[tip: perf/urgent] perf tools: Add arm64 version of get_cpuid()

From: tip-bot2 for John Garry
Date: Sat Feb 15 2020 - 03:42:32 EST


The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: df5a5f3cf24608457bb5e57297dd9f0d528be58f
Gitweb: https://git.kernel.org/tip/df5a5f3cf24608457bb5e57297dd9f0d528be58f
Author: John Garry <john.garry@xxxxxxxxxx>
AuthorDate: Fri, 13 Dec 2019 21:54:15 +08:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Wed, 12 Feb 2020 10:36:51 -03:00

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@xxxxxxxxxx>
Tested-by: Shaokun Zhang <zhangshaokun@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linuxarm@xxxxxxxxxx
Link: http://lore.kernel.org/lkml/1576245255-210926-1-git-send-email-john.garry@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/arch/arm64/util/header.c | 63 +++++++++++++++++++++-------
1 file changed, 48 insertions(+), 15 deletions(-)

diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c
index a32e4b7..d730666 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;
}