+	u64 lun_id;
+	u32 data_len;		/* 4K for read/write */
+	u32 ioadl_len;
+	union {
+		u64 data_ea;	/* min 16 byte aligned */
+		u64 ioadl_ea;
+	};
+	u8 msi;			/* LISN to send on RRQ write */
+#define SISL_MSI_CXL_PFAULT        0	/* reserved for CXL page faults */
+#define SISL_MSI_SYNC_ERROR        1	/* recommended for AFU sync error */
+#define SISL_MSI_RRQ_UPDATED       2	/* recommended for IO completion */
+#define SISL_MSI_ASYNC_ERROR       3	/* master only - for AFU async error */
+
+	u8 rrq;			/* 0 for a single RRQ */
+	u16 timeout;		/* in units specified by req_flags */
+	u32 rsvd1;
+	u8 cdb[16];		/* must be in big endian */
+	struct scsi_cmnd *scp;
+} __packed;
+
+struct sisl_rc {
+	u8 flags;
+#define SISL_RC_FLAGS_SENSE_VALID         0x80U
+#define SISL_RC_FLAGS_FCP_RSP_CODE_VALID  0x40U
+#define SISL_RC_FLAGS_OVERRUN             0x20U
+#define SISL_RC_FLAGS_UNDERRUN            0x10U
+
+	u8 afu_rc;
+#define SISL_AFU_RC_RHT_INVALID           0x01U	/* user error */
+#define SISL_AFU_RC_RHT_UNALIGNED         0x02U	/* should never happen */
+#define SISL_AFU_RC_RHT_OUT_OF_BOUNDS     0x03u	/* user error */
+#define SISL_AFU_RC_RHT_DMA_ERR           0x04u	/* see afu_extra
+						   may retry if afu_retry is off
+						   possible on master exit
+						 */
+#define SISL_AFU_RC_RHT_RW_PERM           0x05u	/* no RW perms, user error */
+#define SISL_AFU_RC_LXT_UNALIGNED         0x12U	/* should never happen */
+#define SISL_AFU_RC_LXT_OUT_OF_BOUNDS     0x13u	/* user error */
+#define SISL_AFU_RC_LXT_DMA_ERR           0x14u	/* see afu_extra
+						   may retry if afu_retry is off
+						   possible on master exit
+						 */
+#define SISL_AFU_RC_LXT_RW_PERM           0x15u	/* no RW perms, user error */
+
+#define SISL_AFU_RC_NOT_XLATE_HOST        0x1au	/* possible if master exited */
+
+	/* NO_CHANNELS means the FC ports selected by dest_port in
+	 * IOARCB or in the LXT entry are down when the AFU tried to select
+	 * a FC port. If the port went down on an active IO, it will set
+	 * fc_rc to =0x54(NOLOGI) or 0x57(LINKDOWN) instead.
+	 */
+#define SISL_AFU_RC_NO_CHANNELS           0x20U	/* see afu_extra, may retry */
+#define SISL_AFU_RC_CAP_VIOLATION         0x21U	/* either user error or
+						   afu reset/master restart
+						 */
+#define SISL_AFU_RC_OUT_OF_DATA_BUFS      0x30U	/* always retry */
+#define SISL_AFU_RC_DATA_DMA_ERR          0x31U	/* see afu_extra
+						   may retry if afu_retry is off
+						 */
+
+	u8 scsi_rc;		/* SCSI status byte, retry as appropriate */
+#define SISL_SCSI_RC_CHECK                0x02U
+#define SISL_SCSI_RC_BUSY                 0x08u
+
+	u8 fc_rc;		/* retry */
+	/*
+	 * We should only see fc_rc=0x57 (LINKDOWN) or 0x54(NOLOGI) for
+	 * commands that are in flight when a link goes down or is logged out.
+	 * If the link is down or logged out before AFU selects the port, either
+	 * it will choose the other port or we will get afu_rc=0x20 (no_channel)
+	 * if there is no valid port to use.
+	 *
+	 * ABORTPEND/ABORTOK/ABORTFAIL/TGTABORT can be retried, typically these
+	 * would happen if a frame is dropped and something times out.
+	 * NOLOGI or LINKDOWN can be retried if the other port is up.
+	 * RESIDERR can be retried as well.
+	 *
+	 * ABORTFAIL might indicate that lots of frames are getting CRC errors.
+	 * So it maybe retried once and reset the link if it happens again.
+	 * The link can also be reset on the CRC error threshold interrupt.
+	 */
+#define SISL_FC_RC_ABORTPEND	0x52	/* exchange timeout or abort request */
+#define SISL_FC_RC_WRABORTPEND	0x53	/* due to write XFER_RDY invalid */
+#define SISL_FC_RC_NOLOGI	0x54	/* port not logged in, in-flight cmds */
+#define SISL_FC_RC_NOEXP	0x55	/* FC protocol error or HW bug */
+#define SISL_FC_RC_INUSE	0x56	/* tag already in use, HW bug */
+#define SISL_FC_RC_LINKDOWN	0x57	/* link down, in-flight cmds */
+#define SISL_FC_RC_ABORTOK	0x58	/* pending abort completed w/success */
+#define SISL_FC_RC_ABORTFAIL	0x59	/* pending abort completed w/fail */
+#define SISL_FC_RC_RESID	0x5A	/* ioasa underrun/overrun flags set */
+#define SISL_FC_RC_RESIDERR	0x5B	/* actual data len does not match SCSI
+					   reported len, possibly due to dropped
+					   frames */
+#define SISL_FC_RC_TGTABORT	0x5C	/* command aborted by target */
+};
+
+#define SISL_SENSE_DATA_LEN     20	/* Sense data length         */
+
+/*
+ * IOASA: 64 bytes & must follow IOARCB, min 16 byte alignment required,
+ * host native endianness
+ */
+struct sisl_ioasa {
+	union {
+		struct sisl_rc rc;
+		u32 ioasc;
+#define SISL_IOASC_GOOD_COMPLETION        0x00000000U
+	};
+	u32 resid;
+	u8 port;
+	u8 afu_extra;
+	/* when afu_rc=0x04, 0x14, 0x31 (_xxx_DMA_ERR):
+	 * afu_exta contains PSL response code. Useful codes are:
+	 */
+#define SISL_AFU_DMA_ERR_PAGE_IN	0x0A	/* AFU_retry_on_pagein Action
+						 *  Enabled            N/A
+						 *  Disabled           retry
+						 */
+#define SISL_AFU_DMA_ERR_INVALID_EA	0x0B	/* this is a hard error
+						 * afu_rc	Implies
+						 * 0x04, 0x14	master exit.
+						 * 0x31         user error.
+						 */
+	/* when afu rc=0x20 (no channels):
+	 * afu_extra bits [4:5]: available portmask,  [6:7]: requested portmask.
+	 */
+#define SISL_AFU_NO_CLANNELS_AMASK(afu_extra) (((afu_extra) & 0x0C) >> 2)
+#define SISL_AFU_NO_CLANNELS_RMASK(afu_extra) ((afu_extra) & 0x03)
+
+	u8 scsi_extra;
+	u8 fc_extra;
+	u8 sense_data[SISL_SENSE_DATA_LEN];
+
+	/* These fields are defined by the SISlite architecture for the
+	 * host to use as they see fit for their implementation.
+	 */
+	union {
+		u64 host_use[4];
+		u8 host_use_b[32];
+	};
+} __packed;
+
+#define SISL_RESP_HANDLE_T_BIT        0x1ULL	/* Toggle bit */
+
+/* MMIO space is required to support only 64-bit access */
+
+/*
+ * This AFU has two mechanisms to deal with endian-ness.
+ * One is a global configuration (in the afu_config) register
+ * below that specifies the endian-ness of the host.
+ * The other is a per context (i.e. application) specification
+ * controlled by the endian_ctrl field here. Since the master
+ * context is one such application the master context's
+ * endian-ness is set to be the same as the host.
+ *
+ * As per the SISlite spec, the MMIO registers are always
+ * big endian.
+ */
+#define SISL_ENDIAN_CTRL_BE           0x8000000000000080ULL
+#define SISL_ENDIAN_CTRL_LE           0x0000000000000000ULL
+
+#ifdef __BIG_ENDIAN
+#define SISL_ENDIAN_CTRL              SISL_ENDIAN_CTRL_BE
+#else
+#define SISL_ENDIAN_CTRL              SISL_ENDIAN_CTRL_LE
+#endif
+
+/* per context host transport MMIO  */
+struct sisl_host_map {
+	__be64 endian_ctrl;     /* Per context Endian Control. The AFU will
+			      * operate on whatever the context is of the
+			      * host application.
+			      */
+
+	__be64 intr_status;	/* this sends LISN# programmed in ctx_ctrl.
+				 * Only recovery in a PERM_ERR is a context
+				 * exit since there is no way to tell which
+				 * command caused the error.
+				 */
+#define SISL_ISTATUS_PERM_ERR_CMDROOM    0x0010ULL	/* b59, user error */
+#define SISL_ISTATUS_PERM_ERR_RCB_READ   0x0008ULL	/* b60, user error */
+#define SISL_ISTATUS_PERM_ERR_SA_WRITE   0x0004ULL	/* b61, user error */
+#define SISL_ISTATUS_PERM_ERR_RRQ_WRITE  0x0002ULL	/* b62, user error */
+	/* Page in wait accessing RCB/IOASA/RRQ is reported in b63.
+	 * Same error in data/LXT/RHT access is reported via IOASA.
+	 */
+#define SISL_ISTATUS_TEMP_ERR_PAGEIN     0x0001ULL	/* b63, can be generated
+							 * only when AFU auto
+							 * retry is disabled.
+							 * If user can determine
+							 * the command that
+							 * caused the error, it
+							 * can be retried.
+							 */
+#define SISL_ISTATUS_UNMASK  (0x001FULL)	/* 1 means unmasked */
+#define SISL_ISTATUS_MASK    ~(SISL_ISTATUS_UNMASK)	/* 1 means masked */
+
+	__be64 intr_clear;
+	__be64 intr_mask;
+	__be64 ioarrin;		/* only write what cmd_room permits */
+	__be64 rrq_start;	/* start & end are both inclusive */
+	__be64 rrq_end;		/* write sequence: start followed by end */
+	__be64 cmd_room;
+	__be64 ctx_ctrl;	/* least significant byte or b56:63 is LISN# */
+	__be64 mbox_w;		/* restricted use */
+};
+
+/* per context provisioning & control MMIO */
+struct sisl_ctrl_map {
+	__be64 rht_start;
+	__be64 rht_cnt_id;
+	/* both cnt & ctx_id args must be ULL */
+#define SISL_RHT_CNT_ID(cnt, ctx_id)  (((cnt) << 48) | ((ctx_id) << 32))
+
+	__be64 ctx_cap;	/* afu_rc below is when the capability is violated */
+#define SISL_CTX_CAP_PROXY_ISSUE       0x8000000000000000ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_REAL_MODE         0x4000000000000000ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_HOST_XLATE        0x2000000000000000ULL /* afu_rc 0x1a */
+#define SISL_CTX_CAP_PROXY_TARGET      0x1000000000000000ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_AFU_CMD           0x0000000000000008ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_GSCSI_CMD         0x0000000000000004ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_WRITE_CMD         0x0000000000000002ULL /* afu_rc 0x21 */
+#define SISL_CTX_CAP_READ_CMD          0x0000000000000001ULL /* afu_rc 0x21 */
+	__be64 mbox_r;
+};
+
+/* single copy global regs */
+struct sisl_global_regs {
+	__be64 aintr_status;
+	/* In cxlflash, each FC port/link gets a byte of status */
+#define SISL_ASTATUS_FC0_OTHER	 0x8000ULL /* b48, other err,
+					      FC_ERRCAP[31:20] */
+#define SISL_ASTATUS_FC0_LOGO    0x4000ULL /* b49, target sent FLOGI/PLOGI/LOGO
+						   while logged in */
+#define SISL_ASTATUS_FC0_CRC_T   0x2000ULL /* b50, CRC threshold exceeded */
+#define SISL_ASTATUS_FC0_LOGI_R  0x1000ULL /* b51, login state machine timed out
+						   and retrying */
+#define SISL_ASTATUS_FC0_LOGI_F  0x0800ULL /* b52, login failed,
+					      FC_ERROR[19:0] */
+#define SISL_ASTATUS_FC0_LOGI_S  0x0400ULL /* b53, login succeeded */
+#define SISL_ASTATUS_FC0_LINK_DN 0x0200ULL /* b54, link online to offline */
+#define SISL_ASTATUS_FC0_LINK_UP 0x0100ULL /* b55, link offline to online */
+
+#define SISL_ASTATUS_FC1_OTHER   0x0080ULL /* b56 */
+#define SISL_ASTATUS_FC1_LOGO    0x0040ULL /* b57 */
+#define SISL_ASTATUS_FC1_CRC_T   0x0020ULL /* b58 */
+#define SISL_ASTATUS_FC1_LOGI_R  0x0010ULL /* b59 */
+#define SISL_ASTATUS_FC1_LOGI_F  0x0008ULL /* b60 */
+#define SISL_ASTATUS_FC1_LOGI_S  0x0004ULL /* b61 */
+#define SISL_ASTATUS_FC1_LINK_DN 0x0002ULL /* b62 */
+#define SISL_ASTATUS_FC1_LINK_UP 0x0001ULL /* b63 */
+
+#define SISL_FC_INTERNAL_UNMASK	0x0000000300000000ULL	/* 1 means unmasked */
+#define SISL_FC_INTERNAL_MASK	~(SISL_FC_INTERNAL_UNMASK)
+#define SISL_FC_INTERNAL_SHIFT	32
+
+#define SISL_ASTATUS_UNMASK	0xFFFFULL		/* 1 means unmasked */
+#define SISL_ASTATUS_MASK	~(SISL_ASTATUS_UNMASK)	/* 1 means masked */
+
+	__be64 aintr_clear;
+	__be64 aintr_mask;
+	__be64 afu_ctrl;
+	__be64 afu_hb;
+	__be64 afu_scratch_pad;
+	__be64 afu_port_sel;
+#define SISL_AFUCONF_AR_IOARCB	0x4000ULL
+#define SISL_AFUCONF_AR_LXT	0x2000ULL
+#define SISL_AFUCONF_AR_RHT	0x1000ULL
+#define SISL_AFUCONF_AR_DATA	0x0800ULL
+#define SISL_AFUCONF_AR_RSRC	0x0400ULL
+#define SISL_AFUCONF_AR_IOASA	0x0200ULL
+#define SISL_AFUCONF_AR_RRQ	0x0100ULL
+/* Aggregate all Auto Retry Bits */
+#define SISL_AFUCONF_AR_ALL	(SISL_AFUCONF_AR_IOARCB|SISL_AFUCONF_AR_LXT| \
+				 SISL_AFUCONF_AR_RHT|SISL_AFUCONF_AR_DATA|   \
+				 SISL_AFUCONF_AR_RSRC|SISL_AFUCONF_AR_IOASA| \
+				 SISL_AFUCONF_AR_RRQ)
+#ifdef __BIG_ENDIAN
+#define SISL_AFUCONF_ENDIAN            0x0000ULL
+#else
+#define SISL_AFUCONF_ENDIAN            0x0020ULL
+#endif
+#define SISL_AFUCONF_MBOX_CLR_READ     0x0010ULL
+	__be64 afu_config;
+	__be64 rsvd[0xf8];
+	__le64 afu_version;
+	__be64 interface_version;
+};
+
+#define CXLFLASH_NUM_FC_PORTS   2
+#define CXLFLASH_MAX_CONTEXT  512	/* how many contexts per afu */
+#define CXLFLASH_NUM_VLUNS    512
+
+struct sisl_global_map {
+	union {
+		struct sisl_global_regs regs;
+		char page0[SIZE_4K];	/* page 0 */
+	};
+
+	char page1[SIZE_4K];	/* page 1 */
+
+	/* pages 2 & 3 */
+	__be64 fc_regs[CXLFLASH_NUM_FC_PORTS][CXLFLASH_NUM_VLUNS];
+
+	/* pages 4 & 5 (lun tbl) */
+	__be64 fc_port[CXLFLASH_NUM_FC_PORTS][CXLFLASH_NUM_VLUNS];
+
+};
+
+/*
+ * CXL Flash Memory Map
+ *
+ *	+-------------------------------+
+ *	|    512 * 64 KB User MMIO      |
+ *	|        (per context)          |
+ *	|       User Accessible         |
+ *	+-------------------------------+
+ *	|    512 * 128 B per context    |
+ *	|    Provisioning and Control   |
+ *	|   Trusted Process accessible  |
+ *	+-------------------------------+
+ *	|         64 KB Global          |
+ *	|   Trusted Process accessible  |
+ *	+-------------------------------+
+*/
+struct cxlflash_afu_map {
+	union {
+		struct sisl_host_map host;
+		char harea[SIZE_64K];	/* 64KB each */
+	} hosts[CXLFLASH_MAX_CONTEXT];
+
+	union {
+		struct sisl_ctrl_map ctrl;
+		char carea[cache_line_size()];	/* 128B each */
+	} ctrls[CXLFLASH_MAX_CONTEXT];
+
+	union {
+		struct sisl_global_map global;
+		char garea[SIZE_64K];	/* 64KB single block */
+	};
+};
+
+/*
+ * LXT - LBA Translation Table
+ * LXT control blocks
+ */
+struct sisl_lxt_entry {
+	u64 rlba_base;	/* bits 0:47 is base
+			 * b48:55 is lun index
+			 * b58:59 is write & read perms
+			 * (if no perm, afu_rc=0x15)
+			 * b60:63 is port_sel mask
+			 */
+};
+
+/*
+ * RHT - Resource Handle Table
+ * Per the SISlite spec, RHT entries are to be 16-byte aligned
+ */
+struct sisl_rht_entry {
+	struct sisl_lxt_entry *lxt_start;
+	u32 lxt_cnt;
+	u16 rsvd;
+	u8 fp;			/* format & perm nibbles.
+				 * (if no perm, afu_rc=0x05)
+				 */
+	u8 nmask;
+} __packed __aligned(16);
+
+struct sisl_rht_entry_f1 {
+	u64 lun_id;
+	union {
+		struct {
+			u8 valid;
+			u8 rsvd[5];
+			u8 fp;
+			u8 port_sel;
+		};
+
+		u64 dw;
+	};
+} __packed __aligned(16);
+
+/* make the fp byte */
+#define SISL_RHT_FP(fmt, perm) (((fmt) << 4) | (perm))
+
+/* make the fp byte for a clone from a source fp and clone flags
+ * flags must be only 2 LSB bits.
