perf header: Refactor get_cpuid to take a CPU for ARM

ARM BIG.little has no notion of a constant CPUID for both core
types. To reflect this reality, change the get_cpuid function to also
pass in a possibly unused logical cpu.

If the dummy value (-1) is passed in then ARM can, as currently happens,
select the first logical CPU's "CPUID".

The changes to ARM getcpuid happen in a follow up change.

Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Zong-You Xie <ben717@andestech.com>
Cc: Benjamin Gray <bgray@linux.ibm.com>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Clément Le Goffic <clement.legoffic@foss.st.com>
Cc: Dima Kogan <dima@secretsauce.net>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Link: https://lore.kernel.org/r/20241107162035.52206-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 8 insertions, 6 deletions

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index ccb464026642..93cabdd7ff43 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -373,7 +373,8 @@ error:
 int perf_env__read_cpuid(struct perf_env *env)
 {
 	char cpuid[128];
-	int err = get_cpuid(cpuid, sizeof(cpuid));
+	struct perf_cpu cpu = {-1};
+	int err = get_cpuid(cpuid, sizeof(cpuid), cpu);
 
 	if (err)
 		return err;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c7552a78a7be..ecf08b458b05 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -856,18 +856,19 @@ int __weak strcmp_cpuid_str(const char *mapcpuid, const char *cpuid)
  * default get_cpuid(): nothing gets recorded
  * actual implementation must be in arch/$(SRCARCH)/util/header.c
  */
-int __weak get_cpuid(char *buffer __maybe_unused, size_t sz __maybe_unused)
+int __weak get_cpuid(char *buffer __maybe_unused, size_t sz __maybe_unused,
+		     struct perf_cpu cpu __maybe_unused)
 {
 	return ENOSYS; /* Not implemented */
 }
 
-static int write_cpuid(struct feat_fd *ff,
-		       struct evlist *evlist __maybe_unused)
+static int write_cpuid(struct feat_fd *ff, struct evlist *evlist)
 {
+	struct perf_cpu cpu = perf_cpu_map__min(evlist->core.all_cpus);
 	char buffer[64];
 	int ret;
 
-	ret = get_cpuid(buffer, sizeof(buffer));
+	ret = get_cpuid(buffer, sizeof(buffer), cpu);
 	if (ret)
 		return -1;
 
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index e91e89d22537..b77f89de12dd 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -201,7 +201,7 @@ int build_caches_for_cpu(u32 cpu, struct cpu_cache_level caches[], u32 *cntp);
 /*
  * arch specific callback
  */
-int get_cpuid(char *buffer, size_t sz);
+int get_cpuid(char *buffer, size_t sz, struct perf_cpu cpu);
 
 char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused);
 int strcmp_cpuid_str(const char *s1, const char *s2);