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>

1 files changed, 700 insertions, 956 deletions

diff --git a/kernel/drivers/dma/ioat/dma.c b/kernel/drivers/dma/ioat/dma.c
index ee0aa9f4c..1d5df2ef1 100644
--- a/kernel/drivers/dma/ioat/dma.c
+++ b/kernel/drivers/dma/ioat/dma.c
@@ -1,6 +1,6 @@
 /*
  * Intel I/OAT DMA Linux driver
- * Copyright(c) 2004 - 2009 Intel Corporation.
+ * Copyright(c) 2004 - 2015 Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -31,31 +31,23 @@
 #include <linux/dma-mapping.h>
 #include <linux/workqueue.h>
 #include <linux/prefetch.h>
-#include <linux/i7300_idle.h>
 #include "dma.h"
 #include "registers.h"
 #include "hw.h"
 
 #include "../dmaengine.h"
 
-int ioat_pending_level = 4;
-module_param(ioat_pending_level, int, 0644);
-MODULE_PARM_DESC(ioat_pending_level,
-		 "high-water mark for pushing ioat descriptors (default: 4)");
-
-/* internal functions */
-static void ioat1_cleanup(struct ioat_dma_chan *ioat);
-static void ioat1_dma_start_null_desc(struct ioat_dma_chan *ioat);
+static void ioat_eh(struct ioatdma_chan *ioat_chan);
 
 /**
  * ioat_dma_do_interrupt - handler used for single vector interrupt mode
  * @irq: interrupt id
  * @data: interrupt data
  */
-static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
+irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
 {
 	struct ioatdma_device *instance = data;
-	struct ioat_chan_common *chan;
+	struct ioatdma_chan *ioat_chan;
 	unsigned long attnstatus;
 	int bit;
 	u8 intrctrl;
@@ -72,9 +64,9 @@ static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
 
 	attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
 	for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
-		chan = ioat_chan_by_index(instance, bit);
-		if (test_bit(IOAT_RUN, &chan->state))
-			tasklet_schedule(&chan->cleanup_task);
+		ioat_chan = ioat_chan_by_index(instance, bit);
+		if (test_bit(IOAT_RUN, &ioat_chan->state))
+			tasklet_schedule(&ioat_chan->cleanup_task);
 	}
 
 	writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
@@ -86,1161 +78,913 @@ static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
  * @irq: interrupt id
  * @data: interrupt data
  */
-static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
+irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
 {
-	struct ioat_chan_common *chan = data;
+	struct ioatdma_chan *ioat_chan = data;
 
-	if (test_bit(IOAT_RUN, &chan->state))
-		tasklet_schedule(&chan->cleanup_task);
+	if (test_bit(IOAT_RUN, &ioat_chan->state))
+		tasklet_schedule(&ioat_chan->cleanup_task);
 
 	return IRQ_HANDLED;
 }
 
-/* common channel initialization */
-void ioat_init_channel(struct ioatdma_device *device, struct ioat_chan_common *chan, int idx)
+void ioat_stop(struct ioatdma_chan *ioat_chan)
 {
-	struct dma_device *dma = &device->common;
-	struct dma_chan *c = &chan->common;
-	unsigned long data = (unsigned long) c;
-
-	chan->device = device;
-	chan->reg_base = device->reg_base + (0x80 * (idx + 1));
-	spin_lock_init(&chan->cleanup_lock);
-	chan->common.device = dma;
-	dma_cookie_init(&chan->common);
-	list_add_tail(&chan->common.device_node, &dma->channels);
-	device->idx[idx] = chan;
-	init_timer(&chan->timer);
-	chan->timer.function = device->timer_fn;
-	chan->timer.data = data;
-	tasklet_init(&chan->cleanup_task, device->cleanup_fn, data);
+	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
+	struct pci_dev *pdev = ioat_dma->pdev;
+	int chan_id = chan_num(ioat_chan);
+	struct msix_entry *msix;
+
+	/* 1/ stop irq from firing tasklets
+	 * 2/ stop the tasklet from re-arming irqs
+	 */
+	clear_bit(IOAT_RUN, &ioat_chan->state);
+
+	/* flush inflight interrupts */
+	switch (ioat_dma->irq_mode) {
+	case IOAT_MSIX:
+		msix = &ioat_dma->msix_entries[chan_id];
+		synchronize_irq(msix->vector);
+		break;
+	case IOAT_MSI:
+	case IOAT_INTX:
+		synchronize_irq(pdev->irq);
+		break;
+	default:
+		break;
+	}
+
+	/* flush inflight timers */
+	del_timer_sync(&ioat_chan->timer);
+
+	/* flush inflight tasklet runs */
+	tasklet_kill(&ioat_chan->cleanup_task);
+
+	/* final cleanup now that everything is quiesced and can't re-arm */
+	ioat_cleanup_event((unsigned long)&ioat_chan->dma_chan);
 }
 
-/**
- * ioat1_dma_enumerate_channels - find and initialize the device's channels
- * @device: the device to be enumerated
- */
-static int ioat1_enumerate_channels(struct ioatdma_device *device)
+static void __ioat_issue_pending(struct ioatdma_chan *ioat_chan)
 {
-	u8 xfercap_scale;
-	u32 xfercap;
-	int i;
-	struct ioat_dma_chan *ioat;
-	struct device *dev = &device->pdev->dev;
-	struct dma_device *dma = &device->common;
-
-	INIT_LIST_HEAD(&dma->channels);
-	dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
-	dma->chancnt &= 0x1f; /* bits [4:0] valid */
-	if (dma->chancnt > ARRAY_SIZE(device->idx)) {
-		dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
-			 dma->chancnt, ARRAY_SIZE(device->idx));
-		dma->chancnt = ARRAY_SIZE(device->idx);
-	}
-	xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
-	xfercap_scale &= 0x1f; /* bits [4:0] valid */
-	xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
-	dev_dbg(dev, "%s: xfercap = %d\n", __func__, xfercap);
-
-#ifdef  CONFIG_I7300_IDLE_IOAT_CHANNEL
-	if (i7300_idle_platform_probe(NULL, NULL, 1) == 0)
-		dma->chancnt--;
-#endif
-	for (i = 0; i < dma->chancnt; i++) {
-		ioat = devm_kzalloc(dev, sizeof(*ioat), GFP_KERNEL);
-		if (!ioat)
-			break;
+	ioat_chan->dmacount += ioat_ring_pending(ioat_chan);
+	ioat_chan->issued = ioat_chan->head;
+	writew(ioat_chan->dmacount,
+	       ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
+	dev_dbg(to_dev(ioat_chan),
+		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
+		__func__, ioat_chan->head, ioat_chan->tail,
+		ioat_chan->issued, ioat_chan->dmacount);
+}
+
+void ioat_issue_pending(struct dma_chan *c)
+{
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
 
-		ioat_init_channel(device, &ioat->base, i);
-		ioat->xfercap = xfercap;
-		spin_lock_init(&ioat->desc_lock);
-		INIT_LIST_HEAD(&ioat->free_desc);
-		INIT_LIST_HEAD(&ioat->used_desc);
+	if (ioat_ring_pending(ioat_chan)) {
+		spin_lock_bh(&ioat_chan->prep_lock);
+		__ioat_issue_pending(ioat_chan);
+		spin_unlock_bh(&ioat_chan->prep_lock);
 	}
-	dma->chancnt = i;
-	return i;
 }
 
 /**
- * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
- *                                 descriptors to hw
- * @chan: DMA channel handle
+ * ioat_update_pending - log pending descriptors
+ * @ioat: ioat+ channel
+ *
+ * Check if the number of unsubmitted descriptors has exceeded the
+ * watermark.  Called with prep_lock held
  */
-static inline void
-__ioat1_dma_memcpy_issue_pending(struct ioat_dma_chan *ioat)
+static void ioat_update_pending(struct ioatdma_chan *ioat_chan)
 {
-	void __iomem *reg_base = ioat->base.reg_base;
-
-	dev_dbg(to_dev(&ioat->base), "%s: pending: %d\n",
-		__func__, ioat->pending);
-	ioat->pending = 0;
-	writeb(IOAT_CHANCMD_APPEND, reg_base + IOAT1_CHANCMD_OFFSET);
+	if (ioat_ring_pending(ioat_chan) > ioat_pending_level)
+		__ioat_issue_pending(ioat_chan);
 }
 
-static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
+static void __ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
 {
-	struct ioat_dma_chan *ioat = to_ioat_chan(chan);
+	struct ioat_ring_ent *desc;
+	struct ioat_dma_descriptor *hw;
 
