[PATCH v5 12/17] perf ftrace: add support for tracing option 'irq-info'

[Changbin Du <changbin.du@gmail.com>]

This adds support to display irq context info for function tracer. To do
this, just specify a '--func-opts irq-info' option.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/Documentation/perf-ftrace.txt |  1 +
 tools/perf/builtin-ftrace.c              | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 2e16e1e588d9..e6e9564d6c2e 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -81,6 +81,7 @@ OPTIONS
 --func-opts::
 	List of options allowed to set:
 	  call-graph - Display kernel stack trace for function tracer.
+	  irq-info   - Display irq context info for function tracer.
 
 -G::
 --graph-funcs=::
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 179c5da678e3..a5906258c413 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -42,6 +42,7 @@ struct perf_ftrace {
 	unsigned long		percpu_buffer_size;
 	bool			inherit;
 	int			func_stack_trace;
+	int			func_irq_info;
 	int			graph_nosleep_time;
 	int			graph_noirqs;
 };
@@ -204,6 +205,7 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
 	write_tracing_option_file("func_stack_trace", "0");
 	write_tracing_option_file("sleep-time", "1");
 	write_tracing_option_file("funcgraph-irqs", "1");
+	write_tracing_option_file("irq-info", "0");
 }
 
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -291,6 +293,17 @@ static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->func_irq_info)
+		return 0;
+
+	if (write_tracing_option_file("irq-info", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int reset_tracing_cpu(void)
 {
 	struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@@ -466,6 +479,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_func_irqinfo(ftrace) < 0) {
+		pr_err("failed to set tracing option irq-info\n");
+		goto out_reset;
+	}
+
 	if (set_tracing_filters(ftrace) < 0) {
 		pr_err("failed to set tracing filters\n");
 		goto out_reset;
@@ -656,6 +674,7 @@ static int parse_func_tracer_opts(const struct option *opt,
 	struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
 	struct sublevel_option func_tracer_opts[] = {
 		{ .name = "call-graph",	.value_ptr = &ftrace->func_stack_trace },
+		{ .name = "irq-info",	.value_ptr = &ftrace->func_irq_info },
 		{ .name = NULL, }
 	};
 
@@ -723,7 +742,7 @@ int cmd_ftrace(int argc, const char **argv)
 	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
 		     "do not trace given functions", parse_filter_func),
 	OPT_CALLBACK(0, "func-opts", &ftrace, "options",
-		     "function tracer options, available options: call-graph",
+		     "function tracer options, available options: call-graph,irq-info",
 		     parse_func_tracer_opts),
 	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
 		     "trace given functions using function_graph tracer",
-- 
2.25.1