linux-kernel - [PATCH 01/29] x86: perfcounter: remove X86_FEATURE_ARCH

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Date:	Wed, 29 Apr 2009 12:46:58 +0200
From:	Robert Richter <robert.richter@....com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
CC:	Paul Mackerras <paulus@...ba.org>, Ingo Molnar <mingo@...e.hu>,
	LKML <linux-kernel@...r.kernel.org>,
	Robert Richter <robert.richter@....com>
Subject: [PATCH 01/29] x86: perfcounter: remove X86_FEATURE_ARCH_PERFMON flag for AMD cpus

X86_FEATURE_ARCH_PERFMON is an Intel hardware feature that does not
work on AMD CPUs. The flag is now only used in Intel specific code
(especially initialization).

Signed-off-by: Robert Richter <robert.richter@....com>
---
 arch/x86/kernel/cpu/amd.c          |    4 ----
 arch/x86/kernel/cpu/perf_counter.c |    6 +++---
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index fd69c51..7e4a459 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -420,10 +420,6 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 	if (c->x86 >= 6)
 		set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
 
-	/* Enable Performance counter for K7 and later */
-	if (c->x86 > 6 && c->x86 <= 0x11)
-		set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
-
 	if (!c->x86_model_id[0]) {
 		switch (c->x86) {
 		case 0xf:
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 0fcbaab..7d0f81d 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -949,6 +949,9 @@ static struct pmc_x86_ops *pmc_intel_init(void)
 	unsigned int unused;
 	unsigned int ebx;
 
+	if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
+		return NULL;
+
 	/*
 	 * Check whether the Architectural PerfMon supports
 	 * Branch Misses Retired Event or not.
@@ -987,9 +990,6 @@ static struct pmc_x86_ops *pmc_amd_init(void)
 
 void __init init_hw_perf_counters(void)
 {
-	if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
-		return;
-
 	switch (boot_cpu_data.x86_vendor) {
 	case X86_VENDOR_INTEL:
 		pmc_ops = pmc_intel_init();
-- 
1.6.1.3


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