drm/i915: Replace custom intel runtime_pm tracker with ref_tracker library

Beside reusing existing code, the main advantage of ref_tracker is
tracking per instance of wakeref. It allows also to catch double
put.
On the other side we lose information about the first acquire and
the last release, but the advantages outweigh it.

Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030-ref_tracker_i915-v1-1-006fe6b96421@intel.com

1 files changed, 33 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_wakeref.h b/drivers/gpu/drm/i915/intel_wakeref.h
index ec881b097368..909cad13ac1f 100644
--- a/drivers/gpu/drm/i915/intel_wakeref.h
+++ b/drivers/gpu/drm/i915/intel_wakeref.h
@@ -7,16 +7,25 @@
 #ifndef INTEL_WAKEREF_H
 #define INTEL_WAKEREF_H
 
+#include <drm/drm_print.h>
+
 #include <linux/atomic.h>
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/lockdep.h>
 #include <linux/mutex.h>
 #include <linux/refcount.h>
+#include <linux/ref_tracker.h>
+#include <linux/slab.h>
 #include <linux/stackdepot.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 
+typedef unsigned long intel_wakeref_t;
+
+#define INTEL_REFTRACK_DEAD_COUNT 16
+#define INTEL_REFTRACK_PRINT_LIMIT 16
+
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
 #define INTEL_WAKEREF_BUG_ON(expr) BUG_ON(expr)
 #else
@@ -26,8 +35,6 @@
 struct intel_runtime_pm;
 struct intel_wakeref;
 
-typedef depot_stack_handle_t intel_wakeref_t;
-
 struct intel_wakeref_ops {
 	int (*get)(struct intel_wakeref *wf);
 	int (*put)(struct intel_wakeref *wf);
@@ -261,6 +268,30 @@ __intel_wakeref_defer_park(struct intel_wakeref *wf)
  */
 int intel_wakeref_wait_for_idle(struct intel_wakeref *wf);
 
+#define INTEL_WAKEREF_DEF ((intel_wakeref_t)(-1))
+
+static inline intel_wakeref_t intel_ref_tracker_alloc(struct ref_tracker_dir *dir)
+{
+	struct ref_tracker *user = NULL;
+
+	ref_tracker_alloc(dir, &user, GFP_NOWAIT);
+
+	return (intel_wakeref_t)user ?: INTEL_WAKEREF_DEF;
+}
+
+static inline void intel_ref_tracker_free(struct ref_tracker_dir *dir,
+					  intel_wakeref_t handle)
+{
+	struct ref_tracker *user;
+
+	user = (handle == INTEL_WAKEREF_DEF) ? NULL : (void *)handle;
+
+	ref_tracker_free(dir, &user);
+}
+
+void intel_ref_tracker_show(struct ref_tracker_dir *dir,
+			    struct drm_printer *p);
+
 struct intel_wakeref_auto {
 	struct drm_i915_private *i915;
 	struct timer_list timer;