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 <ak@linux.intel.com>
---
arch/x86/kernel/cpu/mcheck/mce_64.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
Index: linux/arch/x86/kernel/cpu/mcheck/mce_64.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ linux/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -433,6 +433,7 @@ static __init int periodic_mcheck_init(v
}
__initcall(periodic_mcheck_init);
+static int dont_init_bank0;
/*
* Initialize Machine Checks for a CPU.
@@ -462,7 +463,8 @@ static void mce_init(void *dummy)
wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff);
for (i = 0; i < banks; i++) {
- wrmsrl(MSR_IA32_MC0_CTL+4*i, bank[i]);
+ if (!(i == 0 && dont_init_bank0))
+ wrmsrl(MSR_IA32_MC0_CTL+4*i, bank[i]);
wrmsrl(MSR_IA32_MC0_STATUS+4*i, 0);
}
}
@@ -481,6 +483,18 @@ static void __cpuinit mce_cpu_quirks(str
by default and leave crap in there. Don't log. */
mce_bootlog = 0;
}
+ 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)
+ dont_init_bank0 = 1;
+ }
}
--
