From c3d1fb567a634dcdff4c6f6095b2053260988336 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Mon, 1 Jul 2013 21:08:47 +0530 Subject: mce: acpi/apei: Honour Firmware First for MCA banks listed in APEI HEST CMC The Corrected Machine Check structure (CMC) in HEST has a flag which can be set by the firmware to indicate to the OS that it prefers to process the corrected error events first. In this scenario, the OS is expected to not monitor for corrected errors (through CMCI/polling). Instead, the firmware notifies the OS on corrected error events through GHES. Linux already has support for GHES. This patch adds support for parsing CMC structure and to disable CMCI/polling if the firmware first flag is set. Further, the list of machine check bank structures at the end of CMC is used to determine which MCA banks function in FF mode, so that we continue to monitor error events on the other banks. Signed-off-by: Naveen N. Rao Acked-by: Borislav Petkov Signed-off-by: Tony Luck --- drivers/acpi/apei/hest.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c index f5ef5d54e4ac..b108b116bf28 100644 --- a/drivers/acpi/apei/hest.c +++ b/drivers/acpi/apei/hest.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "apei-internal.h" @@ -121,6 +122,40 @@ int apei_hest_parse(apei_hest_func_t func, void *data) } EXPORT_SYMBOL_GPL(apei_hest_parse); +/* + * 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(struct acpi_hest_header *hest_hdr, void *data) +{ + int i; + struct acpi_hest_ia_corrected *cmc; + struct acpi_hest_ia_error_bank *mc_bank; + + if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) + return 0; + + cmc = (struct acpi_hest_ia_corrected *)hest_hdr; + 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; + + pr_info(HEST_PFX "Enabling Firmware First mode for corrected errors.\n"); + + mc_bank = (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); + + return 1; +} + struct ghes_arr { struct platform_device **ghes_devs; unsigned int count; @@ -227,6 +262,8 @@ void __init acpi_hest_init(void) goto err; } + apei_hest_parse(hest_parse_cmc, NULL); + if (!ghes_disable) { rc = apei_hest_parse(hest_parse_ghes_count, &ghes_count); if (rc) -- cgit v1.2.3