+ */
+#define SISL_RHT_FP_CLONE(src_fp, cln_flags) ((src_fp) & (0xFC | (cln_flags)))
+
+#define RHT_PERM_READ  0x01U
+#define RHT_PERM_WRITE 0x02U
+#define RHT_PERM_RW    (RHT_PERM_READ | RHT_PERM_WRITE)
+
+/* extract the perm bits from a fp */
+#define SISL_RHT_PERM(fp) ((fp) & RHT_PERM_RW)
+
+#define PORT0  0x01U
+#define PORT1  0x02U
+#define BOTH_PORTS    (PORT0 | PORT1)
+
+/* AFU Sync Mode byte */
+#define AFU_LW_SYNC 0x0U
+#define AFU_HW_SYNC 0x1U
+#define AFU_GSYNC   0x2U
+
+/* Special Task Management Function CDB */
+#define TMF_LUN_RESET  0x1U
+#define TMF_CLEAR_ACA  0x2U
+
+
+#define SISLITE_MAX_WS_BLOCKS 512
+
+#endif /* _SISLITE_H */
diff --git a/kernel/drivers/scsi/cxlflash/superpipe.c b/kernel/drivers/scsi/cxlflash/superpipe.c
new file mode 100644
index 000000000..cac2e6a50
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/superpipe.c
@@ -0,0 +1,2143 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
+#include <misc/cxl.h>
+#include <asm/unaligned.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_eh.h>
+#include <uapi/scsi/cxlflash_ioctl.h>
+
+#include "sislite.h"
+#include "common.h"
+#include "vlun.h"
+#include "superpipe.h"
+
+struct cxlflash_global global;
+
+/**
+ * marshal_rele_to_resize() - translate release to resize structure
+ * @rele:	Source structure from which to translate/copy.
+ * @resize:	Destination structure for the translate/copy.
+ */
+static void marshal_rele_to_resize(struct dk_cxlflash_release *release,
+				   struct dk_cxlflash_resize *resize)
+{
+	resize->hdr = release->hdr;
+	resize->context_id = release->context_id;
+	resize->rsrc_handle = release->rsrc_handle;
+}
+
+/**
+ * marshal_det_to_rele() - translate detach to release structure
+ * @detach:	Destination structure for the translate/copy.
+ * @rele:	Source structure from which to translate/copy.
+ */
+static void marshal_det_to_rele(struct dk_cxlflash_detach *detach,
+				struct dk_cxlflash_release *release)
+{
+	release->hdr = detach->hdr;
+	release->context_id = detach->context_id;
+}
+
+/**
+ * cxlflash_free_errpage() - frees resources associated with global error page
+ */
+void cxlflash_free_errpage(void)
+{
+
+	mutex_lock(&global.mutex);
+	if (global.err_page) {
+		__free_page(global.err_page);
+		global.err_page = NULL;
+	}
+	mutex_unlock(&global.mutex);
+}
+
+/**
+ * cxlflash_stop_term_user_contexts() - stops/terminates known user contexts
+ * @cfg:	Internal structure associated with the host.
+ *
+ * When the host needs to go down, all users must be quiesced and their
+ * memory freed. This is accomplished by putting the contexts in error
+ * state which will notify the user and let them 'drive' the tear down.
+ * Meanwhile, this routine camps until all user contexts have been removed.
+ */
+void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg)
+{
+	struct device *dev = &cfg->dev->dev;
+	int i, found;
+
+	cxlflash_mark_contexts_error(cfg);
+
+	while (true) {
+		found = false;
+
+		for (i = 0; i < MAX_CONTEXT; i++)
+			if (cfg->ctx_tbl[i]) {
+				found = true;
+				break;
+			}
+
+		if (!found && list_empty(&cfg->ctx_err_recovery))
+			return;
+
+		dev_dbg(dev, "%s: Wait for user contexts to quiesce...\n",
+			__func__);
+		wake_up_all(&cfg->reset_waitq);
+		ssleep(1);
+	}
+}
+
+/**
+ * find_error_context() - locates a context by cookie on the error recovery list
+ * @cfg:	Internal structure associated with the host.
+ * @rctxid:	Desired context by id.
+ * @file:	Desired context by file.
+ *
+ * Return: Found context on success, NULL on failure
+ */
+static struct ctx_info *find_error_context(struct cxlflash_cfg *cfg, u64 rctxid,
+					   struct file *file)
+{
+	struct ctx_info *ctxi;
+
+	list_for_each_entry(ctxi, &cfg->ctx_err_recovery, list)
+		if ((ctxi->ctxid == rctxid) || (ctxi->file == file))
+			return ctxi;
+
+	return NULL;
+}
+
+/**
+ * get_context() - obtains a validated and locked context reference
+ * @cfg:	Internal structure associated with the host.
+ * @rctxid:	Desired context (raw, un-decoded format).
+ * @arg:	LUN information or file associated with request.
+ * @ctx_ctrl:	Control information to 'steer' desired lookup.
+ *
+ * NOTE: despite the name pid, in linux, current->pid actually refers
+ * to the lightweight process id (tid) and can change if the process is
+ * multi threaded. The tgid remains constant for the process and only changes
+ * when the process of fork. For all intents and purposes, think of tgid
+ * as a pid in the traditional sense.
+ *
+ * Return: Validated context on success, NULL on failure
+ */
+struct ctx_info *get_context(struct cxlflash_cfg *cfg, u64 rctxid,
+			     void *arg, enum ctx_ctrl ctx_ctrl)
+{
+	struct device *dev = &cfg->dev->dev;
+	struct ctx_info *ctxi = NULL;
+	struct lun_access *lun_access = NULL;
+	struct file *file = NULL;
+	struct llun_info *lli = arg;
+	u64 ctxid = DECODE_CTXID(rctxid);
+	int rc;
+	pid_t pid = current->tgid, ctxpid = 0;
+
+	if (ctx_ctrl & CTX_CTRL_FILE) {
+		lli = NULL;
+		file = (struct file *)arg;
+	}
+
+	if (ctx_ctrl & CTX_CTRL_CLONE)
+		pid = current->parent->tgid;
+
+	if (likely(ctxid < MAX_CONTEXT)) {
+		while (true) {
+			mutex_lock(&cfg->ctx_tbl_list_mutex);
+			ctxi = cfg->ctx_tbl[ctxid];
+			if (ctxi)
+				if ((file && (ctxi->file != file)) ||
+				    (!file && (ctxi->ctxid != rctxid)))
+					ctxi = NULL;
+
+			if ((ctx_ctrl & CTX_CTRL_ERR) ||
+			    (!ctxi && (ctx_ctrl & CTX_CTRL_ERR_FALLBACK)))
+				ctxi = find_error_context(cfg, rctxid, file);
+			if (!ctxi) {
+				mutex_unlock(&cfg->ctx_tbl_list_mutex);
+				goto out;
+			}
+
+			/*
+			 * Need to acquire ownership of the context while still
+			 * under the table/list lock to serialize with a remove
+			 * thread. Use the 'try' to avoid stalling the
+			 * table/list lock for a single context.
+			 *
+			 * Note that the lock order is:
+			 *
+			 *	cfg->ctx_tbl_list_mutex -> ctxi->mutex
+			 *
+			 * Therefore release ctx_tbl_list_mutex before retrying.
+			 */
+			rc = mutex_trylock(&ctxi->mutex);
+			mutex_unlock(&cfg->ctx_tbl_list_mutex);
+			if (rc)
+				break; /* got the context's lock! */
+		}
+
+		if (ctxi->unavail)
+			goto denied;
+
+		ctxpid = ctxi->pid;
+		if (likely(!(ctx_ctrl & CTX_CTRL_NOPID)))
+			if (pid != ctxpid)
+				goto denied;
+
+		if (lli) {
+			list_for_each_entry(lun_access, &ctxi->luns, list)
+				if (lun_access->lli == lli)
+					goto out;
+			goto denied;
+		}
+	}
+
+out:
+	dev_dbg(dev, "%s: rctxid=%016llX ctxinfo=%p ctxpid=%u pid=%u "
+		"ctx_ctrl=%u\n", __func__, rctxid, ctxi, ctxpid, pid,
+		ctx_ctrl);
+
+	return ctxi;
+
+denied:
+	mutex_unlock(&ctxi->mutex);
+	ctxi = NULL;
+	goto out;
+}
+
+/**
+ * put_context() - release a context that was retrieved from get_context()
+ * @ctxi:	Context to release.
+ *
+ * For now, releasing the context equates to unlocking it's mutex.
+ */
+void put_context(struct ctx_info *ctxi)
+{
+	mutex_unlock(&ctxi->mutex);
+}
+
+/**
+ * afu_attach() - attach a context to the AFU
+ * @cfg:	Internal structure associated with the host.
+ * @ctxi:	Context to attach.
+ *
+ * Upon setting the context capabilities, they must be confirmed with
+ * a read back operation as the context might have been closed since
+ * the mailbox was unlocked. When this occurs, registration is failed.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int afu_attach(struct cxlflash_cfg *cfg, struct ctx_info *ctxi)
+{
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	struct sisl_ctrl_map __iomem *ctrl_map = ctxi->ctrl_map;
+	int rc = 0;
+	u64 val;
+
+	/* Unlock cap and restrict user to read/write cmds in translated mode */
+	readq_be(&ctrl_map->mbox_r);
+	val = (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD);
+	writeq_be(val, &ctrl_map->ctx_cap);
+	val = readq_be(&ctrl_map->ctx_cap);
+	if (val != (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD)) {
+		dev_err(dev, "%s: ctx may be closed val=%016llX\n",
+			__func__, val);
+		rc = -EAGAIN;
+		goto out;
+	}
+
+	/* Set up MMIO registers pointing to the RHT */
+	writeq_be((u64)ctxi->rht_start, &ctrl_map->rht_start);
+	val = SISL_RHT_CNT_ID((u64)MAX_RHT_PER_CONTEXT, (u64)(afu->ctx_hndl));
+	writeq_be(val, &ctrl_map->rht_cnt_id);
+out:
+	dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * read_cap16() - issues a SCSI READ_CAP16 command
+ * @sdev:	SCSI device associated with LUN.
+ * @lli:	LUN destined for capacity request.
+ *
+ * The READ_CAP16 can take quite a while to complete. Should an EEH occur while
+ * in scsi_execute(), the EEH handler will attempt to recover. As part of the
+ * recovery, the handler drains all currently running ioctls, waiting until they
+ * have completed before proceeding with a reset. As this routine is used on the
+ * ioctl path, this can create a condition where the EEH handler becomes stuck,
+ * infinitely waiting for this ioctl thread. To avoid this behavior, temporarily
+ * unmark this thread as an ioctl thread by releasing the ioctl read semaphore.
+ * This will allow the EEH handler to proceed with a recovery while this thread
+ * is still running. Once the scsi_execute() returns, reacquire the ioctl read
+ * semaphore and check the adapter state in case it changed while inside of
+ * scsi_execute(). The state check will wait if the adapter is still being
+ * recovered or return a failure if the recovery failed. In the event that the
+ * adapter reset failed, simply return the failure as the ioctl would be unable
+ * to continue.
+ *
+ * Note that the above puts a requirement on this routine to only be called on
+ * an ioctl thread.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int read_cap16(struct scsi_device *sdev, struct llun_info *lli)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct glun_info *gli = lli->parent;
+	u8 *cmd_buf = NULL;
+	u8 *scsi_cmd = NULL;
+	u8 *sense_buf = NULL;
+	int rc = 0;
+	int result = 0;
+	int retry_cnt = 0;
+	u32 to = CMD_TIMEOUT * HZ;
+
+retry:
+	cmd_buf = kzalloc(CMD_BUFSIZE, GFP_KERNEL);
+	scsi_cmd = kzalloc(MAX_COMMAND_SIZE, GFP_KERNEL);
+	sense_buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
+	if (unlikely(!cmd_buf || !scsi_cmd || !sense_buf)) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	scsi_cmd[0] = SERVICE_ACTION_IN_16;	/* read cap(16) */
+	scsi_cmd[1] = SAI_READ_CAPACITY_16;	/* service action */
+	put_unaligned_be32(CMD_BUFSIZE, &scsi_cmd[10]);
+
+	dev_dbg(dev, "%s: %ssending cmd(0x%x)\n", __func__,
+		retry_cnt ? "re" : "", scsi_cmd[0]);
+
+	/* Drop the ioctl read semahpore across lengthy call */
+	up_read(&cfg->ioctl_rwsem);
+	result = scsi_execute(sdev, scsi_cmd, DMA_FROM_DEVICE, cmd_buf,
+			      CMD_BUFSIZE, sense_buf, to, CMD_RETRIES, 0, NULL);
+	down_read(&cfg->ioctl_rwsem);
+	rc = check_state(cfg);
+	if (rc) {
+		dev_err(dev, "%s: Failed state! result=0x08%X\n",
+			__func__, result);
+		rc = -ENODEV;
+		goto out;
+	}
+
+	if (driver_byte(result) == DRIVER_SENSE) {
+		result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
+		if (result & SAM_STAT_CHECK_CONDITION) {
+			struct scsi_sense_hdr sshdr;
+
+			scsi_normalize_sense(sense_buf, SCSI_SENSE_BUFFERSIZE,
+					    &sshdr);
+			switch (sshdr.sense_key) {
+			case NO_SENSE:
+			case RECOVERED_ERROR:
+				/* fall through */
+			case NOT_READY:
+				result &= ~SAM_STAT_CHECK_CONDITION;
+				break;
+			case UNIT_ATTENTION:
+				switch (sshdr.asc) {
+				case 0x29: /* Power on Reset or Device Reset */
+					/* fall through */
+				case 0x2A: /* Device capacity changed */
+				case 0x3F: /* Report LUNs changed */
+					/* Retry the command once more */
+					if (retry_cnt++ < 1) {
+						kfree(cmd_buf);
+						kfree(scsi_cmd);
+						kfree(sense_buf);
+						goto retry;
+					}
+				}
+				break;
+			default:
+				break;
+			}
+		}
+	}
+
+	if (result) {
+		dev_err(dev, "%s: command failed, result=0x%x\n",
+			__func__, result);
+		rc = -EIO;
+		goto out;
+	}
+
+	/*
+	 * Read cap was successful, grab values from the buffer;
+	 * note that we don't need to worry about unaligned access
+	 * as the buffer is allocated on an aligned boundary.
+	 */
+	mutex_lock(&gli->mutex);
+	gli->max_lba = be64_to_cpu(*((__be64 *)&cmd_buf[0]));
+	gli->blk_len = be32_to_cpu(*((__be32 *)&cmd_buf[8]));
+	mutex_unlock(&gli->mutex);
+
+out:
+	kfree(cmd_buf);
+	kfree(scsi_cmd);
+	kfree(sense_buf);
+
+	dev_dbg(dev, "%s: maxlba=%lld blklen=%d rc=%d\n",
+		__func__, gli->max_lba, gli->blk_len, rc);
+	return rc;
+}
+
+/**
+ * get_rhte() - obtains validated resource handle table entry reference
+ * @ctxi:	Context owning the resource handle.
+ * @rhndl:	Resource handle associated with entry.
+ * @lli:	LUN associated with request.
+ *
+ * Return: Validated RHTE on success, NULL on failure
+ */
+struct sisl_rht_entry *get_rhte(struct ctx_info *ctxi, res_hndl_t rhndl,
+				struct llun_info *lli)
+{
+	struct sisl_rht_entry *rhte = NULL;
+
+	if (unlikely(!ctxi->rht_start)) {
+		pr_debug("%s: Context does not have allocated RHT!\n",
+			 __func__);
+		goto out;
+	}
+
+	if (unlikely(rhndl >= MAX_RHT_PER_CONTEXT)) {
+		pr_debug("%s: Bad resource handle! (%d)\n", __func__, rhndl);
+		goto out;
+	}
+
+	if (unlikely(ctxi->rht_lun[rhndl] != lli)) {
+		pr_debug("%s: Bad resource handle LUN! (%d)\n",
+			 __func__, rhndl);
+		goto out;
+	}
+
+	rhte = &ctxi->rht_start[rhndl];
+	if (unlikely(rhte->nmask == 0)) {
+		pr_debug("%s: Unopened resource handle! (%d)\n",
+			 __func__, rhndl);
+		rhte = NULL;
+		goto out;
+	}
+
+out:
+	return rhte;
+}
+
+/**
+ * rhte_checkout() - obtains free/empty resource handle table entry
+ * @ctxi:	Context owning the resource handle.
+ * @lli:	LUN associated with request.
+ *
+ * Return: Free RHTE on success, NULL on failure
+ */
+struct sisl_rht_entry *rhte_checkout(struct ctx_info *ctxi,
+				     struct llun_info *lli)
+{
+	struct sisl_rht_entry *rhte = NULL;
+	int i;
+
+	/* Find a free RHT entry */
+	for (i = 0; i < MAX_RHT_PER_CONTEXT; i++)
+		if (ctxi->rht_start[i].nmask == 0) {
+			rhte = &ctxi->rht_start[i];
+			ctxi->rht_out++;
+			break;
+		}
+
+	if (likely(rhte))
+		ctxi->rht_lun[i] = lli;
+
+	pr_debug("%s: returning rhte=%p (%d)\n", __func__, rhte, i);
+	return rhte;
+}
+
+/**
+ * rhte_checkin() - releases a resource handle table entry
+ * @ctxi:	Context owning the resource handle.
+ * @rhte:	RHTE to release.
+ */
+void rhte_checkin(struct ctx_info *ctxi,
+		  struct sisl_rht_entry *rhte)
+{
+	u32 rsrc_handle = rhte - ctxi->rht_start;
+
+	rhte->nmask = 0;
+	rhte->fp = 0;
+	ctxi->rht_out--;
+	ctxi->rht_lun[rsrc_handle] = NULL;
+	ctxi->rht_needs_ws[rsrc_handle] = false;
+}
+
+/**
+ * rhte_format1() - populates a RHTE for format 1
+ * @rhte:	RHTE to populate.
+ * @lun_id:	LUN ID of LUN associated with RHTE.
+ * @perm:	Desired permissions for RHTE.
+ * @port_sel:	Port selection mask
+ */
+static void rht_format1(struct sisl_rht_entry *rhte, u64 lun_id, u32 perm,
+			u32 port_sel)
+{
+	/*
+	 * Populate the Format 1 RHT entry for direct access (physical
+	 * LUN) using the synchronization sequence defined in the
+	 * SISLite specification.
