diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index df28e931d732..ba6b8bb1c036 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1019,6 +1019,24 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) } /* + * The NOPL instruction is supposed to exist on all CPUs of family >= 6; + * unfortunately, that's not true in practice because of early VIA + * chips and (more importantly) broken virtualizers that are not easy + * to detect. In the latter case it doesn't even *fail* reliably, so + * probing for it doesn't even work. Disable it completely on 32-bit + * unless we can find a reliable way to detect all the broken cases. + * Enable it explicitly on 64-bit for non-constant inputs of cpu_has(). + */ +static void detect_nopl(void) +{ +#ifdef CONFIG_X86_32 + setup_clear_cpu_cap(X86_FEATURE_NOPL); +#else + setup_force_cpu_cap(X86_FEATURE_NOPL); +#endif +} + +/* * Do minimum CPU detection early. * Fields really needed: vendor, cpuid_level, family, model, mask, * cache alignment. @@ -1092,6 +1110,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) */ if (!pgtable_l5_enabled()) setup_clear_cpu_cap(X86_FEATURE_LA57); + + detect_nopl(); } void __init early_cpu_init(void) @@ -1127,24 +1147,6 @@ void __init early_cpu_init(void) early_identify_cpu(&boot_cpu_data); } -/* - * The NOPL instruction is supposed to exist on all CPUs of family >= 6; - * unfortunately, that's not true in practice because of early VIA - * chips and (more importantly) broken virtualizers that are not easy - * to detect. In the latter case it doesn't even *fail* reliably, so - * probing for it doesn't even work. Disable it completely on 32-bit - * unless we can find a reliable way to detect all the broken cases. - * Enable it explicitly on 64-bit for non-constant inputs of cpu_has(). - */ -static void detect_nopl(struct cpuinfo_x86 *c) -{ -#ifdef CONFIG_X86_32 - clear_cpu_cap(c, X86_FEATURE_NOPL); -#else - set_cpu_cap(c, X86_FEATURE_NOPL); -#endif -} - static void detect_null_seg_behavior(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_64 @@ -1207,8 +1209,6 @@ static void generic_identify(struct cpuinfo_x86 *c) get_model_name(c); /* Default name */ - detect_nopl(c); - detect_null_seg_behavior(c); /* |