lkml.org 
[lkml]   [2006]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] i386 add Intel BTS cpufeature bit and detection (take 2)
Andi,

Here is a small patch for i386 which adds a cpufeature flag and
detection code for Intel's Branch Trace Store (BTS) feature. This
feature can be found on Intel P4 and Core 2 processors among others.
It can also be used by perfmon.

The patch is relative to 2.6.19-rc5-git7 + x86_64-2.6.19-rc5-git7-061116-2

changelog:
- add CPU_FEATURE_BTS
- add Branch Trace Store detection

signed-off-by: stephane eranian <eranian@hpl.hp.com>

diff --exclude=.git -urNp linux-2.6.19-rc5-git7-ak.orig/arch/i386/kernel/cpu/intel.c linux-2.6.19-rc5-git7-ak/arch/i386/kernel/cpu/intel.c
--- linux-2.6.19-rc5-git7-ak.orig/arch/i386/kernel/cpu/intel.c 2006-11-16 05:15:39.000000000 -0800
+++ linux-2.6.19-rc5-git7-ak/arch/i386/kernel/cpu/intel.c 2006-11-16 05:49:11.000000000 -0800
@@ -199,6 +199,8 @@ static void __cpuinit init_intel(struct
if (cpu_has_ds) {
unsigned int l1;
rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
+ if (!(l1 & (1<<11)))
+ set_bit(X86_FEATURE_BTS, c->x86_capability);
if (!(l1 & (1<<12)))
set_bit(X86_FEATURE_PEBS, c->x86_capability);
}
diff --exclude=.git -urNp linux-2.6.19-rc5-git7-ak.orig/include/asm-i386/cpufeature.h linux-2.6.19-rc5-git7-ak/include/asm-i386/cpufeature.h
--- linux-2.6.19-rc5-git7-ak.orig/include/asm-i386/cpufeature.h 2006-11-16 05:15:39.000000000 -0800
+++ linux-2.6.19-rc5-git7-ak/include/asm-i386/cpufeature.h 2006-11-16 05:48:52.000000000 -0800
@@ -74,6 +74,7 @@
#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 */

/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
@@ -138,6 +139,7 @@
#define cpu_has_ds boot_cpu_has(X86_FEATURE_DS)
#define cpu_has_pebs boot_cpu_has(X86_FEATURE_PEBS)
#define cpu_has_clflush boot_cpu_has(X86_FEATURE_CLFLSH)
+#define cpu_has_bts boot_cpu_has(X86_FEATURE_BTS)

#endif /* __ASM_I386_CPUFEATURE_H */

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-11-16 15:25    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site