+	 */
+	struct sisl_rht_entry_f1 dummy = { 0 };
+	struct sisl_rht_entry_f1 *rhte_f1 = (struct sisl_rht_entry_f1 *)rhte;
+
+	memset(rhte_f1, 0, sizeof(*rhte_f1));
+	rhte_f1->fp = SISL_RHT_FP(1U, 0);
+	dma_wmb(); /* Make setting of format bit visible */
+
+	rhte_f1->lun_id = lun_id;
+	dma_wmb(); /* Make setting of LUN id visible */
+
+	/*
+	 * Use a dummy RHT Format 1 entry to build the second dword
+	 * of the entry that must be populated in a single write when
+	 * enabled (valid bit set to TRUE).
+	 */
+	dummy.valid = 0x80;
+	dummy.fp = SISL_RHT_FP(1U, perm);
+	dummy.port_sel = port_sel;
+	rhte_f1->dw = dummy.dw;
+
+	dma_wmb(); /* Make remaining RHT entry fields visible */
+}
+
+/**
+ * cxlflash_lun_attach() - attaches a user to a LUN and manages the LUN's mode
+ * @gli:	LUN to attach.
+ * @mode:	Desired mode of the LUN.
+ * @locked:	Mutex status on current thread.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_lun_attach(struct glun_info *gli, enum lun_mode mode, bool locked)
+{
+	int rc = 0;
+
+	if (!locked)
+		mutex_lock(&gli->mutex);
+
+	if (gli->mode == MODE_NONE)
+		gli->mode = mode;
+	else if (gli->mode != mode) {
+		pr_debug("%s: LUN operating in mode %d, requested mode %d\n",
+			 __func__, gli->mode, mode);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	gli->users++;
+	WARN_ON(gli->users <= 0);
+out:
+	pr_debug("%s: Returning rc=%d gli->mode=%u gli->users=%u\n",
+		 __func__, rc, gli->mode, gli->users);
+	if (!locked)
+		mutex_unlock(&gli->mutex);
+	return rc;
+}
+
+/**
+ * cxlflash_lun_detach() - detaches a user from a LUN and resets the LUN's mode
+ * @gli:	LUN to detach.
+ *
+ * When resetting the mode, terminate block allocation resources as they
+ * are no longer required (service is safe to call even when block allocation
+ * resources were not present - such as when transitioning from physical mode).
+ * These resources will be reallocated when needed (subsequent transition to
+ * virtual mode).
+ */
+void cxlflash_lun_detach(struct glun_info *gli)
+{
+	mutex_lock(&gli->mutex);
+	WARN_ON(gli->mode == MODE_NONE);
+	if (--gli->users == 0) {
+		gli->mode = MODE_NONE;
+		cxlflash_ba_terminate(&gli->blka.ba_lun);
+	}
+	pr_debug("%s: gli->users=%u\n", __func__, gli->users);
+	WARN_ON(gli->users < 0);
+	mutex_unlock(&gli->mutex);
+}
+
+/**
+ * _cxlflash_disk_release() - releases the specified resource entry
+ * @sdev:	SCSI device associated with LUN.
+ * @ctxi:	Context owning resources.
+ * @release:	Release ioctl data structure.
+ *
+ * For LUNs in virtual mode, the virtual LUN associated with the specified
+ * resource handle is resized to 0 prior to releasing the RHTE. Note that the
+ * AFU sync should _not_ be performed when the context is sitting on the error
+ * recovery list. A context on the error recovery list is not known to the AFU
+ * due to reset. When the context is recovered, it will be reattached and made
+ * known again to the AFU.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int _cxlflash_disk_release(struct scsi_device *sdev,
+			   struct ctx_info *ctxi,
+			   struct dk_cxlflash_release *release)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct afu *afu = cfg->afu;
+	bool put_ctx = false;
+
+	struct dk_cxlflash_resize size;
+	res_hndl_t rhndl = release->rsrc_handle;
+
+	int rc = 0;
+	u64 ctxid = DECODE_CTXID(release->context_id),
+	    rctxid = release->context_id;
+
+	struct sisl_rht_entry *rhte;
+	struct sisl_rht_entry_f1 *rhte_f1;
+
+	dev_dbg(dev, "%s: ctxid=%llu rhndl=0x%llx gli->mode=%u gli->users=%u\n",
+		__func__, ctxid, release->rsrc_handle, gli->mode, gli->users);
+
+	if (!ctxi) {
+		ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
+		if (unlikely(!ctxi)) {
+			dev_dbg(dev, "%s: Bad context! (%llu)\n",
+				__func__, ctxid);
+			rc = -EINVAL;
+			goto out;
+		}
+
+		put_ctx = true;
+	}
+
+	rhte = get_rhte(ctxi, rhndl, lli);
+	if (unlikely(!rhte)) {
+		dev_dbg(dev, "%s: Bad resource handle! (%d)\n",
+			__func__, rhndl);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/*
+	 * Resize to 0 for virtual LUNS by setting the size
+	 * to 0. This will clear LXT_START and LXT_CNT fields
+	 * in the RHT entry and properly sync with the AFU.
+	 *
+	 * Afterwards we clear the remaining fields.
+	 */
+	switch (gli->mode) {
+	case MODE_VIRTUAL:
+		marshal_rele_to_resize(release, &size);
+		size.req_size = 0;
+		rc = _cxlflash_vlun_resize(sdev, ctxi, &size);
+		if (rc) {
+			dev_dbg(dev, "%s: resize failed rc %d\n", __func__, rc);
+			goto out;
+		}
+
+		break;
+	case MODE_PHYSICAL:
+		/*
+		 * Clear the Format 1 RHT entry for direct access
+		 * (physical LUN) using the synchronization sequence
+		 * defined in the SISLite specification.
+		 */
+		rhte_f1 = (struct sisl_rht_entry_f1 *)rhte;
+
+		rhte_f1->valid = 0;
+		dma_wmb(); /* Make revocation of RHT entry visible */
+
+		rhte_f1->lun_id = 0;
+		dma_wmb(); /* Make clearing of LUN id visible */
+
+		rhte_f1->dw = 0;
+		dma_wmb(); /* Make RHT entry bottom-half clearing visible */
+
+		if (!ctxi->err_recovery_active)
+			cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
+		break;
+	default:
+		WARN(1, "Unsupported LUN mode!");
+		goto out;
+	}
+
+	rhte_checkin(ctxi, rhte);
+	cxlflash_lun_detach(gli);
+
+out:
+	if (put_ctx)
+		put_context(ctxi);
+	dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+int cxlflash_disk_release(struct scsi_device *sdev,
+			  struct dk_cxlflash_release *release)
+{
+	return _cxlflash_disk_release(sdev, NULL, release);
+}
+
+/**
+ * destroy_context() - releases a context
+ * @cfg:	Internal structure associated with the host.
+ * @ctxi:	Context to release.
+ *
+ * Note that the rht_lun member of the context was cut from a single
+ * allocation when the context was created and therefore does not need
+ * to be explicitly freed. Also note that we conditionally check for the
+ * existence of the context control map before clearing the RHT registers
+ * and context capabilities because it is possible to destroy a context
+ * while the context is in the error state (previous mapping was removed
+ * [so we don't have to worry about clearing] and context is waiting for
+ * a new mapping).
+ */
+static void destroy_context(struct cxlflash_cfg *cfg,
+			    struct ctx_info *ctxi)
+{
+	struct afu *afu = cfg->afu;
+
+	WARN_ON(!list_empty(&ctxi->luns));
+
+	/* Clear RHT registers and drop all capabilities for this context */
+	if (afu->afu_map && ctxi->ctrl_map) {
+		writeq_be(0, &ctxi->ctrl_map->rht_start);
+		writeq_be(0, &ctxi->ctrl_map->rht_cnt_id);
+		writeq_be(0, &ctxi->ctrl_map->ctx_cap);
+	}
+
+	/* Free memory associated with context */
+	free_page((ulong)ctxi->rht_start);
+	kfree(ctxi->rht_needs_ws);
+	kfree(ctxi->rht_lun);
+	kfree(ctxi);
+}
+
+/**
+ * create_context() - allocates and initializes a context
+ * @cfg:	Internal structure associated with the host.
+ * @ctx:	Previously obtained CXL context reference.
+ * @ctxid:	Previously obtained process element associated with CXL context.
+ * @adap_fd:	Previously obtained adapter fd associated with CXL context.
+ * @file:	Previously obtained file associated with CXL context.
+ * @perms:	User-specified permissions.
+ *
+ * The context's mutex is locked when an allocated context is returned.
+ *
+ * Return: Allocated context on success, NULL on failure
+ */
+static struct ctx_info *create_context(struct cxlflash_cfg *cfg,
+				       struct cxl_context *ctx, int ctxid,
+				       int adap_fd, struct file *file,
+				       u32 perms)
+{
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	struct ctx_info *ctxi = NULL;
+	struct llun_info **lli = NULL;
+	u8 *ws = NULL;
+	struct sisl_rht_entry *rhte;
+
+	ctxi = kzalloc(sizeof(*ctxi), GFP_KERNEL);
+	lli = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*lli)), GFP_KERNEL);
+	ws = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*ws)), GFP_KERNEL);
+	if (unlikely(!ctxi || !lli || !ws)) {
+		dev_err(dev, "%s: Unable to allocate context!\n", __func__);
+		goto err;
+	}
+
+	rhte = (struct sisl_rht_entry *)get_zeroed_page(GFP_KERNEL);
+	if (unlikely(!rhte)) {
+		dev_err(dev, "%s: Unable to allocate RHT!\n", __func__);
+		goto err;
+	}
+
+	ctxi->rht_lun = lli;
+	ctxi->rht_needs_ws = ws;
+	ctxi->rht_start = rhte;
+	ctxi->rht_perms = perms;
+
+	ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl;
+	ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid);
+	ctxi->lfd = adap_fd;
+	ctxi->pid = current->tgid; /* tgid = pid */
+	ctxi->ctx = ctx;
+	ctxi->file = file;
+	mutex_init(&ctxi->mutex);
+	INIT_LIST_HEAD(&ctxi->luns);
+	INIT_LIST_HEAD(&ctxi->list); /* initialize for list_empty() */
+
+	mutex_lock(&ctxi->mutex);
+out:
+	return ctxi;
+
+err:
+	kfree(ws);
+	kfree(lli);
+	kfree(ctxi);
+	ctxi = NULL;
+	goto out;
+}
+
+/**
+ * _cxlflash_disk_detach() - detaches a LUN from a context
+ * @sdev:	SCSI device associated with LUN.
+ * @ctxi:	Context owning resources.
+ * @detach:	Detach ioctl data structure.
+ *
+ * As part of the detach, all per-context resources associated with the LUN
+ * are cleaned up. When detaching the last LUN for a context, the context
+ * itself is cleaned up and released.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int _cxlflash_disk_detach(struct scsi_device *sdev,
+				 struct ctx_info *ctxi,
+				 struct dk_cxlflash_detach *detach)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct lun_access *lun_access, *t;
+	struct dk_cxlflash_release rel;
+	bool put_ctx = false;
+
+	int i;
+	int rc = 0;
+	int lfd;
+	u64 ctxid = DECODE_CTXID(detach->context_id),
+	    rctxid = detach->context_id;
+
+	dev_dbg(dev, "%s: ctxid=%llu\n", __func__, ctxid);
+
+	if (!ctxi) {
+		ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
+		if (unlikely(!ctxi)) {
+			dev_dbg(dev, "%s: Bad context! (%llu)\n",
+				__func__, ctxid);
+			rc = -EINVAL;
+			goto out;
+		}
+
+		put_ctx = true;
+	}
+
+	/* Cleanup outstanding resources tied to this LUN */
+	if (ctxi->rht_out) {
+		marshal_det_to_rele(detach, &rel);
+		for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) {
+			if (ctxi->rht_lun[i] == lli) {
+				rel.rsrc_handle = i;
+				_cxlflash_disk_release(sdev, ctxi, &rel);
+			}
+
+			/* No need to loop further if we're done */
+			if (ctxi->rht_out == 0)
+				break;
+		}
+	}
+
+	/* Take our LUN out of context, free the node */
+	list_for_each_entry_safe(lun_access, t, &ctxi->luns, list)
+		if (lun_access->lli == lli) {
+			list_del(&lun_access->list);
+			kfree(lun_access);
+			lun_access = NULL;
+			break;
+		}
+
+	/* Tear down context following last LUN cleanup */
+	if (list_empty(&ctxi->luns)) {
+		ctxi->unavail = true;
+		mutex_unlock(&ctxi->mutex);
+		mutex_lock(&cfg->ctx_tbl_list_mutex);
+		mutex_lock(&ctxi->mutex);
+
+		/* Might not have been in error list so conditionally remove */
+		if (!list_empty(&ctxi->list))
+			list_del(&ctxi->list);
+		cfg->ctx_tbl[ctxid] = NULL;
+		mutex_unlock(&cfg->ctx_tbl_list_mutex);
+		mutex_unlock(&ctxi->mutex);
+
+		lfd = ctxi->lfd;
+		destroy_context(cfg, ctxi);
+		ctxi = NULL;
+		put_ctx = false;
+
+		/*
+		 * As a last step, clean up external resources when not
+		 * already on an external cleanup thread, i.e.: close(adap_fd).
+		 *
+		 * NOTE: this will free up the context from the CXL services,
+		 * allowing it to dole out the same context_id on a future
+		 * (or even currently in-flight) disk_attach operation.
+		 */
+		if (lfd != -1)
+			sys_close(lfd);
+	}
+
+	/* Release the sdev reference that bound this LUN to the context */
+	scsi_device_put(sdev);
+
+out:
+	if (put_ctx)
+		put_context(ctxi);
+	dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+static int cxlflash_disk_detach(struct scsi_device *sdev,
+				struct dk_cxlflash_detach *detach)
+{
+	return _cxlflash_disk_detach(sdev, NULL, detach);
+}
+
+/**
+ * cxlflash_cxl_release() - release handler for adapter file descriptor
+ * @inode:	File-system inode associated with fd.
+ * @file:	File installed with adapter file descriptor.
+ *
+ * This routine is the release handler for the fops registered with
+ * the CXL services on an initial attach for a context. It is called
+ * when a close is performed on the adapter file descriptor returned
+ * to the user. Programmatically, the user is not required to perform
+ * the close, as it is handled internally via the detach ioctl when
+ * a context is being removed. Note that nothing prevents the user
+ * from performing a close, but the user should be aware that doing
+ * so is considered catastrophic and subsequent usage of the superpipe
+ * API with previously saved off tokens will fail.
+ *
+ * When initiated from an external close (either by the user or via
+ * a process tear down), the routine derives the context reference
+ * and calls detach for each LUN associated with the context. The
+ * final detach operation will cause the context itself to be freed.
+ * Note that the saved off lfd is reset prior to calling detach to
+ * signify that the final detach should not perform a close.
+ *
+ * When initiated from a detach operation as part of the tear down
+ * of a context, the context is first completely freed and then the
+ * close is performed. This routine will fail to derive the context
+ * reference (due to the context having already been freed) and then
+ * call into the CXL release entry point.
+ *
+ * Thus, with exception to when the CXL process element (context id)
+ * lookup fails (a case that should theoretically never occur), every
+ * call into this routine results in a complete freeing of a context.
+ *
+ * As part of the detach, all per-context resources associated with the LUN
+ * are cleaned up. When detaching the last LUN for a context, the context
+ * itself is cleaned up and released.
+ *
+ * Return: 0 on success
+ */
+static int cxlflash_cxl_release(struct inode *inode, struct file *file)
+{
+	struct cxl_context *ctx = cxl_fops_get_context(file);
+	struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
+						cxl_fops);
+	struct device *dev = &cfg->dev->dev;
+	struct ctx_info *ctxi = NULL;
+	struct dk_cxlflash_detach detach = { { 0 }, 0 };
+	struct lun_access *lun_access, *t;
+	enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
+	int ctxid;
+
+	ctxid = cxl_process_element(ctx);
+	if (unlikely(ctxid < 0)) {
+		dev_err(dev, "%s: Context %p was closed! (%d)\n",
+			__func__, ctx, ctxid);
+		goto out;
+	}
+
+	ctxi = get_context(cfg, ctxid, file, ctrl);
+	if (unlikely(!ctxi)) {
+		ctxi = get_context(cfg, ctxid, file, ctrl | CTX_CTRL_CLONE);
+		if (!ctxi) {
+			dev_dbg(dev, "%s: Context %d already free!\n",
+				__func__, ctxid);
+			goto out_release;
+		}
+
+		dev_dbg(dev, "%s: Another process owns context %d!\n",
+			__func__, ctxid);
+		put_context(ctxi);
+		goto out;
+	}
+
+	dev_dbg(dev, "%s: close(%d) for context %d\n",
+		__func__, ctxi->lfd, ctxid);
+
+	/* Reset the file descriptor to indicate we're on a close() thread */
+	ctxi->lfd = -1;
+	detach.context_id = ctxi->ctxid;
+	list_for_each_entry_safe(lun_access, t, &ctxi->luns, list)
+		_cxlflash_disk_detach(lun_access->sdev, ctxi, &detach);
+out_release:
+	cxl_fd_release(inode, file);
+out:
+	dev_dbg(dev, "%s: returning\n", __func__);
+	return 0;
+}
+
+/**
+ * unmap_context() - clears a previously established mapping
+ * @ctxi:	Context owning the mapping.
+ *
+ * This routine is used to switch between the error notification page
+ * (dummy page of all 1's) and the real mapping (established by the CXL
+ * fault handler).
+ */
+static void unmap_context(struct ctx_info *ctxi)
+{
+	unmap_mapping_range(ctxi->file->f_mapping, 0, 0, 1);
+}
+
+/**
+ * get_err_page() - obtains and allocates the error notification page
+ *
+ * Return: error notification page on success, NULL on failure
+ */
+static struct page *get_err_page(void)
+{
+	struct page *err_page = global.err_page;
+
+	if (unlikely(!err_page)) {
+		err_page = alloc_page(GFP_KERNEL);
+		if (unlikely(!err_page)) {
+			pr_err("%s: Unable to allocate err_page!\n", __func__);
+			goto out;
+		}
+
+		memset(page_address(err_page), -1, PAGE_SIZE);
+
+		/* Serialize update w/ other threads to avoid a leak */
+		mutex_lock(&global.mutex);
+		if (likely(!global.err_page))
+			global.err_page = err_page;
+		else {
+			__free_page(err_page);
+			err_page = global.err_page;
+		}
+		mutex_unlock(&global.mutex);
+	}
+
+out:
+	pr_debug("%s: returning err_page=%p\n", __func__, err_page);
+	return err_page;
+}
+
+/**
+ * cxlflash_mmap_fault() - mmap fault handler for adapter file descriptor
+ * @vma:	VM area associated with mapping.