-	if (ioat->pending > 0) {
-		spin_lock_bh(&ioat->desc_lock);
-		__ioat1_dma_memcpy_issue_pending(ioat);
-		spin_unlock_bh(&ioat->desc_lock);
+	if (ioat_ring_space(ioat_chan) < 1) {
+		dev_err(to_dev(ioat_chan),
+			"Unable to start null desc - ring full\n");
+		return;
 	}
+
+	dev_dbg(to_dev(ioat_chan),
+		"%s: head: %#x tail: %#x issued: %#x\n",
+		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
+	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
+
+	hw = desc->hw;
+	hw->ctl = 0;
+	hw->ctl_f.null = 1;
+	hw->ctl_f.int_en = 1;
+	hw->ctl_f.compl_write = 1;
+	/* set size to non-zero value (channel returns error when size is 0) */
+	hw->size = NULL_DESC_BUFFER_SIZE;
+	hw->src_addr = 0;
+	hw->dst_addr = 0;
+	async_tx_ack(&desc->txd);
+	ioat_set_chainaddr(ioat_chan, desc->txd.phys);
+	dump_desc_dbg(ioat_chan, desc);
+	/* make sure descriptors are written before we submit */
+	wmb();
+	ioat_chan->head += 1;
+	__ioat_issue_pending(ioat_chan);
 }
 
-/**
- * ioat1_reset_channel - restart a channel
- * @ioat: IOAT DMA channel handle
- */
-static void ioat1_reset_channel(struct ioat_dma_chan *ioat)
+void ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
 {
-	struct ioat_chan_common *chan = &ioat->base;
-	void __iomem *reg_base = chan->reg_base;
-	u32 chansts, chanerr;
-
-	dev_warn(to_dev(chan), "reset\n");
-	chanerr = readl(reg_base + IOAT_CHANERR_OFFSET);
-	chansts = *chan->completion & IOAT_CHANSTS_STATUS;
-	if (chanerr) {
-		dev_err(to_dev(chan),
-			"chan%d, CHANSTS = 0x%08x CHANERR = 0x%04x, clearing\n",
-			chan_num(chan), chansts, chanerr);
-		writel(chanerr, reg_base + IOAT_CHANERR_OFFSET);
+	spin_lock_bh(&ioat_chan->prep_lock);
+	if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		__ioat_start_null_desc(ioat_chan);
+	spin_unlock_bh(&ioat_chan->prep_lock);
+}
+
+static void __ioat_restart_chan(struct ioatdma_chan *ioat_chan)
+{
+	/* set the tail to be re-issued */
+	ioat_chan->issued = ioat_chan->tail;
+	ioat_chan->dmacount = 0;
+	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+	dev_dbg(to_dev(ioat_chan),
+		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
+		__func__, ioat_chan->head, ioat_chan->tail,
+		ioat_chan->issued, ioat_chan->dmacount);
+
+	if (ioat_ring_pending(ioat_chan)) {
+		struct ioat_ring_ent *desc;
+
+		desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
+		ioat_set_chainaddr(ioat_chan, desc->txd.phys);
+		__ioat_issue_pending(ioat_chan);
+	} else
+		__ioat_start_null_desc(ioat_chan);
+}
+
+static int ioat_quiesce(struct ioatdma_chan *ioat_chan, unsigned long tmo)
+{
+	unsigned long end = jiffies + tmo;
+	int err = 0;
+	u32 status;
+
+	status = ioat_chansts(ioat_chan);
+	if (is_ioat_active(status) || is_ioat_idle(status))
+		ioat_suspend(ioat_chan);
+	while (is_ioat_active(status) || is_ioat_idle(status)) {
+		if (tmo && time_after(jiffies, end)) {
+			err = -ETIMEDOUT;
+			break;
+		}
+		status = ioat_chansts(ioat_chan);
+		cpu_relax();
 	}
 
-	/*
-	 * whack it upside the head with a reset
-	 * and wait for things to settle out.
-	 * force the pending count to a really big negative
-	 * to make sure no one forces an issue_pending
-	 * while we're waiting.
-	 */
+	return err;
+}
 
-	ioat->pending = INT_MIN;
-	writeb(IOAT_CHANCMD_RESET,
-	       reg_base + IOAT_CHANCMD_OFFSET(chan->device->version));
-	set_bit(IOAT_RESET_PENDING, &chan->state);
-	mod_timer(&chan->timer, jiffies + RESET_DELAY);
+static int ioat_reset_sync(struct ioatdma_chan *ioat_chan, unsigned long tmo)
+{
+	unsigned long end = jiffies + tmo;
+	int err = 0;
+
+	ioat_reset(ioat_chan);
+	while (ioat_reset_pending(ioat_chan)) {
+		if (end && time_after(jiffies, end)) {
+			err = -ETIMEDOUT;
+			break;
+		}
+		cpu_relax();
+	}
+
+	return err;
 }
 
-static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
+static dma_cookie_t ioat_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
+	__releases(&ioat_chan->prep_lock)
 {
 	struct dma_chan *c = tx->chan;
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
-	struct ioat_desc_sw *desc = tx_to_ioat_desc(tx);
-	struct ioat_chan_common *chan = &ioat->base;
-	struct ioat_desc_sw *first;
-	struct ioat_desc_sw *chain_tail;
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
 	dma_cookie_t cookie;
 
-	spin_lock_bh(&ioat->desc_lock);
-	/* cookie incr and addition to used_list must be atomic */
 	cookie = dma_cookie_assign(tx);
-	dev_dbg(to_dev(&ioat->base), "%s: cookie: %d\n", __func__, cookie);
+	dev_dbg(to_dev(ioat_chan), "%s: cookie: %d\n", __func__, cookie);
+
+	if (!test_and_set_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
+		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
 
-	/* write address into NextDescriptor field of last desc in chain */
-	first = to_ioat_desc(desc->tx_list.next);
-	chain_tail = to_ioat_desc(ioat->used_desc.prev);
-	/* make descriptor updates globally visible before chaining */
+	/* make descriptor updates visible before advancing ioat->head,
+	 * this is purposefully not smp_wmb() since we are also
+	 * publishing the descriptor updates to a dma device
+	 */
 	wmb();
-	chain_tail->hw->next = first->txd.phys;
-	list_splice_tail_init(&desc->tx_list, &ioat->used_desc);
-	dump_desc_dbg(ioat, chain_tail);
-	dump_desc_dbg(ioat, first);
 
-	if (!test_and_set_bit(IOAT_COMPLETION_PENDING, &chan->state))
-		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+	ioat_chan->head += ioat_chan->produce;
 
-	ioat->active += desc->hw->tx_cnt;
-	ioat->pending += desc->hw->tx_cnt;
-	if (ioat->pending >= ioat_pending_level)
-		__ioat1_dma_memcpy_issue_pending(ioat);
-	spin_unlock_bh(&ioat->desc_lock);
+	ioat_update_pending(ioat_chan);
+	spin_unlock_bh(&ioat_chan->prep_lock);
 
 	return cookie;
 }
 
-/**
- * ioat_dma_alloc_descriptor - allocate and return a sw and hw descriptor pair
- * @ioat: the channel supplying the memory pool for the descriptors
- * @flags: allocation flags
- */
-static struct ioat_desc_sw *
-ioat_dma_alloc_descriptor(struct ioat_dma_chan *ioat, gfp_t flags)
+static struct ioat_ring_ent *
+ioat_alloc_ring_ent(struct dma_chan *chan, gfp_t flags)
 {
-	struct ioat_dma_descriptor *desc;
-	struct ioat_desc_sw *desc_sw;
-	struct ioatdma_device *ioatdma_device;
+	struct ioat_dma_descriptor *hw;
+	struct ioat_ring_ent *desc;
+	struct ioatdma_device *ioat_dma;
 	dma_addr_t phys;
 
-	ioatdma_device = ioat->base.device;
-	desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys);
-	if (unlikely(!desc))
+	ioat_dma = to_ioatdma_device(chan->device);
+	hw = pci_pool_alloc(ioat_dma->dma_pool, flags, &phys);
+	if (!hw)
 		return NULL;
+	memset(hw, 0, sizeof(*hw));
 
-	desc_sw = kzalloc(sizeof(*desc_sw), flags);
-	if (unlikely(!desc_sw)) {
-		pci_pool_free(ioatdma_device->dma_pool, desc, phys);
+	desc = kmem_cache_zalloc(ioat_cache, flags);
+	if (!desc) {
+		pci_pool_free(ioat_dma->dma_pool, hw, phys);
 		return NULL;
 	}
 
-	memset(desc, 0, sizeof(*desc));
+	dma_async_tx_descriptor_init(&desc->txd, chan);
+	desc->txd.tx_submit = ioat_tx_submit_unlock;
+	desc->hw = hw;
+	desc->txd.phys = phys;
+	return desc;
+}
 
-	INIT_LIST_HEAD(&desc_sw->tx_list);
-	dma_async_tx_descriptor_init(&desc_sw->txd, &ioat->base.common);
-	desc_sw->txd.tx_submit = ioat1_tx_submit;
-	desc_sw->hw = desc;
-	desc_sw->txd.phys = phys;
-	set_desc_id(desc_sw, -1);
+void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
+{
+	struct ioatdma_device *ioat_dma;
 
