erst.c 28.2 KB
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/*
 * APEI Error Record Serialization Table support
 *
 * ERST is a way provided by APEI to save and retrieve hardware error
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 * information to and from a persistent store.
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 *
 * For more information about ERST, please refer to ACPI Specification
 * version 4.0, section 17.4.
 *
 * 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/delay.h>
#include <linux/io.h>
#include <linux/acpi.h>
#include <linux/uaccess.h>
#include <linux/cper.h>
#include <linux/nmi.h>
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#include <linux/hardirq.h>
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#include <linux/pstore.h>
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#include <acpi/apei.h>

#include "apei-internal.h"

#define ERST_PFX "ERST: "

/* ERST command status */
#define ERST_STATUS_SUCCESS			0x0
#define ERST_STATUS_NOT_ENOUGH_SPACE		0x1
#define ERST_STATUS_HARDWARE_NOT_AVAILABLE	0x2
#define ERST_STATUS_FAILED			0x3
#define ERST_STATUS_RECORD_STORE_EMPTY		0x4
#define ERST_STATUS_RECORD_NOT_FOUND		0x5

#define ERST_TAB_ENTRY(tab)						\
	((struct acpi_whea_header *)((char *)(tab) +			\
				     sizeof(struct acpi_table_erst)))

#define SPIN_UNIT		100			/* 100ns */
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/* Firmware should respond within 1 milliseconds */
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#define FIRMWARE_TIMEOUT	(1 * NSEC_PER_MSEC)
#define FIRMWARE_MAX_STALL	50			/* 50us */

int erst_disable;
EXPORT_SYMBOL_GPL(erst_disable);

static struct acpi_table_erst *erst_tab;

/* ERST Error Log Address Range atrributes */
#define ERST_RANGE_RESERVED	0x0001
#define ERST_RANGE_NVRAM	0x0002
#define ERST_RANGE_SLOW		0x0004

/*
 * ERST Error Log Address Range, used as buffer for reading/writing
 * error records.
 */
static struct erst_erange {
	u64 base;
	u64 size;
	void __iomem *vaddr;
	u32 attr;
} erst_erange;

/*
 * Prevent ERST interpreter to run simultaneously, because the
 * corresponding firmware implementation may not work properly when
 * invoked simultaneously.
 *
 * It is used to provide exclusive accessing for ERST Error Log
 * Address Range too.
 */
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static DEFINE_RAW_SPINLOCK(erst_lock);
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static inline int erst_errno(int command_status)
{
	switch (command_status) {
	case ERST_STATUS_SUCCESS:
		return 0;
	case ERST_STATUS_HARDWARE_NOT_AVAILABLE:
		return -ENODEV;
	case ERST_STATUS_NOT_ENOUGH_SPACE:
		return -ENOSPC;
	case ERST_STATUS_RECORD_STORE_EMPTY:
	case ERST_STATUS_RECORD_NOT_FOUND:
		return -ENOENT;
	default:
		return -EINVAL;
	}
}

static int erst_timedout(u64 *t, u64 spin_unit)
{
	if ((s64)*t < spin_unit) {
		pr_warning(FW_WARN ERST_PFX
			   "Firmware does not respond in time\n");
		return 1;
	}
	*t -= spin_unit;
	ndelay(spin_unit);
	touch_nmi_watchdog();
	return 0;
}

static int erst_exec_load_var1(struct apei_exec_context *ctx,
			       struct acpi_whea_header *entry)
{
	return __apei_exec_read_register(entry, &ctx->var1);
}

static int erst_exec_load_var2(struct apei_exec_context *ctx,
			       struct acpi_whea_header *entry)
{
	return __apei_exec_read_register(entry, &ctx->var2);
}

static int erst_exec_store_var1(struct apei_exec_context *ctx,
				struct acpi_whea_header *entry)
{
	return __apei_exec_write_register(entry, ctx->var1);
}

static int erst_exec_add(struct apei_exec_context *ctx,
			 struct acpi_whea_header *entry)
{
	ctx->var1 += ctx->var2;
	return 0;
}

static int erst_exec_subtract(struct apei_exec_context *ctx,
			      struct acpi_whea_header *entry)
{
	ctx->var1 -= ctx->var2;
	return 0;
}

