perf cs-etm: Properly deal with cpu maps

This patch allows the CoreSight AUX info section to fit topologies where
only a subset of all available CPUs are present, avoiding at the same
time accessing the ETM configuration areas of CPUs that have been
offlined.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1518478737-24649-1-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index fbfc055..5c655ad 100644 (file)
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -298,12 +298,17 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
 {
        int i;
        int etmv3 = 0, etmv4 = 0;
-       const struct cpu_map *cpus = evlist->cpus;
+       struct cpu_map *event_cpus = evlist->cpus;
+       struct cpu_map *online_cpus = cpu_map__new(NULL);
 
        /* cpu map is not empty, we have specific CPUs to work with */
-       if (!cpu_map__empty(cpus)) {
-               for (i = 0; i < cpu_map__nr(cpus); i++) {
-                       if (cs_etm_is_etmv4(itr, cpus->map[i]))
+       if (!cpu_map__empty(event_cpus)) {
+               for (i = 0; i < cpu__max_cpu(); i++) {
+                       if (!cpu_map__has(event_cpus, i) ||
+                           !cpu_map__has(online_cpus, i))
+                               continue;
+
+                       if (cs_etm_is_etmv4(itr, i))
                                etmv4++;
                        else
                                etmv3++;
@@ -311,6 +316,9 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
        } else {
                /* get configuration for all CPUs in the system */
                for (i = 0; i < cpu__max_cpu(); i++) {
+                       if (!cpu_map__has(online_cpus, i))
+                               continue;
+
                        if (cs_etm_is_etmv4(itr, i))
                                etmv4++;
                        else
@@ -318,6 +326,8 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
                }
        }
 
+       cpu_map__put(online_cpus);
+
        return (CS_ETM_HEADER_SIZE +
               (etmv4 * CS_ETMV4_PRIV_SIZE) +
               (etmv3 * CS_ETMV3_PRIV_SIZE));
@@ -447,7 +457,9 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
        int i;
        u32 offset;
        u64 nr_cpu, type;
-       const struct cpu_map *cpus = session->evlist->cpus;
+       struct cpu_map *cpu_map;
+       struct cpu_map *event_cpus = session->evlist->cpus;
+       struct cpu_map *online_cpus = cpu_map__new(NULL);
        struct cs_etm_recording *ptr =
                        container_of(itr, struct cs_etm_recording, itr);
        struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
@@ -458,8 +470,21 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
        if (!session->evlist->nr_mmaps)
                return -EINVAL;
 
-       /* If the cpu_map is empty all CPUs are involved */
-       nr_cpu = cpu_map__empty(cpus) ? cpu__max_cpu() : cpu_map__nr(cpus);
+       /* If the cpu_map is empty all online CPUs are involved */
+       if (cpu_map__empty(event_cpus)) {
+               cpu_map = online_cpus;
+       } else {
+               /* Make sure all specified CPUs are online */
+               for (i = 0; i < cpu_map__nr(event_cpus); i++) {
+                       if (cpu_map__has(event_cpus, i) &&
+                           !cpu_map__has(online_cpus, i))
+                               return -EINVAL;
+               }
+
+               cpu_map = event_cpus;
+       }
+
+       nr_cpu = cpu_map__nr(cpu_map);
        /* Get PMU type as dynamically assigned by the core */
        type = cs_etm_pmu->type;
 
@@ -472,15 +497,11 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
 
        offset = CS_ETM_SNAPSHOT + 1;
 
-       /* cpu map is not empty, we have specific CPUs to work with */
-       if (!cpu_map__empty(cpus)) {
-               for (i = 0; i < cpu_map__nr(cpus) && offset < priv_size; i++)
-                       cs_etm_get_metadata(cpus->map[i], &offset, itr, info);
-       } else {
-               /* get configuration for all CPUs in the system */
-               for (i = 0; i < cpu__max_cpu(); i++)
+       for (i = 0; i < cpu__max_cpu() && offset < priv_size; i++)
+               if (cpu_map__has(cpu_map, i))
                        cs_etm_get_metadata(i, &offset, itr, info);
-       }
+
+       cpu_map__put(online_cpus);
 
        return 0;
 }