From 06b7a7a5ec917761969444fee967c43868a76468 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 27 Apr 2009 18:37:43 +0200 Subject: [PATCH] x86, mce: implement the PPro bank 0 quirk in the 64bit machine check code Quoting the comment: * SDM documents that on family 6 bank 0 should not be written * because it aliases to another special BIOS controlled * register. * But it's not aliased anymore on model 0x1a+ * Don't ignore bank 0 completely because there could be a valid * event later, merely don't write CTL0. This is mostly a port on the 32bit code, except that 32bit always didn't write it and didn't have the 0x1a heuristic. I checked with the CPU designers that the quirk is not required starting with this model. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin Signed-off-by: Hidetoshi Seto Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mcheck/mce.c | 40 +++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index cd1313b47506..1dcd3be03328 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -65,6 +65,8 @@ static atomic_t mce_events; static char trigger[128]; static char *trigger_argv[2] = { trigger, NULL }; +static unsigned long dont_init_banks; + static DECLARE_WAIT_QUEUE_HEAD(mce_wait); /* MCA banks polled by the period polling timer for corrected events */ @@ -72,6 +74,11 @@ DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = { [0 ... BITS_TO_LONGS(MAX_NR_BANKS)-1] = ~0UL }; +static inline int skip_bank_init(int i) +{ + return i < BITS_PER_LONG && test_bit(i, &dont_init_banks); +} + /* Do initial initialization of a struct mce */ void mce_setup(struct mce *m) { @@ -616,6 +623,8 @@ static void mce_init(void *dummy) wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff); for (i = 0; i < banks; i++) { + if (skip_bank_init(i)) + continue; wrmsrl(MSR_IA32_MC0_CTL+4*i, bank[i]); wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0); } @@ -643,6 +652,19 @@ static void mce_cpu_quirks(struct cpuinfo_x86 *c) } } + if (c->x86_vendor == X86_VENDOR_INTEL) { + /* + * SDM documents that on family 6 bank 0 should not be written + * because it aliases to another special BIOS controlled + * register. + * But it's not aliased anymore on model 0x1a+ + * Don't ignore bank 0 completely because there could be a + * valid event later, merely don't write CTL0. + */ + + if (c->x86 == 6 && c->x86_model < 0x1A) + __set_bit(0, &dont_init_banks); + } } static void mce_cpu_features(struct cpuinfo_x86 *c) @@ -911,8 +933,10 @@ static int mce_disable(void) { int i; - for (i = 0; i < banks; i++) - wrmsrl(MSR_IA32_MC0_CTL + i*4, 0); + for (i = 0; i < banks; i++) { + if (!skip_bank_init(i)) + wrmsrl(MSR_IA32_MC0_CTL + i*4, 0); + } return 0; } @@ -1119,8 +1143,10 @@ static void mce_disable_cpu(void *h) return; if (!(action & CPU_TASKS_FROZEN)) cmci_clear(); - for (i = 0; i < banks; i++) - wrmsrl(MSR_IA32_MC0_CTL + i*4, 0); + for (i = 0; i < banks; i++) { + if (!skip_bank_init(i)) + wrmsrl(MSR_IA32_MC0_CTL + i*4, 0); + } } static void mce_reenable_cpu(void *h) @@ -1133,8 +1159,10 @@ static void mce_reenable_cpu(void *h) if (!(action & CPU_TASKS_FROZEN)) cmci_reenable(); - for (i = 0; i < banks; i++) - wrmsrl(MSR_IA32_MC0_CTL + i*4, bank[i]); + for (i = 0; i < banks; i++) { + if (!skip_bank_init(i)) + wrmsrl(MSR_IA32_MC0_CTL + i*4, bank[i]); + } } /* Get notified when a cpu comes on/off. Be hotplug friendly. */ -- 2.20.1