static int erst_exec_add_value(struct apei_exec_context *ctx,
			       struct acpi_whea_header *entry)
{
	int rc;
	u64 val;

	rc = __apei_exec_read_register(entry, &val);
	if (rc)
		return rc;
	val += ctx->value;
	rc = __apei_exec_write_register(entry, val);
	return rc;
}

static int erst_exec_subtract_value(struct apei_exec_context *ctx,
				    struct acpi_whea_header *entry)
{
	int rc;
	u64 val;

	rc = __apei_exec_read_register(entry, &val);
	if (rc)
		return rc;
	val -= ctx->value;
	rc = __apei_exec_write_register(entry, val);
	return rc;
}

static int erst_exec_stall(struct apei_exec_context *ctx,
			   struct acpi_whea_header *entry)
{
	u64 stall_time;

	if (ctx->value > FIRMWARE_MAX_STALL) {
		if (!in_nmi())
			pr_warning(FW_WARN ERST_PFX
			"Too long stall time for stall instruction: %llx.\n",
				   ctx->value);
		stall_time = FIRMWARE_MAX_STALL;
	} else
		stall_time = ctx->value;
	udelay(stall_time);
	return 0;
}

static int erst_exec_stall_while_true(struct apei_exec_context *ctx,
				      struct acpi_whea_header *entry)
{
	int rc;
	u64 val;
	u64 timeout = FIRMWARE_TIMEOUT;
	u64 stall_time;

	if (ctx->var1 > FIRMWARE_MAX_STALL) {
		if (!in_nmi())
			pr_warning(FW_WARN ERST_PFX
		"Too long stall time for stall while true instruction: %llx.\n",
				   ctx->var1);
		stall_time = FIRMWARE_MAX_STALL;
	} else
		stall_time = ctx->var1;

	for (;;) {
		rc = __apei_exec_read_register(entry, &val);
		if (rc)
			return rc;
		if (val != ctx->value)
			break;
		if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC))
			return -EIO;
	}
	return 0;
}

static int erst_exec_skip_next_instruction_if_true(
	struct apei_exec_context *ctx,
	struct acpi_whea_header *entry)
{
	int rc;
	u64 val;

	rc = __apei_exec_read_register(entry, &val);
	if (rc)
		return rc;
	if (val == ctx->value) {
		ctx->ip += 2;
		return APEI_EXEC_SET_IP;
	}

	return 0;
}

static int erst_exec_goto(struct apei_exec_context *ctx,
			  struct acpi_whea_header *entry)
{
	ctx->ip = ctx->value;
	return APEI_EXEC_SET_IP;
}

static int erst_exec_set_src_address_base(struct apei_exec_context *ctx,
					  struct acpi_whea_header *entry)
{
	return __apei_exec_read_register(entry, &ctx->src_base);
}

static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx,
					  struct acpi_whea_header *entry)
{
	return __apei_exec_read_register(entry, &ctx->dst_base);
}

static int erst_exec_move_data(struct apei_exec_context *ctx,
			       struct acpi_whea_header *entry)
{
	int rc;
	u64 offset;
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	void *src, *dst;

	/* ioremap does not work in interrupt context */
	if (in_interrupt()) {
		pr_warning(ERST_PFX
			   "MOVE_DATA can not be used in interrupt context");
		return -EBUSY;
	}
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	rc = __apei_exec_read_register(entry, &offset);
	if (rc)
		return rc;
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	src = ioremap(ctx->src_base + offset, ctx->var2);
	if (!src)
		return -ENOMEM;
	dst = ioremap(ctx->dst_base + offset, ctx->var2);
	if (!dst)
		return -ENOMEM;

	memmove(dst, src, ctx->var2);

	iounmap(src);
	iounmap(dst);
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	return 0;
}