-	return desc_sw;
+	ioat_dma = to_ioatdma_device(chan->device);
+	pci_pool_free(ioat_dma->dma_pool, desc->hw, desc->txd.phys);
+	kmem_cache_free(ioat_cache, desc);
 }
 
-static int ioat_initial_desc_count = 256;
-module_param(ioat_initial_desc_count, int, 0644);
-MODULE_PARM_DESC(ioat_initial_desc_count,
-		 "ioat1: initial descriptors per channel (default: 256)");
-/**
- * ioat1_dma_alloc_chan_resources - returns the number of allocated descriptors
- * @chan: the channel to be filled out
- */
-static int ioat1_dma_alloc_chan_resources(struct dma_chan *c)
+struct ioat_ring_ent **
+ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
 {
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
-	struct ioat_chan_common *chan = &ioat->base;
-	struct ioat_desc_sw *desc;
-	u32 chanerr;
+	struct ioat_ring_ent **ring;
+	int descs = 1 << order;
 	int i;
-	LIST_HEAD(tmp_list);
-
-	/* have we already been set up? */
-	if (!list_empty(&ioat->free_desc))
-		return ioat->desccount;
 
-	/* Setup register to interrupt and write completion status on error */
-	writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
+	if (order > ioat_get_max_alloc_order())
+		return NULL;
 
-	chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
-	if (chanerr) {
-		dev_err(to_dev(chan), "CHANERR = %x, clearing\n", chanerr);
-		writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET);
+	/* allocate the array to hold the software ring */
+	ring = kcalloc(descs, sizeof(*ring), flags);
+	if (!ring)
+		return NULL;
+	for (i = 0; i < descs; i++) {
+		ring[i] = ioat_alloc_ring_ent(c, flags);
+		if (!ring[i]) {
+			while (i--)
+				ioat_free_ring_ent(ring[i], c);
+			kfree(ring);
+			return NULL;
+		}
+		set_desc_id(ring[i], i);
 	}
 
-	/* Allocate descriptors */
-	for (i = 0; i < ioat_initial_desc_count; i++) {
-		desc = ioat_dma_alloc_descriptor(ioat, GFP_KERNEL);
-		if (!desc) {
-			dev_err(to_dev(chan), "Only %d initial descriptors\n", i);
-			break;
-		}
-		set_desc_id(desc, i);
-		list_add_tail(&desc->node, &tmp_list);
+	/* link descs */
+	for (i = 0; i < descs-1; i++) {
+		struct ioat_ring_ent *next = ring[i+1];
+		struct ioat_dma_descriptor *hw = ring[i]->hw;
+
+		hw->next = next->txd.phys;
 	}
-	spin_lock_bh(&ioat->desc_lock);
-	ioat->desccount = i;
-	list_splice(&tmp_list, &ioat->free_desc);
-	spin_unlock_bh(&ioat->desc_lock);
-
-	/* allocate a completion writeback area */
-	/* doing 2 32bit writes to mmio since 1 64b write doesn't work */
-	chan->completion = pci_pool_alloc(chan->device->completion_pool,
-					  GFP_KERNEL, &chan->completion_dma);
-	memset(chan->completion, 0, sizeof(*chan->completion));
-	writel(((u64) chan->completion_dma) & 0x00000000FFFFFFFF,
-	       chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
-	writel(((u64) chan->completion_dma) >> 32,
-	       chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
-
-	set_bit(IOAT_RUN, &chan->state);
-	ioat1_dma_start_null_desc(ioat);  /* give chain to dma device */
-	dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
-		__func__, ioat->desccount);
-	return ioat->desccount;
+	ring[i]->hw->next = ring[0]->txd.phys;
+
+	return ring;
 }
 
-void ioat_stop(struct ioat_chan_common *chan)
+static bool reshape_ring(struct ioatdma_chan *ioat_chan, int order)
 {
-	struct ioatdma_device *device = chan->device;
-	struct pci_dev *pdev = device->pdev;
-	int chan_id = chan_num(chan);
-	struct msix_entry *msix;
+	/* reshape differs from normal ring allocation in that we want
+	 * to allocate a new software ring while only
+	 * extending/truncating the hardware ring
+	 */
+	struct dma_chan *c = &ioat_chan->dma_chan;
+	const u32 curr_size = ioat_ring_size(ioat_chan);
+	const u16 active = ioat_ring_active(ioat_chan);
+	const u32 new_size = 1 << order;
+	struct ioat_ring_ent **ring;
+	u32 i;
+
+	if (order > ioat_get_max_alloc_order())
+		return false;
 
-	/* 1/ stop irq from firing tasklets
-	 * 2/ stop the tasklet from re-arming irqs
+	/* double check that we have at least 1 free descriptor */
+	if (active == curr_size)
+		return false;
+
+	/* when shrinking, verify that we can hold the current active
+	 * set in the new ring
 	 */
-	clear_bit(IOAT_RUN, &chan->state);
+	if (active >= new_size)
+		return false;
 
-	/* flush inflight interrupts */
-	switch (device->irq_mode) {
-	case IOAT_MSIX:
-		msix = &device->msix_entries[chan_id];
-		synchronize_irq(msix->vector);
-		break;
-	case IOAT_MSI:
-	case IOAT_INTX:
-		synchronize_irq(pdev->irq);
-		break;
-	default:
-		break;
-	}
+	/* allocate the array to hold the software ring */
+	ring = kcalloc(new_size, sizeof(*ring), GFP_NOWAIT);
+	if (!ring)
+		return false;
 
-	/* flush inflight timers */
-	del_timer_sync(&chan->timer);
+	/* allocate/trim descriptors as needed */
+	if (new_size > curr_size) {
+		/* copy current descriptors to the new ring */
+		for (i = 0; i < curr_size; i++) {
+			u16 curr_idx = (ioat_chan->tail+i) & (curr_size-1);
+			u16 new_idx = (ioat_chan->tail+i) & (new_size-1);
 
-	/* flush inflight tasklet runs */
-	tasklet_kill(&chan->cleanup_task);
+			ring[new_idx] = ioat_chan->ring[curr_idx];
+			set_desc_id(ring[new_idx], new_idx);
+		}
 
-	/* final cleanup now that everything is quiesced and can't re-arm */
-	device->cleanup_fn((unsigned long) &chan->common);
-}
+		/* add new descriptors to the ring */
+		for (i = curr_size; i < new_size; i++) {
+			u16 new_idx = (ioat_chan->tail+i) & (new_size-1);
 
-/**
- * ioat1_dma_free_chan_resources - release all the descriptors
- * @chan: the channel to be cleaned
- */
-static void ioat1_dma_free_chan_resources(struct dma_chan *c)
-{
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
-	struct ioat_chan_common *chan = &ioat->base;
-	struct ioatdma_device *ioatdma_device = chan->device;
-	struct ioat_desc_sw *desc, *_desc;
-	int in_use_descs = 0;
-
-	/* Before freeing channel resources first check
-	 * if they have been previously allocated for this channel.
-	 */
-	if (ioat->desccount == 0)
-		return;
+			ring[new_idx] = ioat_alloc_ring_ent(c, GFP_NOWAIT);
+			if (!ring[new_idx]) {
+				while (i--) {
+					u16 new_idx = (ioat_chan->tail+i) &
+						       (new_size-1);
+
+					ioat_free_ring_ent(ring[new_idx], c);
+				}
+				kfree(ring);
+				return false;
+			}
+			set_desc_id(ring[new_idx], new_idx);
+		}
 
-	ioat_stop(chan);
+		/* hw link new descriptors */
+		for (i = curr_size-1; i < new_size; i++) {
+			u16 new_idx = (ioat_chan->tail+i) & (new_size-1);
+			struct ioat_ring_ent *next =
+				ring[(new_idx+1) & (new_size-1)];
+			struct ioat_dma_descriptor *hw = ring[new_idx]->hw;
 
