[tip:perfcounters/core] perf_counter, x86: remove X86_FEATURE_ARCH_PERFMON flag for AMD cpus

From: tip-bot for Robert Richter
Date: Wed Apr 29 2009 - 09:04:26 EST


Commit-ID: da1a776be1ac7f78bb30ececbec4c1383163b079
Gitweb: http://git.kernel.org/tip/da1a776be1ac7f78bb30ececbec4c1383163b079
Author: Robert Richter <robert.richter@xxxxxxx>
AuthorDate: Wed, 29 Apr 2009 12:46:58 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 29 Apr 2009 14:51:00 +0200

perf_counter, x86: 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).

[ Impact: refactor code ]

Signed-off-by: Robert Richter <robert.richter@xxxxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
LKML-Reference: <1241002046-8832-2-git-send-email-robert.richter@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
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();
--
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