static struct apei_exec_ins_type erst_ins_type[] = {
	[ACPI_ERST_READ_REGISTER] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = apei_exec_read_register,
	},
	[ACPI_ERST_READ_REGISTER_VALUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = apei_exec_read_register_value,
	},
	[ACPI_ERST_WRITE_REGISTER] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = apei_exec_write_register,
	},
	[ACPI_ERST_WRITE_REGISTER_VALUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = apei_exec_write_register_value,
	},
	[ACPI_ERST_NOOP] = {
		.flags = 0,
		.run = apei_exec_noop,
	},
	[ACPI_ERST_LOAD_VAR1] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_load_var1,
	},
	[ACPI_ERST_LOAD_VAR2] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_load_var2,
	},
	[ACPI_ERST_STORE_VAR1] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_store_var1,
	},
	[ACPI_ERST_ADD] = {
		.flags = 0,
		.run = erst_exec_add,
	},
	[ACPI_ERST_SUBTRACT] = {
		.flags = 0,
		.run = erst_exec_subtract,
	},
	[ACPI_ERST_ADD_VALUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_add_value,
	},
	[ACPI_ERST_SUBTRACT_VALUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_subtract_value,
	},
	[ACPI_ERST_STALL] = {
		.flags = 0,
		.run = erst_exec_stall,
	},
	[ACPI_ERST_STALL_WHILE_TRUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_stall_while_true,
	},
	[ACPI_ERST_SKIP_NEXT_IF_TRUE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_skip_next_instruction_if_true,
	},
	[ACPI_ERST_GOTO] = {
		.flags = 0,
		.run = erst_exec_goto,
	},
	[ACPI_ERST_SET_SRC_ADDRESS_BASE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_set_src_address_base,
	},
	[ACPI_ERST_SET_DST_ADDRESS_BASE] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_set_dst_address_base,
	},
	[ACPI_ERST_MOVE_DATA] = {
		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
		.run = erst_exec_move_data,
	},
};

static inline void erst_exec_ctx_init(struct apei_exec_context *ctx)
{
	apei_exec_ctx_init(ctx, erst_ins_type, ARRAY_SIZE(erst_ins_type),
			   ERST_TAB_ENTRY(erst_tab), erst_tab->entries);
}

static int erst_get_erange(struct erst_erange *range)
{
	struct apei_exec_context ctx;
	int rc;

	erst_exec_ctx_init(&ctx);
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_RANGE);
	if (rc)
		return rc;
	range->base = apei_exec_ctx_get_output(&ctx);
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_LENGTH);
	if (rc)
		return rc;
	range->size = apei_exec_ctx_get_output(&ctx);
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_ATTRIBUTES);
	if (rc)
		return rc;
	range->attr = apei_exec_ctx_get_output(&ctx);

	return 0;
}

static ssize_t __erst_get_record_count(void)
{
	struct apei_exec_context ctx;
	int rc;

	erst_exec_ctx_init(&ctx);
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_COUNT);
	if (rc)
		return rc;
	return apei_exec_ctx_get_output(&ctx);
}

ssize_t erst_get_record_count(void)
{
	ssize_t count;
	unsigned long flags;

	if (erst_disable)
		return -ENODEV;

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	raw_spin_lock_irqsave(&erst_lock, flags);
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	count = __erst_get_record_count();
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	raw_spin_unlock_irqrestore(&erst_lock, flags);
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	return count;
}
EXPORT_SYMBOL_GPL(erst_get_record_count);

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#define ERST_RECORD_ID_CACHE_SIZE_MIN	16
#define ERST_RECORD_ID_CACHE_SIZE_MAX	1024

struct erst_record_id_cache {
	struct mutex lock;
	u64 *entries;
	int len;
	int size;
	int refcount;
};

static struct erst_record_id_cache erst_record_id_cache = {
	.lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
	.refcount = 0,
};

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static int __erst_get_next_record_id(u64 *record_id)
{
	struct apei_exec_context ctx;
	int rc;

	erst_exec_ctx_init(&ctx);
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID);
	if (rc)
		return rc;
	*record_id = apei_exec_ctx_get_output(&ctx);

	return 0;
}

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int erst_get_record_id_begin(int *pos)
{
	int rc;

	if (erst_disable)
		return -ENODEV;

	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
	if (rc)
		return rc;
	erst_record_id_cache.refcount++;
	mutex_unlock(&erst_record_id_cache.lock);

	*pos = 0;

	return 0;
}
EXPORT_SYMBOL_GPL(erst_get_record_id_begin);

