[Intel-gfx] [PATCH v6 39/57] dyndbg/drm: POC add tracebits sysfs-knob

Jim Cromie
2022-09-04T21:47:24Z

clone DRM.debug interface to DRM.tracebits: ie map bits to
drm-debug-categories, except this interface enables messages to
tracefs, not to syslog.

1- we reuse the class-map added previously.
this reflects the single source of both syslog/trace events

2- add a 2nd struct ddebug_classes_bitmap_param
refs 1, reusing it.
flags = "T", to enable trace-events on this callsite.

3- module_param_cb([2]) - does the sysfs part

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
drivers/gpu/drm/drm_print.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index c50edbf443d3..75d0cecd7e86 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -45,6 +45,9 @@
unsigned long __drm_debug;
EXPORT_SYMBOL(__drm_debug);

+unsigned long __drm_trace;
+EXPORT_SYMBOL(__drm_trace);
+
MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
"\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
"\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
@@ -77,6 +80,13 @@ static struct ddebug_class_param drm_debug_bitmap = {
.map = &drm_debug_classes,
};
module_param_cb(debug, &param_ops_dyndbg_classes, &drm_debug_bitmap, 0600);
+
+static struct ddebug_class_param drm_trace_bitmap = {
+ .bits = &__drm_trace,
+ .flags = "T",
+ .map = &drm_debug_classes,
+};
+module_param_cb(tracecats, &param_ops_dyndbg_classes, &drm_trace_bitmap, 0600);
#endif

void __drm_puts_coredump(struct drm_printer *p, const char *str)
--
2.37.2