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Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/perf_counter.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 22dab06c08a..6cba9d47b71 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -57,12 +57,14 @@ struct pmc_x86_ops {
int max_events;
};
-static struct pmc_x86_ops *pmc_ops;
+static struct pmc_x86_ops *pmc_ops __read_mostly;
static DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters) = {
.enabled = 1,
};
+static __read_mostly int intel_perfmon_version;
+
/*
* Intel PerfMon v3. Used on Core2 and later.
*/
@@ -613,7 +615,7 @@ void perf_counter_print_debug(void)
cpu = smp_processor_id();
cpuc = &per_cpu(cpu_hw_counters, cpu);
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+ if (intel_perfmon_version >= 2) {
rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
@@ -930,10 +932,10 @@ static struct pmc_x86_ops pmc_amd_ops = {
static struct pmc_x86_ops *pmc_intel_init(void)
{
+ union cpuid10_edx edx;
union cpuid10_eax eax;
- unsigned int ebx;
unsigned int unused;
- union cpuid10_edx edx;
+ unsigned int ebx;
/*
* Check whether the Architectural PerfMon supports
@@ -943,8 +945,12 @@ static struct pmc_x86_ops *pmc_intel_init(void)
if (eax.split.mask_length <= ARCH_PERFMON_BRANCH_MISSES_RETIRED)
return NULL;
+ intel_perfmon_version = eax.split.version_id;
+ if (intel_perfmon_version < 2)
+ return NULL;
+
pr_info("Intel Performance Monitoring support detected.\n");
- pr_info("... version: %d\n", eax.split.version_id);
+ pr_info("... version: %d\n", intel_perfmon_version);
pr_info("... bit width: %d\n", eax.split.bit_width);
pr_info("... mask length: %d\n", eax.split.mask_length);