Commit 2ff729d5 authored by Huang Ying's avatar Huang Ying Committed by Len Brown

ACPI, APEI, ERST debug support

This patch adds debugging/testing support to ERST. A misc device is
implemented to export raw ERST read/write/clear etc operations to user
space. With this patch, we can add ERST testing support to
linuxfirmwarekit ISO (linuxfirmwarekit.org) to verify the kernel
support and the firmware implementation.
Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Acked-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 7ad6e943
...@@ -28,3 +28,12 @@ config ACPI_APEI_EINJ ...@@ -28,3 +28,12 @@ config ACPI_APEI_EINJ
EINJ provides a hardware error injection mechanism, it is EINJ provides a hardware error injection mechanism, it is
mainly used for debugging and testing the other parts of mainly used for debugging and testing the other parts of
APEI and some other RAS features. APEI and some other RAS features.
config ACPI_APEI_ERST_DEBUG
tristate "APEI Error Record Serialization Table (ERST) Debug Support"
depends on ACPI_APEI
help
ERST is a way provided by APEI to save and retrieve hardware
error infomation to and from a persistent store. Enable this
if you want to debugging and testing the ERST kernel support
and firmware implementation.
obj-$(CONFIG_ACPI_APEI) += apei.o obj-$(CONFIG_ACPI_APEI) += apei.o
obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o
obj-$(CONFIG_ACPI_APEI_EINJ) += einj.o obj-$(CONFIG_ACPI_APEI_EINJ) += einj.o
obj-$(CONFIG_ACPI_APEI_ERST_DEBUG) += erst-dbg.o
apei-y := apei-base.o hest.o cper.o erst.o apei-y := apei-base.o hest.o cper.o erst.o
/*
* APEI Error Record Serialization Table debug support
*
* ERST is a way provided by APEI to save and retrieve hardware error
* infomation to and from a persistent store. This file provide the
* debugging/testing support for ERST kernel support and firmware
* implementation.
*
* Copyright 2010 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <acpi/apei.h>
#include <linux/miscdevice.h>
#include "apei-internal.h"
#define ERST_DBG_PFX "ERST DBG: "
#define ERST_DBG_RECORD_LEN_MAX 4096
static void *erst_dbg_buf;
static unsigned int erst_dbg_buf_len;
/* Prevent erst_dbg_read/write from being invoked concurrently */
static DEFINE_MUTEX(erst_dbg_mutex);
static int erst_dbg_open(struct inode *inode, struct file *file)
{
if (erst_disable)
return -ENODEV;
return nonseekable_open(inode, file);
}
static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
int rc;
u64 record_id;
u32 record_count;
switch (cmd) {
case APEI_ERST_CLEAR_RECORD:
rc = copy_from_user(&record_id, (void __user *)arg,
sizeof(record_id));
if (rc)
return -EFAULT;
return erst_clear(record_id);
case APEI_ERST_GET_RECORD_COUNT:
rc = erst_get_record_count();
if (rc < 0)
return rc;
record_count = rc;
rc = put_user(record_count, (u32 __user *)arg);
if (rc)
return rc;
return 0;
default:
return -ENOTTY;
}
}
static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
size_t usize, loff_t *off)
{
int rc;
ssize_t len = 0;
u64 id;
if (*off != 0)
return -EINVAL;
if (mutex_lock_interruptible(&erst_dbg_mutex) != 0)
return -EINTR;
retry_next:
rc = erst_get_next_record_id(&id);
if (rc)
goto out;
/* no more record */
if (id == APEI_ERST_INVALID_RECORD_ID)
goto out;
retry:
rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len);
/* The record may be cleared by others, try read next record */
if (rc == -ENOENT)
goto retry_next;
if (rc < 0)
goto out;
if (len > ERST_DBG_RECORD_LEN_MAX) {
pr_warning(ERST_DBG_PFX
"Record (ID: 0x%llx) length is too long: %zd\n",
id, len);
rc = -EIO;
goto out;
}
if (len > erst_dbg_buf_len) {
kfree(erst_dbg_buf);
rc = -ENOMEM;
erst_dbg_buf = kmalloc(len, GFP_KERNEL);
if (!erst_dbg_buf)
goto out;
erst_dbg_buf_len = len;
goto retry;
}
rc = -EINVAL;
if (len > usize)
goto out;
rc = -EFAULT;
if (copy_to_user(ubuf, erst_dbg_buf, len))
goto out;
rc = 0;
out:
mutex_unlock(&erst_dbg_mutex);
return rc ? rc : len;
}
static ssize_t erst_dbg_write(struct file *filp, const char __user *ubuf,
size_t usize, loff_t *off)
{
int rc;
struct cper_record_header *rcd;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (usize > ERST_DBG_RECORD_LEN_MAX) {
pr_err(ERST_DBG_PFX "Too long record to be written\n");
return -EINVAL;
}
if (mutex_lock_interruptible(&erst_dbg_mutex))
return -EINTR;
if (usize > erst_dbg_buf_len) {
kfree(erst_dbg_buf);
rc = -ENOMEM;
erst_dbg_buf = kmalloc(usize, GFP_KERNEL);
if (!erst_dbg_buf)
goto out;
erst_dbg_buf_len = usize;
}
rc = copy_from_user(erst_dbg_buf, ubuf, usize);
if (rc) {
rc = -EFAULT;
goto out;
}
rcd = erst_dbg_buf;
rc = -EINVAL;
if (rcd->record_length != usize)
goto out;
rc = erst_write(erst_dbg_buf);
out:
mutex_unlock(&erst_dbg_mutex);
return rc < 0 ? rc : usize;
}
static const struct file_operations erst_dbg_ops = {
.owner = THIS_MODULE,
.open = erst_dbg_open,
.read = erst_dbg_read,
.write = erst_dbg_write,
.unlocked_ioctl = erst_dbg_ioctl,
};
static struct miscdevice erst_dbg_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "erst_dbg",
.fops = &erst_dbg_ops,
};
static __init int erst_dbg_init(void)
{
return misc_register(&erst_dbg_dev);
}
static __exit void erst_dbg_exit(void)
{
misc_deregister(&erst_dbg_dev);
kfree(erst_dbg_buf);
}
module_init(erst_dbg_init);
module_exit(erst_dbg_exit);
MODULE_AUTHOR("Huang Ying");
MODULE_DESCRIPTION("APEI Error Record Serialization Table debug support");
MODULE_LICENSE("GPL");
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