[RFC PATCH v2 12/15] tracing: of: Add instance node support

Masami Hiramatsu
2019-07-15T05:13:24Z

Add instance node support to devicetree ftrace binding.
User can set some options and event nodes in instance node.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_of.c | 67 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 55 insertions(+), 12 deletions(-)

diff --git a/kernel/trace/trace_of.c b/kernel/trace/trace_of.c
index e9142c63ece1..7fe81c25dc59 100644
--- a/kernel/trace/trace_of.c
+++ b/kernel/trace/trace_of.c
@@ -21,9 +21,10 @@ extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
extern void __init trace_init_tracepoint_printk(void);
extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
unsigned long size, int cpu_id);
+extern struct trace_array *trace_array_create(const char *name);

static void __init
-trace_of_set_ftrace_options(struct trace_array *tr, struct device_node *node)
+trace_of_set_instance_options(struct trace_array *tr, struct device_node *node)
{
struct property *prop;
const char *p;
@@ -48,6 +49,24 @@ trace_of_set_ftrace_options(struct trace_array *tr, struct device_node *node)
pr_err("Failed to set trace clock: %s\n", p);
}

+ /* This accepts per-cpu buffer size in KB */
+ err = of_property_read_u32_index(node, "buffer-size-kb", 0, &v);
+ if (!err) {
+ v <<= 10; /* KB to Byte */
+ if (v < PAGE_SIZE)
+ pr_err("Buffer size is too small: %d KB\n", v >> 10);
+ if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
+ pr_err("Failed to resize trace buffer to %d KB\n",
+ v >> 10);
+ }
+}
+
+static void __init
+trace_of_set_ftrace_options(struct trace_array *tr, struct device_node *node)
+{
+ u32 v = 0;
+ int err;
+
/* Command line boot options */
if (of_find_property(node, "dump-on-oops", NULL)) {
err = of_property_read_u32_index(node, "dump-on-oops", 0, &v);
@@ -63,20 +82,11 @@ trace_of_set_ftrace_options(struct trace_array *tr, struct device_node *node)
if (of_find_property(node, "tp-printk", NULL))
trace_init_tracepoint_printk();

- /* This accepts per-cpu buffer size in KB */
- err = of_property_read_u32_index(node, "buffer-size-kb", 0, &v);
- if (!err) {
- v <<= 10; /* KB to Byte */
- if (v < PAGE_SIZE)
- pr_err("Buffer size is too small: %d KB\n", v >> 10);
- if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
- pr_err("Failed to resize trace buffer to %d KB\n",
- v >> 10);
- }
-
if (of_find_property(node, "alloc-snapshot", NULL))
if (tracing_alloc_snapshot() < 0)
pr_err("Failed to allocate snapshot buffer\n");
+
+ trace_of_set_instance_options(tr, node);
}

#ifdef CONFIG_EVENT_TRACING
@@ -310,6 +320,38 @@ trace_of_enable_tracer(struct trace_array *tr, struct device_node *node)
}
}

+static void __init
+trace_of_init_instances(struct device_node *__node)
+{
+ struct device_node *node;
+ struct trace_array *tr;
+ const char *p;
+ int err;
+
+ for_each_child_of_node(__node, node) {
+ if (!of_node_name_prefix(node, "instance"))
+ continue;
+
+ err = of_property_read_string(node, "instance", &p);
+ if (err) {
+ pr_err("Failed to get instance name on %s\n",
+ of_node_full_name(node));
+ continue;
+ }
+
+ tr = trace_array_create(p);
+ if (IS_ERR(tr)) {
+ pr_err("Failed to create instance %s\n", p);
+ continue;
+ }
+
+ trace_of_set_instance_options(tr, node);
+ trace_of_init_events(tr, node);
+ trace_of_enable_events(tr, node);
+ trace_of_enable_tracer(tr, node);
+ }
+}
+
static struct device_node * __init trace_of_find_ftrace_node(void)
{
if (!of_chosen)
@@ -337,6 +379,7 @@ static int __init trace_of_init(void)
trace_of_init_events(tr, trace_node);
trace_of_enable_events(tr, trace_node);
trace_of_enable_tracer(tr, trace_node);
+ trace_of_init_instances(trace_node);

end:
of_node_put(trace_node);