/*
* apei-base.c - ACPI Platform Error Interface (APEI) supporting
* infrastructure
*
* APEI allows to report errors (for example from the chipset) to the
* the operating system. This improves NMI handling especially. In
* addition it supports error serialization and error injection.
*
* For more information about APEI, please refer to ACPI Specification
* version 4.0, chapter 17.
*
* This file has Common functions used by more than one APEI table,
* including framework of interpreter for ERST and EINJ; resource
* management for APEI registers.
*
* Copyright (C) 2009, 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/slab.h>
#include <linux/io.h>
#include <linux/kref.h>
#include <linux/rculist.h>
#include <linux/interrupt.h>
#include <linux/debugfs.h>
#include <acpi/atomicio.h>
#include "apei-internal.h"
#define APEI_PFX "APEI: "
/*
* APEI ERST (Error Record Serialization Table) and EINJ (Error
* INJection) interpreter framework.
*/
#define APEI_EXEC_PRESERVE_REGISTER 0x1
void apei_exec_ctx_init(struct apei_exec_context *ctx,
struct apei_exec_ins_type *ins_table,
u32 instructions,
struct acpi_whea_header *action_table,
u32 entries)
{
ctx->ins_table = ins_table;
ctx->instructions = instructions;
ctx->action_table = action_table;
ctx->entries = entries;
}
EXPORT_SYMBOL_GPL(apei_exec_ctx_init);
int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val)
{
int rc;
rc = acpi_atomic_read(val, &entry->register_region);
if (rc)
return rc;
*val >>= entry->register_region.bit_offset;
*val &= entry->mask;
return 0;
}
int apei_exec_read_register(struct apei_exec_context *ctx,
struct acpi_whea_header *entry)
{
int rc;
u64 val = 0;
rc = __apei_exec_read_register(entry, &val);
if (rc)
return rc;
ctx->value = val;
return 0;
}
EXPORT_SYMBOL_GPL(apei_exec_read_register);
int apei_exec_read_register_value(struct apei_exec_context *ctx,
struct acpi_whea_header *entry)
{
int rc;
rc = apei_exec_read_register(ctx, entry);
if (rc)
return rc;
ctx->value = (ctx->value == entry->value);
return 0;
}
EXPORT_SYMBOL_GPL(apei_exec_read_register_value);
int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val)
{
int rc;
val &= entry->mask;
val <<= entry->register_region.bit_offset;
if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) {
u64 valr = 0;
rc = acpi_atomic_read(&valr, &entry->register_region);
if (rc)
return rc;
valr &= ~(entry->mask << entry->register_region.bit_offset);
val |= valr;
}
rc = acpi_atomic_write(val, &entry->register_region);
return rc;
}
int apei_exec_write_register(struct apei_exec_context *ctx,
struct acpi_whea_header *entry)
{
return __apei_exec_write_register(entry, ctx->value);
}
EXPORT_SYMBOL_GPL(apei_exec_write_register);
int apei_exec_write_register_value(struct apei_exec_context *ctx,
struct acpi_whea_header *entry)
{
int rc;
ctx->value = entry->value;
rc = apei_exec_write_register(ctx, entry);
return rc;
}
EXPORT_SYMBOL_GPL(apei_exec_write_register_value);
int apei_exec_noop(struct apei_exec_context *ctx,
struct acpi_whea_header *entry)
{
return 0;
}
EXPORT_SYMBOL_GPL(apei_exec_noop);
/*
* Interpret the specified action. Go through whole action table,
* execute all instructions belong to the action.
*/
int apei_exec_run(struct apei_exec_context *ctx, u8 action)
{
int rc;
u32 i, ip;
struct acpi_whea_header *entry;
apei_exec_ins_func_t run;
ctx->ip = 0;
/*
* "ip" is the instruction pointer of current instruction,
* "ctx->ip" specifies the next instruction to executed,
* instruction "run" function may change the "ctx->ip" to
* implement "goto" semantics.
*/
rewind:
ip = 0;
for (i = 0; i < ctx->entries; i++) {
entry = &ctx->action_table[i];
if (entry->action != action)
continue;
if (ip == ctx->ip) {
if (entry->instruction >= ctx->instructions ||
!ctx->ins_table[entry->instruction].run) {
pr_warning(FW_WARN APEI_PFX
"Invalid action table, unknown instruction type: %d\n",
entry->instruction);
return -EINVAL;
}
run = ctx->ins_table[entry->instruction].run;
rc = run(ctx, entry);
if (rc < 0)
return rc;
else if (rc != APEI_EXEC_SET_IP)
ctx->ip++;
}
ip++;
if (ctx->ip < ip)
goto rewind;
}
return 0;
}
EXPORT_SYMBOL_GPL(apei_exec_run);
typedef int (*apei_exec_entry_func_t)(struct apei_exec_context *ctx,
struct acpi_whea_header *entry,
void *data);
static int apei_exec_for_each_entry(struct apei_exec_context *ctx,
apei_exec_entry_func_t func,
void *data,
int *end)
{
u8 ins;
int i, rc;
struct acpi_whea_header *entry;
struct apei_exec_ins_type *ins_table = ctx->ins_table;
for (i = 0; i < ctx->entries; i++) {
entry = ctx->action_table + i;
ins = entry->instruction;
if (end)
*end = i;
if (ins >= ctx->instructions || !ins_table[ins].run) {
pr_warning(FW_WARN APEI_PFX
"Invalid action table, unknown instruction type: %d\n",
ins);
return -EINVAL;
}
rc = func(ctx, entry, data);
if (rc)
return rc;
}
return 0;
}
static int pre_map_gar_callback(struct apei_exec_context *ctx,
struct acpi_whea_header *entry,
void *data)
{
u8 ins = entry->instruction;
if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
return acpi_pre_map_gar(&entry->register_region);
return 0;
}
/*
* Pre-map all GARs in action table to make it possible to access them
* in NMI handler.
