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From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: gregkh@linuxfoundation.org
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 14/16] coresight: Make sysfs functional on topologies with per core sink
Date: Wed, 16 Sep 2020 13:17:35 -0600	[thread overview]
Message-ID: <20200916191737.4001561-15-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20200916191737.4001561-1-mathieu.poirier@linaro.org>

From: Linu Cherian <lcherian@marvell.com>

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.

To fix this, coresight_get_enabled_sink API is updated to
do a connection based search starting from the given source,
instead of bus based search.
With sink selection using sysfs depecrated for perf interface,
provision for reset is removed as well in this API.

Signed-off-by: Linu Cherian <lcherian@marvell.com>
[Fixed indentation problem and removed obsolete comment]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/hwtracing/coresight/coresight-priv.h |  3 +-
 drivers/hwtracing/coresight/coresight.c      | 62 +++++++++-----------
 2 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index f2dc625ea585..5fe773c4d6cc 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -148,7 +148,8 @@ 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);
 struct coresight_device *coresight_get_sink_by_id(u32 id);
 struct coresight_device *
 coresight_find_default_sink(struct coresight_device *csdev);
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index e9c90f2de34a..bb4f9e0a5438 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -540,50 +540,46 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 	return csdev;
 }
 
-static int coresight_enabled_sink(struct device *dev, const void *data)
+static struct coresight_device *
+coresight_find_enabled_sink(struct coresight_device *csdev)
 {
-	const bool *reset = data;
-	struct coresight_device *csdev = to_coresight_device(dev);
+	int i;
+	struct coresight_device *sink;
 
 	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
-	     csdev->activated) {
-		/*
-		 * Now that we have a handle on the sink for this session,
-		 * disable the sysFS "enable_sink" flag so that possible
-		 * concurrent perf session that wish to use another sink don't
-		 * trip on it.  Doing so has no ramification for the current
-		 * session.
-		 */
-		if (*reset)
-			csdev->activated = false;
+	     csdev->activated)
+		return csdev;
 
-		return 1;
+	/*
+	 * Recursively explore each port found on this element.
+	 */
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_device *child_dev;
+
+		child_dev = csdev->pdata->conns[i].child_dev;
+		if (child_dev)
+			sink = coresight_find_enabled_sink(child_dev);
+		if (sink)
+			return sink;
 	}
 
-	return 0;
+	return NULL;
 }
 
 /**
- * coresight_get_enabled_sink - returns the first enabled sink found on the bus
- * @deactivate:	Whether the 'enable_sink' flag should be reset
- *
- * When operated from perf the deactivate parameter should be set to 'true'.
- * That way the "enabled_sink" flag of the sink that was selected can be reset,
- * allowing for other concurrent perf sessions to choose a different sink.
+ * coresight_get_enabled_sink - returns the first enabled sink using
+ * connection based search starting from the source reference
  *
- * When operated from sysFS users have full control and as such the deactivate
- * parameter should be set to 'false', hence mandating users to explicitly
- * clear the flag.
+ * @source: Coresight source device reference
  */
-struct coresight_device *coresight_get_enabled_sink(bool deactivate)
+struct coresight_device *
+coresight_get_enabled_sink(struct coresight_device *source)
 {
-	struct device *dev = NULL;
-
-	dev = bus_find_device(&coresight_bustype, NULL, &deactivate,
-			      coresight_enabled_sink);
+	if (!source)
+		return NULL;
 
-	return dev ? to_coresight_device(dev) : NULL;
+	return coresight_find_enabled_sink(source);
 }
 
 static int coresight_sink_by_id(struct device *dev, const void *data)
@@ -988,11 +984,7 @@ int coresight_enable(struct coresight_device *csdev)
 		goto out;
 	}
 
-	/*
-	 * 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);
 	if (!sink) {
 		ret = -EINVAL;
 		goto out;
-- 
2.25.1


WARNING: multiple messages have this Message-ID
From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: gregkh@linuxfoundation.org
Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH 14/16] coresight: Make sysfs functional on topologies with per core sink
Date: Wed, 16 Sep 2020 13:17:35 -0600	[thread overview]
Message-ID: <20200916191737.4001561-15-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20200916191737.4001561-1-mathieu.poirier@linaro.org>

From: Linu Cherian <lcherian@marvell.com>

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.

To fix this, coresight_get_enabled_sink API is updated to
do a connection based search starting from the given source,
instead of bus based search.
With sink selection using sysfs depecrated for perf interface,
provision for reset is removed as well in this API.