+ * @vmf:	VM fault associated with current fault.
+ *
+ * To support error notification via MMIO, faults are 'caught' by this routine
+ * that was inserted before passing back the adapter file descriptor on attach.
+ * When a fault occurs, this routine evaluates if error recovery is active and
+ * if so, installs the error page to 'notify' the user about the error state.
+ * During normal operation, the fault is simply handled by the original fault
+ * handler that was installed by CXL services as part of initializing the
+ * adapter file descriptor. The VMA's page protection bits are toggled to
+ * indicate cached/not-cached depending on the memory backing the fault.
+ *
+ * Return: 0 on success, VM_FAULT_SIGBUS on failure
+ */
+static int cxlflash_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct file *file = vma->vm_file;
+	struct cxl_context *ctx = cxl_fops_get_context(file);
+	struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
+						cxl_fops);
+	struct device *dev = &cfg->dev->dev;
+	struct ctx_info *ctxi = NULL;
+	struct page *err_page = NULL;
+	enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
+	int rc = 0;
+	int ctxid;
+
+	ctxid = cxl_process_element(ctx);
+	if (unlikely(ctxid < 0)) {
+		dev_err(dev, "%s: Context %p was closed! (%d)\n",
+			__func__, ctx, ctxid);
+		goto err;
+	}
+
+	ctxi = get_context(cfg, ctxid, file, ctrl);
+	if (unlikely(!ctxi)) {
+		dev_dbg(dev, "%s: Bad context! (%d)\n", __func__, ctxid);
+		goto err;
+	}
+
+	dev_dbg(dev, "%s: fault(%d) for context %d\n",
+		__func__, ctxi->lfd, ctxid);
+
+	if (likely(!ctxi->err_recovery_active)) {
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+		rc = ctxi->cxl_mmap_vmops->fault(vma, vmf);
+	} else {
+		dev_dbg(dev, "%s: err recovery active, use err_page!\n",
+			__func__);
+
+		err_page = get_err_page();
+		if (unlikely(!err_page)) {
+			dev_err(dev, "%s: Could not obtain error page!\n",
+				__func__);
+			rc = VM_FAULT_RETRY;
+			goto out;
+		}
+
+		get_page(err_page);
+		vmf->page = err_page;
+		vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
+	}
+
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
+	return rc;
+
+err:
+	rc = VM_FAULT_SIGBUS;
+	goto out;
+}
+
+/*
+ * Local MMAP vmops to 'catch' faults
+ */
+static const struct vm_operations_struct cxlflash_mmap_vmops = {
+	.fault = cxlflash_mmap_fault,
+};
+
+/**
+ * cxlflash_cxl_mmap() - mmap handler for adapter file descriptor
+ * @file:	File installed with adapter file descriptor.
+ * @vma:	VM area associated with mapping.
+ *
+ * Installs local mmap vmops to 'catch' faults for error notification support.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_cxl_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct cxl_context *ctx = cxl_fops_get_context(file);
+	struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
+						cxl_fops);
+	struct device *dev = &cfg->dev->dev;
+	struct ctx_info *ctxi = NULL;
+	enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
+	int ctxid;
+	int rc = 0;
+
+	ctxid = cxl_process_element(ctx);
+	if (unlikely(ctxid < 0)) {
+		dev_err(dev, "%s: Context %p was closed! (%d)\n",
+			__func__, ctx, ctxid);
+		rc = -EIO;
+		goto out;
+	}
+
+	ctxi = get_context(cfg, ctxid, file, ctrl);
+	if (unlikely(!ctxi)) {
+		dev_dbg(dev, "%s: Bad context! (%d)\n", __func__, ctxid);
+		rc = -EIO;
+		goto out;
+	}
+
+	dev_dbg(dev, "%s: mmap(%d) for context %d\n",
+		__func__, ctxi->lfd, ctxid);
+
+	rc = cxl_fd_mmap(file, vma);
+	if (likely(!rc)) {
+		/* Insert ourself in the mmap fault handler path */
+		ctxi->cxl_mmap_vmops = vma->vm_ops;
+		vma->vm_ops = &cxlflash_mmap_vmops;
+	}
+
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	return rc;
+}
+
+const struct file_operations cxlflash_cxl_fops = {
+	.owner = THIS_MODULE,
+	.mmap = cxlflash_cxl_mmap,
+	.release = cxlflash_cxl_release,
+};
+
+/**
+ * cxlflash_mark_contexts_error() - move contexts to error state and list
+ * @cfg:	Internal structure associated with the host.
+ *
+ * A context is only moved over to the error list when there are no outstanding
+ * references to it. This ensures that a running operation has completed.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg)
+{
+	int i, rc = 0;
+	struct ctx_info *ctxi = NULL;
+
+	mutex_lock(&cfg->ctx_tbl_list_mutex);
+
+	for (i = 0; i < MAX_CONTEXT; i++) {
+		ctxi = cfg->ctx_tbl[i];
+		if (ctxi) {
+			mutex_lock(&ctxi->mutex);
+			cfg->ctx_tbl[i] = NULL;
+			list_add(&ctxi->list, &cfg->ctx_err_recovery);
+			ctxi->err_recovery_active = true;
+			ctxi->ctrl_map = NULL;
+			unmap_context(ctxi);
+			mutex_unlock(&ctxi->mutex);
+		}
+	}
+
+	mutex_unlock(&cfg->ctx_tbl_list_mutex);
+	return rc;
+}
+
+/*
+ * Dummy NULL fops
+ */
+static const struct file_operations null_fops = {
+	.owner = THIS_MODULE,
+};
+
+/**
+ * check_state() - checks and responds to the current adapter state
+ * @cfg:	Internal structure associated with the host.
+ *
+ * This routine can block and should only be used on process context.
+ * It assumes that the caller is an ioctl thread and holding the ioctl
+ * read semaphore. This is temporarily let up across the wait to allow
+ * for draining actively running ioctls. Also note that when waking up
+ * from waiting in reset, the state is unknown and must be checked again
+ * before proceeding.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int check_state(struct cxlflash_cfg *cfg)
+{
+	struct device *dev = &cfg->dev->dev;
+	int rc = 0;
+
+retry:
+	switch (cfg->state) {
+	case STATE_RESET:
+		dev_dbg(dev, "%s: Reset state, going to wait...\n", __func__);
+		up_read(&cfg->ioctl_rwsem);
+		rc = wait_event_interruptible(cfg->reset_waitq,
+					      cfg->state != STATE_RESET);
+		down_read(&cfg->ioctl_rwsem);
+		if (unlikely(rc))
+			break;
+		goto retry;
+	case STATE_FAILTERM:
+		dev_dbg(dev, "%s: Failed/Terminating!\n", __func__);
+		rc = -ENODEV;
+		break;
+	default:
+		break;
+	}
+
+	return rc;
+}
+
+/**
+ * cxlflash_disk_attach() - attach a LUN to a context
+ * @sdev:	SCSI device associated with LUN.
+ * @attach:	Attach ioctl data structure.
+ *
+ * Creates a context and attaches LUN to it. A LUN can only be attached
+ * one time to a context (subsequent attaches for the same context/LUN pair
+ * are not supported). Additional LUNs can be attached to a context by
+ * specifying the 'reuse' flag defined in the cxlflash_ioctl.h header.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_disk_attach(struct scsi_device *sdev,
+				struct dk_cxlflash_attach *attach)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct cxl_ioctl_start_work *work;
+	struct ctx_info *ctxi = NULL;
+	struct lun_access *lun_access = NULL;
+	int rc = 0;
+	u32 perms;
+	int ctxid = -1;
+	u64 rctxid = 0UL;
+	struct file *file;
+
+	struct cxl_context *ctx;
+
+	int fd = -1;
+
+	if (attach->num_interrupts > 4) {
+		dev_dbg(dev, "%s: Cannot support this many interrupts %llu\n",
+			__func__, attach->num_interrupts);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (gli->max_lba == 0) {
+		dev_dbg(dev, "%s: No capacity info for this LUN (%016llX)\n",
+			__func__, lli->lun_id[sdev->channel]);
+		rc = read_cap16(sdev, lli);
+		if (rc) {
+			dev_err(dev, "%s: Invalid device! (%d)\n",
+				__func__, rc);
+			rc = -ENODEV;
+			goto out;
+		}
+		dev_dbg(dev, "%s: LBA = %016llX\n", __func__, gli->max_lba);
+		dev_dbg(dev, "%s: BLK_LEN = %08X\n", __func__, gli->blk_len);
+	}
+
+	if (attach->hdr.flags & DK_CXLFLASH_ATTACH_REUSE_CONTEXT) {
+		rctxid = attach->context_id;
+		ctxi = get_context(cfg, rctxid, NULL, 0);
+		if (!ctxi) {
+			dev_dbg(dev, "%s: Bad context! (%016llX)\n",
+				__func__, rctxid);
+			rc = -EINVAL;
+			goto out;
+		}
+
+		list_for_each_entry(lun_access, &ctxi->luns, list)
+			if (lun_access->lli == lli) {
+				dev_dbg(dev, "%s: Already attached!\n",
+					__func__);
+				rc = -EINVAL;
+				goto out;
+			}
+	}
+
+	rc = scsi_device_get(sdev);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: Unable to get sdev reference!\n", __func__);
+		goto out;
+	}
+
+	lun_access = kzalloc(sizeof(*lun_access), GFP_KERNEL);
+	if (unlikely(!lun_access)) {
+		dev_err(dev, "%s: Unable to allocate lun_access!\n", __func__);
+		rc = -ENOMEM;
+		goto err0;
+	}
+
+	lun_access->lli = lli;
+	lun_access->sdev = sdev;
+
+	/* Non-NULL context indicates reuse */
+	if (ctxi) {
+		dev_dbg(dev, "%s: Reusing context for LUN! (%016llX)\n",
+			__func__, rctxid);
+		list_add(&lun_access->list, &ctxi->luns);
+		fd = ctxi->lfd;
+		goto out_attach;
+	}
+
+	ctx = cxl_dev_context_init(cfg->dev);
+	if (unlikely(IS_ERR_OR_NULL(ctx))) {
+		dev_err(dev, "%s: Could not initialize context %p\n",
+			__func__, ctx);
+		rc = -ENODEV;
+		goto err1;
+	}
+
+	ctxid = cxl_process_element(ctx);
+	if (unlikely((ctxid > MAX_CONTEXT) || (ctxid < 0))) {
+		dev_err(dev, "%s: ctxid (%d) invalid!\n", __func__, ctxid);
+		rc = -EPERM;
+		goto err2;
+	}
+
+	file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);
+	if (unlikely(fd < 0)) {
+		rc = -ENODEV;
+		dev_err(dev, "%s: Could not get file descriptor\n", __func__);
+		goto err2;
+	}
+
+	/* Translate read/write O_* flags from fcntl.h to AFU permission bits */
+	perms = SISL_RHT_PERM(attach->hdr.flags + 1);
+
+	ctxi = create_context(cfg, ctx, ctxid, fd, file, perms);
+	if (unlikely(!ctxi)) {
+		dev_err(dev, "%s: Failed to create context! (%d)\n",
+			__func__, ctxid);
+		goto err3;
+	}
+
+	work = &ctxi->work;
+	work->num_interrupts = attach->num_interrupts;
+	work->flags = CXL_START_WORK_NUM_IRQS;
+
+	rc = cxl_start_work(ctx, work);
+	if (unlikely(rc)) {
+		dev_dbg(dev, "%s: Could not start context rc=%d\n",
+			__func__, rc);
+		goto err4;
+	}
+
+	rc = afu_attach(cfg, ctxi);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
+		goto err5;
+	}
+
+	/*
+	 * No error paths after this point. Once the fd is installed it's
+	 * visible to user space and can't be undone safely on this thread.
+	 * There is no need to worry about a deadlock here because no one
+	 * knows about us yet; we can be the only one holding our mutex.
+	 */
+	list_add(&lun_access->list, &ctxi->luns);
+	mutex_unlock(&ctxi->mutex);
+	mutex_lock(&cfg->ctx_tbl_list_mutex);
+	mutex_lock(&ctxi->mutex);
+	cfg->ctx_tbl[ctxid] = ctxi;
+	mutex_unlock(&cfg->ctx_tbl_list_mutex);
+	fd_install(fd, file);
+
+out_attach:
+	attach->hdr.return_flags = 0;
+	attach->context_id = ctxi->ctxid;
+	attach->block_size = gli->blk_len;
+	attach->mmio_size = sizeof(afu->afu_map->hosts[0].harea);
+	attach->last_lba = gli->max_lba;
+	attach->max_xfer = sdev->host->max_sectors * MAX_SECTOR_UNIT;
+	attach->max_xfer /= gli->blk_len;
+
+out:
+	attach->adap_fd = fd;
+
+	if (ctxi)
+		put_context(ctxi);
+
+	dev_dbg(dev, "%s: returning ctxid=%d fd=%d bs=%lld rc=%d llba=%lld\n",
+		__func__, ctxid, fd, attach->block_size, rc, attach->last_lba);
+	return rc;
+
+err5:
+	cxl_stop_context(ctx);
+err4:
+	put_context(ctxi);
+	destroy_context(cfg, ctxi);
+	ctxi = NULL;
+err3:
+	/*
+	 * Here, we're overriding the fops with a dummy all-NULL fops because
+	 * fput() calls the release fop, which will cause us to mistakenly
+	 * call into the CXL code. Rather than try to add yet more complexity
+	 * to that routine (cxlflash_cxl_release) we should try to fix the
+	 * issue here.
+	 */
+	file->f_op = &null_fops;
+	fput(file);
+	put_unused_fd(fd);
+	fd = -1;
+err2:
+	cxl_release_context(ctx);
+err1:
+	kfree(lun_access);
+err0:
+	scsi_device_put(sdev);
+	goto out;
+}
+
+/**
+ * recover_context() - recovers a context in error
+ * @cfg:	Internal structure associated with the host.
+ * @ctxi:	Context to release.
+ *
+ * Restablishes the state for a context-in-error.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi)
+{
+	struct device *dev = &cfg->dev->dev;
+	int rc = 0;
+	int old_fd, fd = -1;
+	int ctxid = -1;
+	struct file *file;
+	struct cxl_context *ctx;
+	struct afu *afu = cfg->afu;
+
+	ctx = cxl_dev_context_init(cfg->dev);
+	if (unlikely(IS_ERR_OR_NULL(ctx))) {
+		dev_err(dev, "%s: Could not initialize context %p\n",
+			__func__, ctx);
+		rc = -ENODEV;
+		goto out;
+	}
+
+	ctxid = cxl_process_element(ctx);
+	if (unlikely((ctxid > MAX_CONTEXT) || (ctxid < 0))) {
+		dev_err(dev, "%s: ctxid (%d) invalid!\n", __func__, ctxid);
+		rc = -EPERM;
+		goto err1;
+	}
+
+	file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);
+	if (unlikely(fd < 0)) {
+		rc = -ENODEV;
+		dev_err(dev, "%s: Could not get file descriptor\n", __func__);
+		goto err1;
+	}
+
+	rc = cxl_start_work(ctx, &ctxi->work);
+	if (unlikely(rc)) {
+		dev_dbg(dev, "%s: Could not start context rc=%d\n",
+			__func__, rc);
+		goto err2;
+	}
+
+	/* Update with new MMIO area based on updated context id */
+	ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl;
+
+	rc = afu_attach(cfg, ctxi);
+	if (rc) {
+		dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
+		goto err3;
+	}
+
+	/*
+	 * No error paths after this point. Once the fd is installed it's
+	 * visible to user space and can't be undone safely on this thread.
+	 */
+	old_fd = ctxi->lfd;
+	ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid);
+	ctxi->lfd = fd;
+	ctxi->ctx = ctx;
+	ctxi->file = file;
+
+	/*
+	 * Put context back in table (note the reinit of the context list);
+	 * we must first drop the context's mutex and then acquire it in
+	 * order with the table/list mutex to avoid a deadlock - safe to do
+	 * here because no one can find us at this moment in time.
+	 */
+	mutex_unlock(&ctxi->mutex);
+	mutex_lock(&cfg->ctx_tbl_list_mutex);
+	mutex_lock(&ctxi->mutex);
+	list_del_init(&ctxi->list);
+	cfg->ctx_tbl[ctxid] = ctxi;
+	mutex_unlock(&cfg->ctx_tbl_list_mutex);
+	fd_install(fd, file);
+
+	/* Release the original adapter fd and associated CXL resources */
+	sys_close(old_fd);
+out:
+	dev_dbg(dev, "%s: returning ctxid=%d fd=%d rc=%d\n",
+		__func__, ctxid, fd, rc);
+	return rc;
+
+err3:
+	cxl_stop_context(ctx);
+err2:
+	fput(file);
+	put_unused_fd(fd);
+err1:
+	cxl_release_context(ctx);
+	goto out;
+}
+
+/**
+ * cxlflash_afu_recover() - initiates AFU recovery
+ * @sdev:	SCSI device associated with LUN.
+ * @recover:	Recover ioctl data structure.
+ *
+ * Only a single recovery is allowed at a time to avoid exhausting CXL
+ * resources (leading to recovery failure) in the event that we're up
+ * against the maximum number of contexts limit. For similar reasons,
+ * a context recovery is retried if there are multiple recoveries taking
+ * place at the same time and the failure was due to CXL services being
+ * unable to keep up.
+ *
+ * Because a user can detect an error condition before the kernel, it is
+ * quite possible for this routine to act as the kernel's EEH detection
+ * source (MMIO read of mbox_r). Because of this, there is a window of
+ * time where an EEH might have been detected but not yet 'serviced'
+ * (callback invoked, causing the device to enter reset state). To avoid
+ * looping in this routine during that window, a 1 second sleep is in place
+ * between the time the MMIO failure is detected and the time a wait on the
+ * reset wait queue is attempted via check_state().
