/*
* APEI Generic Hardware Error Source support
*
* Generic Hardware Error Source provides a way to report platform
* hardware errors (such as that from chipset). It works in so called
* "Firmware First" mode, that is, hardware errors are reported to
* firmware firstly, then reported to Linux by firmware. This way,
* some non-standard hardware error registers or non-standard hardware
* link can be checked by firmware to produce more hardware error
* information for Linux.
*
* For more information about Generic Hardware Error Source, please
* refer to ACPI Specification version 4.0, section 17.3.2.6
*
* Now, only SCI notification type and memory errors are
* supported. More notification type and hardware error type will be
* added later.
*
* 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/init.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/cper.h>
#include <linux/kdebug.h>
#include <acpi/apei.h>
#include <acpi/atomicio.h>
#include <acpi/hed.h>
#include <asm/mce.h>
#include "apei-internal.h"
#define GHES_PFX "GHES: "
#define GHES_ESTATUS_MAX_SIZE 65536
/*
* One struct ghes is created for each generic hardware error
* source.
*
* It provides the context for APEI hardware error timer/IRQ/SCI/NMI
* handler. Handler for one generic hardware error source is only
* triggered after the previous one is done. So handler can uses
* struct ghes without locking.
*
* estatus: memory buffer for error status block, allocated during
* HEST parsing.
*/
#define GHES_TO_CLEAR 0x0001
struct ghes {
struct acpi_hest_generic *generic;
struct acpi_hest_generic_status *estatus;
struct list_head list;
u64 buffer_paddr;
unsigned long flags;
};
/*
* Error source lists, one list for each notification method. The
* members in lists are struct ghes.
*
* The list members are only added in HEST parsing and deleted during
* module_exit, that is, single-threaded. So no lock is needed for
* that.
*
* But the mutual exclusion is needed between members adding/deleting
* and timer/IRQ/SCI/NMI handler, which may traverse the list. RCU is
* used for that.
*/
static LIST_HEAD(ghes_sci);
static struct ghes *ghes_new(struct acpi_hest_generic *generic)
{
struct ghes *ghes;
unsigned int error_block_length;
int rc;
ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
if (!ghes)
return ERR_PTR(-ENOMEM);
ghes->generic = generic;
INIT_LIST_HEAD(&ghes->list);
rc = acpi_pre_map_gar(&generic->error_status_address);
if (rc)
goto err_free;
error_block_length = generic->error_block_length;
if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
pr_warning(FW_WARN GHES_PFX
"Error status block length is too long: %u for "
"generic hardware error source: %d.\n",
error_block_length, generic->header.source_id);
error_block_length = GHES_ESTATUS_MAX_SIZE;
}
ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
if (!ghes->estatus) {
rc = -ENOMEM;
goto err_unmap;
}
return ghes;
err_unmap:
acpi_post_unmap_gar(&generic->error_status_address);
err_free:
kfree(ghes);
return ERR_PTR(rc);
}
static void ghes_fini(struct ghes *ghes)
{
kfree(ghes->estatus);
acpi_post_unmap_gar(&ghes->generic->error_status_address);
}
enum {
GHES_SER_NO = 0x0,
GHES_SER_CORRECTED = 0x1,
GHES_SER_RECOVERABLE = 0x2,
GHES_SER_PANIC = 0x3,
};
static inline int ghes_severity(int severity)
{
switch (severity) {
case CPER_SER_INFORMATIONAL:
return GHES_SER_NO;
case CPER_SER_CORRECTED:
return GHES_SER_CORRECTED;
case CPER_SER_RECOVERABLE:
return GHES_SER_RECOVERABLE;
case CPER_SER_FATAL:
return GHES_SER_PANIC;
default:
/* Unkown, go panic */
return GHES_SER_PANIC;
}
}
/* SCI handler run in work queue, so ioremap can be used here */
static int ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
int from_phys)
{
void *vaddr;
vaddr = ioremap_cache(paddr, len);
if (!vaddr)
return -ENOMEM;
if (from_phys)
memcpy(buffer, vaddr, len);
else
memcpy(vaddr, buffer, len);
iounmap(vaddr);
return 0;
}
static int ghes_read_estatus(struct ghes *ghes, int silent)
{
struct acpi_hest_generic *g = ghes->generic;
u64 buf_paddr;
u32 len;
int rc;
rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
if (rc) {
if (!silent && printk_ratelimit())
pr_warning(FW_WARN GHES_PFX
"Failed to read error status block address for hardware error source: %d.\n",
g->header.source_id);
return -EIO;
}
if (!buf_paddr)
return -ENOENT;
rc = ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
sizeof(*ghes->estatus), 1);
if (rc)
return rc;
if (!ghes->estatus->block_status)
return -ENOENT;
ghes->buffer_paddr = buf_paddr;
ghes->flags |= GHES_TO_CLEAR;
rc = -EIO;
len = apei_estatus_len(ghes->estatus);
if (len < sizeof(*ghes->estatus))
goto err_read_block;