-	/* Delay 100ms after reset to allow internal DMA logic to quiesce
-	 * before removing DMA descriptor resources.
-	 */
-	writeb(IOAT_CHANCMD_RESET,
-	       chan->reg_base + IOAT_CHANCMD_OFFSET(chan->device->version));
-	mdelay(100);
-
-	spin_lock_bh(&ioat->desc_lock);
-	list_for_each_entry_safe(desc, _desc, &ioat->used_desc, node) {
-		dev_dbg(to_dev(chan), "%s: freeing %d from used list\n",
-			__func__, desc_id(desc));
-		dump_desc_dbg(ioat, desc);
-		in_use_descs++;
-		list_del(&desc->node);
-		pci_pool_free(ioatdma_device->dma_pool, desc->hw,
-			      desc->txd.phys);
-		kfree(desc);
-	}
-	list_for_each_entry_safe(desc, _desc,
-				 &ioat->free_desc, node) {
-		list_del(&desc->node);
-		pci_pool_free(ioatdma_device->dma_pool, desc->hw,
-			      desc->txd.phys);
-		kfree(desc);
+			hw->next = next->txd.phys;
+		}
+	} else {
+		struct ioat_dma_descriptor *hw;
+		struct ioat_ring_ent *next;
+
+		/* copy current descriptors to the new ring, dropping the
+		 * removed descriptors
+		 */
+		for (i = 0; i < new_size; i++) {
+			u16 curr_idx = (ioat_chan->tail+i) & (curr_size-1);
+			u16 new_idx = (ioat_chan->tail+i) & (new_size-1);
+
+			ring[new_idx] = ioat_chan->ring[curr_idx];
+			set_desc_id(ring[new_idx], new_idx);
+		}
+
+		/* free deleted descriptors */
+		for (i = new_size; i < curr_size; i++) {
+			struct ioat_ring_ent *ent;
+
+			ent = ioat_get_ring_ent(ioat_chan, ioat_chan->tail+i);
+			ioat_free_ring_ent(ent, c);
+		}
+
+		/* fix up hardware ring */
+		hw = ring[(ioat_chan->tail+new_size-1) & (new_size-1)]->hw;
+		next = ring[(ioat_chan->tail+new_size) & (new_size-1)];
+		hw->next = next->txd.phys;
 	}
-	spin_unlock_bh(&ioat->desc_lock);
 
-	pci_pool_free(ioatdma_device->completion_pool,
-		      chan->completion,
-		      chan->completion_dma);
+	dev_dbg(to_dev(ioat_chan), "%s: allocated %d descriptors\n",
+		__func__, new_size);
 
-	/* one is ok since we left it on there on purpose */
-	if (in_use_descs > 1)
-		dev_err(to_dev(chan), "Freeing %d in use descriptors!\n",
-			in_use_descs - 1);
+	kfree(ioat_chan->ring);
+	ioat_chan->ring = ring;
+	ioat_chan->alloc_order = order;
 
-	chan->last_completion = 0;
-	chan->completion_dma = 0;
-	ioat->pending = 0;
-	ioat->desccount = 0;
+	return true;
 }
 
 /**
- * ioat1_dma_get_next_descriptor - return the next available descriptor
- * @ioat: IOAT DMA channel handle
- *
- * Gets the next descriptor from the chain, and must be called with the
- * channel's desc_lock held.  Allocates more descriptors if the channel
- * has run out.
+ * ioat_check_space_lock - verify space and grab ring producer lock
+ * @ioat: ioat,3 channel (ring) to operate on
+ * @num_descs: allocation length
  */
-static struct ioat_desc_sw *
-ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat)
+int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
+	__acquires(&ioat_chan->prep_lock)
 {
-	struct ioat_desc_sw *new;
+	bool retry;
 
-	if (!list_empty(&ioat->free_desc)) {
-		new = to_ioat_desc(ioat->free_desc.next);
-		list_del(&new->node);
-	} else {
-		/* try to get another desc */
-		new = ioat_dma_alloc_descriptor(ioat, GFP_ATOMIC);
-		if (!new) {
-			dev_err(to_dev(&ioat->base), "alloc failed\n");
-			return NULL;
-		}
+ retry:
+	spin_lock_bh(&ioat_chan->prep_lock);
+	/* never allow the last descriptor to be consumed, we need at
+	 * least one free at all times to allow for on-the-fly ring
+	 * resizing.
+	 */
+	if (likely(ioat_ring_space(ioat_chan) > num_descs)) {
+		dev_dbg(to_dev(ioat_chan), "%s: num_descs: %d (%x:%x:%x)\n",
+			__func__, num_descs, ioat_chan->head,
+			ioat_chan->tail, ioat_chan->issued);
+		ioat_chan->produce = num_descs;
+		return 0;  /* with ioat->prep_lock held */
+	}
+	retry = test_and_set_bit(IOAT_RESHAPE_PENDING, &ioat_chan->state);
+	spin_unlock_bh(&ioat_chan->prep_lock);
+
+	/* is another cpu already trying to expand the ring? */
+	if (retry)
+		goto retry;
+
+	spin_lock_bh(&ioat_chan->cleanup_lock);
+	spin_lock_bh(&ioat_chan->prep_lock);
+	retry = reshape_ring(ioat_chan, ioat_chan->alloc_order + 1);
+	clear_bit(IOAT_RESHAPE_PENDING, &ioat_chan->state);
+	spin_unlock_bh(&ioat_chan->prep_lock);
+	spin_unlock_bh(&ioat_chan->cleanup_lock);
+
+	/* if we were able to expand the ring retry the allocation */
+	if (retry)
+		goto retry;
+
+	dev_dbg_ratelimited(to_dev(ioat_chan),
+			    "%s: ring full! num_descs: %d (%x:%x:%x)\n",
+			    __func__, num_descs, ioat_chan->head,
+			    ioat_chan->tail, ioat_chan->issued);
+
+	/* progress reclaim in the allocation failure case we may be
+	 * called under bh_disabled so we need to trigger the timer
+	 * event directly
+	 */
+	if (time_is_before_jiffies(ioat_chan->timer.expires)
+	    && timer_pending(&ioat_chan->timer)) {
+		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+		ioat_timer_event((unsigned long)ioat_chan);
 	}
-	dev_dbg(to_dev(&ioat->base), "%s: allocated: %d\n",
-		__func__, desc_id(new));
-	prefetch(new->hw);
-	return new;
+
+	return -ENOMEM;
 }
 
-static struct dma_async_tx_descriptor *
-ioat1_dma_prep_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
-		      dma_addr_t dma_src, size_t len, unsigned long flags)
+static bool desc_has_ext(struct ioat_ring_ent *desc)
 {
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
-	struct ioat_desc_sw *desc;
-	size_t copy;
-	LIST_HEAD(chain);
-	dma_addr_t src = dma_src;
-	dma_addr_t dest = dma_dest;
-	size_t total_len = len;
-	struct ioat_dma_descriptor *hw = NULL;
-	int tx_cnt = 0;
-
-	spin_lock_bh(&ioat->desc_lock);
-	desc = ioat1_dma_get_next_descriptor(ioat);
-	do {
-		if (!desc)
-			break;
-
-		tx_cnt++;
-		copy = min_t(size_t, len, ioat->xfercap);
+	struct ioat_dma_descriptor *hw = desc->hw;
 
-		hw = desc->hw;
-		hw->size = copy;
-		hw->ctl = 0;
-		hw->src_addr = src;
-		hw->dst_addr = dest;
+	if (hw->ctl_f.op == IOAT_OP_XOR ||
+	    hw->ctl_f.op == IOAT_OP_XOR_VAL) {
+		struct ioat_xor_descriptor *xor = desc->xor;
 
-		list_add_tail(&desc->node, &chain);
+		if (src_cnt_to_sw(xor->ctl_f.src_cnt) > 5)
+			return true;
+	} else if (hw->ctl_f.op == IOAT_OP_PQ ||
+		   hw->ctl_f.op == IOAT_OP_PQ_VAL) {
+		struct ioat_pq_descriptor *pq = desc->pq;
 
-		len -= copy;
-		dest += copy;
-		src += copy;
-		if (len) {
-			struct ioat_desc_sw *next;
-
-			async_tx_ack(&desc->txd);
-			next = ioat1_dma_get_next_descriptor(ioat);
-			hw->next = next ? next->txd.phys : 0;
-			dump_desc_dbg(ioat, desc);
-			desc = next;
-		} else
-			hw->next = 0;
-	} while (len);
-
-	if (!desc) {
-		struct ioat_chan_common *chan = &ioat->base;
-
-		dev_err(to_dev(chan),
-			"chan%d - get_next_desc failed\n", chan_num(chan));
-		list_splice(&chain, &ioat->free_desc);
-		spin_unlock_bh(&ioat->desc_lock);
-		return NULL;
+		if (src_cnt_to_sw(pq->ctl_f.src_cnt) > 3)
+			return true;
 	}
-	spin_unlock_bh(&ioat->desc_lock);
 
-	desc->txd.flags = flags;
-	desc->len = total_len;
-	list_splice(&chain, &desc->tx_list);
-	hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
-	hw->ctl_f.compl_write = 1;
-	hw->tx_cnt = tx_cnt;
-	dump_desc_dbg(ioat, desc);
-
-	return &desc->txd;
+	return false;
 }
 
-static void ioat1_cleanup_event(unsigned long data)
+static void
+ioat_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
 {
-	struct ioat_dma_chan *ioat = to_ioat_chan((void *) data);
-	struct ioat_chan_common *chan = &ioat->base;
-
-	ioat1_cleanup(ioat);
-	if (!test_bit(IOAT_RUN, &chan->state))
+	if (!sed)
 		return;
-	writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
+
+	dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
+	kmem_cache_free(ioat_sed_cache, sed);
 }
 
