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author | Ingo Molnar <mingo@elte.hu> | 2008-10-10 13:30:08 -0400 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-10-10 13:30:08 -0400 |
commit | 3dd392a407d15250a501fa109cc1f93fee95ef85 (patch) | |
tree | c1faca3fa8bd0f7c8790b3e0887229b4a5a90e8b /arch/x86/kernel/cpu/common.c | |
parent | b27a43c1e90582facad44de67d02bc9e9f900289 (diff) | |
parent | d403a6484f0341bf0624d17ece46f24f741b6a92 (diff) |
Merge branch 'linus' into x86/pat2
Conflicts:
arch/x86/mm/init_64.c
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8aab8517642e..4e456bd955bb 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c | |||
@@ -344,31 +344,15 @@ static void __init early_cpu_detect(void) | |||
344 | 344 | ||
345 | /* | 345 | /* |
346 | * The NOPL instruction is supposed to exist on all CPUs with | 346 | * The NOPL instruction is supposed to exist on all CPUs with |
347 | * family >= 6, unfortunately, that's not true in practice because | 347 | * family >= 6; unfortunately, that's not true in practice because |
348 | * of early VIA chips and (more importantly) broken virtualizers that | 348 | * of early VIA chips and (more importantly) broken virtualizers that |
349 | * are not easy to detect. Hence, probe for it based on first | 349 | * are not easy to detect. In the latter case it doesn't even *fail* |
350 | * principles. | 350 | * reliably, so probing for it doesn't even work. Disable it completely |
351 | * unless we can find a reliable way to detect all the broken cases. | ||
351 | */ | 352 | */ |
352 | static void __cpuinit detect_nopl(struct cpuinfo_x86 *c) | 353 | static void __cpuinit detect_nopl(struct cpuinfo_x86 *c) |
353 | { | 354 | { |
354 | const u32 nopl_signature = 0x888c53b1; /* Random number */ | ||
355 | u32 has_nopl = nopl_signature; | ||
356 | |||
357 | clear_cpu_cap(c, X86_FEATURE_NOPL); | 355 | clear_cpu_cap(c, X86_FEATURE_NOPL); |
358 | if (c->x86 >= 6) { | ||
359 | asm volatile("\n" | ||
360 | "1: .byte 0x0f,0x1f,0xc0\n" /* nopl %eax */ | ||
361 | "2:\n" | ||
362 | " .section .fixup,\"ax\"\n" | ||
363 | "3: xor %0,%0\n" | ||
364 | " jmp 2b\n" | ||
365 | " .previous\n" | ||
366 | _ASM_EXTABLE(1b,3b) | ||
367 | : "+a" (has_nopl)); | ||
368 | |||
369 | if (has_nopl == nopl_signature) | ||
370 | set_cpu_cap(c, X86_FEATURE_NOPL); | ||
371 | } | ||
372 | } | 356 | } |
373 | 357 | ||
374 | static void __cpuinit generic_identify(struct cpuinfo_x86 *c) | 358 | static void __cpuinit generic_identify(struct cpuinfo_x86 *c) |