From fb2531953fd8855abdcf458459020fd382c5deca Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 7 Oct 2009 13:20:38 +0200 Subject: 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/kernel/cpu/mcheck/mce.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) (limited to 'arch/x86/kernel/cpu') 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); } /* -- cgit v1.2.3 From 93ae5012a79b11e7fc855b52c7ce1e16fe1540b0 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Thu, 15 Oct 2009 14:21:14 -0700 Subject: x86: Don't print number of MCE banks for every CPU The MCE initialization code explicitly says it doesn't handle asymmetric configurations where different CPUs support different numbers of MCE banks, and it prints a big warning in that case. Therefore, printing the "mce: CPU supports MCE banks" message into the kernel log for every CPU is pure redundancy that clutters the log significantly for systems with lots of CPUs. Signed-off-by: Roland Dreier LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index b1598a9436d..721a77ca811 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1214,7 +1214,8 @@ static int __cpuinit mce_cap_init(void) rdmsrl(MSR_IA32_MCG_CAP, cap); b = cap & MCG_BANKCNT_MASK; - printk(KERN_INFO "mce: CPU supports %d MCE banks\n", b); + if (!banks) + printk(KERN_INFO "mce: CPU supports %d MCE banks\n", b); if (b > MAX_NR_BANKS) { printk(KERN_WARNING -- cgit v1.2.3