path: root/drivers/acpi/apei/erst.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * APEI Error Record Serialization Table support
 *
 * ERST is a way provided by APEI to save and retrieve hardware error
 * information to and from a persistent store.
 *
 * 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>
 */

#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>
#include <linux/hardirq.h>
#include <linux/pstore.h>
#include <linux/vmalloc.h>
#include <linux/mm.h> /* kvfree() */
#include <acpi/apei.h>

#include "apei-internal.h"

#undef pr_fmt
#define pr_fmt(fmt) "ERST: " fmt

/* 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 */
/* Firmware should respond within 1 milliseconds */
#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.
 */
static DEFINE_RAW_SPINLOCK(erst_lock);

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_warn(FW_WARN "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