x86: add NOPL as a synthetic CPU feature bit
The long noops ("NOPL") are supposed to be detected by family >= 6.
Unfortunately, several non-Intel x86 implementations, both hardware
and software, don't obey this dictum. Instead, probe for NOPL
directly by executing a NOPL instruction and see if we get #UD.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 762f6a6..9489283 100644
--- a/include/asm-x86/cpufeature.h
+++ b/include/asm-x86/cpufeature.h
@@ -72,14 +72,15 @@
#define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */
#define X86_FEATURE_FXSAVE_LEAK (3*32+10) /* FXSAVE leaks FOP/FIP/FOP */
#define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */
-#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
-#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
-#define X86_FEATURE_SYSCALL32 (3*32+14) /* syscall in ia32 userspace */
-#define X86_FEATURE_SYSENTER32 (3*32+15) /* sysenter in ia32 userspace */
+#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
+#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
+#define X86_FEATURE_SYSCALL32 (3*32+14) /* syscall in ia32 userspace */
+#define X86_FEATURE_SYSENTER32 (3*32+15) /* sysenter in ia32 userspace */
#define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well on this CPU */
#define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* Mfence synchronizes RDTSC */
#define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */
-#define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */
+#define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */
+#define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */