Messages in this thread Patch in this message | | | Date | Fri, 23 Sep 2005 16:17:57 -0700 | From | Venkatesh Pallipadi <> | Subject | [PATCH] [x86] Bug fix in P6 Machine check initialization |
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Make P6 MCA initialization code complaint with guidelines in IA-32 SDM Vol3. Bank 0 control register should not be set by OS and clear status registers on all banks on reset.
This will preven false MCE alarms on the systems that has some non-MCE information left-over in MC0_STATUS on reboot.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Index: linux-2.6.12/arch/i386/kernel/cpu/mcheck/p6.c =================================================================== --- linux-2.6.12.orig/arch/i386/kernel/cpu/mcheck/p6.c 2005-08-30 11:10:46.000000000 -0700 +++ linux-2.6.12/arch/i386/kernel/cpu/mcheck/p6.c 2005-09-22 15:37:53.653669656 -0700 @@ -103,11 +103,16 @@ wrmsr(MSR_IA32_MCG_CTL, 0xffffffff, 0xffffffff); nr_mce_banks = l & 0xff; - /* Don't enable bank 0 on intel P6 cores, it goes bang quickly. */ - for (i=1; i<nr_mce_banks; i++) { + /* + * Following the example in IA-32 SDM Vol 3: + * - MC0_CTL should not be written + * - Status registers on all banks should be cleared on reset + */ + for (i=1; i<nr_mce_banks; i++) wrmsr (MSR_IA32_MC0_CTL+4*i, 0xffffffff, 0xffffffff); + + for (i=0; i<nr_mce_banks; i++) wrmsr (MSR_IA32_MC0_STATUS+4*i, 0x0, 0x0); - } set_in_cr4 (X86_CR4_MCE); printk (KERN_INFO "Intel machine check reporting enabled on CPU#%d.\n", - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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