perf cs-etm: Add fix for coresight trace for any range of CPUs

The current implementation supports coresight trace decode for a range
of CPUs, if the first CPU is CPU0.

Perf report segfaults, if tried for sparse CPUs list and also for
any range of CPUs(non zero first CPU).

Adding a fix to perf report for any range of CPUs and for sparse list.

Signed-off-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20230421055253.83912-1-gankulkarni@os.amperecomputing.com
Cc: suzuki.poulose@arm.com
Cc: acme@kernel.org
Cc: mathieu.poirier@linaro.org
Cc: mike.leach@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: darren@os.amperecomputing.com
Cc: scclevenger@os.amperecomputing.com
Cc: scott@os.amperecomputing.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 456994564d6e4d4a70b8bb8996e7bdad598d111a..91299cc56bf7881990ca1fe6d91c2a5927e21221 100644 (file)
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -290,6 +290,25 @@ static int cs_etm__metadata_set_trace_id(u8 trace_chan_id, u64 *cpu_metadata)
                (typeof(_mask))(((_reg) & (_mask)) >> __bf_shf(_mask)); \
        })
 
+/*
+ * Get a metadata for a specific cpu from an array.
+ *
+ */
+static u64 *get_cpu_data(struct cs_etm_auxtrace *etm, int cpu)
+{
+       int i;
+       u64 *metadata = NULL;
+
+       for (i = 0; i < etm->num_cpu; i++) {
+               if (etm->metadata[i][CS_ETM_CPU] == (u64)cpu) {
+                       metadata = etm->metadata[i];
+                       break;
+               }
+       }
+
+       return metadata;
+}
+
 /*
  * Handle the PERF_RECORD_AUX_OUTPUT_HW_ID event.
  *
@@ -359,8 +378,11 @@ static int cs_etm__process_aux_output_hw_id(struct perf_session *session,
                return 0;
        }
 
+       cpu_data = get_cpu_data(etm, cpu);
+       if (cpu_data == NULL)
+               return err;
+
        /* not one we've seen before - lets map it */
-       cpu_data = etm->metadata[cpu];
        err = cs_etm__map_trace_id(trace_chan_id, cpu_data);
        if (err)
                return err;