hest.c

Go to the documentation of this file.

/*
 * APEI Hardware Error Souce Table support
 *
 * HEST describes error sources in detail; communicates operational
 * parameters (i.e. severity levels, masking bits, and threshold
 * values) to Linux as necessary. It also allows the BIOS to report
 * non-standard error sources to Linux (for example, chipset-specific
 * error registers).
 *
 * For more information about HEST, please refer to ACPI Specification
 * version 4.0, section 17.3.2.
 *
 * Copyright 2009 Intel Corp.
 *   Author: Huang Ying <[email protected]>
 *
 * 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/kdebug.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <acpi/apei.h>

#include "apei-internal.h"

#define HEST_PFX "HEST: "

bool hest_disable;
EXPORT_SYMBOL_GPL(hest_disable);

/* HEST table parsing */

static struct acpi_table_hest *__read_mostly hest_tab;

static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
    [ACPI_HEST_TYPE_IA32_CHECK] = -1,   /* need further calculation */
    [ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
    [ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
    [ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
    [ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
    [ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
    [ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
};

static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
{
    u16 hest_type = hest_hdr->type;
    int len;

    if (hest_type >= ACPI_HEST_TYPE_RESERVED)
        return 0;

    len = hest_esrc_len_tab[hest_type];

    if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
        struct acpi_hest_ia_corrected *cmc;
        cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
        len = sizeof(*cmc) + cmc->num_hardware_banks *
            sizeof(struct acpi_hest_ia_error_bank);
    } else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
        struct acpi_hest_ia_machine_check *mc;
        mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
        len = sizeof(*mc) + mc->num_hardware_banks *
            sizeof(struct acpi_hest_ia_error_bank);
    }
    BUG_ON(len == -1);

    return len;
};

int apei_hest_parse(apei_hest_func_t func, void *data)
{
    struct acpi_hest_header *hest_hdr;
    int i, rc, len;

    if (hest_disable)
        return -EINVAL;

    hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
    for (i = 0; i < hest_tab->error_source_count; i++) {
        len = hest_esrc_len(hest_hdr);
        if (!len) {
            pr_warning(FW_WARN HEST_PFX
                   "Unknown or unused hardware error source "
                   "type: %d for hardware error source: %d.\n",
                   hest_hdr->type, hest_hdr->source_id);
            return -EINVAL;
        }
        if ((void *)hest_hdr + len >
            (void *)hest_tab + hest_tab->header.length) {
            pr_warning(FW_BUG HEST_PFX
        "Table contents overflow for hardware error source: %d.\n",
                hest_hdr->source_id);
            return -EINVAL;
        }

        rc = func(hest_hdr, data);
        if (rc)
            return rc;

        hest_hdr = (void *)hest_hdr + len;
    }

    return 0;
}
EXPORT_SYMBOL_GPL(apei_hest_parse);

struct ghes_arr {
    struct platform_device **ghes_devs;
    unsigned int count;
};

static int __init hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)
{
    int *count = data;

    if (hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR)
        (*count)++;
    return 0;
}

static int __init hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
{
    struct platform_device *ghes_dev;
    struct ghes_arr *ghes_arr = data;
    int rc, i;

    if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
        return 0;

    if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
        return 0;
    for (i = 0; i < ghes_arr->count; i++) {
        struct acpi_hest_header *hdr;
        ghes_dev = ghes_arr->ghes_devs[i];
        hdr = *(struct acpi_hest_header **)ghes_dev->dev.platform_data;
        if (hdr->source_id == hest_hdr->source_id) {
            pr_warning(FW_WARN HEST_PFX "Duplicated hardware error source ID: %d.\n",
                   hdr->source_id);
            return -EIO;
        }
    }
    ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
    if (!ghes_dev)
        return -ENOMEM;

    rc = platform_device_add_data(ghes_dev, &hest_hdr, sizeof(void *));
    if (rc)
        goto err;

    rc = platform_device_add(ghes_dev);
    if (rc)
        goto err;
    ghes_arr->ghes_devs[ghes_arr->count++] = ghes_dev;

    return 0;
err:
    platform_device_put(ghes_dev);
    return rc;
}

static int __init hest_ghes_dev_register(unsigned int ghes_count)
{
    int rc, i;
    struct ghes_arr ghes_arr;

    ghes_arr.count = 0;
    ghes_arr.ghes_devs = kmalloc(sizeof(void *) * ghes_count, GFP_KERNEL);
    if (!ghes_arr.ghes_devs)
        return -ENOMEM;

    rc = apei_hest_parse(hest_parse_ghes, &ghes_arr);
    if (rc)
        goto err;
out:
    kfree(ghes_arr.ghes_devs);
    return rc;
err:
    for (i = 0; i < ghes_arr.count; i++)
        platform_device_unregister(ghes_arr.ghes_devs[i]);
    goto out;
}

static int __init setup_hest_disable(char *str)
{
    hest_disable = 1;
    return 0;
}

__setup("hest_disable", setup_hest_disable);

void __init acpi_hest_init(void)
{
    acpi_status status;
    int rc = -ENODEV;
    unsigned int ghes_count = 0;

    if (hest_disable) {
        pr_info(HEST_PFX "Table parsing disabled.\n");
        return;
    }

    if (acpi_disabled)
        goto err;

    status = acpi_get_table(ACPI_SIG_HEST, 0,
                (struct acpi_table_header **)&hest_tab);
    if (status == AE_NOT_FOUND)
        goto err;
    else if (ACPI_FAILURE(status)) {
        const char *msg = acpi_format_exception(status);
        pr_err(HEST_PFX "Failed to get table, %s\n", msg);
        rc = -EINVAL;
        goto err;
    }

    if (!ghes_disable) {
        rc = apei_hest_parse(hest_parse_ghes_count, &ghes_count);
        if (rc)
            goto err;
        rc = hest_ghes_dev_register(ghes_count);
        if (rc)
            goto err;
    }

    pr_info(HEST_PFX "Table parsing has been initialized.\n");
    return;
err:
    hest_disable = 1;
}