In some cases, when probing a perf MSR, we're probing certain bits of the MSR instead of the whole register, thus only these bits should be checked.
For example, for RAPL ENERGY_STATUS MSR, only the lower 32 bits represents the energy counter, and the higher 32bits are reserved. Introduce a new mask field in struct perf_msr to allow probing certain bits of a MSR. This change is transparent to the current perf_msr_probe() users. Signed-off-by: Zhang Rui <rui.zh...@intel.com> Reviewed-by: Andi Kleen <a...@linux.intel.com> --- arch/x86/events/probe.c | 5 ++++- arch/x86/events/probe.h | 7 ++++--- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/events/probe.c b/arch/x86/events/probe.c index 136a1e847254..a0a19c404cb5 100644 --- a/arch/x86/events/probe.c +++ b/arch/x86/events/probe.c @@ -28,6 +28,7 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data) for (bit = 0; bit < cnt; bit++) { if (!msr[bit].no_check) { struct attribute_group *grp = msr[bit].grp; + u64 mask; /* skip entry with no group */ if (!grp) @@ -44,8 +45,10 @@ perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data) /* Virt sucks; you cannot tell if a R/O MSR is present :/ */ if (rdmsrl_safe(msr[bit].msr, &val)) continue; + + mask = msr[bit].mask ? msr[bit].mask : U64_MAX; /* Disable zero counters if requested. */ - if (!zero && !val) + if (!zero && !(val & mask)) continue; grp->is_visible = NULL; diff --git a/arch/x86/events/probe.h b/arch/x86/events/probe.h index 4c8e0afc5fb5..261b9bda24e3 100644 --- a/arch/x86/events/probe.h +++ b/arch/x86/events/probe.h @@ -4,10 +4,11 @@ #include <linux/sysfs.h> struct perf_msr { - u64 msr; - struct attribute_group *grp; + u64 msr; + struct attribute_group *grp; bool (*test)(int idx, void *data); - bool no_check; + bool no_check; + u64 mask; }; unsigned long -- 2.17.1