/*

 * 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 <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, see <http://www.gnu.org/licenses/>.

 */

#include <xen/errno.h>

#include <xen/init.h>

#include <xen/kernel.h>

#include <xen/mm.h>

#include <xen/pfn.h>

#include <acpi/acpi.h>

#include <acpi/apei.h>

#include "apei-internal.h"

#define HEST_PFX "HEST: "

static bool_t hest_disable;

boolean_param("hest_disable", 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(const 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) {

    const struct acpi_hest_ia_corrected *cmc =

      container_of(hest_hdr,

             const struct acpi_hest_ia_corrected,

             header);

    len = sizeof(*cmc) + cmc->num_hardware_banks *

          sizeof(struct acpi_hest_ia_error_bank);

  } else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {

    const struct acpi_hest_ia_machine_check *mc =

      container_of(hest_hdr,

             const struct acpi_hest_ia_machine_check,

             header);

    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 || !hest_tab)

    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) {

      printk(XENLOG_WARNING 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) {

      printk(XENLOG_WARNING 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;

}

/*

 * Check if firmware advertises firmware first mode. We need FF bit to be set

 * along with a set of MC banks which work in FF mode.

 */

static int __init hest_parse_cmc(const struct acpi_hest_header *hest_hdr,

         void *data)

{

#ifdef CONFIG_X86_MCE

  unsigned int i;

  const struct acpi_hest_ia_corrected *cmc;

  const struct acpi_hest_ia_error_bank *mc_bank;

  if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK)

    return 0;

  cmc = container_of(hest_hdr, const struct acpi_hest_ia_corrected, header);

  if (!cmc->enabled)

    return 0;

  /*

   * We expect HEST to provide a list of MC banks that report errors

   * in firmware first mode. Otherwise, return non-zero value to

   * indicate that we are done parsing HEST.

   */

  if (!(cmc->flags & ACPI_HEST_FIRMWARE_FIRST) || !cmc->num_hardware_banks)

    return 1;

  printk(XENLOG_INFO HEST_PFX "Enabling Firmware First mode for corrected errors.\n");

  mc_bank = (const struct acpi_hest_ia_error_bank *)(cmc + 1);

  for (i = 0; i < cmc->num_hardware_banks; i++, mc_bank++)

    mce_disable_bank(mc_bank->bank_number);

#else

# define acpi_disable_cmcff 1

#endif

  return 1;

}

void __init acpi_hest_init(void)

{

  acpi_status status;

  acpi_physical_address hest_addr;

  acpi_native_uint hest_len;

  if (acpi_disabled)

    return;

  if (hest_disable) {

    printk(XENLOG_INFO HEST_PFX "Table parsing disabled.\n");

    return;

  }

  status = acpi_get_table_phys(ACPI_SIG_HEST, 0, &hest_addr, &hest_len);

  if (status == AE_NOT_FOUND)

    goto err;

  if (ACPI_FAILURE(status)) {

    printk(XENLOG_ERR HEST_PFX "Failed to get table, %s\n",

           acpi_format_exception(status));

    goto err;

  }

  map_pages_to_xen((unsigned long)__va(hest_addr), PFN_DOWN(hest_addr),

       PFN_UP(hest_addr + hest_len) - PFN_DOWN(hest_addr),

       PAGE_HYPERVISOR);

  hest_tab = __va(hest_addr);

  if (!acpi_disable_cmcff)

    apei_hest_parse(hest_parse_cmc, NULL);

  printk(XENLOG_INFO HEST_PFX "Table parsing has been initialized\n");

  return;

err:

  hest_disable = 1;

}