Merge "coresight: add support to enable multiple coresight paths" (70eee89e) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/hwtracing/coresight/coresight.c

+56 −45

Original line number	Diff line number	Diff line
		@@ -36,18 +36,16 @@ struct coresight_node {
		};

		/*
		* When operating Coresight drivers from the sysFS interface, only a single
		* path can exist from a tracer (associated to a CPU) to a sink.
		* struct coresight_path - path from source to sink
		* @path: Address of path list.
		* @link: hook to the list.
		*/
		static DEFINE_PER_CPU(struct list_head *, tracer_path);
		struct coresight_path {
		struct list_head *path;
		struct list_head link;
		};

		/*
		* As of this writing only a single STM can be found in CS topologies. Since
		* there is no way to know if we'll ever see more and what kind of
		* configuration they will enact, for the time being only define a single path
		* for STM.
		*/
		static struct list_head *stm_path;
		static LIST_HEAD(cs_active_paths);

		/*
		* When losing synchronisation a new barrier packet needs to be inserted at the
		@@ -247,7 +245,7 @@ static void coresight_disable_sink(struct coresight_device *csdev)
		ret = sink_ops(csdev)->disable(csdev);
		if (ret)
		return;
		csdev->enable = false;
		csdev->activated = false;
		}

		static int coresight_enable_link(struct coresight_device *csdev,
		@@ -484,6 +482,20 @@ int coresight_enable_path(struct list_head path, u32 mode, void sink_data)
		goto out;
		}

		static struct coresight_device coresight_get_source(struct list_head path)
		{
		struct coresight_device *csdev;

		if (!path)
		return NULL;

		csdev = list_first_entry(path, struct coresight_node, link)->csdev;
		if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
		return NULL;

		return csdev;
		}

		struct coresight_device coresight_get_sink(struct list_head path)
		{
		struct coresight_device *csdev;
		@@ -756,9 +768,23 @@ static int coresight_validate_source(struct coresight_device *csdev,
		return 0;
		}

		static int coresight_store_path(struct list_head *path)
		{
		struct coresight_path *node;

		node = kzalloc(sizeof(struct coresight_path), GFP_KERNEL);
		if (!node)
		return -ENOMEM;

		node->path = path;
		list_add(&node->link, &cs_active_paths);

		return 0;
		}

		int coresight_enable(struct coresight_device *csdev)
		{
		int cpu, ret = 0;
		int ret = 0;
		struct coresight_device *sink;
		struct list_head *path;
		enum coresight_dev_subtype_source subtype;
		@@ -807,25 +833,9 @@ int coresight_enable(struct coresight_device *csdev)
		if (ret)
		goto err_source;

		switch (subtype) {
		case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
		/*
		* When working from sysFS it is important to keep track
		* of the paths that were created so that they can be
		* undone in 'coresight_disable()'. Since there can only
		* be a single session per tracer (when working from sysFS)
		* a per-cpu variable will do just fine.
		*/
		cpu = source_ops(csdev)->cpu_id(csdev);
		per_cpu(tracer_path, cpu) = path;
		break;
		case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
		stm_path = path;
		break;
		default:
		/* We can't be here */
		break;
		}
		ret = coresight_store_path(path);
		if (ret)
		goto err_source;

		out:
		mutex_unlock(&coresight_mutex);
		@@ -842,8 +852,11 @@ EXPORT_SYMBOL_GPL(coresight_enable);

		void coresight_disable(struct coresight_device *csdev)
		{
		int cpu, ret;
		int ret;
		struct list_head *path = NULL;
		struct coresight_path *cspath = NULL;
		struct coresight_path *cspath_next = NULL;
		struct coresight_device *src_csdev = NULL;

		mutex_lock(&coresight_mutex);

		@@ -854,20 +867,18 @@ void coresight_disable(struct coresight_device *csdev)
		if (!csdev->enable \|\| !coresight_disable_source(csdev))
		goto out;

		switch (csdev->subtype.source_subtype) {
		case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
		cpu = source_ops(csdev)->cpu_id(csdev);
		path = per_cpu(tracer_path, cpu);
		per_cpu(tracer_path, cpu) = NULL;
		break;
		case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
		path = stm_path;
		stm_path = NULL;
		break;
		default:
		/* We can't be here */
		break;
		list_for_each_entry_safe(cspath, cspath_next, &cs_active_paths, link) {
		src_csdev = coresight_get_source(cspath->path);
		if (!src_csdev)
		continue;
		if (src_csdev == csdev) {
		path = cspath->path;
		list_del(&cspath->link);
		kfree(cspath);
		}
		}
		if (path == NULL)
		goto out;

		coresight_disable_path(path);
		coresight_release_path(path);