/* erst_record_id_cache.lock must be held by caller */
static int __erst_record_id_cache_add_one(void)
{
	u64 id, prev_id, first_id;
	int i, rc;
	u64 *entries;
	unsigned long flags;

	id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
retry:
	raw_spin_lock_irqsave(&erst_lock, flags);
	rc = __erst_get_next_record_id(&id);
	raw_spin_unlock_irqrestore(&erst_lock, flags);
	if (rc == -ENOENT)
		return 0;
	if (rc)
		return rc;
	if (id == APEI_ERST_INVALID_RECORD_ID)
		return 0;
	/* can not skip current ID, or loop back to first ID */
	if (id == prev_id || id == first_id)
		return 0;
	if (first_id == APEI_ERST_INVALID_RECORD_ID)
		first_id = id;
	prev_id = id;

	entries = erst_record_id_cache.entries;
	for (i = 0; i < erst_record_id_cache.len; i++) {
		if (entries[i] == id)
			break;
	}
	/* record id already in cache, try next */
	if (i < erst_record_id_cache.len)
		goto retry;
	if (erst_record_id_cache.len >= erst_record_id_cache.size) {
		int new_size, alloc_size;
		u64 *new_entries;

		new_size = erst_record_id_cache.size * 2;
		new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
				     ERST_RECORD_ID_CACHE_SIZE_MAX);
		if (new_size <= erst_record_id_cache.size) {
			if (printk_ratelimit())
				pr_warning(FW_WARN ERST_PFX
					   "too many record ID!\n");
			return 0;
		}
		alloc_size = new_size * sizeof(entries[0]);
		if (alloc_size < PAGE_SIZE)
			new_entries = kmalloc(alloc_size, GFP_KERNEL);
		else
			new_entries = vmalloc(alloc_size);
		if (!new_entries)
			return -ENOMEM;
		memcpy(new_entries, entries,
		       erst_record_id_cache.len * sizeof(entries[0]));
		if (erst_record_id_cache.size < PAGE_SIZE)
			kfree(entries);
		else
			vfree(entries);
		erst_record_id_cache.entries = entries = new_entries;
		erst_record_id_cache.size = new_size;
	}
	entries[i] = id;
	erst_record_id_cache.len++;

	return 1;
}

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/*
 * Get the record ID of an existing error record on the persistent
 * storage. If there is no error record on the persistent storage, the
 * returned record_id is APEI_ERST_INVALID_RECORD_ID.
 */
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int erst_get_record_id_next(int *pos, u64 *record_id)
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{
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	int rc = 0;
	u64 *entries;
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	if (erst_disable)
		return -ENODEV;

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	/* must be enclosed by erst_get_record_id_begin/end */
	BUG_ON(!erst_record_id_cache.refcount);
	BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);

	mutex_lock(&erst_record_id_cache.lock);
	entries = erst_record_id_cache.entries;
	for (; *pos < erst_record_id_cache.len; (*pos)++)
		if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
			break;
	/* found next record id in cache */
	if (*pos < erst_record_id_cache.len) {
		*record_id = entries[*pos];
		(*pos)++;
		goto out_unlock;
	}

	/* Try to add one more record ID to cache */
	rc = __erst_record_id_cache_add_one();
	if (rc < 0)
		goto out_unlock;
	/* successfully add one new ID */
	if (rc == 1) {
		*record_id = erst_record_id_cache.entries[*pos];
		(*pos)++;
		rc = 0;
	} else {
		*pos = -1;
		*record_id = APEI_ERST_INVALID_RECORD_ID;
	}
out_unlock:
	mutex_unlock(&erst_record_id_cache.lock);
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	return rc;
}
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EXPORT_SYMBOL_GPL(erst_get_record_id_next);

/* erst_record_id_cache.lock must be held by caller */
static void __erst_record_id_cache_compact(void)
{
	int i, wpos = 0;
	u64 *entries;

	if (erst_record_id_cache.refcount)
		return;

	entries = erst_record_id_cache.entries;
	for (i = 0; i < erst_record_id_cache.len; i++) {
		if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
			continue;
		if (wpos != i)
			memcpy(&entries[wpos], &entries[i], sizeof(entries[i]));
		wpos++;
	}
	erst_record_id_cache.len = wpos;
}

void erst_get_record_id_end(void)
{
	/*
	 * erst_disable != 0 should be detected by invoker via the
	 * return value of erst_get_record_id_begin/next, so this
	 * function should not be called for erst_disable != 0.
	 */
	BUG_ON(erst_disable);

