diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-12-13 15:53:31 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-12-13 15:53:31 +0000 |
| commit | 474b9c86b0c65e9ca6a77d8b7bf132c4d5993b9c (patch) | |
| tree | 9ce213f7a268d13f8871b84f1d22c2b9ff55afcf /arch/x86/kernel/cpu/perf_event.c | |
| parent | 49db7e7b995f5c61c5e24198f833ed01d99f5e7d (diff) | |
| parent | fdea0571ddca8e3f22448f66d72a034575abea28 (diff) | |
Merge branch 'topic/asoc' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 into for-2.6.38
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index ed6310183efb..6d75b9145b13 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -381,6 +381,20 @@ static void release_pmc_hardware(void) {} #endif +static bool check_hw_exists(void) +{ + u64 val, val_new = 0; + int ret = 0; + + val = 0xabcdUL; + ret |= checking_wrmsrl(x86_pmu.perfctr, val); + ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new); + if (ret || val != val_new) + return false; + + return true; +} + static void reserve_ds_buffers(void); static void release_ds_buffers(void); @@ -1372,6 +1386,12 @@ void __init init_hw_perf_events(void) pmu_check_apic(); + /* sanity check that the hardware exists or is emulated */ + if (!check_hw_exists()) { + pr_cont("Broken PMU hardware detected, software events only.\n"); + return; + } + pr_cont("%s PMU driver.\n", x86_pmu.name); if (x86_pmu.quirks) |