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authorH. Peter Anvin <hpa@zytor.com>2008-08-18 17:39:32 -0700
committerH. Peter Anvin <hpa@zytor.com>2008-08-18 18:22:17 -0700
commit7e00df5818964298c9821365a6cb7a8304227c5c (patch)
tree5fdfc9a40deb0a4157bddffed28322a2ff9e5875 /include
parente2fe16d91228a005811335fbc4fbad5d4f5b75af (diff)
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>
Diffstat (limited to 'include')
-rw-r--r--include/asm-x86/cpufeature.h11
-rw-r--r--include/asm-x86/required-features.h8
2 files changed, 13 insertions, 6 deletions
diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 2f5a792b0ac..be8b2ad5d41 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 */
diff --git a/include/asm-x86/required-features.h b/include/asm-x86/required-features.h
index adec887dd7c..5c2ff4bc298 100644
--- a/include/asm-x86/required-features.h
+++ b/include/asm-x86/required-features.h
@@ -41,6 +41,12 @@
# define NEED_3DNOW 0
#endif
+#if defined(CONFIG_X86_P6_NOP) || defined(CONFIG_X86_64)
+# define NEED_NOPL (1<<(X86_FEATURE_NOPL & 31))
+#else
+# define NEED_NOPL 0
+#endif
+
#ifdef CONFIG_X86_64
#define NEED_PSE 0
#define NEED_MSR (1<<(X86_FEATURE_MSR & 31))
@@ -67,7 +73,7 @@
#define REQUIRED_MASK1 (NEED_LM|NEED_3DNOW)
#define REQUIRED_MASK2 0
-#define REQUIRED_MASK3 0
+#define REQUIRED_MASK3 (NEED_NOPL)
#define REQUIRED_MASK4 0
#define REQUIRED_MASK5 0
#define REQUIRED_MASK6 0