diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/platforms/powernv/opal-msglog.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/powerpc/platforms/powernv/opal-msglog.c')
-rw-r--r-- | kernel/arch/powerpc/platforms/powernv/opal-msglog.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/platforms/powernv/opal-msglog.c b/kernel/arch/powerpc/platforms/powernv/opal-msglog.c new file mode 100644 index 000000000..44ed78af1 --- /dev/null +++ b/kernel/arch/powerpc/platforms/powernv/opal-msglog.c @@ -0,0 +1,124 @@ +/* + * PowerNV OPAL in-memory console interface + * + * Copyright 2014 IBM Corp. + * + * 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 <asm/io.h> +#include <asm/opal.h> +#include <linux/debugfs.h> +#include <linux/of.h> +#include <linux/types.h> +#include <asm/barrier.h> + +/* OPAL in-memory console. Defined in OPAL source at core/console.c */ +struct memcons { + __be64 magic; +#define MEMCONS_MAGIC 0x6630696567726173L + __be64 obuf_phys; + __be64 ibuf_phys; + __be32 obuf_size; + __be32 ibuf_size; + __be32 out_pos; +#define MEMCONS_OUT_POS_WRAP 0x80000000u +#define MEMCONS_OUT_POS_MASK 0x00ffffffu + __be32 in_prod; + __be32 in_cons; +}; + +static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, char *to, + loff_t pos, size_t count) +{ + struct memcons *mc = bin_attr->private; + const char *conbuf; + ssize_t ret; + size_t first_read = 0; + uint32_t out_pos, avail; + + if (!mc) + return -ENODEV; + + out_pos = be32_to_cpu(ACCESS_ONCE(mc->out_pos)); + + /* Now we've read out_pos, put a barrier in before reading the new + * data it points to in conbuf. */ + smp_rmb(); + + conbuf = phys_to_virt(be64_to_cpu(mc->obuf_phys)); + + /* When the buffer has wrapped, read from the out_pos marker to the end + * of the buffer, and then read the remaining data as in the un-wrapped + * case. */ + if (out_pos & MEMCONS_OUT_POS_WRAP) { + + out_pos &= MEMCONS_OUT_POS_MASK; + avail = be32_to_cpu(mc->obuf_size) - out_pos; + + ret = memory_read_from_buffer(to, count, &pos, + conbuf + out_pos, avail); + + if (ret < 0) + goto out; + + first_read = ret; + to += first_read; + count -= first_read; + pos -= avail; + + if (count <= 0) + goto out; + } + + /* Sanity check. The firmware should not do this to us. */ + if (out_pos > be32_to_cpu(mc->obuf_size)) { + pr_err("OPAL: memory console corruption. Aborting read.\n"); + return -EINVAL; + } + + ret = memory_read_from_buffer(to, count, &pos, conbuf, out_pos); + + if (ret < 0) + goto out; + + ret += first_read; +out: + return ret; +} + +static struct bin_attribute opal_msglog_attr = { + .attr = {.name = "msglog", .mode = 0444}, + .read = opal_msglog_read +}; + +void __init opal_msglog_init(void) +{ + u64 mcaddr; + struct memcons *mc; + + if (of_property_read_u64(opal_node, "ibm,opal-memcons", &mcaddr)) { + pr_warn("OPAL: Property ibm,opal-memcons not found, no message log\n"); + return; + } + + mc = phys_to_virt(mcaddr); + if (!mc) { + pr_warn("OPAL: memory console address is invalid\n"); + return; + } + + if (be64_to_cpu(mc->magic) != MEMCONS_MAGIC) { + pr_warn("OPAL: memory console version is invalid\n"); + return; + } + + opal_msglog_attr.private = mc; + + if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0) + pr_warn("OPAL: sysfs file creation failed\n"); +} |