Commit-ID: b57df28893543db3466172088786fae39b7fc3ad
Gitweb: https://git.kernel.org/tip/b57df28893543db3466172088786fae39b7fc3ad
Author: Ganapatrao Kulkarni <ganapatrao.kulkarni@xxxxxxxxxx>
AuthorDate: Tue, 17 Oct 2017 00:02:19 +0530
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
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.kulkarni@xxxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Ganapatrao Kulkarni <gklkml16@xxxxxxxxx>
Cc: Jayachandran C <jnair@xxxxxxxxxxxxxxxxxx>
Cc: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Robert Richter <robert.richter@xxxxxxxxxx>
Cc: Shaokun Zhang <zhangshaokun@xxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20171016183222.25750-3-ganapatrao.kulkarni@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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;
+}
--
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