From: Ingo Molnar <mingo@elte.hu>
Date: Sun, 14 Dec 2008 17:36:30 +0000 (+0100)
Subject: perfcounters: fix non-intel-perfmon CPUs
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2b9ff0db19b5e2c77000b7201525f9c3d6e8328d;p=mv-sheeva.git

perfcounters: fix non-intel-perfmon CPUs

Do not write MSR_CORE_PERF_GLOBAL_CTRL on CPUs where it does not exist.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 5afae13d8d5..6d30f603b62 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -157,6 +157,9 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
 
 void hw_perf_enable_all(void)
 {
+	if (unlikely(!perf_counters_initialized))
+		return;
+
 	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, perf_counter_mask, 0);
 }
 
@@ -164,14 +167,21 @@ u64 hw_perf_save_disable(void)
 {
 	u64 ctrl;
 
+	if (unlikely(!perf_counters_initialized))
+		return 0;
+
 	rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
 	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0, 0);
+
 	return ctrl;
 }
 EXPORT_SYMBOL_GPL(hw_perf_save_disable);
 
 void hw_perf_restore(u64 ctrl)
 {
+	if (unlikely(!perf_counters_initialized))
+		return;
+
 	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, ctrl, 0);
 }
 EXPORT_SYMBOL_GPL(hw_perf_restore);