drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.

Use DECLARE_DYNDBG_CLASSMAP across DRM:

 - in .c files, since macro defines/initializes a record

 - in drivers, $mod_{drv,drm,param}.c
   ie where param setup is done, since a classmap is param related

 - in drm/drm_print.c
   since existing __drm_debug param is defined there,
   and we ifdef it, and provide an elaborated alternative.

 - in drm_*_helper modules:
   dp/drm_dp - 1st item in makefile target
   drivers/gpu/drm/drm_crtc_helper.c - random pick iirc.

Since these modules all use identical CLASSMAP declarations (ie: names
and .class_id's) they will all respond together to "class DRM_UT_*"
query-commands:

  :#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control

NOTES:

This changes __drm_debug from int to ulong, so BIT() is usable on it.

DRM's enum drm_debug_category values need to sync with the index of
their respective class-names here.  Then .class_id == category, and
dyndbg's class FOO mechanisms will enable drm_dbg(DRM_UT_KMS, ...).

Though DRM needs consistent categories across all modules, thats not
generally needed; modules X and Y could define FOO differently (ie a
different NAME => class_id mapping), changes are made according to
each module's private class-map.

No callsites are actually selected by this patch, since none are
class'd yet.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220912052852.1123868-3-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 561309d447e0..fd99ec0f4257 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -28,6 +28,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
 #include <linux/mmu_notifier.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_crtc_helper.h>
@@ -70,6 +71,18 @@
 #include "nouveau_svm.h"
 #include "nouveau_dmem.h"
 
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
+
 MODULE_PARM_DESC(config, "option string to pass to driver core");
 static char *nouveau_config;
 module_param_named(config, nouveau_config, charp, 0400);