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| author | Olof Johansson <olof@lixom.net> | 2012-11-06 06:48:05 -0800 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2012-11-06 06:48:05 -0800 |
| commit | 3b19119b95a52200c8ae3df3aa89c21c9a1a8894 (patch) | |
| tree | 3ae74b8a35b3d1f639a68c1690af1c06e14a1571 /arch/x86/kernel/cpu/perf_event.c | |
| parent | ccb1cfcb964fa8a8acd58b7783b2e82d7ad7975b (diff) | |
| parent | e095c0d122c09efabe7d4136ce77f72c636c4879 (diff) | |
Merge tag 'calxeda-ecx-2000' of git://sources.calxeda.com/kernel/linux into next/soc
Support for Calxeda ECX-2000 SOC from Rob Herring
* tag 'calxeda-ecx-2000' of git://sources.calxeda.com/kernel/linux:
ARM: highbank: Add initial ECX-2000 support
ARM: highbank: abstract out SCU usage
ARM: smp_twd: don't warn on no DT node
ARM: dts: Add Calxeda ECX-2000 support
ARM: highbank: enable coherent DMA for xgmac in dts
ARM: highbank: disable unused sdhci and gpio in dts
+ sync to Linux 3.7-rc3
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 3373f84d1397..4a3374e61a93 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -208,12 +208,14 @@ static bool check_hw_exists(void) } /* - * Now write a value and read it back to see if it matches, - * this is needed to detect certain hardware emulators (qemu/kvm) - * that don't trap on the MSR access and always return 0s. + * Read the current value, change it and read it back to see if it + * matches, this is needed to detect certain hardware emulators + * (qemu/kvm) that don't trap on the MSR access and always return 0s. */ - val = 0xabcdUL; reg = x86_pmu_event_addr(0); + if (rdmsrl_safe(reg, &val)) + goto msr_fail; + val ^= 0xffffUL; ret = wrmsrl_safe(reg, val); ret |= rdmsrl_safe(reg, &val_new); if (ret || val != val_new) |