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_afu_recover(struct scsi_device *sdev,
+				struct dk_cxlflash_recover_afu *recover)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct afu *afu = cfg->afu;
+	struct ctx_info *ctxi = NULL;
+	struct mutex *mutex = &cfg->ctx_recovery_mutex;
+	u64 ctxid = DECODE_CTXID(recover->context_id),
+	    rctxid = recover->context_id;
+	long reg;
+	int lretry = 20; /* up to 2 seconds */
+	int rc = 0;
+
+	atomic_inc(&cfg->recovery_threads);
+	rc = mutex_lock_interruptible(mutex);
+	if (rc)
+		goto out;
+
+	dev_dbg(dev, "%s: reason 0x%016llX rctxid=%016llX\n",
+		__func__, recover->reason, rctxid);
+
+retry:
+	/* Ensure that this process is attached to the context */
+	ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
+	if (unlikely(!ctxi)) {
+		dev_dbg(dev, "%s: Bad context! (%llu)\n", __func__, ctxid);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (ctxi->err_recovery_active) {
+retry_recover:
+		rc = recover_context(cfg, ctxi);
+		if (unlikely(rc)) {
+			dev_err(dev, "%s: Recovery failed for context %llu (rc=%d)\n",
+				__func__, ctxid, rc);
+			if ((rc == -ENODEV) &&
+			    ((atomic_read(&cfg->recovery_threads) > 1) ||
+			     (lretry--))) {
+				dev_dbg(dev, "%s: Going to try again!\n",
+					__func__);
+				mutex_unlock(mutex);
+				msleep(100);
+				rc = mutex_lock_interruptible(mutex);
+				if (rc)
+					goto out;
+				goto retry_recover;
+			}
+
+			goto out;
+		}
+
+		ctxi->err_recovery_active = false;
+		recover->context_id = ctxi->ctxid;
+		recover->adap_fd = ctxi->lfd;
+		recover->mmio_size = sizeof(afu->afu_map->hosts[0].harea);
+		recover->hdr.return_flags |=
+			DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET;
+		goto out;
+	}
+
+	/* Test if in error state */
+	reg = readq_be(&afu->ctrl_map->mbox_r);
+	if (reg == -1) {
+		dev_dbg(dev, "%s: MMIO fail, wait for recovery.\n", __func__);
+
+		/*
+		 * Before checking the state, put back the context obtained with
+		 * get_context() as it is no longer needed and sleep for a short
+		 * period of time (see prolog notes).
+		 */
+		put_context(ctxi);
+		ctxi = NULL;
+		ssleep(1);
+		rc = check_state(cfg);
+		if (unlikely(rc))
+			goto out;
+		goto retry;
+	}
+
+	dev_dbg(dev, "%s: MMIO working, no recovery required!\n", __func__);
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	mutex_unlock(mutex);
+	atomic_dec_if_positive(&cfg->recovery_threads);
+	return rc;
+}
+
+/**
+ * process_sense() - evaluates and processes sense data
+ * @sdev:	SCSI device associated with LUN.
+ * @verify:	Verify ioctl data structure.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int process_sense(struct scsi_device *sdev,
+			 struct dk_cxlflash_verify *verify)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	u64 prev_lba = gli->max_lba;
+	struct scsi_sense_hdr sshdr = { 0 };
+	int rc = 0;
+
+	rc = scsi_normalize_sense((const u8 *)&verify->sense_data,
+				  DK_CXLFLASH_VERIFY_SENSE_LEN, &sshdr);
+	if (!rc) {
+		dev_err(dev, "%s: Failed to normalize sense data!\n", __func__);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	switch (sshdr.sense_key) {
+	case NO_SENSE:
+	case RECOVERED_ERROR:
+		/* fall through */
+	case NOT_READY:
+		break;
+	case UNIT_ATTENTION:
+		switch (sshdr.asc) {
+		case 0x29: /* Power on Reset or Device Reset */
+			/* fall through */
+		case 0x2A: /* Device settings/capacity changed */
+			rc = read_cap16(sdev, lli);
+			if (rc) {
+				rc = -ENODEV;
+				break;
+			}
+			if (prev_lba != gli->max_lba)
+				dev_dbg(dev, "%s: Capacity changed old=%lld "
+					"new=%lld\n", __func__, prev_lba,
+					gli->max_lba);
+			break;
+		case 0x3F: /* Report LUNs changed, Rescan. */
+			scsi_scan_host(cfg->host);
+			break;
+		default:
+			rc = -EIO;
+			break;
+		}
+		break;
+	default:
+		rc = -EIO;
+		break;
+	}
+out:
+	dev_dbg(dev, "%s: sense_key %x asc %x ascq %x rc %d\n", __func__,
+		sshdr.sense_key, sshdr.asc, sshdr.ascq, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_disk_verify() - verifies a LUN is the same and handle size changes
+ * @sdev:	SCSI device associated with LUN.
+ * @verify:	Verify ioctl data structure.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_disk_verify(struct scsi_device *sdev,
+				struct dk_cxlflash_verify *verify)
+{
+	int rc = 0;
+	struct ctx_info *ctxi = NULL;
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct sisl_rht_entry *rhte = NULL;
+	res_hndl_t rhndl = verify->rsrc_handle;
+	u64 ctxid = DECODE_CTXID(verify->context_id),
+	    rctxid = verify->context_id;
+	u64 last_lba = 0;
+
+	dev_dbg(dev, "%s: ctxid=%llu rhndl=%016llX, hint=%016llX, "
+		"flags=%016llX\n", __func__, ctxid, verify->rsrc_handle,
+		verify->hint, verify->hdr.flags);
+
+	ctxi = get_context(cfg, rctxid, lli, 0);
+	if (unlikely(!ctxi)) {
+		dev_dbg(dev, "%s: Bad context! (%llu)\n", __func__, ctxid);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	rhte = get_rhte(ctxi, rhndl, lli);
+	if (unlikely(!rhte)) {
+		dev_dbg(dev, "%s: Bad resource handle! (%d)\n",
+			__func__, rhndl);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/*
+	 * Look at the hint/sense to see if it requires us to redrive
+	 * inquiry (i.e. the Unit attention is due to the WWN changing).
+	 */
+	if (verify->hint & DK_CXLFLASH_VERIFY_HINT_SENSE) {
+		/* Can't hold mutex across process_sense/read_cap16,
+		 * since we could have an intervening EEH event.
+		 */
+		ctxi->unavail = true;
+		mutex_unlock(&ctxi->mutex);
+		rc = process_sense(sdev, verify);
+		if (unlikely(rc)) {
+			dev_err(dev, "%s: Failed to validate sense data (%d)\n",
+				__func__, rc);
+			mutex_lock(&ctxi->mutex);
+			ctxi->unavail = false;
+			goto out;
+		}
+		mutex_lock(&ctxi->mutex);
+		ctxi->unavail = false;
+	}
+
+	switch (gli->mode) {
+	case MODE_PHYSICAL:
+		last_lba = gli->max_lba;
+		break;
+	case MODE_VIRTUAL:
+		/* Cast lxt_cnt to u64 for multiply to be treated as 64bit op */
+		last_lba = ((u64)rhte->lxt_cnt * MC_CHUNK_SIZE * gli->blk_len);
+		last_lba /= CXLFLASH_BLOCK_SIZE;
+		last_lba--;
+		break;
+	default:
+		WARN(1, "Unsupported LUN mode!");
+	}
+
+	verify->last_lba = last_lba;
+
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	dev_dbg(dev, "%s: returning rc=%d llba=%llX\n",
+		__func__, rc, verify->last_lba);
+	return rc;
+}
+
+/**
+ * decode_ioctl() - translates an encoded ioctl to an easily identifiable string
+ * @cmd:	The ioctl command to decode.
+ *
+ * Return: A string identifying the decoded ioctl.
+ */
+static char *decode_ioctl(int cmd)
+{
+	switch (cmd) {
+	case DK_CXLFLASH_ATTACH:
+		return __stringify_1(DK_CXLFLASH_ATTACH);
+	case DK_CXLFLASH_USER_DIRECT:
+		return __stringify_1(DK_CXLFLASH_USER_DIRECT);
+	case DK_CXLFLASH_USER_VIRTUAL:
+		return __stringify_1(DK_CXLFLASH_USER_VIRTUAL);
+	case DK_CXLFLASH_VLUN_RESIZE:
+		return __stringify_1(DK_CXLFLASH_VLUN_RESIZE);
+	case DK_CXLFLASH_RELEASE:
+		return __stringify_1(DK_CXLFLASH_RELEASE);
+	case DK_CXLFLASH_DETACH:
+		return __stringify_1(DK_CXLFLASH_DETACH);
+	case DK_CXLFLASH_VERIFY:
+		return __stringify_1(DK_CXLFLASH_VERIFY);
+	case DK_CXLFLASH_VLUN_CLONE:
+		return __stringify_1(DK_CXLFLASH_VLUN_CLONE);
+	case DK_CXLFLASH_RECOVER_AFU:
+		return __stringify_1(DK_CXLFLASH_RECOVER_AFU);
+	case DK_CXLFLASH_MANAGE_LUN:
+		return __stringify_1(DK_CXLFLASH_MANAGE_LUN);
+	}
+
+	return "UNKNOWN";
+}
+
+/**
+ * cxlflash_disk_direct_open() - opens a direct (physical) disk
+ * @sdev:	SCSI device associated with LUN.
+ * @arg:	UDirect ioctl data structure.
+ *
+ * On successful return, the user is informed of the resource handle
+ * to be used to identify the direct lun and the size (in blocks) of
+ * the direct lun in last LBA format.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+
+	struct dk_cxlflash_udirect *pphys = (struct dk_cxlflash_udirect *)arg;
+
+	u64 ctxid = DECODE_CTXID(pphys->context_id),
+	    rctxid = pphys->context_id;
+	u64 lun_size = 0;
+	u64 last_lba = 0;
+	u64 rsrc_handle = -1;
+	u32 port = CHAN2PORT(sdev->channel);
+
+	int rc = 0;
+
+	struct ctx_info *ctxi = NULL;
+	struct sisl_rht_entry *rhte = NULL;
+
+	pr_debug("%s: ctxid=%llu ls=0x%llx\n", __func__, ctxid, lun_size);
+
+	rc = cxlflash_lun_attach(gli, MODE_PHYSICAL, false);
+	if (unlikely(rc)) {
+		dev_dbg(dev, "%s: Failed to attach to LUN! (PHYSICAL)\n",
+			__func__);
+		goto out;
+	}
+
+	ctxi = get_context(cfg, rctxid, lli, 0);
+	if (unlikely(!ctxi)) {
+		dev_dbg(dev, "%s: Bad context! (%llu)\n", __func__, ctxid);
+		rc = -EINVAL;
+		goto err1;
+	}
+
+	rhte = rhte_checkout(ctxi, lli);
+	if (unlikely(!rhte)) {
+		dev_dbg(dev, "%s: too many opens for this context\n", __func__);
+		rc = -EMFILE;	/* too many opens  */
+		goto err1;
+	}
+
+	rsrc_handle = (rhte - ctxi->rht_start);
+
+	rht_format1(rhte, lli->lun_id[sdev->channel], ctxi->rht_perms, port);
+	cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC);
+
+	last_lba = gli->max_lba;
+	pphys->hdr.return_flags = 0;
+	pphys->last_lba = last_lba;
+	pphys->rsrc_handle = rsrc_handle;
+
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	dev_dbg(dev, "%s: returning handle 0x%llx rc=%d llba %lld\n",
+		__func__, rsrc_handle, rc, last_lba);
+	return rc;
+
+err1:
+	cxlflash_lun_detach(gli);
+	goto out;
+}
+
+/**
+ * ioctl_common() - common IOCTL handler for driver
+ * @sdev:	SCSI device associated with LUN.
+ * @cmd:	IOCTL command.
+ *
+ * Handles common fencing operations that are valid for multiple ioctls. Always
+ * allow through ioctls that are cleanup oriented in nature, even when operating
+ * in a failed/terminating state.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int ioctl_common(struct scsi_device *sdev, int cmd)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	int rc = 0;
+
+	if (unlikely(!lli)) {
+		dev_dbg(dev, "%s: Unknown LUN\n", __func__);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	rc = check_state(cfg);
+	if (unlikely(rc) && (cfg->state == STATE_FAILTERM)) {
+		switch (cmd) {
+		case DK_CXLFLASH_VLUN_RESIZE:
+		case DK_CXLFLASH_RELEASE:
+		case DK_CXLFLASH_DETACH:
+			dev_dbg(dev, "%s: Command override! (%d)\n",
+				__func__, rc);
+			rc = 0;
+			break;
+		}
+	}
+out:
+	return rc;
+}
+
+/**
+ * cxlflash_ioctl() - IOCTL handler for driver
+ * @sdev:	SCSI device associated with LUN.
+ * @cmd:	IOCTL command.
+ * @arg:	Userspace ioctl data structure.
+ *
+ * A read/write semaphore is used to implement a 'drain' of currently
+ * running ioctls. The read semaphore is taken at the beginning of each
+ * ioctl thread and released upon concluding execution. Additionally the
+ * semaphore should be released and then reacquired in any ioctl execution
+ * path which will wait for an event to occur that is outside the scope of
+ * the ioctl (i.e. an adapter reset). To drain the ioctls currently running,
+ * a thread simply needs to acquire the write semaphore.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
+{
+	typedef int (*sioctl) (struct scsi_device *, void *);
+
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct afu *afu = cfg->afu;
+	struct dk_cxlflash_hdr *hdr;
+	char buf[sizeof(union cxlflash_ioctls)];
+	size_t size = 0;
+	bool known_ioctl = false;
+	int idx;
+	int rc = 0;
+	struct Scsi_Host *shost = sdev->host;
+	sioctl do_ioctl = NULL;
+
+	static const struct {
+		size_t size;
+		sioctl ioctl;
+	} ioctl_tbl[] = {	/* NOTE: order matters here */
+	{sizeof(struct dk_cxlflash_attach), (sioctl)cxlflash_disk_attach},
+	{sizeof(struct dk_cxlflash_udirect), cxlflash_disk_direct_open},
+	{sizeof(struct dk_cxlflash_release), (sioctl)cxlflash_disk_release},
+	{sizeof(struct dk_cxlflash_detach), (sioctl)cxlflash_disk_detach},
+	{sizeof(struct dk_cxlflash_verify), (sioctl)cxlflash_disk_verify},
+	{sizeof(struct dk_cxlflash_recover_afu), (sioctl)cxlflash_afu_recover},
+	{sizeof(struct dk_cxlflash_manage_lun), (sioctl)cxlflash_manage_lun},
+	{sizeof(struct dk_cxlflash_uvirtual), cxlflash_disk_virtual_open},
+	{sizeof(struct dk_cxlflash_resize), (sioctl)cxlflash_vlun_resize},
+	{sizeof(struct dk_cxlflash_clone), (sioctl)cxlflash_disk_clone},
+	};
+
+	/* Hold read semaphore so we can drain if needed */
+	down_read(&cfg->ioctl_rwsem);
+
+	/* Restrict command set to physical support only for internal LUN */
+	if (afu->internal_lun)
+		switch (cmd) {
+		case DK_CXLFLASH_RELEASE:
+		case DK_CXLFLASH_USER_VIRTUAL:
+		case DK_CXLFLASH_VLUN_RESIZE:
+		case DK_CXLFLASH_VLUN_CLONE:
+			dev_dbg(dev, "%s: %s not supported for lun_mode=%d\n",
+				__func__, decode_ioctl(cmd), afu->internal_lun);
+			rc = -EINVAL;
+			goto cxlflash_ioctl_exit;
+		}
+
+	switch (cmd) {
+	case DK_CXLFLASH_ATTACH:
+	case DK_CXLFLASH_USER_DIRECT:
+	case DK_CXLFLASH_RELEASE:
+	case DK_CXLFLASH_DETACH:
+	case DK_CXLFLASH_VERIFY:
+	case DK_CXLFLASH_RECOVER_AFU:
+	case DK_CXLFLASH_USER_VIRTUAL:
+	case DK_CXLFLASH_VLUN_RESIZE:
+	case DK_CXLFLASH_VLUN_CLONE:
+		dev_dbg(dev, "%s: %s (%08X) on dev(%d/%d/%d/%llu)\n",
+			__func__, decode_ioctl(cmd), cmd, shost->host_no,
+			sdev->channel, sdev->id, sdev->lun);
+		rc = ioctl_common(sdev, cmd);
+		if (unlikely(rc))
+			goto cxlflash_ioctl_exit;
+
+		/* fall through */
+
+	case DK_CXLFLASH_MANAGE_LUN:
+		known_ioctl = true;
+		idx = _IOC_NR(cmd) - _IOC_NR(DK_CXLFLASH_ATTACH);
+		size = ioctl_tbl[idx].size;
+		do_ioctl = ioctl_tbl[idx].ioctl;
+
+		if (likely(do_ioctl))
+			break;
+
+		/* fall through */
+	default:
+		rc = -EINVAL;
+		goto cxlflash_ioctl_exit;
+	}
+
+	if (unlikely(copy_from_user(&buf, arg, size))) {
+		dev_err(dev, "%s: copy_from_user() fail! "
+			"size=%lu cmd=%d (%s) arg=%p\n",
+			__func__, size, cmd, decode_ioctl(cmd), arg);
+		rc = -EFAULT;
+		goto cxlflash_ioctl_exit;
+	}
+
+	hdr = (struct dk_cxlflash_hdr *)&buf;
+	if (hdr->version != DK_CXLFLASH_VERSION_0) {
+		dev_dbg(dev, "%s: Version %u not supported for %s\n",
+			__func__, hdr->version, decode_ioctl(cmd));
+		rc = -EINVAL;
+		goto cxlflash_ioctl_exit;
+	}
+
+	if (hdr->rsvd[0] || hdr->rsvd[1] || hdr->rsvd[2] || hdr->return_flags) {
+		dev_dbg(dev, "%s: Reserved/rflags populated!\n", __func__);
+		rc = -EINVAL;
+		goto cxlflash_ioctl_exit;
+	}
+
+	rc = do_ioctl(sdev, (void *)&buf);
+	if (likely(!rc))
+		if (unlikely(copy_to_user(arg, &buf, size))) {
+			dev_err(dev, "%s: copy_to_user() fail! "
+				"size=%lu cmd=%d (%s) arg=%p\n",
+				__func__, size, cmd, decode_ioctl(cmd), arg);
+			rc = -EFAULT;
+		}
+
+	/* fall through to exit */
+
+cxlflash_ioctl_exit:
+	up_read(&cfg->ioctl_rwsem);
+	if (unlikely(rc && known_ioctl))
+		dev_err(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) "
+			"returned rc %d\n", __func__,
+			decode_ioctl(cmd), cmd, shost->host_no,
+			sdev->channel, sdev->id, sdev->lun, rc);
+	else
+		dev_dbg(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) "
+			"returned rc %d\n", __func__, decode_ioctl(cmd),
+			cmd, shost->host_no, sdev->channel, sdev->id,
+			sdev->lun, rc);
+	return rc;
+}
diff --git a/kernel/drivers/scsi/cxlflash/superpipe.h b/kernel/drivers/scsi/cxlflash/superpipe.h
new file mode 100644
index 000000000..bede574bc
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/superpipe.h
@@ -0,0 +1,151 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXLFLASH_SUPERPIPE_H
+#define _CXLFLASH_SUPERPIPE_H
+
+extern struct cxlflash_global global;
+
+/*
+ * Terminology: use afu (and not adapter) to refer to the HW.