	mutex_lock(&erst_record_id_cache.lock);
	erst_record_id_cache.refcount--;
	BUG_ON(erst_record_id_cache.refcount < 0);
	__erst_record_id_cache_compact();
	mutex_unlock(&erst_record_id_cache.lock);
}
EXPORT_SYMBOL_GPL(erst_get_record_id_end);
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static int __erst_write_to_storage(u64 offset)
{
	struct apei_exec_context ctx;
	u64 timeout = FIRMWARE_TIMEOUT;
	u64 val;
	int rc;

	erst_exec_ctx_init(&ctx);
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	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
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	if (rc)
		return rc;
	apei_exec_ctx_set_input(&ctx, offset);
	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
	if (rc)
		return rc;
	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
	if (rc)
		return rc;
	for (;;) {
		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
		if (rc)
			return rc;
		val = apei_exec_ctx_get_output(&ctx);
		if (!val)
			break;
		if (erst_timedout(&timeout, SPIN_UNIT))
			return -EIO;
	}
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
	if (rc)
		return rc;
	val = apei_exec_ctx_get_output(&ctx);
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	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
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	if (rc)
		return rc;

	return erst_errno(val);
}

static int __erst_read_from_storage(u64 record_id, u64 offset)
{
	struct apei_exec_context ctx;
	u64 timeout = FIRMWARE_TIMEOUT;
	u64 val;
	int rc;

	erst_exec_ctx_init(&ctx);
684
	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711
	if (rc)
		return rc;
	apei_exec_ctx_set_input(&ctx, offset);
	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
	if (rc)
		return rc;
	apei_exec_ctx_set_input(&ctx, record_id);
	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
	if (rc)
		return rc;
	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
	if (rc)
		return rc;
	for (;;) {
		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
		if (rc)
			return rc;
		val = apei_exec_ctx_get_output(&ctx);
		if (!val)
			break;
		if (erst_timedout(&timeout, SPIN_UNIT))
			return -EIO;
	};
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
	if (rc)
		return rc;
	val = apei_exec_ctx_get_output(&ctx);
712
	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
713 714 715 716 717 718 719 720 721 722 723 724 725 726
	if (rc)
		return rc;

	return erst_errno(val);
}

static int __erst_clear_from_storage(u64 record_id)
{
	struct apei_exec_context ctx;
	u64 timeout = FIRMWARE_TIMEOUT;
	u64 val;
	int rc;

	erst_exec_ctx_init(&ctx);
727
	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750
	if (rc)
		return rc;
	apei_exec_ctx_set_input(&ctx, record_id);
	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
	if (rc)
		return rc;
	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
	if (rc)
		return rc;
	for (;;) {
		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
		if (rc)
			return rc;
		val = apei_exec_ctx_get_output(&ctx);
		if (!val)
			break;
		if (erst_timedout(&timeout, SPIN_UNIT))
			return -EIO;
	}
	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
	if (rc)
		return rc;
	val = apei_exec_ctx_get_output(&ctx);
751
	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796
	if (rc)
		return rc;

	return erst_errno(val);
}

/* NVRAM ERST Error Log Address Range is not supported yet */
static void pr_unimpl_nvram(void)
{
	if (printk_ratelimit())
		pr_warning(ERST_PFX
		"NVRAM ERST Log Address Range is not implemented yet\n");
}

static int __erst_write_to_nvram(const struct cper_record_header *record)
{
	/* do not print message, because printk is not safe for NMI */
	return -ENOSYS;
}

static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
{
	pr_unimpl_nvram();
	return -ENOSYS;
}

static int __erst_clear_from_nvram(u64 record_id)
{
	pr_unimpl_nvram();
	return -ENOSYS;
}

int erst_write(const struct cper_record_header *record)
{
	int rc;
	unsigned long flags;
	struct cper_record_header *rcd_erange;

	if (erst_disable)
		return -ENODEV;

	if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE))
		return -EINVAL;

	if (erst_erange.attr & ERST_RANGE_NVRAM) {
H
Huang Ying 已提交
797
		if (!raw_spin_trylock_irqsave(&erst_lock, flags))
798 799
			return -EBUSY;
		rc = __erst_write_to_nvram(record);
H
Huang Ying 已提交
800
		raw_spin_unlock_irqrestore(&erst_lock, flags);
801 802 803 804 805 806
		return rc;
	}

	if (record->record_length > erst_erange.size)
		return -EINVAL;

