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Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, cpu: Fix X86_FEATURE_NOPL
  x86, cpu: Re-run get_cpu_cap() after adjusting the CPUID level
This commit is contained in:
Linus Torvalds 2010-10-21 13:18:36 -07:00
parent d60a2793ba 366d4a43b1
commit bf70030dc0
2 changed files with 11 additions and 5 deletions
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15
arch/x86/kernel/cpu/common.c
View File

@ -704,16 +704,21 @@ void __init early_cpu_init(void)
}
/*
* The NOPL instruction is supposed to exist on all CPUs with
* 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
* 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 __cpuinit 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 __cpuinit generic_identify(struct cpuinfo_x86 *c)

1
arch/x86/kernel/cpu/cpu.h
View File

@ -32,6 +32,7 @@ struct cpu_dev {
extern const struct cpu_dev *const __x86_cpu_dev_start[],
*const __x86_cpu_dev_end[];
extern void get_cpu_cap(struct cpuinfo_x86 *c);
extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
extern void get_cpu_cap(struct cpuinfo_x86 *c);