Signed-off-by: Linu Cherian <lcherian@marvell.com>
[Fixed indentation problem and removed obsolete comment]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/hwtracing/coresight/coresight-priv.h |  3 +-
 drivers/hwtracing/coresight/coresight.c      | 62 +++++++++-----------
 2 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index f2dc625ea585..5fe773c4d6cc 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -148,7 +148,8 @@ 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);
 struct coresight_device *coresight_get_sink_by_id(u32 id);
 struct coresight_device *
 coresight_find_default_sink(struct coresight_device *csdev);
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index e9c90f2de34a..bb4f9e0a5438 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -540,50 +540,46 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 	return csdev;
 }
 
-static int coresight_enabled_sink(struct device *dev, const void *data)
+static struct coresight_device *
+coresight_find_enabled_sink(struct coresight_device *csdev)
 {
-	const bool *reset = data;
-	struct coresight_device *csdev = to_coresight_device(dev);
+	int i;
+	struct coresight_device *sink;
 
 	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
-	     csdev->activated) {
-		/*
-		 * Now that we have a handle on the sink for this session,
-		 * disable the sysFS "enable_sink" flag so that possible
-		 * concurrent perf session that wish to use another sink don't
-		 * trip on it.  Doing so has no ramification for the current
-		 * session.
-		 */
-		if (*reset)
-			csdev->activated = false;
+	     csdev->activated)
+		return csdev;
 
-		return 1;
+	/*
+	 * Recursively explore each port found on this element.
+	 */
+	for (i = 0; i < csdev->pdata->nr_outport; i++) {
+		struct coresight_device *child_dev;
+
+		child_dev = csdev->pdata->conns[i].child_dev;
+		if (child_dev)
+			sink = coresight_find_enabled_sink(child_dev);
+		if (sink)
+			return sink;
 	}
 
-	return 0;
+	return NULL;
 }
 
 /**
- * coresight_get_enabled_sink - returns the first enabled sink found on the bus
- * @deactivate:	Whether the 'enable_sink' flag should be reset
- *
- * When operated from perf the deactivate parameter should be set to 'true'.
- * That way the "enabled_sink" flag of the sink that was selected can be reset,
- * allowing for other concurrent perf sessions to choose a different sink.
+ * coresight_get_enabled_sink - returns the first enabled sink using
+ * connection based search starting from the source reference
  *
- * When operated from sysFS users have full control and as such the deactivate
- * parameter should be set to 'false', hence mandating users to explicitly
- * clear the flag.
+ * @source: Coresight source device reference
  */
-struct coresight_device *coresight_get_enabled_sink(bool deactivate)
+struct coresight_device *
+coresight_get_enabled_sink(struct coresight_device *source)
 {
-	struct device *dev = NULL;
-
-	dev = bus_find_device(&coresight_bustype, NULL, &deactivate,
-			      coresight_enabled_sink);
+	if (!source)
+		return NULL;
 
-	return dev ? to_coresight_device(dev) : NULL;
+	return coresight_find_enabled_sink(source);
 }
 
 static int coresight_sink_by_id(struct device *dev, const void *data)
@@ -988,11 +984,7 @@ int coresight_enable(struct coresight_device *csdev)
 		goto out;
 	}
 
-	/*
-	 * 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);
 	if (!sink) {
 		ret = -EINVAL;
 		goto out;
-- 
2.25.1


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-09-16 19:37 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 19:17 [PATCH 00/16] coresight: next v5.9-rc5 Mathieu Poirier
2020-09-16 19:17 ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 01/16] coresight: etm4x: Fix etm4_count race by moving cpuhp callbacks to init Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 02/16] coresight: stm: Support marked packet Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 03/16] coresight: fix offset by one error in counting ports Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 04/16] coresight: etm4x: Add Support for HiSilicon ETM device Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 05/16] coresight: cti: disclaim device only when it's claimed Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 06/16] coresight: cti: remove pm_runtime_get_sync() from CPU hotplug Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 07/16] coresight: etm4x: Ensure default perf settings filter user/kernel Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 08/16] coresight: etm4x: Fix issues within reset interface of sysfs Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 09/16] coresight: cti: Write regsiters directly in cti_enable_hw() Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 10/16] coresight: etm4x: Handle unreachable sink in perf mode Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 11/16] coresight: etm4x: Fix issues on trcseqevr access Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 12/16] MAINTAINERS: Add CoreSight mailing list Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 13/16] coresight: etm: perf: Sink selection using sysfs is deprecated Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` Mathieu Poirier [this message]
2020-09-16 19:17   ` [PATCH 14/16] coresight: Make sysfs functional on topologies with per core sink Mathieu Poirier
2020-09-16 19:17 ` [PATCH 15/16] coresight: etm4x: Fix mis-usage of nr_resource in sysfs interface Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-16 19:17 ` [PATCH 16/16] coresight: etm4x: Fix number of resources check for ETM 4.3 and above Mathieu Poirier
2020-09-16 19:17   ` Mathieu Poirier
2020-09-17  9:08 ` [PATCH 00/16] coresight: next v5.9-rc5 Greg KH
2020-09-17  9:08   ` Greg KH
2020-09-17 14:35   ` Mathieu Poirier
2020-09-17 14:35     ` Mathieu Poirier

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