1 files changed, 113 insertions, 0 deletions

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 2d3c2576bab7..f0332bd3a501 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -122,6 +122,119 @@ void event_format__print(struct tep_event *event,
 	return event_format__fprintf(event, cpu, data, size, stdout);
 }
 
+/*
+ * prev_state is of size long, which is 32 bits on 32 bit architectures.
+ * As it needs to have the same bits for both 32 bit and 64 bit architectures
+ * we can just assume that the flags we care about will all be within
+ * the 32 bits.
+ */
+#define MAX_STATE_BITS 32
+
+static const char *convert_sym(struct tep_print_flag_sym *sym)
+{
+	static char save_states[MAX_STATE_BITS + 1];
+
+	memset(save_states, 0, sizeof(save_states));
+
+	/* This is the flags for the prev_state_field, now make them into a string */
+	for (; sym; sym = sym->next) {
+		long bitmask = strtoul(sym->value, NULL, 0);
+		int i;
+
+		for (i = 0; !(bitmask & 1); i++)
+			bitmask >>= 1;
+
+		if (i >= MAX_STATE_BITS)
+			continue;
+
+		save_states[i] = sym->str[0];
+	}
+
+	return save_states;
+}
+
+static struct tep_print_arg_field *
+find_arg_field(struct tep_format_field *prev_state_field, struct tep_print_arg *arg)
+{
+	struct tep_print_arg_field *field;
+
+	if (!arg)
+		return NULL;
+
+	if (arg->type == TEP_PRINT_FIELD)
+		return &arg->field;
+
+	if (arg->type == TEP_PRINT_OP) {
+		field = find_arg_field(prev_state_field, arg->op.left);
+		if (field && field->field == prev_state_field)
+			return field;
+		field = find_arg_field(prev_state_field, arg->op.right);
+		if (field && field->field == prev_state_field)
+			return field;
+	}
+	return NULL;
+}
+
+static struct tep_print_flag_sym *
+test_flags(struct tep_format_field *prev_state_field, struct tep_print_arg *arg)
+{
+	struct tep_print_arg_field *field;
+
+	field = find_arg_field(prev_state_field, arg->flags.field);
+	if (!field)
+		return NULL;
+
+	return arg->flags.flags;
+}
+
+static struct tep_print_flag_sym *
+search_op(struct tep_format_field *prev_state_field, struct tep_print_arg *arg)
+{
+	struct tep_print_flag_sym *sym = NULL;
+
+	if (!arg)
+		return NULL;
+
+	if (arg->type == TEP_PRINT_OP) {
+		sym = search_op(prev_state_field, arg->op.left);
+		if (sym)
+			return sym;
+
+		sym = search_op(prev_state_field, arg->op.right);
+		if (sym)
+			return sym;
+	} else if (arg->type == TEP_PRINT_FLAGS) {
+		sym = test_flags(prev_state_field, arg);
+	}
+
+	return sym;
+}
+
+const char *parse_task_states(struct tep_format_field *state_field)
+{
+	struct tep_print_flag_sym *sym;
+	struct tep_print_arg *arg;
+	struct tep_event *event;
+
+	event = state_field->event;
+
+	/*
+	 * Look at the event format fields, and search for where
+	 * the prev_state is parsed via the format flags.
+	 */
+	for (arg = event->print_fmt.args; arg; arg = arg->next) {
+		/*
+		 * Currently, the __print_flags() for the prev_state
+		 * is embedded in operations, so they too must be
+		 * searched.
+		 */
+		sym = search_op(state_field, arg);
+		if (sym)
+			return convert_sym(sym);
+	}
+	return NULL;
+}
+
 void parse_ftrace_printk(struct tep_handle *pevent,
 			 char *file, unsigned int size __maybe_unused)
 {