-dma_addr_t ioat_get_current_completion(struct ioat_chan_common *chan)
+static u64 ioat_get_current_completion(struct ioatdma_chan *ioat_chan)
 {
-	dma_addr_t phys_complete;
+	u64 phys_complete;
 	u64 completion;
 
-	completion = *chan->completion;
+	completion = *ioat_chan->completion;
 	phys_complete = ioat_chansts_to_addr(completion);
 
-	dev_dbg(to_dev(chan), "%s: phys_complete: %#llx\n", __func__,
+	dev_dbg(to_dev(ioat_chan), "%s: phys_complete: %#llx\n", __func__,
 		(unsigned long long) phys_complete);
 
-	if (is_ioat_halted(completion)) {
-		u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
-		dev_err(to_dev(chan), "Channel halted, chanerr = %x\n",
-			chanerr);
-
-		/* TODO do something to salvage the situation */
-	}
-
 	return phys_complete;
 }
 
-bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
-			   dma_addr_t *phys_complete)
+static bool ioat_cleanup_preamble(struct ioatdma_chan *ioat_chan,
+				   u64 *phys_complete)
 {
-	*phys_complete = ioat_get_current_completion(chan);
-	if (*phys_complete == chan->last_completion)
+	*phys_complete = ioat_get_current_completion(ioat_chan);
+	if (*phys_complete == ioat_chan->last_completion)
 		return false;
-	clear_bit(IOAT_COMPLETION_ACK, &chan->state);
-	mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+	clear_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
+	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
 
 	return true;
 }
 
-static void __cleanup(struct ioat_dma_chan *ioat, dma_addr_t phys_complete)
+static void
+desc_get_errstat(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc)
 {
-	struct ioat_chan_common *chan = &ioat->base;
-	struct list_head *_desc, *n;
-	struct dma_async_tx_descriptor *tx;
+	struct ioat_dma_descriptor *hw = desc->hw;
 
-	dev_dbg(to_dev(chan), "%s: phys_complete: %llx\n",
-		 __func__, (unsigned long long) phys_complete);
-	list_for_each_safe(_desc, n, &ioat->used_desc) {
-		struct ioat_desc_sw *desc;
+	switch (hw->ctl_f.op) {
+	case IOAT_OP_PQ_VAL:
+	case IOAT_OP_PQ_VAL_16S:
+	{
+		struct ioat_pq_descriptor *pq = desc->pq;
 
-		prefetch(n);
-		desc = list_entry(_desc, typeof(*desc), node);
-		tx = &desc->txd;
-		/*
-		 * Incoming DMA requests may use multiple descriptors,
-		 * due to exceeding xfercap, perhaps. If so, only the
-		 * last one will have a cookie, and require unmapping.
-		 */
-		dump_desc_dbg(ioat, desc);
-		if (tx->cookie) {
-			dma_cookie_complete(tx);
-			dma_descriptor_unmap(tx);
-			ioat->active -= desc->hw->tx_cnt;
-			if (tx->callback) {
-				tx->callback(tx->callback_param);
-				tx->callback = NULL;
-			}
-		}
+		/* check if there's error written */
+		if (!pq->dwbes_f.wbes)
+			return;
 
-		if (tx->phys != phys_complete) {
-			/*
-			 * a completed entry, but not the last, so clean
-			 * up if the client is done with the descriptor
-			 */
-			if (async_tx_test_ack(tx))
-				list_move_tail(&desc->node, &ioat->free_desc);
-		} else {
-			/*
-			 * last used desc. Do not remove, so we can
-			 * append from it.
-			 */
-
-			/* if nothing else is pending, cancel the
-			 * completion timeout
-			 */
-			if (n == &ioat->used_desc) {
-				dev_dbg(to_dev(chan),
-					"%s cancel completion timeout\n",
-					__func__);
-				clear_bit(IOAT_COMPLETION_PENDING, &chan->state);
-			}
+		/* need to set a chanerr var for checking to clear later */
 
-			/* TODO check status bits? */
-			break;
-		}
-	}
+		if (pq->dwbes_f.p_val_err)
+			*desc->result |= SUM_CHECK_P_RESULT;
+
+		if (pq->dwbes_f.q_val_err)
+			*desc->result |= SUM_CHECK_Q_RESULT;
 
-	chan->last_completion = phys_complete;
+		return;
+	}
+	default:
+		return;
+	}
 }
 
 /**
- * ioat1_cleanup - cleanup up finished descriptors
- * @chan: ioat channel to be cleaned up
- *
- * To prevent lock contention we defer cleanup when the locks are
- * contended with a terminal timeout that forces cleanup and catches
- * completion notification errors.
+ * __cleanup - reclaim used descriptors
+ * @ioat: channel (ring) to clean
  */
-static void ioat1_cleanup(struct ioat_dma_chan *ioat)
+static void __cleanup(struct ioatdma_chan *ioat_chan, dma_addr_t phys_complete)
 {
-	struct ioat_chan_common *chan = &ioat->base;
-	dma_addr_t phys_complete;
-
-	prefetch(chan->completion);
-
-	if (!spin_trylock_bh(&chan->cleanup_lock))
-		return;
+	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
+	struct ioat_ring_ent *desc;
+	bool seen_current = false;
+	int idx = ioat_chan->tail, i;
+	u16 active;
 
-	if (!ioat_cleanup_preamble(chan, &phys_complete)) {
-		spin_unlock_bh(&chan->cleanup_lock);
-		return;
-	}
+	dev_dbg(to_dev(ioat_chan), "%s: head: %#x tail: %#x issued: %#x\n",
+		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
 
-	if (!spin_trylock_bh(&ioat->desc_lock)) {
-		spin_unlock_bh(&chan->cleanup_lock);
+	/*
+	 * At restart of the channel, the completion address and the
+	 * channel status will be 0 due to starting a new chain. Since
+	 * it's new chain and the first descriptor "fails", there is
+	 * nothing to clean up. We do not want to reap the entire submitted
+	 * chain due to this 0 address value and then BUG.
+	 */
+	if (!phys_complete)
 		return;
-	}
 
-	__cleanup(ioat, phys_complete);
+	active = ioat_ring_active(ioat_chan);
+	for (i = 0; i < active && !seen_current; i++) {
+		struct dma_async_tx_descriptor *tx;
 
-	spin_unlock_bh(&ioat->desc_lock);
-	spin_unlock_bh(&chan->cleanup_lock);
-}
-
-static void ioat1_timer_event(unsigned long data)
-{
-	struct ioat_dma_chan *ioat = to_ioat_chan((void *) data);
-	struct ioat_chan_common *chan = &ioat->base;
+		smp_read_barrier_depends();
+		prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
+		desc = ioat_get_ring_ent(ioat_chan, idx + i);
+		dump_desc_dbg(ioat_chan, desc);
 
-	dev_dbg(to_dev(chan), "%s: state: %lx\n", __func__, chan->state);
+		/* set err stat if we are using dwbes */
+		if (ioat_dma->cap & IOAT_CAP_DWBES)
+			desc_get_errstat(ioat_chan, desc);
 
-	spin_lock_bh(&chan->cleanup_lock);
-	if (test_and_clear_bit(IOAT_RESET_PENDING, &chan->state)) {
-		struct ioat_desc_sw *desc;
-
-		spin_lock_bh(&ioat->desc_lock);
+		tx = &desc->txd;
+		if (tx->cookie) {
+			dma_cookie_complete(tx);
+			dma_descriptor_unmap(tx);
+			if (tx->callback) {
+				tx->callback(tx->callback_param);
+				tx->callback = NULL;
+			}
+		}
 
-		/* restart active descriptors */
-		desc = to_ioat_desc(ioat->used_desc.prev);
-		ioat_set_chainaddr(ioat, desc->txd.phys);
-		ioat_start(chan);
+		if (tx->phys == phys_complete)
+			seen_current = true;
 
-		ioat->pending = 0;
-		set_bit(IOAT_COMPLETION_PENDING, &chan->state);
-		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
-		spin_unlock_bh(&ioat->desc_lock);
-	} else if (test_bit(IOAT_COMPLETION_PENDING, &chan->state)) {
-		dma_addr_t phys_complete;
+		/* skip extended descriptors */
+		if (desc_has_ext(desc)) {
+			BUG_ON(i + 1 >= active);
+			i++;
+		}
 