+ * Adapter is the entire slot and includes PSL out of which
+ * only the AFU is visible to user space.
+ */
+
+/* Chunk size parms: note sislite minimum chunk size is
+   0x10000 LBAs corresponding to a NMASK or 16.
+*/
+#define MC_CHUNK_SIZE     (1 << MC_RHT_NMASK)	/* in LBAs */
+
+#define CMD_TIMEOUT 30  /* 30 secs */
+#define CMD_RETRIES 5   /* 5 retries for scsi_execute */
+
+#define MAX_SECTOR_UNIT  512 /* max_sector is in 512 byte multiples */
+
+#define CHAN2PORT(_x)	((_x) + 1)
+#define PORT2CHAN(_x)	((_x) - 1)
+
+enum lun_mode {
+	MODE_NONE = 0,
+	MODE_VIRTUAL,
+	MODE_PHYSICAL
+};
+
+/* Global (entire driver, spans adapters) lun_info structure */
+struct glun_info {
+	u64 max_lba;		/* from read cap(16) */
+	u32 blk_len;		/* from read cap(16) */
+	enum lun_mode mode;	/* NONE, VIRTUAL, PHYSICAL */
+	int users;		/* Number of users w/ references to LUN */
+
+	u8 wwid[16];
+
+	struct mutex mutex;
+
+	struct blka blka;
+	struct list_head list;
+};
+
+/* Local (per-adapter) lun_info structure */
+struct llun_info {
+	u64 lun_id[CXLFLASH_NUM_FC_PORTS]; /* from REPORT_LUNS */
+	u32 lun_index;		/* Index in the LUN table */
+	u32 host_no;		/* host_no from Scsi_host */
+	u32 port_sel;		/* What port to use for this LUN */
+	bool in_table;		/* Whether a LUN table entry was created */
+
+	u8 wwid[16];		/* Keep a duplicate copy here? */
+
+	struct glun_info *parent; /* Pointer to entry in global LUN structure */
+	struct scsi_device *sdev;
+	struct list_head list;
+};
+
+struct lun_access {
+	struct llun_info *lli;
+	struct scsi_device *sdev;
+	struct list_head list;
+};
+
+enum ctx_ctrl {
+	CTX_CTRL_CLONE		= (1 << 1),
+	CTX_CTRL_ERR		= (1 << 2),
+	CTX_CTRL_ERR_FALLBACK	= (1 << 3),
+	CTX_CTRL_NOPID		= (1 << 4),
+	CTX_CTRL_FILE		= (1 << 5)
+};
+
+#define ENCODE_CTXID(_ctx, _id)	(((((u64)_ctx) & 0xFFFFFFFF0ULL) << 28) | _id)
+#define DECODE_CTXID(_val)	(_val & 0xFFFFFFFF)
+
+struct ctx_info {
+	struct sisl_ctrl_map __iomem *ctrl_map; /* initialized at startup */
+	struct sisl_rht_entry *rht_start; /* 1 page (req'd for alignment),
+					     alloc/free on attach/detach */
+	u32 rht_out;		/* Number of checked out RHT entries */
+	u32 rht_perms;		/* User-defined permissions for RHT entries */
+	struct llun_info **rht_lun;       /* Mapping of RHT entries to LUNs */
+	u8 *rht_needs_ws;	/* User-desired write-same function per RHTE */
+
+	struct cxl_ioctl_start_work work;
+	u64 ctxid;
+	int lfd;
+	pid_t pid;
+	bool unavail;
+	bool err_recovery_active;
+	struct mutex mutex; /* Context protection */
+	struct cxl_context *ctx;
+	struct list_head luns;	/* LUNs attached to this context */
+	const struct vm_operations_struct *cxl_mmap_vmops;
+	struct file *file;
+	struct list_head list; /* Link contexts in error recovery */
+};
+
+struct cxlflash_global {
+	struct mutex mutex;
+	struct list_head gluns;/* list of glun_info structs */
+	struct page *err_page; /* One page of all 0xF for error notification */
+};
+
+int cxlflash_vlun_resize(struct scsi_device *, struct dk_cxlflash_resize *);
+int _cxlflash_vlun_resize(struct scsi_device *, struct ctx_info *,
+			  struct dk_cxlflash_resize *);
+
+int cxlflash_disk_release(struct scsi_device *, struct dk_cxlflash_release *);
+int _cxlflash_disk_release(struct scsi_device *, struct ctx_info *,
+			   struct dk_cxlflash_release *);
+
+int cxlflash_disk_clone(struct scsi_device *, struct dk_cxlflash_clone *);
+
+int cxlflash_disk_virtual_open(struct scsi_device *, void *);
+
+int cxlflash_lun_attach(struct glun_info *, enum lun_mode, bool);
+void cxlflash_lun_detach(struct glun_info *);
+
+struct ctx_info *get_context(struct cxlflash_cfg *, u64, void *, enum ctx_ctrl);
+void put_context(struct ctx_info *);
+
+struct sisl_rht_entry *get_rhte(struct ctx_info *, res_hndl_t,
+				struct llun_info *);
+
+struct sisl_rht_entry *rhte_checkout(struct ctx_info *, struct llun_info *);
+void rhte_checkin(struct ctx_info *, struct sisl_rht_entry *);
+
+void cxlflash_ba_terminate(struct ba_lun *);
+
+int cxlflash_manage_lun(struct scsi_device *, struct dk_cxlflash_manage_lun *);
+
+int check_state(struct cxlflash_cfg *);
+
+#endif /* ifndef _CXLFLASH_SUPERPIPE_H */
diff --git a/kernel/drivers/scsi/cxlflash/vlun.c b/kernel/drivers/scsi/cxlflash/vlun.c
new file mode 100644
index 000000000..a53f583e2
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/vlun.c
@@ -0,0 +1,1273 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/syscalls.h>
+#include <misc/cxl.h>
+#include <asm/unaligned.h>
+#include <asm/bitsperlong.h>
+
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <uapi/scsi/cxlflash_ioctl.h>
+
+#include "sislite.h"
+#include "common.h"
+#include "vlun.h"
+#include "superpipe.h"
+
+/**
+ * marshal_virt_to_resize() - translate uvirtual to resize structure
+ * @virt:	Source structure from which to translate/copy.
+ * @resize:	Destination structure for the translate/copy.
+ */
+static void marshal_virt_to_resize(struct dk_cxlflash_uvirtual *virt,
+				   struct dk_cxlflash_resize *resize)
+{
+	resize->hdr = virt->hdr;
+	resize->context_id = virt->context_id;
+	resize->rsrc_handle = virt->rsrc_handle;
+	resize->req_size = virt->lun_size;
+	resize->last_lba = virt->last_lba;
+}
+
+/**
+ * marshal_clone_to_rele() - translate clone to release structure
+ * @clone:	Source structure from which to translate/copy.
+ * @rele:	Destination structure for the translate/copy.
+ */
+static void marshal_clone_to_rele(struct dk_cxlflash_clone *clone,
+				  struct dk_cxlflash_release *release)
+{
+	release->hdr = clone->hdr;
+	release->context_id = clone->context_id_dst;
+}
+
+/**
+ * ba_init() - initializes a block allocator
+ * @ba_lun:	Block allocator to initialize.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int ba_init(struct ba_lun *ba_lun)
+{
+	struct ba_lun_info *bali = NULL;
+	int lun_size_au = 0, i = 0;
+	int last_word_underflow = 0;
+	u64 *lam;
+
+	pr_debug("%s: Initializing LUN: lun_id = %llX, "
+		 "ba_lun->lsize = %lX, ba_lun->au_size = %lX\n",
+		__func__, ba_lun->lun_id, ba_lun->lsize, ba_lun->au_size);
+
+	/* Calculate bit map size */
+	lun_size_au = ba_lun->lsize / ba_lun->au_size;
+	if (lun_size_au == 0) {
+		pr_debug("%s: Requested LUN size of 0!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Allocate lun information container */
+	bali = kzalloc(sizeof(struct ba_lun_info), GFP_KERNEL);
+	if (unlikely(!bali)) {
+		pr_err("%s: Failed to allocate lun_info for lun_id %llX\n",
+		       __func__, ba_lun->lun_id);
+		return -ENOMEM;
+	}
+
+	bali->total_aus = lun_size_au;
+	bali->lun_bmap_size = lun_size_au / BITS_PER_LONG;
+
+	if (lun_size_au % BITS_PER_LONG)
+		bali->lun_bmap_size++;
+
+	/* Allocate bitmap space */
+	bali->lun_alloc_map = kzalloc((bali->lun_bmap_size * sizeof(u64)),
+				      GFP_KERNEL);
+	if (unlikely(!bali->lun_alloc_map)) {
+		pr_err("%s: Failed to allocate lun allocation map: "
+		       "lun_id = %llX\n", __func__, ba_lun->lun_id);
+		kfree(bali);
+		return -ENOMEM;
+	}
+
+	/* Initialize the bit map size and set all bits to '1' */
+	bali->free_aun_cnt = lun_size_au;
+
+	for (i = 0; i < bali->lun_bmap_size; i++)
+		bali->lun_alloc_map[i] = 0xFFFFFFFFFFFFFFFFULL;
+
+	/* If the last word not fully utilized, mark extra bits as allocated */
+	last_word_underflow = (bali->lun_bmap_size * BITS_PER_LONG);
+	last_word_underflow -= bali->free_aun_cnt;
+	if (last_word_underflow > 0) {
+		lam = &bali->lun_alloc_map[bali->lun_bmap_size - 1];
+		for (i = (HIBIT - last_word_underflow + 1);
+		     i < BITS_PER_LONG;
+		     i++)
+			clear_bit(i, (ulong *)lam);
+	}
+
+	/* Initialize high elevator index, low/curr already at 0 from kzalloc */
+	bali->free_high_idx = bali->lun_bmap_size;
+
+	/* Allocate clone map */
+	bali->aun_clone_map = kzalloc((bali->total_aus * sizeof(u8)),
+				      GFP_KERNEL);
+	if (unlikely(!bali->aun_clone_map)) {
+		pr_err("%s: Failed to allocate clone map: lun_id = %llX\n",
+		       __func__, ba_lun->lun_id);
+		kfree(bali->lun_alloc_map);
+		kfree(bali);
+		return -ENOMEM;
+	}
+
+	/* Pass the allocated LUN info as a handle to the user */
+	ba_lun->ba_lun_handle = bali;
+
+	pr_debug("%s: Successfully initialized the LUN: "
+		 "lun_id = %llX, bitmap size = %X, free_aun_cnt = %llX\n",
+		__func__, ba_lun->lun_id, bali->lun_bmap_size,
+		bali->free_aun_cnt);
+	return 0;
+}
+
+/**
+ * find_free_range() - locates a free bit within the block allocator
+ * @low:	First word in block allocator to start search.
+ * @high:	Last word in block allocator to search.
+ * @bali:	LUN information structure owning the block allocator to search.
+ * @bit_word:	Passes back the word in the block allocator owning the free bit.
+ *
+ * Return: The bit position within the passed back word, -1 on failure
+ */
+static int find_free_range(u32 low,
+			   u32 high,
+			   struct ba_lun_info *bali, int *bit_word)
+{
+	int i;
+	u64 bit_pos = -1;
+	ulong *lam, num_bits;
+
+	for (i = low; i < high; i++)
+		if (bali->lun_alloc_map[i] != 0) {
+			lam = (ulong *)&bali->lun_alloc_map[i];
+			num_bits = (sizeof(*lam) * BITS_PER_BYTE);
+			bit_pos = find_first_bit(lam, num_bits);
+
+			pr_devel("%s: Found free bit %llX in LUN "
+				 "map entry %llX at bitmap index = %X\n",
+				 __func__, bit_pos, bali->lun_alloc_map[i],
+				 i);
+
+			*bit_word = i;
+			bali->free_aun_cnt--;
+			clear_bit(bit_pos, lam);
+			break;
+		}
+
+	return bit_pos;
+}
+
+/**
+ * ba_alloc() - allocates a block from the block allocator
+ * @ba_lun:	Block allocator from which to allocate a block.
+ *
+ * Return: The allocated block, -1 on failure
+ */
+static u64 ba_alloc(struct ba_lun *ba_lun)
+{
+	u64 bit_pos = -1;
+	int bit_word = 0;
+	struct ba_lun_info *bali = NULL;
+
+	bali = ba_lun->ba_lun_handle;
+
+	pr_debug("%s: Received block allocation request: "
+		 "lun_id = %llX, free_aun_cnt = %llX\n",
+		 __func__, ba_lun->lun_id, bali->free_aun_cnt);
+
+	if (bali->free_aun_cnt == 0) {
+		pr_debug("%s: No space left on LUN: lun_id = %llX\n",
+			 __func__, ba_lun->lun_id);
+		return -1ULL;
+	}
+
+	/* Search to find a free entry, curr->high then low->curr */
+	bit_pos = find_free_range(bali->free_curr_idx,
+				  bali->free_high_idx, bali, &bit_word);
+	if (bit_pos == -1) {
+		bit_pos = find_free_range(bali->free_low_idx,
+					  bali->free_curr_idx,
+					  bali, &bit_word);
+		if (bit_pos == -1) {
+			pr_debug("%s: Could not find an allocation unit on LUN:"
+				 " lun_id = %llX\n", __func__, ba_lun->lun_id);
+			return -1ULL;
+		}
+	}
+
+	/* Update the free_curr_idx */
+	if (bit_pos == HIBIT)
+		bali->free_curr_idx = bit_word + 1;
+	else
+		bali->free_curr_idx = bit_word;
+
+	pr_debug("%s: Allocating AU number %llX, on lun_id %llX, "
+		 "free_aun_cnt = %llX\n", __func__,
+		 ((bit_word * BITS_PER_LONG) + bit_pos), ba_lun->lun_id,
+		 bali->free_aun_cnt);
+
+	return (u64) ((bit_word * BITS_PER_LONG) + bit_pos);
+}
+
+/**
+ * validate_alloc() - validates the specified block has been allocated
+ * @ba_lun_info:	LUN info owning the block allocator.
+ * @aun:		Block to validate.
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int validate_alloc(struct ba_lun_info *bali, u64 aun)
+{
+	int idx = 0, bit_pos = 0;
+
+	idx = aun / BITS_PER_LONG;
+	bit_pos = aun % BITS_PER_LONG;
+
+	if (test_bit(bit_pos, (ulong *)&bali->lun_alloc_map[idx]))
+		return -1;
+
+	return 0;
+}
+
+/**
+ * ba_free() - frees a block from the block allocator
+ * @ba_lun:	Block allocator from which to allocate a block.
+ * @to_free:	Block to free.
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int ba_free(struct ba_lun *ba_lun, u64 to_free)
+{
+	int idx = 0, bit_pos = 0;
+	struct ba_lun_info *bali = NULL;
+
+	bali = ba_lun->ba_lun_handle;
+
+	if (validate_alloc(bali, to_free)) {
+		pr_debug("%s: The AUN %llX is not allocated on lun_id %llX\n",
+			 __func__, to_free, ba_lun->lun_id);
+		return -1;
+	}
+
+	pr_debug("%s: Received a request to free AU %llX on lun_id %llX, "
+		 "free_aun_cnt = %llX\n", __func__, to_free, ba_lun->lun_id,
+		 bali->free_aun_cnt);
+
+	if (bali->aun_clone_map[to_free] > 0) {
+		pr_debug("%s: AUN %llX on lun_id %llX has been cloned. Clone "
+			 "count = %X\n", __func__, to_free, ba_lun->lun_id,
+			 bali->aun_clone_map[to_free]);
+		bali->aun_clone_map[to_free]--;
+		return 0;
+	}
+
+	idx = to_free / BITS_PER_LONG;
+	bit_pos = to_free % BITS_PER_LONG;
+
+	set_bit(bit_pos, (ulong *)&bali->lun_alloc_map[idx]);
+	bali->free_aun_cnt++;
+
+	if (idx < bali->free_low_idx)
+		bali->free_low_idx = idx;
+	else if (idx > bali->free_high_idx)
+		bali->free_high_idx = idx;
+
+	pr_debug("%s: Successfully freed AU at bit_pos %X, bit map index %X on "
+		 "lun_id %llX, free_aun_cnt = %llX\n", __func__, bit_pos, idx,
+		 ba_lun->lun_id, bali->free_aun_cnt);
+
+	return 0;
+}
+
+/**
+ * ba_clone() - Clone a chunk of the block allocation table
+ * @ba_lun:	Block allocator from which to allocate a block.
+ * @to_free:	Block to free.
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int ba_clone(struct ba_lun *ba_lun, u64 to_clone)
+{
+	struct ba_lun_info *bali = ba_lun->ba_lun_handle;
+
+	if (validate_alloc(bali, to_clone)) {
+		pr_debug("%s: AUN %llX is not allocated on lun_id %llX\n",
+			 __func__, to_clone, ba_lun->lun_id);
+		return -1;
+	}
+
+	pr_debug("%s: Received a request to clone AUN %llX on lun_id %llX\n",
+		 __func__, to_clone, ba_lun->lun_id);
+
+	if (bali->aun_clone_map[to_clone] == MAX_AUN_CLONE_CNT) {
+		pr_debug("%s: AUN %llX on lun_id %llX hit max clones already\n",
+			 __func__, to_clone, ba_lun->lun_id);
+		return -1;
+	}
+
+	bali->aun_clone_map[to_clone]++;
+
+	return 0;
+}
+
+/**
+ * ba_space() - returns the amount of free space left in the block allocator
+ * @ba_lun:	Block allocator.
