Commit-ID: b57df28893543db3466172088786fae39b7fc3ad Gitweb: https://git.kernel.org/tip/b57df28893543db3466172088786fae39b7fc3ad Author: Ganapatrao Kulkarni <ganapatrao.kulka...@cavium.com> AuthorDate: Tue, 17 Oct 2017 00:02:19 +0530 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 5 Dec 2017 10:24:33 -0300
perf tools arm64: Add support for get_cpuid_str function. The get_cpuid_str function returns the MIDR string of the first online cpu from the range of cpus associated with the PMU CORE device. Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulka...@cavium.com> Acked-by: Will Deacon <will.dea...@arm.com> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Ganapatrao Kulkarni <gklkm...@gmail.com> Cc: Jayachandran C <jn...@caviumnetworks.com> Cc: Jonathan Cameron <jonathan.came...@huawei.com> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Robert Richter <robert.rich...@cavium.com> Cc: Shaokun Zhang <zhangshao...@hisilicon.com> Cc: linux-arm-ker...@lists.infradead.org Link: http://lkml.kernel.org/r/20171016183222.25750-3-ganapatrao.kulka...@cavium.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/arch/arm64/util/Build | 1 + tools/perf/arch/arm64/util/header.c | 65 +++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build index cef6fb3..b1ab72d 100644 --- a/tools/perf/arch/arm64/util/Build +++ b/tools/perf/arch/arm64/util/Build @@ -1,3 +1,4 @@ +libperf-y += header.o libperf-$(CONFIG_DWARF) += dwarf-regs.o libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c new file mode 100644 index 0000000..534cd25 --- /dev/null +++ b/tools/perf/arch/arm64/util/header.c @@ -0,0 +1,65 @@ +#include <stdio.h> +#include <stdlib.h> +#include <api/fs/fs.h> +#include "header.h" + +#define MIDR "/regs/identification/midr_el1" +#define MIDR_SIZE 19 +#define MIDR_REVISION_MASK 0xf +#define MIDR_VARIANT_SHIFT 20 +#define MIDR_VARIANT_MASK (0xf << MIDR_VARIANT_SHIFT) + +char *get_cpuid_str(struct perf_pmu *pmu) +{ + char *buf = NULL; + char path[PATH_MAX]; + const char *sysfs = sysfs__mountpoint(); + int cpu; + u64 midr = 0; + struct cpu_map *cpus; + FILE *file; + + if (!sysfs || !pmu || !pmu->cpus) + return NULL; + + buf = malloc(MIDR_SIZE); + if (!buf) + return NULL; + + /* read midr from list of cpus mapped to this pmu */ + cpus = cpu_map__get(pmu->cpus); + for (cpu = 0; cpu < cpus->nr; cpu++) { + scnprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d"MIDR, + sysfs, cpus->map[cpu]); + + file = fopen(path, "r"); + if (!file) { + pr_debug("fopen failed for file %s\n", path); + continue; + } + + if (!fgets(buf, MIDR_SIZE, file)) { + fclose(file); + continue; + } + fclose(file); + + /* Ignore/clear Variant[23:20] and + * Revision[3:0] of MIDR + */ + midr = strtoul(buf, NULL, 16); + midr &= (~(MIDR_VARIANT_MASK | MIDR_REVISION_MASK)); + scnprintf(buf, MIDR_SIZE, "0x%016lx", midr); + /* got midr break loop */ + break; + } + + if (!midr) { + pr_err("failed to get cpuid string for PMU %s\n", pmu->name); + free(buf); + buf = NULL; + } + + cpu_map__put(cpus); + return buf; +}
