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-rw-r--r--arch/x86/kernel/cpu/common.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index f2f9ac7da25c..927e630aeaf3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -704,16 +704,21 @@ void __init early_cpu_init(void)
704} 704}
705 705
706/* 706/*
707 * The NOPL instruction is supposed to exist on all CPUs with 707 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
708 * family >= 6; unfortunately, that's not true in practice because 708 * unfortunately, that's not true in practice because of early VIA
709 * of early VIA chips and (more importantly) broken virtualizers that 709 * chips and (more importantly) broken virtualizers that are not easy
710 * are not easy to detect. In the latter case it doesn't even *fail* 710 * to detect. In the latter case it doesn't even *fail* reliably, so
711 * reliably, so probing for it doesn't even work. Disable it completely 711 * probing for it doesn't even work. Disable it completely on 32-bit
712 * unless we can find a reliable way to detect all the broken cases. 712 * unless we can find a reliable way to detect all the broken cases.
713 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
713 */ 714 */
714static void __cpuinit detect_nopl(struct cpuinfo_x86 *c) 715static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
715{ 716{
717#ifdef CONFIG_X86_32
716 clear_cpu_cap(c, X86_FEATURE_NOPL); 718 clear_cpu_cap(c, X86_FEATURE_NOPL);
719#else
720 set_cpu_cap(c, X86_FEATURE_NOPL);
721#endif
717} 722}
718 723
719static void __cpuinit generic_identify(struct cpuinfo_x86 *c) 724static void __cpuinit generic_identify(struct cpuinfo_x86 *c)