From c3d1fb567a634dcdff4c6f6095b2053260988336 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Mon, 1 Jul 2013 21:08:47 +0530 Subject: [PATCH] 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 --- arch/x86/include/asm/mce.h | 3 ++ arch/x86/kernel/cpu/mcheck/mce-internal.h | 3 ++ arch/x86/kernel/cpu/mcheck/mce.c | 28 +++++++++++++++ arch/x86/kernel/cpu/mcheck/mce_intel.c | 42 +++++++++++++++++------ drivers/acpi/apei/hest.c | 37 ++++++++++++++++++++ 5 files changed, 103 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index fa5f71e021d536..9c91683ab5e67d 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -188,6 +188,9 @@ extern void register_mce_write_callback(ssize_t (*)(struct file *filp, const char __user *ubuf, size_t usize, loff_t *off)); +/* Disable CMCI/polling for MCA bank claimed by firmware */ +extern void mce_disable_bank(int bank); + /* * Exception handler */ diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h index 5b7d4fa5d3b726..09edd0b65fefbb 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-internal.h +++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h @@ -25,15 +25,18 @@ int mce_severity(struct mce *a, int tolerant, char **msg); struct dentry *mce_get_debugfs_dir(void); extern struct mce_bank *mce_banks; +extern mce_banks_t mce_banks_ce_disabled; #ifdef CONFIG_X86_MCE_INTEL unsigned long mce_intel_adjust_timer(unsigned long interval); void mce_intel_cmci_poll(void); void mce_intel_hcpu_update(unsigned long cpu); +void cmci_disable_bank(int bank); #else # define mce_intel_adjust_timer mce_adjust_timer_default static inline void mce_intel_cmci_poll(void) { } static inline void mce_intel_hcpu_update(unsigned long cpu) { } +static inline void cmci_disable_bank(int bank) { } #endif void mce_timer_kick(unsigned long interval); diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 9239504b41cbc6..5bf32c70a9c0bd 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -94,6 +94,15 @@ DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = { [0 ... BITS_TO_LONGS(MAX_NR_BANKS)-1] = ~0UL }; +/* + * MCA banks controlled through firmware first for corrected errors. + * This is a global list of banks for which we won't enable CMCI and we + * won't poll. Firmware controls these banks and is responsible for + * reporting corrected errors through GHES. Uncorrected/recoverable + * errors are still notified through a machine check. + */ +mce_banks_t mce_banks_ce_disabled; + static DEFINE_PER_CPU(struct work_struct, mce_work); static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs); @@ -1932,6 +1941,25 @@ static struct miscdevice mce_chrdev_device = { &mce_chrdev_ops, }; +static void __mce_disable_bank(void *arg) +{ + int bank = *((int *)arg); + __clear_bit(bank, __get_cpu_var(mce_poll_banks)); + cmci_disable_bank(bank); +} + +void mce_disable_bank(int bank) +{ + if (bank >= mca_cfg.banks) { + pr_warn(FW_BUG + "Ignoring request to disable invalid MCA bank %d.\n", + bank); + return; + } + set_bit(bank, mce_banks_ce_disabled); + on_each_cpu(__mce_disable_bank, &bank, 1); +} + /* * mce=off Disables machine check * mce=no_cmci Disables CMCI diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c index ae1697c2afe392..488eae3ec3e2bb 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c @@ -191,6 +191,10 @@ static void cmci_discover(int banks) if (test_bit(i, owned)) continue; + /* Skip banks in firmware first mode */ + if (test_bit(i, mce_banks_ce_disabled)) + continue; + rdmsrl(MSR_IA32_MCx_CTL2(i), val); /* Already owned by someone else? */ @@ -259,6 +263,19 @@ void cmci_recheck(void) local_irq_restore(flags); } +/* Caller must hold the lock on cmci_discover_lock */ +static void __cmci_disable_bank(int bank) +{ + u64 val; + + if (!test_bit(bank, __get_cpu_var(mce_banks_owned))) + return; + rdmsrl(MSR_IA32_MCx_CTL2(bank), val); + val &= ~MCI_CTL2_CMCI_EN; + wrmsrl(MSR_IA32_MCx_CTL2(bank), val); + __clear_bit(bank, __get_cpu_var(mce_banks_owned)); +} + /* * Disable CMCI on this CPU for all banks it owns when it goes down. * This allows other CPUs to claim the banks on rediscovery. @@ -268,20 +285,12 @@ void cmci_clear(void) unsigned long flags; int i; int banks; - u64 val; if (!cmci_supported(&banks)) return; raw_spin_lock_irqsave(&cmci_discover_lock, flags); - for (i = 0; i < banks; i++) { - if (!test_bit(i, __get_cpu_var(mce_banks_owned))) - continue; - /* Disable CMCI */ - rdmsrl(MSR_IA32_MCx_CTL2(i), val); - val &= ~MCI_CTL2_CMCI_EN; - wrmsrl(MSR_IA32_MCx_CTL2(i), val); - __clear_bit(i, __get_cpu_var(mce_banks_owned)); - } + for (i = 0; i < banks; i++) + __cmci_disable_bank(i); raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); } @@ -315,6 +324,19 @@ void cmci_reenable(void) cmci_discover(banks); } +void cmci_disable_bank(int bank) +{ + int banks; + unsigned long flags; + + if (!cmci_supported(&banks)) + return; + + raw_spin_lock_irqsave(&cmci_discover_lock, flags); + __cmci_disable_bank(bank); + raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); +} + static void intel_init_cmci(void) { int banks; diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c index f5ef5d54e4ac2e..b108b116bf28a2 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)