H
Huang Ying 已提交
807
	if (!raw_spin_trylock_irqsave(&erst_lock, flags))
808 809 810 811 812 813 814
		return -EBUSY;
	memcpy(erst_erange.vaddr, record, record->record_length);
	rcd_erange = erst_erange.vaddr;
	/* signature for serialization system */
	memcpy(&rcd_erange->persistence_information, "ER", 2);

	rc = __erst_write_to_storage(0);
H
Huang Ying 已提交
815
	raw_spin_unlock_irqrestore(&erst_lock, flags);
816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868

	return rc;
}
EXPORT_SYMBOL_GPL(erst_write);

static int __erst_read_to_erange(u64 record_id, u64 *offset)
{
	int rc;

	if (erst_erange.attr & ERST_RANGE_NVRAM)
		return __erst_read_to_erange_from_nvram(
			record_id, offset);

	rc = __erst_read_from_storage(record_id, 0);
	if (rc)
		return rc;
	*offset = 0;

	return 0;
}

static ssize_t __erst_read(u64 record_id, struct cper_record_header *record,
			   size_t buflen)
{
	int rc;
	u64 offset, len = 0;
	struct cper_record_header *rcd_tmp;

	rc = __erst_read_to_erange(record_id, &offset);
	if (rc)
		return rc;
	rcd_tmp = erst_erange.vaddr + offset;
	len = rcd_tmp->record_length;
	if (len <= buflen)
		memcpy(record, rcd_tmp, len);

	return len;
}

/*
 * If return value > buflen, the buffer size is not big enough,
 * else if return value < 0, something goes wrong,
 * else everything is OK, and return value is record length
 */
ssize_t erst_read(u64 record_id, struct cper_record_header *record,
		  size_t buflen)
{
	ssize_t len;
	unsigned long flags;

	if (erst_disable)
		return -ENODEV;

H
Huang Ying 已提交
869
	raw_spin_lock_irqsave(&erst_lock, flags);
870
	len = __erst_read(record_id, record, buflen);
H
Huang Ying 已提交
871
	raw_spin_unlock_irqrestore(&erst_lock, flags);
872 873 874 875 876 877
	return len;
}
EXPORT_SYMBOL_GPL(erst_read);

int erst_clear(u64 record_id)
{
878
	int rc, i;
879
	unsigned long flags;
880
	u64 *entries;
881 882 883 884

	if (erst_disable)
		return -ENODEV;

885 886 887
	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
	if (rc)
		return rc;
H
Huang Ying 已提交
888
	raw_spin_lock_irqsave(&erst_lock, flags);
889 890 891 892
	if (erst_erange.attr & ERST_RANGE_NVRAM)
		rc = __erst_clear_from_nvram(record_id);
	else
		rc = __erst_clear_from_storage(record_id);
H
Huang Ying 已提交
893
	raw_spin_unlock_irqrestore(&erst_lock, flags);
894 895 896 897 898 899 900 901 902 903
	if (rc)
		goto out;
	entries = erst_record_id_cache.entries;
	for (i = 0; i < erst_record_id_cache.len; i++) {
		if (entries[i] == record_id)
			entries[i] = APEI_ERST_INVALID_RECORD_ID;
	}
	__erst_record_id_cache_compact();
out:
	mutex_unlock(&erst_record_id_cache.lock);
904 905 906 907 908 909 910 911 912 913 914 915 916 917
	return rc;
}
EXPORT_SYMBOL_GPL(erst_clear);

static int __init setup_erst_disable(char *str)
{
	erst_disable = 1;
	return 0;
}

