From fb2531953fd8855abdcf458459020fd382c5deca Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 7 Oct 2009 13:20:38 +0200 Subject: [PATCH] mce, edac: Use an atomic notifier for MCEs decoding Add an atomic notifier which ensures proper locking when conveying MCE info to EDAC for decoding. The actual notifier call overrides a default, negative priority notifier. Note: make sure we register the default decoder only once since mcheck_init() runs on each CPU. Signed-off-by: Borislav Petkov LKML-Reference: <20091003065752.GA8935@liondog.tnic> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/mce.h | 3 ++- arch/x86/kernel/cpu/mcheck/mce.c | 29 ++++++++++++++++++++--------- drivers/edac/edac_mce_amd.c | 21 ++++++++++++--------- 3 files changed, 34 insertions(+), 19 deletions(-) diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index f1363b72364..227a72df644 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -108,6 +108,8 @@ struct mce_log { #define K8_MCE_THRESHOLD_BANK_5 (MCE_THRESHOLD_BASE + 5 * 9) #define K8_MCE_THRESHOLD_DRAM_ECC (MCE_THRESHOLD_BANK_4 + 0) +extern struct atomic_notifier_head x86_mce_decoder_chain; + #ifdef __KERNEL__ #include @@ -213,6 +215,5 @@ extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu); void intel_init_thermal(struct cpuinfo_x86 *c); void mce_log_therm_throt_event(__u64 status); - #endif /* __KERNEL__ */ #endif /* _ASM_X86_MCE_H */ diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index b1598a9436d..15ba9c972d7 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -85,18 +85,26 @@ static DECLARE_WAIT_QUEUE_HEAD(mce_wait); static DEFINE_PER_CPU(struct mce, mces_seen); static int cpu_missing; -static void default_decode_mce(struct mce *m) +/* + * CPU/chipset specific EDAC code can register a notifier call here to print + * MCE errors in a human-readable form. + */ +ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain); +EXPORT_SYMBOL_GPL(x86_mce_decoder_chain); + +static int default_decode_mce(struct notifier_block *nb, unsigned long val, + void *data) { pr_emerg("No human readable MCE decoding support on this CPU type.\n"); pr_emerg("Run the message through 'mcelog --ascii' to decode.\n"); + + return NOTIFY_STOP; } -/* - * CPU/chipset specific EDAC code can register a callback here to print - * MCE errors in a human-readable form: - */ -void (*x86_mce_decode_callback)(struct mce *m) = default_decode_mce; -EXPORT_SYMBOL(x86_mce_decode_callback); +static struct notifier_block mce_dec_nb = { + .notifier_call = default_decode_mce, + .priority = -1, +}; /* MCA banks polled by the period polling timer for corrected events */ DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = { @@ -204,9 +212,9 @@ static void print_mce(struct mce *m) /* * Print out human-readable details about the MCE error, - * (if the CPU has an implementation for that): + * (if the CPU has an implementation for that) */ - x86_mce_decode_callback(m); + atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m); } static void print_mce_head(void) @@ -1420,6 +1428,9 @@ void __cpuinit mcheck_init(struct cpuinfo_x86 *c) mce_cpu_features(c); mce_init_timer(); INIT_WORK(&__get_cpu_var(mce_work), mce_process_work); + + if (raw_smp_processor_id() == 0) + atomic_notifier_chain_register(&x86_mce_decoder_chain, &mce_dec_nb); } /* diff --git a/drivers/edac/edac_mce_amd.c b/drivers/edac/edac_mce_amd.c index 713ed7d3724..689cc6a6214 100644 --- a/drivers/edac/edac_mce_amd.c +++ b/drivers/edac/edac_mce_amd.c @@ -3,7 +3,6 @@ static bool report_gart_errors; static void (*nb_bus_decoder)(int node_id, struct err_regs *regs); -static void (*orig_mce_callback)(struct mce *m); void amd_report_gart_errors(bool v) { @@ -363,8 +362,10 @@ static inline void amd_decode_err_code(unsigned int ec) pr_warning("Huh? Unknown MCE error 0x%x\n", ec); } -static void amd_decode_mce(struct mce *m) +static int amd_decode_mce(struct notifier_block *nb, unsigned long val, + void *data) { + struct mce *m = (struct mce *)data; struct err_regs regs; int node, ecc; @@ -420,20 +421,22 @@ static void amd_decode_mce(struct mce *m) } amd_decode_err_code(m->status & 0xffff); + + return NOTIFY_STOP; } +static struct notifier_block amd_mce_dec_nb = { + .notifier_call = amd_decode_mce, +}; + static int __init mce_amd_init(void) { /* * We can decode MCEs for Opteron and later CPUs: */ if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && - (boot_cpu_data.x86 >= 0xf)) { - /* safe the default decode mce callback */ - orig_mce_callback = x86_mce_decode_callback; - - x86_mce_decode_callback = amd_decode_mce; - } + (boot_cpu_data.x86 >= 0xf)) + atomic_notifier_chain_register(&x86_mce_decoder_chain, &amd_mce_dec_nb); return 0; } @@ -442,7 +445,7 @@ early_initcall(mce_amd_init); #ifdef MODULE static void __exit mce_amd_exit(void) { - x86_mce_decode_callback = orig_mce_callback; + atomic_notifier_chain_unregister(&x86_mce_decoder_chain, &amd_mce_dec_nb); } MODULE_DESCRIPTION("AMD MCE decoder"); -- 2.39.3