+ *
+ * Return: Amount of free space in block allocator
+ */
+static u64 ba_space(struct ba_lun *ba_lun)
+{
+	struct ba_lun_info *bali = ba_lun->ba_lun_handle;
+
+	return bali->free_aun_cnt;
+}
+
+/**
+ * cxlflash_ba_terminate() - frees resources associated with the block allocator
+ * @ba_lun:	Block allocator.
+ *
+ * Safe to call in a partially allocated state.
+ */
+void cxlflash_ba_terminate(struct ba_lun *ba_lun)
+{
+	struct ba_lun_info *bali = ba_lun->ba_lun_handle;
+
+	if (bali) {
+		kfree(bali->aun_clone_map);
+		kfree(bali->lun_alloc_map);
+		kfree(bali);
+		ba_lun->ba_lun_handle = NULL;
+	}
+}
+
+/**
+ * init_vlun() - initializes a LUN for virtual use
+ * @lun_info:	LUN information structure that owns the block allocator.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_vlun(struct llun_info *lli)
+{
+	int rc = 0;
+	struct glun_info *gli = lli->parent;
+	struct blka *blka = &gli->blka;
+
+	memset(blka, 0, sizeof(*blka));
+	mutex_init(&blka->mutex);
+
+	/* LUN IDs are unique per port, save the index instead */
+	blka->ba_lun.lun_id = lli->lun_index;
+	blka->ba_lun.lsize = gli->max_lba + 1;
+	blka->ba_lun.lba_size = gli->blk_len;
+
+	blka->ba_lun.au_size = MC_CHUNK_SIZE;
+	blka->nchunk = blka->ba_lun.lsize / MC_CHUNK_SIZE;
+
+	rc = ba_init(&blka->ba_lun);
+	if (unlikely(rc))
+		pr_debug("%s: cannot init block_alloc, rc=%d\n", __func__, rc);
+
+	pr_debug("%s: returning rc=%d lli=%p\n", __func__, rc, lli);
+	return rc;
+}
+
+/**
+ * write_same16() - sends a SCSI WRITE_SAME16 (0) command to specified LUN
+ * @sdev:	SCSI device associated with LUN.
+ * @lba:	Logical block address to start write same.
+ * @nblks:	Number of logical blocks to write same.
+ *
+ * The SCSI WRITE_SAME16 can take quite a while to complete. Should an EEH occur
+ * while in scsi_execute(), the EEH handler will attempt to recover. As part of
+ * the recovery, the handler drains all currently running ioctls, waiting until
+ * they have completed before proceeding with a reset. As this routine is used
+ * on the ioctl path, this can create a condition where the EEH handler becomes
+ * stuck, infinitely waiting for this ioctl thread. To avoid this behavior,
+ * temporarily unmark this thread as an ioctl thread by releasing the ioctl read
+ * semaphore. This will allow the EEH handler to proceed with a recovery while
+ * this thread is still running. Once the scsi_execute() returns, reacquire the
+ * ioctl read semaphore and check the adapter state in case it changed while
+ * inside of scsi_execute(). The state check will wait if the adapter is still
+ * being recovered or return a failure if the recovery failed. In the event that
+ * the adapter reset failed, simply return the failure as the ioctl would be
+ * unable to continue.
+ *
+ * Note that the above puts a requirement on this routine to only be called on
+ * an ioctl thread.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int write_same16(struct scsi_device *sdev,
+			u64 lba,
+			u32 nblks)
+{
+	u8 *cmd_buf = NULL;
+	u8 *scsi_cmd = NULL;
+	u8 *sense_buf = NULL;
+	int rc = 0;
+	int result = 0;
+	int ws_limit = SISLITE_MAX_WS_BLOCKS;
+	u64 offset = lba;
+	int left = nblks;
+	u32 to = sdev->request_queue->rq_timeout;
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+
+	cmd_buf = kzalloc(CMD_BUFSIZE, GFP_KERNEL);
+	scsi_cmd = kzalloc(MAX_COMMAND_SIZE, GFP_KERNEL);
+	sense_buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
+	if (unlikely(!cmd_buf || !scsi_cmd || !sense_buf)) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	while (left > 0) {
+
+		scsi_cmd[0] = WRITE_SAME_16;
+		put_unaligned_be64(offset, &scsi_cmd[2]);
+		put_unaligned_be32(ws_limit < left ? ws_limit : left,
+				   &scsi_cmd[10]);
+
+		/* Drop the ioctl read semahpore across lengthy call */
+		up_read(&cfg->ioctl_rwsem);
+		result = scsi_execute(sdev, scsi_cmd, DMA_TO_DEVICE, cmd_buf,
+				      CMD_BUFSIZE, sense_buf, to, CMD_RETRIES,
+				      0, NULL);
+		down_read(&cfg->ioctl_rwsem);
+		rc = check_state(cfg);
+		if (rc) {
+			dev_err(dev, "%s: Failed state! result=0x08%X\n",
+				__func__, result);
+			rc = -ENODEV;
+			goto out;
+		}
+
+		if (result) {
+			dev_err_ratelimited(dev, "%s: command failed for "
+					    "offset %lld result=0x%x\n",
+					    __func__, offset, result);
+			rc = -EIO;
+			goto out;
+		}
+		left -= ws_limit;
+		offset += ws_limit;
+	}
+
+out:
+	kfree(cmd_buf);
+	kfree(scsi_cmd);
+	kfree(sense_buf);
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * grow_lxt() - expands the translation table associated with the specified RHTE
+ * @afu:	AFU associated with the host.
+ * @sdev:	SCSI device associated with LUN.
+ * @ctxid:	Context ID of context owning the RHTE.
+ * @rhndl:	Resource handle associated with the RHTE.
+ * @rhte:	Resource handle entry (RHTE).
+ * @new_size:	Number of translation entries associated with RHTE.
+ *
+ * By design, this routine employs a 'best attempt' allocation and will
+ * truncate the requested size down if there is not sufficient space in
+ * the block allocator to satisfy the request but there does exist some
+ * amount of space. The user is made aware of this by returning the size
+ * allocated.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int grow_lxt(struct afu *afu,
+		    struct scsi_device *sdev,
+		    ctx_hndl_t ctxid,
+		    res_hndl_t rhndl,
+		    struct sisl_rht_entry *rhte,
+		    u64 *new_size)
+{
+	struct sisl_lxt_entry *lxt = NULL, *lxt_old = NULL;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct blka *blka = &gli->blka;
+	u32 av_size;
+	u32 ngrps, ngrps_old;
+	u64 aun;		/* chunk# allocated by block allocator */
+	u64 delta = *new_size - rhte->lxt_cnt;
+	u64 my_new_size;
+	int i, rc = 0;
+
+	/*
+	 * Check what is available in the block allocator before re-allocating
+	 * LXT array. This is done up front under the mutex which must not be
+	 * released until after allocation is complete.
+	 */
+	mutex_lock(&blka->mutex);
+	av_size = ba_space(&blka->ba_lun);
+	if (unlikely(av_size <= 0)) {
+		pr_debug("%s: ba_space error: av_size %d\n", __func__, av_size);
+		mutex_unlock(&blka->mutex);
+		rc = -ENOSPC;
+		goto out;
+	}
+
+	if (av_size < delta)
+		delta = av_size;
+
+	lxt_old = rhte->lxt_start;
+	ngrps_old = LXT_NUM_GROUPS(rhte->lxt_cnt);
+	ngrps = LXT_NUM_GROUPS(rhte->lxt_cnt + delta);
+
+	if (ngrps != ngrps_old) {
+		/* reallocate to fit new size */
+		lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps),
+			      GFP_KERNEL);
+		if (unlikely(!lxt)) {
+			mutex_unlock(&blka->mutex);
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		/* copy over all old entries */
+		memcpy(lxt, lxt_old, (sizeof(*lxt) * rhte->lxt_cnt));
+	} else
+		lxt = lxt_old;
+
+	/* nothing can fail from now on */
+	my_new_size = rhte->lxt_cnt + delta;
+
+	/* add new entries to the end */
+	for (i = rhte->lxt_cnt; i < my_new_size; i++) {
+		/*
+		 * Due to the earlier check of available space, ba_alloc
+		 * cannot fail here. If it did due to internal error,
+		 * leave a rlba_base of -1u which will likely be a
+		 * invalid LUN (too large).
+		 */
+		aun = ba_alloc(&blka->ba_lun);
+		if ((aun == -1ULL) || (aun >= blka->nchunk))
+			pr_debug("%s: ba_alloc error: allocated chunk# %llX, "
+				 "max %llX\n", __func__, aun, blka->nchunk - 1);
+
+		/* select both ports, use r/w perms from RHT */
+		lxt[i].rlba_base = ((aun << MC_CHUNK_SHIFT) |
+				    (lli->lun_index << LXT_LUNIDX_SHIFT) |
+				    (RHT_PERM_RW << LXT_PERM_SHIFT |
+				     lli->port_sel));
+	}
+
+	mutex_unlock(&blka->mutex);
+
+	/*
+	 * The following sequence is prescribed in the SISlite spec
+	 * for syncing up with the AFU when adding LXT entries.
+	 */
+	dma_wmb(); /* Make LXT updates are visible */
+
+	rhte->lxt_start = lxt;
+	dma_wmb(); /* Make RHT entry's LXT table update visible */
+
+	rhte->lxt_cnt = my_new_size;
+	dma_wmb(); /* Make RHT entry's LXT table size update visible */
+
+	cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
+
+	/* free old lxt if reallocated */
+	if (lxt != lxt_old)
+		kfree(lxt_old);
+	*new_size = my_new_size;
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * shrink_lxt() - reduces translation table associated with the specified RHTE
+ * @afu:	AFU associated with the host.
+ * @sdev:	SCSI device associated with LUN.
+ * @rhndl:	Resource handle associated with the RHTE.
+ * @rhte:	Resource handle entry (RHTE).
+ * @ctxi:	Context owning resources.
+ * @new_size:	Number of translation entries associated with RHTE.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int shrink_lxt(struct afu *afu,
+		      struct scsi_device *sdev,
+		      res_hndl_t rhndl,
+		      struct sisl_rht_entry *rhte,
+		      struct ctx_info *ctxi,
+		      u64 *new_size)
+{
+	struct sisl_lxt_entry *lxt, *lxt_old;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct blka *blka = &gli->blka;
+	ctx_hndl_t ctxid = DECODE_CTXID(ctxi->ctxid);
+	bool needs_ws = ctxi->rht_needs_ws[rhndl];
+	bool needs_sync = !ctxi->err_recovery_active;
+	u32 ngrps, ngrps_old;
+	u64 aun;		/* chunk# allocated by block allocator */
+	u64 delta = rhte->lxt_cnt - *new_size;
+	u64 my_new_size;
+	int i, rc = 0;
+
+	lxt_old = rhte->lxt_start;
+	ngrps_old = LXT_NUM_GROUPS(rhte->lxt_cnt);
+	ngrps = LXT_NUM_GROUPS(rhte->lxt_cnt - delta);
+
+	if (ngrps != ngrps_old) {
+		/* Reallocate to fit new size unless new size is 0 */
+		if (ngrps) {
+			lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps),
+				      GFP_KERNEL);
+			if (unlikely(!lxt)) {
+				rc = -ENOMEM;
+				goto out;
+			}
+
+			/* Copy over old entries that will remain */
+			memcpy(lxt, lxt_old,
+			       (sizeof(*lxt) * (rhte->lxt_cnt - delta)));
+		} else
+			lxt = NULL;
+	} else
+		lxt = lxt_old;
+
+	/* Nothing can fail from now on */
+	my_new_size = rhte->lxt_cnt - delta;
+
+	/*
+	 * The following sequence is prescribed in the SISlite spec
+	 * for syncing up with the AFU when removing LXT entries.
+	 */
+	rhte->lxt_cnt = my_new_size;
+	dma_wmb(); /* Make RHT entry's LXT table size update visible */
+
+	rhte->lxt_start = lxt;
+	dma_wmb(); /* Make RHT entry's LXT table update visible */
+
+	if (needs_sync)
+		cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
+
+	if (needs_ws) {
+		/*
+		 * Mark the context as unavailable, so that we can release
+		 * the mutex safely.
+		 */
+		ctxi->unavail = true;
+		mutex_unlock(&ctxi->mutex);
+	}
+
+	/* Free LBAs allocated to freed chunks */
+	mutex_lock(&blka->mutex);
+	for (i = delta - 1; i >= 0; i--) {
+		/* Mask the higher 48 bits before shifting, even though
+		 * it is a noop
+		 */
+		aun = (lxt_old[my_new_size + i].rlba_base & SISL_ASTATUS_MASK);
+		aun = (aun >> MC_CHUNK_SHIFT);
+		if (needs_ws)
+			write_same16(sdev, aun, MC_CHUNK_SIZE);
+		ba_free(&blka->ba_lun, aun);
+	}
+	mutex_unlock(&blka->mutex);
+
+	if (needs_ws) {
+		/* Make the context visible again */
+		mutex_lock(&ctxi->mutex);
+		ctxi->unavail = false;
+	}
+
+	/* Free old lxt if reallocated */
+	if (lxt != lxt_old)
+		kfree(lxt_old);
+	*new_size = my_new_size;
+out:
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * _cxlflash_vlun_resize() - changes the size of a virtual LUN
+ * @sdev:	SCSI device associated with LUN owning virtual LUN.
+ * @ctxi:	Context owning resources.
+ * @resize:	Resize ioctl data structure.
+ *
+ * On successful return, the user is informed of the new size (in blocks)
+ * of the virtual LUN in last LBA format. When the size of the virtual
+ * LUN is zero, the last LBA is reflected as -1. See comment in the
+ * prologue for _cxlflash_disk_release() regarding AFU syncs and contexts
+ * on the error recovery list.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int _cxlflash_vlun_resize(struct scsi_device *sdev,
+			  struct ctx_info *ctxi,
+			  struct dk_cxlflash_resize *resize)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct afu *afu = cfg->afu;
+	bool put_ctx = false;
+
+	res_hndl_t rhndl = resize->rsrc_handle;
+	u64 new_size;
+	u64 nsectors;
+	u64 ctxid = DECODE_CTXID(resize->context_id),
+	    rctxid = resize->context_id;
+
+	struct sisl_rht_entry *rhte;
+
+	int rc = 0;
+
+	/*
+	 * The requested size (req_size) is always assumed to be in 4k blocks,
+	 * so we have to convert it here from 4k to chunk size.
+	 */
+	nsectors = (resize->req_size * CXLFLASH_BLOCK_SIZE) / gli->blk_len;
+	new_size = DIV_ROUND_UP(nsectors, MC_CHUNK_SIZE);
+
+	pr_debug("%s: ctxid=%llu rhndl=0x%llx, req_size=0x%llx,"
+		 "new_size=%llx\n", __func__, ctxid, resize->rsrc_handle,
+		 resize->req_size, new_size);
+
+	if (unlikely(gli->mode != MODE_VIRTUAL)) {
+		pr_debug("%s: LUN mode does not support resize! (%d)\n",
+			 __func__, gli->mode);
+		rc = -EINVAL;
+		goto out;
+
+	}
+
+	if (!ctxi) {
+		ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
+		if (unlikely(!ctxi)) {
+			pr_debug("%s: Bad context! (%llu)\n", __func__, ctxid);
+			rc = -EINVAL;
+			goto out;
+		}
+
+		put_ctx = true;
+	}
+
+	rhte = get_rhte(ctxi, rhndl, lli);
+	if (unlikely(!rhte)) {
+		pr_debug("%s: Bad resource handle! (%u)\n", __func__, rhndl);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (new_size > rhte->lxt_cnt)
+		rc = grow_lxt(afu, sdev, ctxid, rhndl, rhte, &new_size);
+	else if (new_size < rhte->lxt_cnt)
+		rc = shrink_lxt(afu, sdev, rhndl, rhte, ctxi, &new_size);
+
+	resize->hdr.return_flags = 0;
+	resize->last_lba = (new_size * MC_CHUNK_SIZE * gli->blk_len);
+	resize->last_lba /= CXLFLASH_BLOCK_SIZE;
+	resize->last_lba--;
+
+out:
+	if (put_ctx)
+		put_context(ctxi);
+	pr_debug("%s: resized to %lld returning rc=%d\n",
+		 __func__, resize->last_lba, rc);
+	return rc;
+}
+
+int cxlflash_vlun_resize(struct scsi_device *sdev,
+			 struct dk_cxlflash_resize *resize)
+{
+	return _cxlflash_vlun_resize(sdev, NULL, resize);
+}
+
+/**
+ * cxlflash_restore_luntable() - Restore LUN table to prior state
+ * @cfg:	Internal structure associated with the host.
+ */
+void cxlflash_restore_luntable(struct cxlflash_cfg *cfg)
+{
+	struct llun_info *lli, *temp;
+	u32 chan;
+	u32 lind;
+	struct afu *afu = cfg->afu;
+	struct sisl_global_map __iomem *agm = &afu->afu_map->global;
+
+	mutex_lock(&global.mutex);
+
+	list_for_each_entry_safe(lli, temp, &cfg->lluns, list) {
+		if (!lli->in_table)
+			continue;
+
+		lind = lli->lun_index;
+
+		if (lli->port_sel == BOTH_PORTS) {
+			writeq_be(lli->lun_id[0], &agm->fc_port[0][lind]);
+			writeq_be(lli->lun_id[1], &agm->fc_port[1][lind]);
+			pr_debug("%s: Virtual LUN on slot %d  id0=%llx, "
+				 "id1=%llx\n", __func__, lind,
+				 lli->lun_id[0], lli->lun_id[1]);
+		} else {
+			chan = PORT2CHAN(lli->port_sel);
+			writeq_be(lli->lun_id[chan], &agm->fc_port[chan][lind]);
+			pr_debug("%s: Virtual LUN on slot %d chan=%d, "
+				 "id=%llx\n", __func__, lind, chan,
+				 lli->lun_id[chan]);
+		}
+	}
+
+	mutex_unlock(&global.mutex);
+}
+
+/**
+ * init_luntable() - write an entry in the LUN table
+ * @cfg:	Internal structure associated with the host.
+ * @lli:	Per adapter LUN information structure.
+ *
+ * On successful return, a LUN table entry is created.
+ * At the top for LUNs visible on both ports.
