x86: Add Intel Processor Trace (INTEL_PT) cpu feature detection

Intel Processor Trace is an architecture extension that allows for program
flow tracing.

Signed-off-by: Alexander Shishkin <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Kaixu Xia <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Robert Richter <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/1421237903-181015-11-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 361922dcc9b1fc32308fef578c2d3268b678df71..c1553b70fed4fa2b560a89fd0b918ab3d7683ba7 100644 (file)
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -195,6 +195,7 @@
 #define X86_FEATURE_HWP_ACT_WINDOW ( 7*32+ 12) /* Intel HWP_ACT_WINDOW */
 #define X86_FEATURE_HWP_EPP    ( 7*32+13) /* Intel HWP_EPP */
 #define X86_FEATURE_HWP_PKG_REQ ( 7*32+14) /* Intel HWP_PKG_REQ */
+#define X86_FEATURE_INTEL_PT   ( 7*32+15) /* Intel Processor Trace */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW  ( 8*32+ 0) /* Intel TPR Shadow */

diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 60639093d536a98806d21f9f675ffba6526c1322..3d423a101fae05ccd722a4e564b83ba5e0112b6e 100644 (file)
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -41,6 +41,7 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
                { X86_FEATURE_HWP_ACT_WINDOW,   CR_EAX, 9, 0x00000006, 0 },
                { X86_FEATURE_HWP_EPP,          CR_EAX,10, 0x00000006, 0 },
                { X86_FEATURE_HWP_PKG_REQ,      CR_EAX,11, 0x00000006, 0 },
+               { X86_FEATURE_INTEL_PT,         CR_EBX,25, 0x00000007, 0 },
                { X86_FEATURE_APERFMPERF,       CR_ECX, 0, 0x00000006, 0 },
                { X86_FEATURE_EPB,              CR_ECX, 3, 0x00000006, 0 },
                { X86_FEATURE_HW_PSTATE,        CR_EDX, 7, 0x80000007, 0 },