Merge "interconnect: Add interconnect_graph file to debugfs" (2ec6c066) · Commits · e / devices / android_kernel_fairphone_FP5

Documentation/driver-api/interconnect.rst

+22 −0

Original line number	Diff line number	Diff line
		@@ -91,3 +91,25 @@ Interconnect consumers are the clients which use the interconnect APIs to
		get paths between endpoints and set their bandwidth/latency/QoS requirements
		for these interconnect paths. These interfaces are not currently
		documented.

		Interconnect debugfs interfaces
		-------------------------------

		Like several other subsystems interconnect will create some files for debugging
		and introspection. Files in debugfs are not considered ABI so application
		software shouldn't rely on format details change between kernel versions.

		``/sys/kernel/debug/interconnect/interconnect_summary``:

		Show all interconnect nodes in the system with their aggregated bandwidth
		request. Indented under each node show bandwidth requests from each device.

		``/sys/kernel/debug/interconnect/interconnect_graph``:

		Show the interconnect graph in the graphviz dot format. It shows all
		interconnect nodes and links in the system and groups together nodes from the
		same provider as subgraphs. The format is human-readable and can also be piped
		through dot to generate diagrams in many graphical formats::

		$ cat /sys/kernel/debug/interconnect/interconnect_graph \| \
		dot -Tsvg > interconnect_graph.svg

drivers/interconnect/core.c

+66 −0

Original line number	Diff line number	Diff line
		@@ -68,6 +68,70 @@ static int icc_summary_show(struct seq_file s, void data)
		}
		DEFINE_SHOW_ATTRIBUTE(icc_summary);

		static void icc_graph_show_link(struct seq_file *s, int level,
		struct icc_node n, struct icc_node m)
		{
		seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
		level == 2 ? "\t\t" : "\t",
		n->id, n->name, m->id, m->name);
		}

		static void icc_graph_show_node(struct seq_file s, struct icc_node n)
		{
		seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
		n->id, n->name, n->id, n->name);
		seq_printf(s, "\n\t\t\t\|avg_bw=%ukBps", n->avg_bw);
		seq_printf(s, "\n\t\t\t\|peak_bw=%ukBps", n->peak_bw);
		seq_puts(s, "\"]\n");
		}

		static int icc_graph_show(struct seq_file s, void data)
		{
		struct icc_provider *provider;
		struct icc_node *n;
		int cluster_index = 0;
		int i;

		seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
		mutex_lock(&icc_lock);

		/* draw providers as cluster subgraphs */
		cluster_index = 0;
		list_for_each_entry(provider, &icc_providers, provider_list) {
		seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
		if (provider->dev)
		seq_printf(s, "\t\tlabel = \"%s\"\n",
		dev_name(provider->dev));

		/* draw nodes */
		list_for_each_entry(n, &provider->nodes, node_list)
		icc_graph_show_node(s, n);

		/* draw internal links */
		list_for_each_entry(n, &provider->nodes, node_list)
		for (i = 0; i < n->num_links; ++i)
		if (n->provider == n->links[i]->provider)
		icc_graph_show_link(s, 2, n,
		n->links[i]);

		seq_puts(s, "\t}\n");
		}

		/* draw external links */
		list_for_each_entry(provider, &icc_providers, provider_list)
		list_for_each_entry(n, &provider->nodes, node_list)
		for (i = 0; i < n->num_links; ++i)
		if (n->provider != n->links[i]->provider)
		icc_graph_show_link(s, 1, n,
		n->links[i]);

		mutex_unlock(&icc_lock);
		seq_puts(s, "}");

		return 0;
		}
		DEFINE_SHOW_ATTRIBUTE(icc_graph);

		static struct icc_node *node_find(const int id)
		{
		return idr_find(&icc_idr, id);
		@@ -776,6 +840,8 @@ static int __init icc_init(void)
		icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
		debugfs_create_file("interconnect_summary", 0444,
		icc_debugfs_dir, NULL, &icc_summary_fops);
		debugfs_create_file("interconnect_graph", 0444,
		icc_debugfs_dir, NULL, &icc_graph_fops);
		return 0;
		}