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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-18 11:16:55 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-18 11:16:55 +1000 |
| commit | 4b337c5f245b6587ba844ac7bb13c313a2912f7b (patch) | |
| tree | 999c6a6580b76a083c8efb9dabff709d1c49fcd0 /arch/x86/kernel/cpu/intel.c | |
| parent | 492b057c426e4aa747484958e18e9da29003985d (diff) | |
| parent | 3fe0344faf7fdcb158bd5c1a9aec960a8d70c8e8 (diff) | |
| download | kernel-crypto-4b337c5f245b6587ba844ac7bb13c313a2912f7b.tar.gz kernel-crypto-4b337c5f245b6587ba844ac7bb13c313a2912f7b.tar.xz kernel-crypto-4b337c5f245b6587ba844ac7bb13c313a2912f7b.zip | |
Merge commit 'origin/master' into next
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index daed39ba261..3260ab04499 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -86,6 +86,29 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) */ if (c->x86 == 6 && c->x86_model < 15) clear_cpu_cap(c, X86_FEATURE_PAT); + +#ifdef CONFIG_KMEMCHECK + /* + * P4s have a "fast strings" feature which causes single- + * stepping REP instructions to only generate a #DB on + * cache-line boundaries. + * + * Ingo Molnar reported a Pentium D (model 6) and a Xeon + * (model 2) with the same problem. + */ + if (c->x86 == 15) { + u64 misc_enable; + + rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); + + if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) { + printk(KERN_INFO "kmemcheck: Disabling fast string operations\n"); + + misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING; + wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable); + } + } +#endif } #ifdef CONFIG_X86_32 |