-		spin_lock_bh(&ioat->desc_lock);
-		/* if we haven't made progress and we have already
-		 * acknowledged a pending completion once, then be more
-		 * forceful with a restart
-		 */
-		if (ioat_cleanup_preamble(chan, &phys_complete))
-			__cleanup(ioat, phys_complete);
-		else if (test_bit(IOAT_COMPLETION_ACK, &chan->state))
-			ioat1_reset_channel(ioat);
-		else {
-			u64 status = ioat_chansts(chan);
-
-			/* manually update the last completion address */
-			if (ioat_chansts_to_addr(status) != 0)
-				*chan->completion = status;
-
-			set_bit(IOAT_COMPLETION_ACK, &chan->state);
-			mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+		/* cleanup super extended descriptors */
+		if (desc->sed) {
+			ioat_free_sed(ioat_dma, desc->sed);
+			desc->sed = NULL;
 		}
-		spin_unlock_bh(&ioat->desc_lock);
 	}
-	spin_unlock_bh(&chan->cleanup_lock);
-}
-
-enum dma_status
-ioat_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie,
-		   struct dma_tx_state *txstate)
-{
-	struct ioat_chan_common *chan = to_chan_common(c);
-	struct ioatdma_device *device = chan->device;
-	enum dma_status ret;
 
-	ret = dma_cookie_status(c, cookie, txstate);
-	if (ret == DMA_COMPLETE)
-		return ret;
+	/* finish all descriptor reads before incrementing tail */
+	smp_mb();
+	ioat_chan->tail = idx + i;
+	/* no active descs have written a completion? */
+	BUG_ON(active && !seen_current);
+	ioat_chan->last_completion = phys_complete;
 
-	device->cleanup_fn((unsigned long) c);
+	if (active - i == 0) {
+		dev_dbg(to_dev(ioat_chan), "%s: cancel completion timeout\n",
+			__func__);
+		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
+	}
 
-	return dma_cookie_status(c, cookie, txstate);
+	/* 5 microsecond delay per pending descriptor */
+	writew(min((5 * (active - i)), IOAT_INTRDELAY_MASK),
+	       ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET);
 }
 
-static void ioat1_dma_start_null_desc(struct ioat_dma_chan *ioat)
+static void ioat_cleanup(struct ioatdma_chan *ioat_chan)
 {
-	struct ioat_chan_common *chan = &ioat->base;
-	struct ioat_desc_sw *desc;
-	struct ioat_dma_descriptor *hw;
+	u64 phys_complete;
 
-	spin_lock_bh(&ioat->desc_lock);
+	spin_lock_bh(&ioat_chan->cleanup_lock);
 
-	desc = ioat1_dma_get_next_descriptor(ioat);
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
+		__cleanup(ioat_chan, phys_complete);
 
-	if (!desc) {
-		dev_err(to_dev(chan),
-			"Unable to start null desc - get next desc failed\n");
-		spin_unlock_bh(&ioat->desc_lock);
-		return;
-	}
+	if (is_ioat_halted(*ioat_chan->completion)) {
+		u32 chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 
-	hw = desc->hw;
-	hw->ctl = 0;
-	hw->ctl_f.null = 1;
-	hw->ctl_f.int_en = 1;
-	hw->ctl_f.compl_write = 1;
-	/* set size to non-zero value (channel returns error when size is 0) */
-	hw->size = NULL_DESC_BUFFER_SIZE;
-	hw->src_addr = 0;
-	hw->dst_addr = 0;
-	async_tx_ack(&desc->txd);
-	hw->next = 0;
-	list_add_tail(&desc->node, &ioat->used_desc);
-	dump_desc_dbg(ioat, desc);
+		if (chanerr & IOAT_CHANERR_HANDLE_MASK) {
+			mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
+			ioat_eh(ioat_chan);
+		}
+	}
 
-	ioat_set_chainaddr(ioat, desc->txd.phys);
-	ioat_start(chan);
-	spin_unlock_bh(&ioat->desc_lock);
+	spin_unlock_bh(&ioat_chan->cleanup_lock);
 }
 
-/*
- * Perform a IOAT transaction to verify the HW works.
- */
-#define IOAT_TEST_SIZE 2000
+void ioat_cleanup_event(unsigned long data)
+{
+	struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
+
+	ioat_cleanup(ioat_chan);
+	if (!test_bit(IOAT_RUN, &ioat_chan->state))
+		return;
+	writew(IOAT_CHANCTRL_RUN, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
+}
 
-static void ioat_dma_test_callback(void *dma_async_param)
+static void ioat_restart_channel(struct ioatdma_chan *ioat_chan)
 {
-	struct completion *cmp = dma_async_param;
+	u64 phys_complete;
+
+	ioat_quiesce(ioat_chan, 0);
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
+		__cleanup(ioat_chan, phys_complete);
 
-	complete(cmp);
+	__ioat_restart_chan(ioat_chan);
 }
 
-/**
- * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
- * @device: device to be tested
- */
-int ioat_dma_self_test(struct ioatdma_device *device)
+static void ioat_eh(struct ioatdma_chan *ioat_chan)
 {
-	int i;
-	u8 *src;
-	u8 *dest;
-	struct dma_device *dma = &device->common;
-	struct device *dev = &device->pdev->dev;
-	struct dma_chan *dma_chan;
+	struct pci_dev *pdev = to_pdev(ioat_chan);
+	struct ioat_dma_descriptor *hw;
 	struct dma_async_tx_descriptor *tx;
-	dma_addr_t dma_dest, dma_src;
-	dma_cookie_t cookie;
-	int err = 0;
-	struct completion cmp;
-	unsigned long tmo;
-	unsigned long flags;
-
-	src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
-	if (!src)
-		return -ENOMEM;
-	dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
-	if (!dest) {
-		kfree(src);
-		return -ENOMEM;
-	}
+	u64 phys_complete;
+	struct ioat_ring_ent *desc;
+	u32 err_handled = 0;
+	u32 chanerr_int;
+	u32 chanerr;
 
-	/* Fill in src buffer */
-	for (i = 0; i < IOAT_TEST_SIZE; i++)
-		src[i] = (u8)i;
-
-	/* Start copy, using first DMA channel */
-	dma_chan = container_of(dma->channels.next, struct dma_chan,
-				device_node);
-	if (dma->device_alloc_chan_resources(dma_chan) < 1) {
-		dev_err(dev, "selftest cannot allocate chan resource\n");
-		err = -ENODEV;
-		goto out;
-	}
+	/* cleanup so tail points to descriptor that caused the error */
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
+		__cleanup(ioat_chan, phys_complete);
 
-	dma_src = dma_map_single(dev, src, IOAT_TEST_SIZE, DMA_TO_DEVICE);
-	if (dma_mapping_error(dev, dma_src)) {
-		dev_err(dev, "mapping src buffer failed\n");
-		goto free_resources;
-	}
-	dma_dest = dma_map_single(dev, dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE);
-	if (dma_mapping_error(dev, dma_dest)) {
-		dev_err(dev, "mapping dest buffer failed\n");
-		goto unmap_src;
-	}
-	flags = DMA_PREP_INTERRUPT;
-	tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src,
-						   IOAT_TEST_SIZE, flags);
-	if (!tx) {
-		dev_err(dev, "Self-test prep failed, disabling\n");
-		err = -ENODEV;
-		goto unmap_dma;
-	}
+	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
+	pci_read_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, &chanerr_int);
 
-	async_tx_ack(tx);
-	init_completion(&cmp);
-	tx->callback = ioat_dma_test_callback;
-	tx->callback_param = &cmp;
-	cookie = tx->tx_submit(tx);
-	if (cookie < 0) {
-		dev_err(dev, "Self-test setup failed, disabling\n");
-		err = -ENODEV;
-		goto unmap_dma;
-	}
-	dma->device_issue_pending(dma_chan);
+	dev_dbg(to_dev(ioat_chan), "%s: error = %x:%x\n",
+		__func__, chanerr, chanerr_int);
 
-	tmo = wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000));
+	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
+	hw = desc->hw;
+	dump_desc_dbg(ioat_chan, desc);
 
-	if (tmo == 0 ||
-	    dma->device_tx_status(dma_chan, cookie, NULL)
-					!= DMA_COMPLETE) {
-		dev_err(dev, "Self-test copy timed out, disabling\n");
-		err = -ENODEV;
-		goto unmap_dma;
-	}
-	if (memcmp(src, dest, IOAT_TEST_SIZE)) {
-		dev_err(dev, "Self-test copy failed compare, disabling\n");
-		err = -ENODEV;
-		goto free_resources;
+	switch (hw->ctl_f.op) {
+	case IOAT_OP_XOR_VAL:
+		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
+			*desc->result |= SUM_CHECK_P_RESULT;
+			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
+		}
+		break;
+	case IOAT_OP_PQ_VAL:
+	case IOAT_OP_PQ_VAL_16S:
+		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
+			*desc->result |= SUM_CHECK_P_RESULT;
+			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
+		}
+		if (chanerr & IOAT_CHANERR_XOR_Q_ERR) {
+			*desc->result |= SUM_CHECK_Q_RESULT;
+			err_handled |= IOAT_CHANERR_XOR_Q_ERR;
+		}
+		break;
 	}
 