if (len > ghes->generic->error_block_length)
goto err_read_block;
if (apei_estatus_check_header(ghes->estatus))
goto err_read_block;
rc = ghes_copy_tofrom_phys(ghes->estatus + 1,
buf_paddr + sizeof(*ghes->estatus),
len - sizeof(*ghes->estatus), 1);
if (rc)
return rc;
if (apei_estatus_check(ghes->estatus))
goto err_read_block;
rc = 0;
err_read_block:
if (rc && !silent)
pr_warning(FW_WARN GHES_PFX
"Failed to read error status block!\n");
return rc;
}
static void ghes_clear_estatus(struct ghes *ghes)
{
ghes->estatus->block_status = 0;
if (!(ghes->flags & GHES_TO_CLEAR))
return;
ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
sizeof(ghes->estatus->block_status), 0);
ghes->flags &= ~GHES_TO_CLEAR;
}
static void ghes_do_proc(struct ghes *ghes)
{
int ser, processed = 0;
struct acpi_hest_generic_data *gdata;
ser = ghes_severity(ghes->estatus->error_severity);
apei_estatus_for_each_section(ghes->estatus, gdata) {
#ifdef CONFIG_X86_MCE
if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
CPER_SEC_PLATFORM_MEM)) {
apei_mce_report_mem_error(
ser == GHES_SER_CORRECTED,
(struct cper_sec_mem_err *)(gdata+1));
processed = 1;
}
#endif
}
if (!processed && printk_ratelimit())
pr_warning(GHES_PFX
"Unknown error record from generic hardware error source: %d\n",
ghes->generic->header.source_id);
}
static int ghes_proc(struct ghes *ghes)
{
int rc;
rc = ghes_read_estatus(ghes, 0);
if (rc)
goto out;
ghes_do_proc(ghes);
out:
ghes_clear_estatus(ghes);
return 0;
}
static int ghes_notify_sci(struct notifier_block *this,
unsigned long event, void *data)
{
struct ghes *ghes;
int ret = NOTIFY_DONE;
rcu_read_lock();
list_for_each_entry_rcu(ghes, &ghes_sci, list) {
if (!ghes_proc(ghes))
ret = NOTIFY_OK;
}
rcu_read_unlock();
return ret;
}
static struct notifier_block ghes_notifier_sci = {
.notifier_call = ghes_notify_sci,
};
static int hest_ghes_parse(struct acpi_hest_header *hest_hdr, void *data)
{
struct acpi_hest_generic *generic;
struct ghes *ghes = NULL;
int rc = 0;
if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
return 0;
generic = (struct acpi_hest_generic *)hest_hdr;
if (!generic->enabled)
return 0;
if (generic->error_block_length <
sizeof(struct acpi_hest_generic_status)) {
pr_warning(FW_BUG GHES_PFX
"Invalid error block length: %u for generic hardware error source: %d\n",
generic->error_block_length,
generic->header.source_id);
goto err;
}
if (generic->records_to_preallocate == 0) {
pr_warning(FW_BUG GHES_PFX
"Invalid records to preallocate: %u for generic hardware error source: %d\n",
generic->records_to_preallocate,
generic->header.source_id);
goto err;
}
ghes = ghes_new(generic);
if (IS_ERR(ghes)) {
rc = PTR_ERR(ghes);
ghes = NULL;
goto err;
}
switch (generic->notify.type) {
case ACPI_HEST_NOTIFY_POLLED:
pr_warning(GHES_PFX
"Generic hardware error source: %d notified via POLL is not supported!\n",
generic->header.source_id);
break;
case ACPI_HEST_NOTIFY_EXTERNAL:
case ACPI_HEST_NOTIFY_LOCAL:
pr_warning(GHES_PFX
"Generic hardware error source: %d notified via IRQ is not supported!\n",
generic->header.source_id);
break;
case ACPI_HEST_NOTIFY_SCI:
if (list_empty(&ghes_sci))
register_acpi_hed_notifier(&ghes_notifier_sci);
list_add_rcu(&ghes->list, &ghes_sci);
break;
case ACPI_HEST_NOTIFY_NMI:
pr_warning(GHES_PFX
"Generic hardware error source: %d notified via NMI is not supported!\n",
generic->header.source_id);
break;
default:
pr_warning(FW_WARN GHES_PFX
"Unknown notification type: %u for generic hardware error source: %d\n",
generic->notify.type, generic->header.source_id);
break;
}
return 0;
err:
if (ghes)
ghes_fini(ghes);
return rc;
}
static void ghes_cleanup(void)
{
struct ghes *ghes, *nghes;
if (!list_empty(&ghes_sci))
unregister_acpi_hed_notifier(&ghes_notifier_sci);
synchronize_rcu();
list_for_each_entry_safe(ghes, nghes, &ghes_sci, list) {
list_del(&ghes->list);
ghes_fini(ghes);
kfree(ghes);
}
}
static int __init ghes_init(void)
{
int rc;
if (acpi_disabled)
return -ENODEV;
if (hest_disable) {
pr_info(GHES_PFX "HEST is not enabled!\n");
return -EINVAL;
}
rc = apei_hest_parse(hest_ghes_parse, NULL);
if (rc) {
pr_err(GHES_PFX
"Error during parsing HEST generic hardware error sources.\n");
goto err_cleanup;
}
if (list_empty(&ghes_sci)) {
pr_info(GHES_PFX
"No functional generic hardware error sources.\n");
rc = -ENODEV;
goto err_cleanup;
}
pr_info(GHES_PFX
"Generic Hardware Error Source support is initialized.\n");
return 0;
err_cleanup:
ghes_cleanup();
return rc;
}
static void __exit ghes_exit(void)
{
ghes_cleanup();
}
module_init(ghes_init);
module_exit(ghes_exit);
MODULE_AUTHOR("Huang Ying");
MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
MODULE_LICENSE("GPL");
