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Subject[PATCH] perf tools: Add arm64 version of get_cpuid()
Date
Add an arm64 version of get_cpuid(), which is used for various annotation
and headers - for example, I now get the CPUID in "perf report --header",
as shown in this snippet:

# hostname : ubuntu
# os release : 5.5.0-rc1-dirty
# perf version : 5.5.rc1.gbf8a13dc9851
# arch : aarch64
# nrcpus online : 96
# nrcpus avail : 96
# cpuid : 0x00000000480fd010

Since much of the code to read the MIDR is already in get_cpuid_str(),
factor out this code.

Signed-off-by: John Garry <john.garry@huawei.com>

diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c
index a32e4b72a98f..d730666ab95d 100644
--- a/tools/perf/arch/arm64/util/header.c
+++ b/tools/perf/arch/arm64/util/header.c
@@ -1,8 +1,10 @@
#include <stdio.h>
#include <stdlib.h>
#include <perf/cpumap.h>
+#include <util/cpumap.h>
#include <internal/cpumap.h>
#include <api/fs/fs.h>
+#include <errno.h>
#include "debug.h"
#include "header.h"

@@ -12,26 +14,21 @@
#define MIDR_VARIANT_SHIFT 20
#define MIDR_VARIANT_MASK (0xf << MIDR_VARIANT_SHIFT)

-char *get_cpuid_str(struct perf_pmu *pmu)
+static int _get_cpuid(char *buf, size_t sz, struct perf_cpu_map *cpus)
{
- char *buf = NULL;
- char path[PATH_MAX];
const char *sysfs = sysfs__mountpoint();
- int cpu;
u64 midr = 0;
- struct perf_cpu_map *cpus;
- FILE *file;
+ int cpu;

- if (!sysfs || !pmu || !pmu->cpus)
- return NULL;
+ if (!sysfs || sz < MIDR_SIZE)
+ return EINVAL;

- buf = malloc(MIDR_SIZE);
- if (!buf)
- return NULL;
+ cpus = perf_cpu_map__get(cpus);

- /* read midr from list of cpus mapped to this pmu */
- cpus = perf_cpu_map__get(pmu->cpus);
for (cpu = 0; cpu < perf_cpu_map__nr(cpus); cpu++) {
+ char path[PATH_MAX];
+ FILE *file;
+
scnprintf(path, PATH_MAX, "%s/devices/system/cpu/cpu%d"MIDR,
sysfs, cpus->map[cpu]);

@@ -57,12 +54,48 @@ char *get_cpuid_str(struct perf_pmu *pmu)
break;
}

- if (!midr) {
+ perf_cpu_map__put(cpus);
+
+ if (!midr)
+ return EINVAL;
+
+ return 0;
+}
+
+int get_cpuid(char *buf, size_t sz)
+{
+ struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
+ int ret;
+
+ if (!cpus)
+ return EINVAL;
+
+ ret = _get_cpuid(buf, sz, cpus);
+
+ perf_cpu_map__put(cpus);
+
+ return ret;
+}
+
+char *get_cpuid_str(struct perf_pmu *pmu)
+{
+ char *buf = NULL;
+ int res;
+
+ if (!pmu || !pmu->cpus)
+ return NULL;
+
+ buf = malloc(MIDR_SIZE);
+ if (!buf)
+ return NULL;
+
+ /* read midr from list of cpus mapped to this pmu */
+ res = _get_cpuid(buf, MIDR_SIZE, pmu->cpus);
+ if (res) {
pr_err("failed to get cpuid string for PMU %s\n", pmu->name);
free(buf);
buf = NULL;
}

- perf_cpu_map__put(cpus);
return buf;
}
--
2.17.1
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