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authorIngo Molnar <mingo@elte.hu>2008-09-23 23:26:42 +0200
committerIngo Molnar <mingo@elte.hu>2008-09-23 23:26:42 +0200
commit07bbc16a8676b06950a21f35b59f69b2fe763bbd (patch)
treef87fbfea747e9d92591c8d0a54db7c487e3c3d78 /arch/x86/kernel/cpu
parent6a9e91846bf52cc70a0417de19fdfac224c435c4 (diff)
parentf8e256c687eb53850685747757c8d75e58756e15 (diff)
Merge branch 'timers/urgent' into x86/xen
Conflicts: arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c Manual merge: arch/x86/kernel/smpboot.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/common.c24
1 files changed, 4 insertions, 20 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1c7d39f0e89..9983bc3f5d1 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)
/*
* The NOPL instruction is supposed to exist on all CPUs with
- * family >= 6, unfortunately, that's not true in practice because
+ * 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. Hence, probe for it based on first
- * principles.
+ * 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
+ * unless we can find a reliable way to detect all the broken cases.
*/
static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
{
- const u32 nopl_signature = 0x888c53b1; /* Random number */
- u32 has_nopl = nopl_signature;
-
clear_cpu_cap(c, X86_FEATURE_NOPL);
- if (c->x86 >= 6) {
- asm volatile("\n"
- "1: .byte 0x0f,0x1f,0xc0\n" /* nopl %eax */
- "2:\n"
- " .section .fixup,\"ax\"\n"
- "3: xor %0,%0\n"
- " jmp 2b\n"
- " .previous\n"
- _ASM_EXTABLE(1b,3b)
- : "+a" (has_nopl));
-
- if (has_nopl == nopl_signature)
- set_cpu_cap(c, X86_FEATURE_NOPL);
- }
}
static void __cpuinit generic_identify(struct cpuinfo_x86 *c)