*/
int apei_exec_pre_map_gars(struct apei_exec_context *ctx)
{
int rc, end;
rc = apei_exec_for_each_entry(ctx, pre_map_gar_callback,
NULL, &end);
if (rc) {
struct apei_exec_context ctx_unmap;
memcpy(&ctx_unmap, ctx, sizeof(*ctx));
ctx_unmap.entries = end;
apei_exec_post_unmap_gars(&ctx_unmap);
}
return rc;
}
EXPORT_SYMBOL_GPL(apei_exec_pre_map_gars);
static int post_unmap_gar_callback(struct apei_exec_context *ctx,
struct acpi_whea_header *entry,
void *data)
{
u8 ins = entry->instruction;
if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
acpi_post_unmap_gar(&entry->register_region);
return 0;
}
/* Post-unmap all GAR in action table. */
int apei_exec_post_unmap_gars(struct apei_exec_context *ctx)
{
return apei_exec_for_each_entry(ctx, post_unmap_gar_callback,
NULL, NULL);
}
EXPORT_SYMBOL_GPL(apei_exec_post_unmap_gars);
/*
* Resource management for GARs in APEI
*/
struct apei_res {
struct list_head list;
unsigned long start;
unsigned long end;
};
/* Collect all resources requested, to avoid conflict */
struct apei_resources apei_resources_all = {
.iomem = LIST_HEAD_INIT(apei_resources_all.iomem),
.ioport = LIST_HEAD_INIT(apei_resources_all.ioport),
};
static int apei_res_add(struct list_head *res_list,
unsigned long start, unsigned long size)
{
struct apei_res *res, *resn, *res_ins = NULL;
unsigned long end = start + size;
if (end <= start)
return 0;
repeat:
list_for_each_entry_safe(res, resn, res_list, list) {
if (res->start > end || res->end < start)
continue;
else if (end <= res->end && start >= res->start) {
kfree(res_ins);
return 0;
}
list_del(&res->list);
res->start = start = min(res->start, start);
res->end = end = max(res->end, end);
kfree(res_ins);
res_ins = res;
goto repeat;
}
if (res_ins)
list_add(&res_ins->list, res_list);
else {
res_ins = kmalloc(sizeof(*res), GFP_KERNEL);
if (!res_ins)
return -ENOMEM;
res_ins->start = start;
res_ins->end = end;
list_add(&res_ins->list, res_list);
}
return 0;
}
static int apei_res_sub(struct list_head *res_list1,
struct list_head *res_list2)
{
struct apei_res *res1, *resn1, *res2, *res;
res1 = list_entry(res_list1->next, struct apei_res, list);
resn1 = list_entry(res1->list.next, struct apei_res, list);
while (&res1->list != res_list1) {
list_for_each_entry(res2, res_list2, list) {
if (res1->start >= res2->end ||
res1->end <= res2->start)
continue;
else if (res1->end <= res2->end &&
res1->start >= res2->start) {
list_del(&res1->list);
kfree(res1);
break;
} else if (res1->end > res2->end &&
res1->start < res2->start) {
res = kmalloc(sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
res->start = res2->end;
res->end = res1->end;
res1->end = res2->start;
list_add(&res->list, &res1->list);
resn1 = res;
} else {
if (res1->start < res2->start)
res1->end = res2->start;
else
res1->start = res2->end;
}
}
res1 = resn1;
resn1 = list_entry(resn1->list.next, struct apei_res, list);
}
return 0;
}
static void apei_res_clean(struct list_head *res_list)
{
struct apei_res *res, *resn;
list_for_each_entry_safe(res, resn, res_list, list) {
list_del(&res->list);
kfree(res);
}
}
void apei_resources_fini(struct apei_resources *resources)
{
apei_res_clean(&resources->iomem);
apei_res_clean(&resources->ioport);
}
EXPORT_SYMBOL_GPL(apei_resources_fini);
static int apei_resources_merge(struct apei_resources *resources1,
struct apei_resources *resources2)
{
int rc;
struct apei_res *res;
list_for_each_entry(res, &resources2->iomem, list) {
rc = apei_res_add(&resources1->iomem, res->start,
res->end - res->start);
if (rc)
return rc;
}
list_for_each_entry(res, &resources2->ioport, list) {
rc = apei_res_add(&resources1->ioport, res->start,
res->end - res->start);
if (rc)
return rc;
}
return 0;
}
/*
* EINJ has two groups of GARs (EINJ table entry and trigger table
* entry), so common resources are subtracted from the trigger table
* resources before the second requesting.