-unmap_dma:
-	dma_unmap_single(dev, dma_dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE);
-unmap_src:
-	dma_unmap_single(dev, dma_src, IOAT_TEST_SIZE, DMA_TO_DEVICE);
-free_resources:
-	dma->device_free_chan_resources(dma_chan);
-out:
-	kfree(src);
-	kfree(dest);
-	return err;
-}
-
-static char ioat_interrupt_style[32] = "msix";
-module_param_string(ioat_interrupt_style, ioat_interrupt_style,
-		    sizeof(ioat_interrupt_style), 0644);
-MODULE_PARM_DESC(ioat_interrupt_style,
-		 "set ioat interrupt style: msix (default), msi, intx");
-
-/**
- * ioat_dma_setup_interrupts - setup interrupt handler
- * @device: ioat device
- */
-int ioat_dma_setup_interrupts(struct ioatdma_device *device)
-{
-	struct ioat_chan_common *chan;
-	struct pci_dev *pdev = device->pdev;
-	struct device *dev = &pdev->dev;
-	struct msix_entry *msix;
-	int i, j, msixcnt;
-	int err = -EINVAL;
-	u8 intrctrl = 0;
-
-	if (!strcmp(ioat_interrupt_style, "msix"))
-		goto msix;
-	if (!strcmp(ioat_interrupt_style, "msi"))
-		goto msi;
-	if (!strcmp(ioat_interrupt_style, "intx"))
-		goto intx;
-	dev_err(dev, "invalid ioat_interrupt_style %s\n", ioat_interrupt_style);
-	goto err_no_irq;
-
-msix:
-	/* The number of MSI-X vectors should equal the number of channels */
-	msixcnt = device->common.chancnt;
-	for (i = 0; i < msixcnt; i++)
-		device->msix_entries[i].entry = i;
-
-	err = pci_enable_msix_exact(pdev, device->msix_entries, msixcnt);
-	if (err)
-		goto msi;
-
-	for (i = 0; i < msixcnt; i++) {
-		msix = &device->msix_entries[i];
-		chan = ioat_chan_by_index(device, i);
-		err = devm_request_irq(dev, msix->vector,
-				       ioat_dma_do_interrupt_msix, 0,
-				       "ioat-msix", chan);
-		if (err) {
-			for (j = 0; j < i; j++) {
-				msix = &device->msix_entries[j];
-				chan = ioat_chan_by_index(device, j);
-				devm_free_irq(dev, msix->vector, chan);
+	/* fault on unhandled error or spurious halt */
+	if (chanerr ^ err_handled || chanerr == 0) {
+		dev_err(to_dev(ioat_chan), "%s: fatal error (%x:%x)\n",
+			__func__, chanerr, err_handled);
+		BUG();
+	} else { /* cleanup the faulty descriptor */
+		tx = &desc->txd;
+		if (tx->cookie) {
+			dma_cookie_complete(tx);
+			dma_descriptor_unmap(tx);
+			if (tx->callback) {
+				tx->callback(tx->callback_param);
+				tx->callback = NULL;
 			}
-			goto msi;
 		}
 	}
-	intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
-	device->irq_mode = IOAT_MSIX;
-	goto done;
 
-msi:
-	err = pci_enable_msi(pdev);
-	if (err)
-		goto intx;
+	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
+	pci_write_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, chanerr_int);
 
-	err = devm_request_irq(dev, pdev->irq, ioat_dma_do_interrupt, 0,
-			       "ioat-msi", device);
-	if (err) {
-		pci_disable_msi(pdev);
-		goto intx;
-	}
-	device->irq_mode = IOAT_MSI;
-	goto done;
-
-intx:
-	err = devm_request_irq(dev, pdev->irq, ioat_dma_do_interrupt,
-			       IRQF_SHARED, "ioat-intx", device);
-	if (err)
-		goto err_no_irq;
-
-	device->irq_mode = IOAT_INTX;
-done:
-	if (device->intr_quirk)
-		device->intr_quirk(device);
-	intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN;
-	writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET);
-	return 0;
-
-err_no_irq:
-	/* Disable all interrupt generation */
-	writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
-	device->irq_mode = IOAT_NOIRQ;
-	dev_err(dev, "no usable interrupts\n");
-	return err;
-}
-EXPORT_SYMBOL(ioat_dma_setup_interrupts);
+	/* mark faulting descriptor as complete */
+	*ioat_chan->completion = desc->txd.phys;
 
-static void ioat_disable_interrupts(struct ioatdma_device *device)
-{
-	/* Disable all interrupt generation */
-	writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
+	spin_lock_bh(&ioat_chan->prep_lock);
+	ioat_restart_channel(ioat_chan);
+	spin_unlock_bh(&ioat_chan->prep_lock);
 }
 
-int ioat_probe(struct ioatdma_device *device)
+static void check_active(struct ioatdma_chan *ioat_chan)
 {
-	int err = -ENODEV;
-	struct dma_device *dma = &device->common;
-	struct pci_dev *pdev = device->pdev;
-	struct device *dev = &pdev->dev;
-
-	/* DMA coherent memory pool for DMA descriptor allocations */
-	device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
-					   sizeof(struct ioat_dma_descriptor),
-					   64, 0);
-	if (!device->dma_pool) {
-		err = -ENOMEM;
-		goto err_dma_pool;
-	}
-
-	device->completion_pool = pci_pool_create("completion_pool", pdev,
-						  sizeof(u64), SMP_CACHE_BYTES,
-						  SMP_CACHE_BYTES);
-
-	if (!device->completion_pool) {
-		err = -ENOMEM;
-		goto err_completion_pool;
+	if (ioat_ring_active(ioat_chan)) {
+		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+		return;
 	}
 
-	device->enumerate_channels(device);
-
-	dma_cap_set(DMA_MEMCPY, dma->cap_mask);
-	dma->dev = &pdev->dev;
+	if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
+		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
+	else if (ioat_chan->alloc_order > ioat_get_alloc_order()) {
+		/* if the ring is idle, empty, and oversized try to step
+		 * down the size
+		 */
+		reshape_ring(ioat_chan, ioat_chan->alloc_order - 1);
 
-	if (!dma->chancnt) {
-		dev_err(dev, "channel enumeration error\n");
-		goto err_setup_interrupts;
+		/* keep shrinking until we get back to our minimum
+		 * default size
+		 */
+		if (ioat_chan->alloc_order > ioat_get_alloc_order())
+			mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
 	}
 
-	err = ioat_dma_setup_interrupts(device);
-	if (err)
-		goto err_setup_interrupts;
+}
 
-	err = device->self_test(device);
-	if (err)
-		goto err_self_test;
+void ioat_timer_event(unsigned long data)
+{
+	struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
+	dma_addr_t phys_complete;
+	u64 status;
 
-	return 0;
+	status = ioat_chansts(ioat_chan);
 
-err_self_test:
-	ioat_disable_interrupts(device);
-err_setup_interrupts:
-	pci_pool_destroy(device->completion_pool);
-err_completion_pool:
-	pci_pool_destroy(device->dma_pool);
-err_dma_pool:
-	return err;
-}
+	/* when halted due to errors check for channel
+	 * programming errors before advancing the completion state
+	 */
+	if (is_ioat_halted(status)) {
+		u32 chanerr;
 
-int ioat_register(struct ioatdma_device *device)
-{
-	int err = dma_async_device_register(&device->common);
+		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
+		dev_err(to_dev(ioat_chan), "%s: Channel halted (%x)\n",
+			__func__, chanerr);
+		if (test_bit(IOAT_RUN, &ioat_chan->state))
+			BUG_ON(is_ioat_bug(chanerr));
+		else /* we never got off the ground */
+			return;
+	}
 
-	if (err) {
-		ioat_disable_interrupts(device);
-		pci_pool_destroy(device->completion_pool);
-		pci_pool_destroy(device->dma_pool);
+	/* if we haven't made progress and we have already
+	 * acknowledged a pending completion once, then be more
+	 * forceful with a restart
+	 */
+	spin_lock_bh(&ioat_chan->cleanup_lock);
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
+		__cleanup(ioat_chan, phys_complete);
+	else if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
+		spin_lock_bh(&ioat_chan->prep_lock);
+		ioat_restart_channel(ioat_chan);
+		spin_unlock_bh(&ioat_chan->prep_lock);
+		spin_unlock_bh(&ioat_chan->cleanup_lock);
+		return;
+	} else {
+		set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
+		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
 	}
 
