Commit-ID: 65c7e6f1c4810e9bce935520f44f6d2613cd1b40 Gitweb: http://git.kernel.org/tip/65c7e6f1c4810e9bce935520f44f6d2613cd1b40 Author: Alexander Shishkin <[email protected]> AuthorDate: Wed, 19 Aug 2015 17:02:10 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 5 May 2016 10:16:28 +0200
perf/x86/intel/pt: Export CPU frequency ratios needed by PT decoders Intel PT decoders need access to various bits of timing related information to be able to correctly decode timing packets from a PT stream (MTC and CBR packets). This patch exports all the necessary bits as sysfs attributes for the sake of consistency: * max_nonturbo_ratio: ratio between the invariant TSC and base clock; * tsc_art_ratio: TSC to core crystal clock ratio (also available as CPUID.15H). Signed-off-by: Alexander Shishkin <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mathieu Poirier <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/events/intel/pt.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/events/intel/pt.h | 6 ++++++ 2 files changed, 60 insertions(+) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 2d1ce2c..c3a359c 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -127,9 +127,46 @@ 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); + + switch (pmu_attr->id) { + case 0: + return sprintf(page, "%lu\n", pt_pmu.max_nonturbo_ratio); + case 1: + return sprintf(page, "%u:%u\n", + pt_pmu.tsc_art_num, + pt_pmu.tsc_art_den); + 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, }; @@ -142,6 +179,23 @@ static int __init pt_pmu_hw_init(void) int ret; long i; + rdmsrl(MSR_PLATFORM_INFO, reg); + pt_pmu.max_nonturbo_ratio = (reg & 0xff00) >> 8; + + /* + * if available, read in TSC to core crystal clock ratio, + * otherwise, zero for numerator stands for "not enumerated" + * as per SDM + */ + if (boot_cpu_data.cpuid_level >= CPUID_TSC_LEAF) { + u32 eax, ebx, ecx, edx; + + cpuid(CPUID_TSC_LEAF, &eax, &ebx, &ecx, &edx); + + pt_pmu.tsc_art_num = ebx; + pt_pmu.tsc_art_den = eax; + } + if (boot_cpu_has(X86_FEATURE_VMX)) { /* * Intel SDM, 36.5 "Tracing post-VMXON" says that diff --git a/arch/x86/events/intel/pt.h b/arch/x86/events/intel/pt.h index ca64599..efffa4a 100644 --- a/arch/x86/events/intel/pt.h +++ b/arch/x86/events/intel/pt.h @@ -82,6 +82,9 @@ struct topa_entry { #define PT_CPUID_LEAVES 2 #define PT_CPUID_REGS_NUM 4 /* number of regsters (eax, ebx, ecx, edx) */ +/* TSC to Core Crystal Clock Ratio */ +#define CPUID_TSC_LEAF 0x15 + enum pt_capabilities { PT_CAP_max_subleaf = 0, PT_CAP_cr3_filtering, @@ -102,6 +105,9 @@ struct pt_pmu { struct pmu pmu; u32 caps[PT_CPUID_REGS_NUM * PT_CPUID_LEAVES]; bool vmx; + unsigned long max_nonturbo_ratio; + unsigned int tsc_art_num; + unsigned int tsc_art_den; }; /**
