In order to do performance optimization, this patch adds macro
cpu_has_mpx which will directly return 0 when MPX is not supported
by kernel.
Community gave a lot of comments on this macro cpu_has_mpx in previous
version. Dave will introduce a patchset about disabled features to fix
it later.
In this code:
if (cpu_has_mpx)
do_some_mpx_thing();
The patch series from Dave will introduce a new macro cpu_feature_enabled()
(if merged after this patchset) to replace the cpu_has_mpx.
if (cpu_feature_enabled(X86_FEATURE_MPX))
do_some_mpx_thing();
Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
---
arch/x86/include/asm/cpufeature.h | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index e265ff9..f302d08 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -339,6 +339,12 @@ extern const char * const x86_power_flags[32];
#define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU)
#define cpu_has_topoext boot_cpu_has(X86_FEATURE_TOPOEXT)
+#ifdef CONFIG_X86_INTEL_MPX
+#define cpu_has_mpx boot_cpu_has(X86_FEATURE_MPX)
+#else
+#define cpu_has_mpx 0
+#endif /* CONFIG_X86_INTEL_MPX */
+
#ifdef CONFIG_X86_64
#undef cpu_has_vme
--
1.7.1
--
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