In order for Intel PT decoders to infer correct crystal clock and bus frequencies that are required to correctly decode timing information from a PT stream (MTC and CBR packets), export them as sysfs attributes:
* max_nonturbo_ratio: ratio between the invariant TSC and base clock; * tsc_art_ratio: TSC to core crystal clock ratio. Signed-off-by: Alexander Shishkin <[email protected]> --- arch/x86/kernel/cpu/perf_event_intel_pt.c | 40 +++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index c534261068..e76aa5a30c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -126,9 +126,49 @@ static struct attribute_group pt_format_group = { .attrs = pt_formats_attr, }; +static ssize_t +pt_timing_attr_show(struct device *dev, struct device_attribute *attr, + char *page) +{ + struct perf_pmu_events_attr *pmu_attr = + container_of(attr, struct perf_pmu_events_attr, attr); + u32 eax, ebx, ecx, edx; + unsigned long val; + + switch (pmu_attr->id) { + case 0: + rdmsrl(MSR_PLATFORM_INFO, val); + val = (val & 0xff00) >> 8; + return sprintf(page, "%lu\n", val); + case 1: + cpuid(0x15, &eax, &ebx, &ecx, &edx); + return sprintf(page, "%u:%u\n", ebx, eax); + default: + break; + } + + return -EINVAL; +} + +PMU_EVENT_ATTR(max_nonturbo_ratio, timing_attr_max_nonturbo_ratio, 0, + pt_timing_attr_show); +PMU_EVENT_ATTR(tsc_art_ratio, timing_attr_tsc_art_ratio, 1, + pt_timing_attr_show); + +static struct attribute *pt_timing_attr[] = { + &timing_attr_max_nonturbo_ratio.attr.attr, + &timing_attr_tsc_art_ratio.attr.attr, + NULL, +}; + +static struct attribute_group pt_timing_group = { + .attrs = pt_timing_attr, +}; + static const struct attribute_group *pt_attr_groups[] = { &pt_cap_group, &pt_format_group, + &pt_timing_group, NULL, }; -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
