From: Mike Leach <mike.leach@linaro.org>
Date: Thu, 16 Jul 2020 11:57:45 -0600
Subject: coresight: etm: perf: Add default sink selection to etm perf
Git-commit: bbfb8f3e4e3f10c7b0b76f9159b8a9608abdea91
Patch-mainline: v5.9-rc1
References: jsc#SLE-13629,jsc#SLE-14776
Add default sink selection to the perf trace handling in the etm driver.
Uses the select default sink infrastructure to select a sink for the perf
session, if no other sink is specified.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200716175746.3338735-17-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
.../hwtracing/coresight/coresight-etm-perf.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 84f1dcb69827..1a3169e69bb1 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -226,9 +226,6 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
sink = coresight_get_enabled_sink(true);
}
- if (!sink)
- goto err;
-
mask = &event_data->mask;
/*
@@ -253,6 +250,16 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
continue;
}
+ /*
+ * No sink provided - look for a default sink for one of the
+ * devices. At present we only support topology where all CPUs
+ * use the same sink [N:1], so only need to find one sink. The
+ * coresight_build_path later will remove any CPU that does not
+ * attach to the sink, or if we have not found a sink.
+ */
+ if (!sink)
+ sink = coresight_find_default_sink(csdev);
+
/*
* Building a path doesn't enable it, it simply builds a
* list of devices from source to sink that can be
@@ -267,6 +274,10 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
*etm_event_cpu_path_ptr(event_data, cpu) = path;
}
+ /* no sink found for any CPU - cannot trace */
+ if (!sink)
+ goto err;
+
/* If we don't have any CPUs ready for tracing, abort */
cpu = cpumask_first(mask);
if (cpu >= nr_cpu_ids)
--
2.26.2