*/
int apei_resources_sub(struct apei_resources *resources1,
struct apei_resources *resources2)
{
int rc;
rc = apei_res_sub(&resources1->iomem, &resources2->iomem);
if (rc)
return rc;
return apei_res_sub(&resources1->ioport, &resources2->ioport);
}
EXPORT_SYMBOL_GPL(apei_resources_sub);
/*
* IO memory/port rersource management mechanism is used to check
* whether memory/port area used by GARs conflicts with normal memory
* or IO memory/port of devices.
*/
int apei_resources_request(struct apei_resources *resources,
const char *desc)
{
struct apei_res *res, *res_bak = NULL;
struct resource *r;
int rc;
rc = apei_resources_sub(resources, &apei_resources_all);
if (rc)
return rc;
rc = -EINVAL;
list_for_each_entry(res, &resources->iomem, list) {
r = request_mem_region(res->start, res->end - res->start,
desc);
if (!r) {
pr_err(APEI_PFX
"Can not request iomem region <%016llx-%016llx> for GARs.\n",
(unsigned long long)res->start,
(unsigned long long)res->end);
res_bak = res;
goto err_unmap_iomem;
}
}
list_for_each_entry(res, &resources->ioport, list) {
r = request_region(res->start, res->end - res->start, desc);
if (!r) {
pr_err(APEI_PFX
"Can not request ioport region <%016llx-%016llx> for GARs.\n",
(unsigned long long)res->start,
(unsigned long long)res->end);
res_bak = res;
goto err_unmap_ioport;
}
}
rc = apei_resources_merge(&apei_resources_all, resources);
if (rc) {
pr_err(APEI_PFX "Fail to merge resources!\n");
goto err_unmap_ioport;
}
return 0;
err_unmap_ioport:
list_for_each_entry(res, &resources->ioport, list) {
if (res == res_bak)
break;
release_region(res->start, res->end - res->start);
}
res_bak = NULL;
err_unmap_iomem:
list_for_each_entry(res, &resources->iomem, list) {
if (res == res_bak)
break;
release_mem_region(res->start, res->end - res->start);
}
return rc;
}
EXPORT_SYMBOL_GPL(apei_resources_request);
void apei_resources_release(struct apei_resources *resources)
{
int rc;
struct apei_res *res;
list_for_each_entry(res, &resources->iomem, list)
release_mem_region(res->start, res->end - res->start);
list_for_each_entry(res, &resources->ioport, list)
release_region(res->start, res->end - res->start);
rc = apei_resources_sub(&apei_resources_all, resources);
if (rc)
pr_err(APEI_PFX "Fail to sub resources!\n");
}
EXPORT_SYMBOL_GPL(apei_resources_release);
static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr)
{
u32 width, space_id;
width = reg->bit_width;
space_id = reg->space_id;
/* Handle possible alignment issues */
memcpy(paddr, ®->address, sizeof(*paddr));
if (!*paddr) {
pr_warning(FW_BUG APEI_PFX
"Invalid physical address in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
if ((width != 8) && (width != 16) && (width != 32) && (width != 64)) {
pr_warning(FW_BUG APEI_PFX
"Invalid bit width in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
pr_warning(FW_BUG APEI_PFX
"Invalid address space type in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
return 0;
}
static int collect_res_callback(struct apei_exec_context *ctx,
struct acpi_whea_header *entry,
void *data)
{
struct apei_resources *resources = data;
struct acpi_generic_address *reg = &entry->register_region;
u8 ins = entry->instruction;
u64 paddr;
int rc;
if (!(ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER))
return 0;
rc = apei_check_gar(reg, &paddr);
if (rc)
return rc;
switch (reg->space_id) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
return apei_res_add(&resources->iomem, paddr,
reg->bit_width / 8);
case ACPI_ADR_SPACE_SYSTEM_IO:
return apei_res_add(&resources->ioport, paddr,
reg->bit_width / 8);
default:
return -EINVAL;
}
}
/*
* Same register may be used by multiple instructions in GARs, so
* resources are collected before requesting.
*/
int apei_exec_collect_resources(struct apei_exec_context *ctx,
struct apei_resources *resources)
{
return apei_exec_for_each_entry(ctx, collect_res_callback,
resources, NULL);
}
EXPORT_SYMBOL_GPL(apei_exec_collect_resources);
struct dentry *apei_get_debugfs_dir(void)
{
static struct dentry *dapei;
if (!dapei)
dapei = debugfs_create_dir("apei", NULL);
return dapei;
}
EXPORT_SYMBOL_GPL(apei_get_debugfs_dir);