__setup("erst_disable", setup_erst_disable);

static int erst_check_table(struct acpi_table_erst *erst_tab)
{
918 919 920
	if ((erst_tab->header_length !=
	     (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
	    && (erst_tab->header_length != sizeof(struct acpi_table_einj)))
921 922 923 924 925 926 927 928 929 930 931
		return -EINVAL;
	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
		return -EINVAL;
	if (erst_tab->entries !=
	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
	    sizeof(struct acpi_erst_entry))
		return -EINVAL;

	return 0;
}

932 933
static int erst_open_pstore(struct pstore_info *psi);
static int erst_close_pstore(struct pstore_info *psi);
934
static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
935
			   struct timespec *time, struct pstore_info *psi);
M
Matthew Garrett 已提交
936 937
static u64 erst_writer(enum pstore_type_id type, unsigned int part,
		       size_t size, struct pstore_info *psi);
938 939
static int erst_clearer(enum pstore_type_id type, u64 id,
			struct pstore_info *psi);
940 941 942 943

static struct pstore_info erst_info = {
	.owner		= THIS_MODULE,
	.name		= "erst",
944 945
	.open		= erst_open_pstore,
	.close		= erst_close_pstore,
946 947
	.read		= erst_reader,
	.write		= erst_writer,
948
	.erase		= erst_clearer
949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966
};

#define CPER_CREATOR_PSTORE						\
	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
		0x64, 0x90, 0xb8, 0x9d)
#define CPER_SECTION_TYPE_DMESG						\
	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
		0x94, 0x19, 0xeb, 0x12)
#define CPER_SECTION_TYPE_MCE						\
	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
		0x04, 0x4a, 0x38, 0xfc)

struct cper_pstore_record {
	struct cper_record_header hdr;
	struct cper_section_descriptor sec_hdr;
	char data[];
} __packed;

967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987
static int reader_pos;

static int erst_open_pstore(struct pstore_info *psi)
{
	int rc;

	if (erst_disable)
		return -ENODEV;

	rc = erst_get_record_id_begin(&reader_pos);

	return rc;
}

static int erst_close_pstore(struct pstore_info *psi)
{
	erst_get_record_id_end();

	return 0;
}

988
static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
989
			   struct timespec *time, struct pstore_info *psi)
990 991
{
	int rc;
992
	ssize_t len = 0;
993 994 995 996 997 998 999 1000
	u64 record_id;
	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
					(erst_info.buf - sizeof(*rcd));

	if (erst_disable)
		return -ENODEV;

skip:
1001 1002 1003 1004
	rc = erst_get_record_id_next(&reader_pos, &record_id);
	if (rc)
		goto out;

1005 1006
	/* no more record */
	if (record_id == APEI_ERST_INVALID_RECORD_ID) {
1007 1008
		rc = -1;
		goto out;
1009 1010
	}

1011
	len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
1012 1013 1014 1015 1016 1017 1018 1019
			erst_info.bufsize);
	/* The record may be cleared by others, try read next record */
	if (len == -ENOENT)
		goto skip;
	else if (len < 0) {
		rc = -1;
		goto out;
	}
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
		goto skip;

	*id = record_id;
	if (uuid_le_cmp(rcd->sec_hdr.section_type,
			CPER_SECTION_TYPE_DMESG) == 0)
		*type = PSTORE_TYPE_DMESG;
	else if (uuid_le_cmp(rcd->sec_hdr.section_type,
			     CPER_SECTION_TYPE_MCE) == 0)
		*type = PSTORE_TYPE_MCE;
	else
		*type = PSTORE_TYPE_UNKNOWN;

	if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
		time->tv_sec = rcd->hdr.timestamp;
	else
		time->tv_sec = 0;
	time->tv_nsec = 0;

1039 1040
out:
	return (rc < 0) ? rc : (len - sizeof(*rcd));
1041 1042
}

M
Matthew Garrett 已提交
1043 1044
static u64 erst_writer(enum pstore_type_id type, unsigned int part,
		       size_t size, struct pstore_info *psi)
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
{
	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
					(erst_info.buf - sizeof(*rcd));

	memset(rcd, 0, sizeof(*rcd));
	memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
	rcd->hdr.revision = CPER_RECORD_REV;
	rcd->hdr.signature_end = CPER_SIG_END;
	rcd->hdr.section_count = 1;
	rcd->hdr.error_severity = CPER_SEV_FATAL;
	/* timestamp valid. platform_id, partition_id are invalid */
	rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
	rcd->hdr.timestamp = get_seconds();
	rcd->hdr.record_length = sizeof(*rcd) + size;
	rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
	rcd->hdr.notification_type = CPER_NOTIFY_MCE;
	rcd->hdr.record_id = cper_next_record_id();
	rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;