+ * At the bottom for LUNs visible only on one port.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int init_luntable(struct cxlflash_cfg *cfg, struct llun_info *lli)
+{
+	u32 chan;
+	u32 lind;
+	int rc = 0;
+	struct afu *afu = cfg->afu;
+	struct sisl_global_map __iomem *agm = &afu->afu_map->global;
+
+	mutex_lock(&global.mutex);
+
+	if (lli->in_table)
+		goto out;
+
+	if (lli->port_sel == BOTH_PORTS) {
+		/*
+		 * If this LUN is visible from both ports, we will put
+		 * it in the top half of the LUN table.
+		 */
+		if ((cfg->promote_lun_index == cfg->last_lun_index[0]) ||
+		    (cfg->promote_lun_index == cfg->last_lun_index[1])) {
+			rc = -ENOSPC;
+			goto out;
+		}
+
+		lind = lli->lun_index = cfg->promote_lun_index;
+		writeq_be(lli->lun_id[0], &agm->fc_port[0][lind]);
+		writeq_be(lli->lun_id[1], &agm->fc_port[1][lind]);
+		cfg->promote_lun_index++;
+		pr_debug("%s: Virtual LUN on slot %d  id0=%llx, id1=%llx\n",
+			 __func__, lind, lli->lun_id[0], lli->lun_id[1]);
+	} else {
+		/*
+		 * If this LUN is visible only from one port, we will put
+		 * it in the bottom half of the LUN table.
+		 */
+		chan = PORT2CHAN(lli->port_sel);
+		if (cfg->promote_lun_index == cfg->last_lun_index[chan]) {
+			rc = -ENOSPC;
+			goto out;
+		}
+
+		lind = lli->lun_index = cfg->last_lun_index[chan];
+		writeq_be(lli->lun_id[chan], &agm->fc_port[chan][lind]);
+		cfg->last_lun_index[chan]--;
+		pr_debug("%s: Virtual LUN on slot %d  chan=%d, id=%llx\n",
+			 __func__, lind, chan, lli->lun_id[chan]);
+	}
+
+	lli->in_table = true;
+out:
+	mutex_unlock(&global.mutex);
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+}
+
+/**
+ * cxlflash_disk_virtual_open() - open a virtual disk of specified size
+ * @sdev:	SCSI device associated with LUN owning virtual LUN.
+ * @arg:	UVirtual ioctl data structure.
+ *
+ * On successful return, the user is informed of the resource handle
+ * to be used to identify the virtual LUN and the size (in blocks) of
+ * the virtual LUN in last LBA format. When the size of the virtual LUN
+ * is zero, the last LBA is reflected as -1.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_disk_virtual_open(struct scsi_device *sdev, void *arg)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct device *dev = &cfg->dev->dev;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+
+	struct dk_cxlflash_uvirtual *virt = (struct dk_cxlflash_uvirtual *)arg;
+	struct dk_cxlflash_resize resize;
+
+	u64 ctxid = DECODE_CTXID(virt->context_id),
+	    rctxid = virt->context_id;
+	u64 lun_size = virt->lun_size;
+	u64 last_lba = 0;
+	u64 rsrc_handle = -1;
+
+	int rc = 0;
+
+	struct ctx_info *ctxi = NULL;
+	struct sisl_rht_entry *rhte = NULL;
+
+	pr_debug("%s: ctxid=%llu ls=0x%llx\n", __func__, ctxid, lun_size);
+
+	/* Setup the LUNs block allocator on first call */
+	mutex_lock(&gli->mutex);
+	if (gli->mode == MODE_NONE) {
+		rc = init_vlun(lli);
+		if (rc) {
+			dev_err(dev, "%s: call to init_vlun failed rc=%d!\n",
+				__func__, rc);
+			rc = -ENOMEM;
+			goto err0;
+		}
+	}
+
+	rc = cxlflash_lun_attach(gli, MODE_VIRTUAL, true);
+	if (unlikely(rc)) {
+		dev_err(dev, "%s: Failed to attach to LUN! (VIRTUAL)\n",
+			__func__);
+		goto err0;
+	}
+	mutex_unlock(&gli->mutex);
+
+	rc = init_luntable(cfg, lli);
+	if (rc) {
+		dev_err(dev, "%s: call to init_luntable failed rc=%d!\n",
+			__func__, rc);
+		goto err1;
+	}
+
+	ctxi = get_context(cfg, rctxid, lli, 0);
+	if (unlikely(!ctxi)) {
+		dev_err(dev, "%s: Bad context! (%llu)\n", __func__, ctxid);
+		rc = -EINVAL;
+		goto err1;
+	}
+
+	rhte = rhte_checkout(ctxi, lli);
+	if (unlikely(!rhte)) {
+		dev_err(dev, "%s: too many opens for this context\n", __func__);
+		rc = -EMFILE;	/* too many opens  */
+		goto err1;
+	}
+
+	rsrc_handle = (rhte - ctxi->rht_start);
+
+	/* Populate RHT format 0 */
+	rhte->nmask = MC_RHT_NMASK;
+	rhte->fp = SISL_RHT_FP(0U, ctxi->rht_perms);
+
+	/* Resize even if requested size is 0 */
+	marshal_virt_to_resize(virt, &resize);
+	resize.rsrc_handle = rsrc_handle;
+	rc = _cxlflash_vlun_resize(sdev, ctxi, &resize);
+	if (rc) {
+		dev_err(dev, "%s: resize failed rc %d\n", __func__, rc);
+		goto err2;
+	}
+	last_lba = resize.last_lba;
+
+	if (virt->hdr.flags & DK_CXLFLASH_UVIRTUAL_NEED_WRITE_SAME)
+		ctxi->rht_needs_ws[rsrc_handle] = true;
+
+	virt->hdr.return_flags = 0;
+	virt->last_lba = last_lba;
+	virt->rsrc_handle = rsrc_handle;
+
+out:
+	if (likely(ctxi))
+		put_context(ctxi);
+	pr_debug("%s: returning handle 0x%llx rc=%d llba %lld\n",
+		 __func__, rsrc_handle, rc, last_lba);
+	return rc;
+
+err2:
+	rhte_checkin(ctxi, rhte);
+err1:
+	cxlflash_lun_detach(gli);
+	goto out;
+err0:
+	/* Special common cleanup prior to successful LUN attach */
+	cxlflash_ba_terminate(&gli->blka.ba_lun);
+	mutex_unlock(&gli->mutex);
+	goto out;
+}
+
+/**
+ * clone_lxt() - copies translation tables from source to destination RHTE
+ * @afu:	AFU associated with the host.
+ * @blka:	Block allocator associated with LUN.
+ * @ctxid:	Context ID of context owning the RHTE.
+ * @rhndl:	Resource handle associated with the RHTE.
+ * @rhte:	Destination resource handle entry (RHTE).
+ * @rhte_src:	Source resource handle entry (RHTE).
+ *
+ * Return: 0 on success, -errno on failure
+ */
+static int clone_lxt(struct afu *afu,
+		     struct blka *blka,
+		     ctx_hndl_t ctxid,
+		     res_hndl_t rhndl,
+		     struct sisl_rht_entry *rhte,
+		     struct sisl_rht_entry *rhte_src)
+{
+	struct sisl_lxt_entry *lxt;
+	u32 ngrps;
+	u64 aun;		/* chunk# allocated by block allocator */
+	int i, j;
+
+	ngrps = LXT_NUM_GROUPS(rhte_src->lxt_cnt);
+
+	if (ngrps) {
+		/* allocate new LXTs for clone */
+		lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps),
+				GFP_KERNEL);
+		if (unlikely(!lxt))
+			return -ENOMEM;
+
+		/* copy over */
+		memcpy(lxt, rhte_src->lxt_start,
+		       (sizeof(*lxt) * rhte_src->lxt_cnt));
+
+		/* clone the LBAs in block allocator via ref_cnt */
+		mutex_lock(&blka->mutex);
+		for (i = 0; i < rhte_src->lxt_cnt; i++) {
+			aun = (lxt[i].rlba_base >> MC_CHUNK_SHIFT);
+			if (ba_clone(&blka->ba_lun, aun) == -1ULL) {
+				/* free the clones already made */
+				for (j = 0; j < i; j++) {
+					aun = (lxt[j].rlba_base >>
+					       MC_CHUNK_SHIFT);
+					ba_free(&blka->ba_lun, aun);
+				}
+
+				mutex_unlock(&blka->mutex);
+				kfree(lxt);
+				return -EIO;
+			}
+		}
+		mutex_unlock(&blka->mutex);
+	} else {
+		lxt = NULL;
+	}
+
+	/*
+	 * The following sequence is prescribed in the SISlite spec
+	 * for syncing up with the AFU when adding LXT entries.
+	 */
+	dma_wmb(); /* Make LXT updates are visible */
+
+	rhte->lxt_start = lxt;
+	dma_wmb(); /* Make RHT entry's LXT table update visible */
+
+	rhte->lxt_cnt = rhte_src->lxt_cnt;
+	dma_wmb(); /* Make RHT entry's LXT table size update visible */
+
+	cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC);
+
+	pr_debug("%s: returning\n", __func__);
+	return 0;
+}
+
+/**
+ * cxlflash_disk_clone() - clone a context by making snapshot of another
+ * @sdev:	SCSI device associated with LUN owning virtual LUN.
+ * @clone:	Clone ioctl data structure.
+ *
+ * This routine effectively performs cxlflash_disk_open operation for each
+ * in-use virtual resource in the source context. Note that the destination
+ * context must be in pristine state and cannot have any resource handles
+ * open at the time of the clone.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int cxlflash_disk_clone(struct scsi_device *sdev,
+			struct dk_cxlflash_clone *clone)
+{
+	struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata;
+	struct llun_info *lli = sdev->hostdata;
+	struct glun_info *gli = lli->parent;
+	struct blka *blka = &gli->blka;
+	struct afu *afu = cfg->afu;
+	struct dk_cxlflash_release release = { { 0 }, 0 };
+
+	struct ctx_info *ctxi_src = NULL,
+			*ctxi_dst = NULL;
+	struct lun_access *lun_access_src, *lun_access_dst;
+	u32 perms;
+	u64 ctxid_src = DECODE_CTXID(clone->context_id_src),
+	    ctxid_dst = DECODE_CTXID(clone->context_id_dst),
+	    rctxid_src = clone->context_id_src,
+	    rctxid_dst = clone->context_id_dst;
+	int adap_fd_src = clone->adap_fd_src;
+	int i, j;
+	int rc = 0;
+	bool found;
+	LIST_HEAD(sidecar);
+
+	pr_debug("%s: ctxid_src=%llu ctxid_dst=%llu adap_fd_src=%d\n",
+		 __func__, ctxid_src, ctxid_dst, adap_fd_src);
+
+	/* Do not clone yourself */
+	if (unlikely(rctxid_src == rctxid_dst)) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (unlikely(gli->mode != MODE_VIRTUAL)) {
+		rc = -EINVAL;
+		pr_debug("%s: Clone not supported on physical LUNs! (%d)\n",
+			 __func__, gli->mode);
+		goto out;
+	}
+
+	ctxi_src = get_context(cfg, rctxid_src, lli, CTX_CTRL_CLONE);
+	ctxi_dst = get_context(cfg, rctxid_dst, lli, 0);
+	if (unlikely(!ctxi_src || !ctxi_dst)) {
+		pr_debug("%s: Bad context! (%llu,%llu)\n", __func__,
+			 ctxid_src, ctxid_dst);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (unlikely(adap_fd_src != ctxi_src->lfd)) {
+		pr_debug("%s: Invalid source adapter fd! (%d)\n",
+			 __func__, adap_fd_src);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/* Verify there is no open resource handle in the destination context */
+	for (i = 0; i < MAX_RHT_PER_CONTEXT; i++)
+		if (ctxi_dst->rht_start[i].nmask != 0) {
+			rc = -EINVAL;
+			goto out;
+		}
+
+	/* Clone LUN access list */
+	list_for_each_entry(lun_access_src, &ctxi_src->luns, list) {
+		found = false;
+		list_for_each_entry(lun_access_dst, &ctxi_dst->luns, list)
+			if (lun_access_dst->sdev == lun_access_src->sdev) {
+				found = true;
+				break;
+			}
+
+		if (!found) {
+			lun_access_dst = kzalloc(sizeof(*lun_access_dst),
+						 GFP_KERNEL);
+			if (unlikely(!lun_access_dst)) {
+				pr_err("%s: Unable to allocate lun_access!\n",
+				       __func__);
+				rc = -ENOMEM;
+				goto out;
+			}
+
+			*lun_access_dst = *lun_access_src;
+			list_add(&lun_access_dst->list, &sidecar);
+		}
+	}
+
+	if (unlikely(!ctxi_src->rht_out)) {
+		pr_debug("%s: Nothing to clone!\n", __func__);
+		goto out_success;
+	}
+
+	/* User specified permission on attach */
+	perms = ctxi_dst->rht_perms;
+
+	/*
+	 * Copy over checked-out RHT (and their associated LXT) entries by
+	 * hand, stopping after we've copied all outstanding entries and
+	 * cleaning up if the clone fails.
+	 *
+	 * Note: This loop is equivalent to performing cxlflash_disk_open and
+	 * cxlflash_vlun_resize. As such, LUN accounting needs to be taken into
+	 * account by attaching after each successful RHT entry clone. In the
+	 * event that a clone failure is experienced, the LUN detach is handled
+	 * via the cleanup performed by _cxlflash_disk_release.
+	 */
+	for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) {
+		if (ctxi_src->rht_out == ctxi_dst->rht_out)
+			break;
+		if (ctxi_src->rht_start[i].nmask == 0)
+			continue;
+
+		/* Consume a destination RHT entry */
+		ctxi_dst->rht_out++;
+		ctxi_dst->rht_start[i].nmask = ctxi_src->rht_start[i].nmask;
+		ctxi_dst->rht_start[i].fp =
+		    SISL_RHT_FP_CLONE(ctxi_src->rht_start[i].fp, perms);
+		ctxi_dst->rht_lun[i] = ctxi_src->rht_lun[i];
+
+		rc = clone_lxt(afu, blka, ctxid_dst, i,
+			       &ctxi_dst->rht_start[i],
+			       &ctxi_src->rht_start[i]);
+		if (rc) {
+			marshal_clone_to_rele(clone, &release);
+			for (j = 0; j < i; j++) {
+				release.rsrc_handle = j;
+				_cxlflash_disk_release(sdev, ctxi_dst,
+						       &release);
+			}
+
+			/* Put back the one we failed on */
+			rhte_checkin(ctxi_dst, &ctxi_dst->rht_start[i]);
+			goto err;
+		}
+
+		cxlflash_lun_attach(gli, gli->mode, false);
+	}
+
+out_success:
+	list_splice(&sidecar, &ctxi_dst->luns);
+	sys_close(adap_fd_src);
+
+	/* fall through */
+out:
+	if (ctxi_src)
+		put_context(ctxi_src);
+	if (ctxi_dst)
+		put_context(ctxi_dst);
+	pr_debug("%s: returning rc=%d\n", __func__, rc);
+	return rc;
+
+err:
+	list_for_each_entry_safe(lun_access_src, lun_access_dst, &sidecar, list)
+		kfree(lun_access_src);
+	goto out;
+}
diff --git a/kernel/drivers/scsi/cxlflash/vlun.h b/kernel/drivers/scsi/cxlflash/vlun.h
new file mode 100644
index 000000000..8b29a7494
--- /dev/null
+++ b/kernel/drivers/scsi/cxlflash/vlun.h
@@ -0,0 +1,86 @@
+/*
+ * CXL Flash Device Driver
+ *
+ * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
+ *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
+ *
+ * Copyright (C) 2015 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _CXLFLASH_VLUN_H
+#define _CXLFLASH_VLUN_H
+
+/* RHT - Resource Handle Table */
+#define MC_RHT_NMASK      16	/* in bits */
+#define MC_CHUNK_SHIFT    MC_RHT_NMASK	/* shift to go from LBA to chunk# */
+
+#define HIBIT             (BITS_PER_LONG - 1)
+
+#define MAX_AUN_CLONE_CNT 0xFF
+
+/*
+ * LXT - LBA Translation Table
+ *
+ * +-------+-------+-------+-------+-------+-------+-------+---+---+
+ * | RLBA_BASE                                     |LUN_IDX| P |SEL|
+ * +-------+-------+-------+-------+-------+-------+-------+---+---+
+ *
+ * The LXT Entry contains the physical LBA where the chunk starts (RLBA_BASE).
+ * AFU ORes the low order bits from the virtual LBA (offset into the chunk)
+ * with RLBA_BASE. The result is the physical LBA to be sent to storage.
+ * The LXT Entry also contains an index to a LUN TBL and a bitmask of which
+ * outgoing (FC) * ports can be selected. The port select bit-mask is ANDed
+ * with a global port select bit-mask maintained by the driver.
+ * In addition, it has permission bits that are ANDed with the
+ * RHT permissions to arrive at the final permissions for the chunk.
+ *
+ * LXT tables are allocated dynamically in groups. This is done to avoid
+ * a malloc/free overhead each time the LXT has to grow or shrink.
+ *
+ * Based on the current lxt_cnt (used), it is always possible to know
+ * how many are allocated (used+free). The number of allocated entries is
+ * not stored anywhere.
+ *
+ * The LXT table is re-allocated whenever it needs to cross into another group.
+*/
+#define LXT_GROUP_SIZE          8
+#define LXT_NUM_GROUPS(lxt_cnt) (((lxt_cnt) + 7)/8)	/* alloc'ed groups */
+#define LXT_LUNIDX_SHIFT  8	/* LXT entry, shift for LUN index */
+#define LXT_PERM_SHIFT    4	/* LXT entry, shift for permission bits */
+
+struct ba_lun_info {
+	u64 *lun_alloc_map;
+	u32 lun_bmap_size;
+	u32 total_aus;
+	u64 free_aun_cnt;
+
+	/* indices to be used for elevator lookup of free map */
+	u32 free_low_idx;
+	u32 free_curr_idx;
+	u32 free_high_idx;
+
+	u8 *aun_clone_map;
+};
+
+struct ba_lun {
+	u64 lun_id;
+	u64 wwpn;
+	size_t lsize;		/* LUN size in number of LBAs             */
+	size_t lba_size;	/* LBA size in number of bytes            */
+	size_t au_size;		/* Allocation Unit size in number of LBAs */
+	struct ba_lun_info *ba_lun_handle;
+};
+
+/* Block Allocator */
+struct blka {
+	struct ba_lun ba_lun;
+	u64 nchunk;		/* number of chunks */
+	struct mutex mutex;
+};
+
+#endif /* ifndef _CXLFLASH_SUPERPIPE_H */