linux/tools/perf/arch/arm64/util/header.c
John Garry df5a5f3cf2 perf tools: Add arm64 version of get_cpuid()
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.

Tester notes:

I tested this patch on my new ARM64 Kunpeng 920 server.
[root@node1 zsk]# ./perf --version
perf version 5.6.rc1.g2cdb955b7252

Both perf list and perf stat can work.

Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1576245255-210926-1-git-send-email-john.garry@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-02-12 10:36:51 -03:00

102 lines
1.9 KiB
C

#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"
#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)
static int _get_cpuid(char *buf, size_t sz, struct perf_cpu_map *cpus)
{
const char *sysfs = sysfs__mountpoint();
u64 midr = 0;
int cpu;
if (!sysfs || sz < MIDR_SIZE)
return EINVAL;
cpus = perf_cpu_map__get(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]);
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;
}
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;
}
return buf;
}