	rcd->sec_hdr.section_offset = sizeof(*rcd);
	rcd->sec_hdr.section_length = size;
	rcd->sec_hdr.revision = CPER_SEC_REV;
	/* fru_id and fru_text is invalid */
	rcd->sec_hdr.validation_bits = 0;
	rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
	switch (type) {
	case PSTORE_TYPE_DMESG:
		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
		break;
	case PSTORE_TYPE_MCE:
		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
		break;
	default:
		return -EINVAL;
	}
	rcd->sec_hdr.section_severity = CPER_SEV_FATAL;

	erst_write(&rcd->hdr);

	return rcd->hdr.record_id;
}

1087 1088
static int erst_clearer(enum pstore_type_id type, u64 id,
			struct pstore_info *psi)
1089 1090 1091 1092
{
	return erst_clear(id);
}

1093 1094 1095 1096 1097 1098 1099
static int __init erst_init(void)
{
	int rc = 0;
	acpi_status status;
	struct apei_exec_context ctx;
	struct apei_resources erst_resources;
	struct resource *r;
1100
	char *buf;
1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113

	if (acpi_disabled)
		goto err;

	if (erst_disable) {
		pr_info(ERST_PFX
	"Error Record Serialization Table (ERST) support is disabled.\n");
		goto err;
	}

	status = acpi_get_table(ACPI_SIG_ERST, 0,
				(struct acpi_table_header **)&erst_tab);
	if (status == AE_NOT_FOUND) {
1114
		pr_info(ERST_PFX "Table is not found!\n");
1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166
		goto err;
	} else if (ACPI_FAILURE(status)) {
		const char *msg = acpi_format_exception(status);
		pr_err(ERST_PFX "Failed to get table, %s\n", msg);
		rc = -EINVAL;
		goto err;
	}

	rc = erst_check_table(erst_tab);
	if (rc) {
		pr_err(FW_BUG ERST_PFX "ERST table is invalid\n");
		goto err;
	}

	apei_resources_init(&erst_resources);
	erst_exec_ctx_init(&ctx);
	rc = apei_exec_collect_resources(&ctx, &erst_resources);
	if (rc)
		goto err_fini;
	rc = apei_resources_request(&erst_resources, "APEI ERST");
	if (rc)
		goto err_fini;
	rc = apei_exec_pre_map_gars(&ctx);
	if (rc)
		goto err_release;
	rc = erst_get_erange(&erst_erange);
	if (rc) {
		if (rc == -ENODEV)
			pr_info(ERST_PFX
	"The corresponding hardware device or firmware implementation "
	"is not available.\n");
		else
			pr_err(ERST_PFX
			       "Failed to get Error Log Address Range.\n");
		goto err_unmap_reg;
	}

	r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST");
	if (!r) {
		pr_err(ERST_PFX
		"Can not request iomem region <0x%16llx-0x%16llx> for ERST.\n",
		(unsigned long long)erst_erange.base,
		(unsigned long long)erst_erange.base + erst_erange.size);
		rc = -EIO;
		goto err_unmap_reg;
	}
	rc = -ENOMEM;
	erst_erange.vaddr = ioremap_cache(erst_erange.base,
					  erst_erange.size);
	if (!erst_erange.vaddr)
		goto err_release_erange;

1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178
	buf = kmalloc(erst_erange.size, GFP_KERNEL);
	mutex_init(&erst_info.buf_mutex);
	if (buf) {
		erst_info.buf = buf + sizeof(struct cper_pstore_record);
		erst_info.bufsize = erst_erange.size -
				    sizeof(struct cper_pstore_record);
		if (pstore_register(&erst_info)) {
			pr_info(ERST_PFX "Could not register with persistent store\n");
			kfree(buf);
		}
	}

1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197
	pr_info(ERST_PFX
	"Error Record Serialization Table (ERST) support is initialized.\n");

	return 0;

err_release_erange:
	release_mem_region(erst_erange.base, erst_erange.size);
err_unmap_reg:
	apei_exec_post_unmap_gars(&ctx);
err_release:
	apei_resources_release(&erst_resources);
err_fini:
	apei_resources_fini(&erst_resources);
err:
	erst_disable = 1;
	return rc;
}

device_initcall(erst_init);