-	return err;
-}
 
-/* ioat1_intr_quirk - fix up dma ctrl register to enable / disable msi */
-static void ioat1_intr_quirk(struct ioatdma_device *device)
-{
-	struct pci_dev *pdev = device->pdev;
-	u32 dmactrl;
-
-	pci_read_config_dword(pdev, IOAT_PCI_DMACTRL_OFFSET, &dmactrl);
-	if (pdev->msi_enabled)
-		dmactrl |= IOAT_PCI_DMACTRL_MSI_EN;
-	else
-		dmactrl &= ~IOAT_PCI_DMACTRL_MSI_EN;
-	pci_write_config_dword(pdev, IOAT_PCI_DMACTRL_OFFSET, dmactrl);
+	if (ioat_ring_active(ioat_chan))
+		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+	else {
+		spin_lock_bh(&ioat_chan->prep_lock);
+		check_active(ioat_chan);
+		spin_unlock_bh(&ioat_chan->prep_lock);
+	}
+	spin_unlock_bh(&ioat_chan->cleanup_lock);
 }
 
-static ssize_t ring_size_show(struct dma_chan *c, char *page)
+enum dma_status
+ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
+		struct dma_tx_state *txstate)
 {
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
+	enum dma_status ret;
 
-	return sprintf(page, "%d\n", ioat->desccount);
-}
-static struct ioat_sysfs_entry ring_size_attr = __ATTR_RO(ring_size);
+	ret = dma_cookie_status(c, cookie, txstate);
+	if (ret == DMA_COMPLETE)
+		return ret;
 
-static ssize_t ring_active_show(struct dma_chan *c, char *page)
-{
-	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	ioat_cleanup(ioat_chan);
 
-	return sprintf(page, "%d\n", ioat->active);
+	return dma_cookie_status(c, cookie, txstate);
 }
-static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active);
 
-static ssize_t cap_show(struct dma_chan *c, char *page)
+static int ioat_irq_reinit(struct ioatdma_device *ioat_dma)
 {
-	struct dma_device *dma = c->device;
+	struct pci_dev *pdev = ioat_dma->pdev;
+	int irq = pdev->irq, i;
 
-	return sprintf(page, "copy%s%s%s%s%s\n",
-		       dma_has_cap(DMA_PQ, dma->cap_mask) ? " pq" : "",
-		       dma_has_cap(DMA_PQ_VAL, dma->cap_mask) ? " pq_val" : "",
-		       dma_has_cap(DMA_XOR, dma->cap_mask) ? " xor" : "",
-		       dma_has_cap(DMA_XOR_VAL, dma->cap_mask) ? " xor_val" : "",
-		       dma_has_cap(DMA_INTERRUPT, dma->cap_mask) ? " intr" : "");
+	if (!is_bwd_ioat(pdev))
+		return 0;
 
-}
-struct ioat_sysfs_entry ioat_cap_attr = __ATTR_RO(cap);
-
-static ssize_t version_show(struct dma_chan *c, char *page)
-{
-	struct dma_device *dma = c->device;
-	struct ioatdma_device *device = to_ioatdma_device(dma);
+	switch (ioat_dma->irq_mode) {
+	case IOAT_MSIX:
+		for (i = 0; i < ioat_dma->dma_dev.chancnt; i++) {
+			struct msix_entry *msix = &ioat_dma->msix_entries[i];
+			struct ioatdma_chan *ioat_chan;
 
-	return sprintf(page, "%d.%d\n",
-		       device->version >> 4, device->version & 0xf);
-}
-struct ioat_sysfs_entry ioat_version_attr = __ATTR_RO(version);
-
-static struct attribute *ioat1_attrs[] = {
-	&ring_size_attr.attr,
-	&ring_active_attr.attr,
-	&ioat_cap_attr.attr,
-	&ioat_version_attr.attr,
-	NULL,
-};
-
-static ssize_t
-ioat_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
-	struct ioat_sysfs_entry *entry;
-	struct ioat_chan_common *chan;
+			ioat_chan = ioat_chan_by_index(ioat_dma, i);
+			devm_free_irq(&pdev->dev, msix->vector, ioat_chan);
+		}
 
-	entry = container_of(attr, struct ioat_sysfs_entry, attr);
-	chan = container_of(kobj, struct ioat_chan_common, kobj);
+		pci_disable_msix(pdev);
+		break;
+	case IOAT_MSI:
+		pci_disable_msi(pdev);
+		/* fall through */
+	case IOAT_INTX:
+		devm_free_irq(&pdev->dev, irq, ioat_dma);
+		break;
+	default:
+		return 0;
+	}
+	ioat_dma->irq_mode = IOAT_NOIRQ;
 
-	if (!entry->show)
-		return -EIO;
-	return entry->show(&chan->common, page);
+	return ioat_dma_setup_interrupts(ioat_dma);
 }
 
-const struct sysfs_ops ioat_sysfs_ops = {
-	.show	= ioat_attr_show,
-};
-
-static struct kobj_type ioat1_ktype = {
-	.sysfs_ops = &ioat_sysfs_ops,
-	.default_attrs = ioat1_attrs,
-};
-
-void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type)
+int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
 {
-	struct dma_device *dma = &device->common;
-	struct dma_chan *c;
+	/* throw away whatever the channel was doing and get it
+	 * initialized, with ioat3 specific workarounds
+	 */
+	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
+	struct pci_dev *pdev = ioat_dma->pdev;
+	u32 chanerr;
+	u16 dev_id;
+	int err;
+
+	ioat_quiesce(ioat_chan, msecs_to_jiffies(100));
 
-	list_for_each_entry(c, &dma->channels, device_node) {
-		struct ioat_chan_common *chan = to_chan_common(c);
-		struct kobject *parent = &c->dev->device.kobj;
-		int err;
+	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
+	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 
-		err = kobject_init_and_add(&chan->kobj, type, parent, "quickdata");
+	if (ioat_dma->version < IOAT_VER_3_3) {
+		/* clear any pending errors */
+		err = pci_read_config_dword(pdev,
+				IOAT_PCI_CHANERR_INT_OFFSET, &chanerr);
 		if (err) {
-			dev_warn(to_dev(chan),
-				 "sysfs init error (%d), continuing...\n", err);
-			kobject_put(&chan->kobj);
-			set_bit(IOAT_KOBJ_INIT_FAIL, &chan->state);
+			dev_err(&pdev->dev,
+				"channel error register unreachable\n");
+			return err;
 		}
-	}
-}
+		pci_write_config_dword(pdev,
+				IOAT_PCI_CHANERR_INT_OFFSET, chanerr);
 
-void ioat_kobject_del(struct ioatdma_device *device)
-{
-	struct dma_device *dma = &device->common;
-	struct dma_chan *c;
-
-	list_for_each_entry(c, &dma->channels, device_node) {
-		struct ioat_chan_common *chan = to_chan_common(c);
-
-		if (!test_bit(IOAT_KOBJ_INIT_FAIL, &chan->state)) {
-			kobject_del(&chan->kobj);
-			kobject_put(&chan->kobj);
+		/* Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
+		 * (workaround for spurious config parity error after restart)
+		 */
+		pci_read_config_word(pdev, IOAT_PCI_DEVICE_ID_OFFSET, &dev_id);
+		if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
+			pci_write_config_dword(pdev,
+					       IOAT_PCI_DMAUNCERRSTS_OFFSET,
+					       0x10);
 		}
 	}
-}
 
-int ioat1_dma_probe(struct ioatdma_device *device, int dca)
-{
-	struct pci_dev *pdev = device->pdev;
-	struct dma_device *dma;
-	int err;
+	err = ioat_reset_sync(ioat_chan, msecs_to_jiffies(200));
+	if (!err)
+		err = ioat_irq_reinit(ioat_dma);
 
-	device->intr_quirk = ioat1_intr_quirk;
-	device->enumerate_channels = ioat1_enumerate_channels;
-	device->self_test = ioat_dma_self_test;
-	device->timer_fn = ioat1_timer_event;
-	device->cleanup_fn = ioat1_cleanup_event;
-	dma = &device->common;
-	dma->device_prep_dma_memcpy = ioat1_dma_prep_memcpy;
-	dma->device_issue_pending = ioat1_dma_memcpy_issue_pending;
-	dma->device_alloc_chan_resources = ioat1_dma_alloc_chan_resources;
-	dma->device_free_chan_resources = ioat1_dma_free_chan_resources;
-	dma->device_tx_status = ioat_dma_tx_status;
-
-	err = ioat_probe(device);
-	if (err)
-		return err;
-	err = ioat_register(device);
 	if (err)
-		return err;
-	ioat_kobject_add(device, &ioat1_ktype);
-
-	if (dca)
-		device->dca = ioat_dca_init(pdev, device->reg_base);
+		dev_err(&pdev->dev, "Failed to reset: %d\n", err);
 
 	return err;
 }
-
-void ioat_dma_remove(struct ioatdma_device *device)
-{
-	struct dma_device *dma = &device->common;
-
-	ioat_disable_interrupts(device);
-
-	ioat_kobject_del(device);
-
-	dma_async_device_unregister(dma);
-
-	pci_pool_destroy(device->dma_pool);
-	pci_pool_destroy(device->completion_pool);
-
-	INIT_LIST_HEAD(&dma->channels);
-}