Coresight driver assumes sink is common across all the ETMs, and tries to build a path between ETM and the first enabled sink found using bus based search. This breaks sysFS usage on implementations that has multiple per core sinks in enabled state.
For this, - coresight_find_sink API is updated with an additional flag so that it is able to return an enabled sink - coresight_get_enabled_sink API is updated to do a connection based search, when a source reference is given.
Change-Id: I6cc91ddb3ef8936a8f41a5f7c7c455b0ece9d85d Signed-off-by: Linu Cherian lcherian@marvell.com --- Applies on https://git.linaro.org/kernel/coresight.git/log/?h=next
Changes in V2: - Fixed few typos in commit message - Rephrased commit message
.../hwtracing/coresight/coresight-etm-perf.c | 2 +- drivers/hwtracing/coresight/coresight-priv.h | 5 +- drivers/hwtracing/coresight/coresight.c | 51 +++++++++++++++++-- 3 files changed, 51 insertions(+), 7 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 1a3169e69bb1..25041d2654e3 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -223,7 +223,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, id = (u32)event->attr.config2; sink = coresight_get_sink_by_id(id); } else { - sink = coresight_get_enabled_sink(true); + sink = coresight_get_enabled_sink(NULL, true); }
mask = &event_data->mask; diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index f2dc625ea585..010ed26db340 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -148,10 +148,13 @@ static inline void coresight_write_reg_pair(void __iomem *addr, u64 val, void coresight_disable_path(struct list_head *path); int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data); struct coresight_device *coresight_get_sink(struct list_head *path); -struct coresight_device *coresight_get_enabled_sink(bool reset); +struct coresight_device * +coresight_get_enabled_sink(struct coresight_device *source, bool reset); struct coresight_device *coresight_get_sink_by_id(u32 id); struct coresight_device * coresight_find_default_sink(struct coresight_device *csdev); +struct coresight_device * +coresight_find_enabled_sink(struct coresight_device *csdev); struct list_head *coresight_build_path(struct coresight_device *csdev, struct coresight_device *sink); void coresight_release_path(struct list_head *path); diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index e9c90f2de34a..ae69169c58d3 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -566,6 +566,10 @@ static int coresight_enabled_sink(struct device *dev, const void *data)
/** * coresight_get_enabled_sink - returns the first enabled sink found on the bus + * When a source reference is given, enabled sink is found using connection based + * search. + * + * @source: Coresight source device reference * @deactivate: Whether the 'enable_sink' flag should be reset * * When operated from perf the deactivate parameter should be set to 'true'. @@ -576,10 +580,21 @@ static int coresight_enabled_sink(struct device *dev, const void *data) * parameter should be set to 'false', hence mandating users to explicitly * clear the flag. */ -struct coresight_device *coresight_get_enabled_sink(bool deactivate) +struct coresight_device * +coresight_get_enabled_sink(struct coresight_device *source, bool deactivate) { struct device *dev = NULL; + struct coresight_device *sink; + + if (!source) + goto bus_search; + sink = coresight_find_enabled_sink(source); + if (sink && deactivate) + sink->activated = false; + + return sink;
+bus_search: dev = bus_find_device(&coresight_bustype, NULL, &deactivate, coresight_enabled_sink);
@@ -828,6 +843,7 @@ coresight_select_best_sink(struct coresight_device *sink, int *depth, * * @csdev: source / current device to check. * @depth: [in] search depth of calling dev, [out] depth of found sink. + * @enabled: flag to search only enabled sinks * * This will walk the connection path from a source (ETM) till a suitable * sink is encountered and return that sink to the original caller. @@ -839,7 +855,7 @@ coresight_select_best_sink(struct coresight_device *sink, int *depth, * return best sink found, or NULL if not found at this node or child nodes. */ static struct coresight_device * -coresight_find_sink(struct coresight_device *csdev, int *depth) +coresight_find_sink(struct coresight_device *csdev, int *depth, bool enabled) { int i, curr_depth = *depth + 1, found_depth = 0; struct coresight_device *found_sink = NULL; @@ -862,7 +878,8 @@ coresight_find_sink(struct coresight_device *csdev, int *depth)
child_dev = csdev->pdata->conns[i].child_dev; if (child_dev) - sink = coresight_find_sink(child_dev, &child_depth); + sink = coresight_find_sink(child_dev, &child_depth, + enabled);
if (sink) found_sink = coresight_select_best_sink(found_sink, @@ -872,6 +889,10 @@ coresight_find_sink(struct coresight_device *csdev, int *depth) }
return_def_sink: + /* Check if we need to return an enabled sink */ + if (enabled && found_sink) + if (!found_sink->activated) + found_sink = NULL; /* return found sink and depth */ if (found_sink) *depth = found_depth; @@ -901,10 +922,30 @@ coresight_find_default_sink(struct coresight_device *csdev)
/* look for a default sink if we have not found for this device */ if (!csdev->def_sink) - csdev->def_sink = coresight_find_sink(csdev, &depth); + csdev->def_sink = coresight_find_sink(csdev, &depth, false); return csdev->def_sink; }
+/** + * coresight_find_enabled_sink: Find the suitable enabled sink + * + * @csdev: starting source to find a connected sink. + * + * Walks connections graph looking for a suitable sink to enable for the + * supplied source. Uses CoreSight device subtypes and distance from source + * to select the best sink. + * + * Used in cases where the CoreSight user (sysfs) has selected a sink. + */ +struct coresight_device * +coresight_find_enabled_sink(struct coresight_device *csdev) +{ + int depth = 0; + + /* look for the enabled sink */ + return coresight_find_sink(csdev, &depth, true); +} + static int coresight_remove_sink_ref(struct device *dev, void *data) { struct coresight_device *sink = data; @@ -992,7 +1033,7 @@ int coresight_enable(struct coresight_device *csdev) * Search for a valid sink for this session but don't reset the * "enable_sink" flag in sysFS. Users get to do that explicitly. */ - sink = coresight_get_enabled_sink(false); + sink = coresight_get_enabled_sink(csdev, false); if (!sink) { ret = -EINVAL; goto out;