drm/vc4: Replace IDR with XArray for perfmon tracking

The IDR interface is deprecated and the XArray API is the recommended
replacement. Replace the per-file IDR used to track perfmons with an
XArray. This allows us to remove the external mutex that protects the
IDR.

While at it, introduce the vc4_perfmon_delete() helper to consolidate
the perfmon cleanup logic used by both vc4_perfmon_close_file() and
vc4_perfmon_destroy_ioctl(). Also, remove the redundant assignment of
vc4file->dev to itself in vc4_perfmon_open_file().

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Link: https://patch.msgid.link/20260127115822.64401-2-mcanal@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>

2 files changed, 22 insertions, 34 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 221d8e01d539..dbcc83b7df00 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -791,10 +791,7 @@ struct vc4_exec_info {
 struct vc4_file {
 	struct vc4_dev *dev;
 
-	struct {
-		struct idr idr;
-		struct mutex lock;
-	} perfmon;
+	struct xarray perfmons;
 
 	bool bin_bo_used;
 };
diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c
index 1ac80c0b258f..c02609b3ca47 100644
--- a/drivers/gpu/drm/vc4/vc4_perfmon.c
+++ b/drivers/gpu/drm/vc4/vc4_perfmon.c
@@ -14,9 +14,6 @@
 #include "vc4_drv.h"
 #include "vc4_regs.h"
 
-#define VC4_PERFMONID_MIN	1
-#define VC4_PERFMONID_MAX	U32_MAX
-
 void vc4_perfmon_get(struct vc4_perfmon *perfmon)
 {
 	struct vc4_dev *vc4;
@@ -95,10 +92,10 @@ struct vc4_perfmon *vc4_perfmon_find(struct vc4_file *vc4file, int id)
 	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
 		return NULL;
 
-	mutex_lock(&vc4file->perfmon.lock);
-	perfmon = idr_find(&vc4file->perfmon.idr, id);
+	xa_lock(&vc4file->perfmons);
+	perfmon = xa_load(&vc4file->perfmons, id);
 	vc4_perfmon_get(perfmon);
-	mutex_unlock(&vc4file->perfmon.lock);
+	xa_unlock(&vc4file->perfmons);
 
 	return perfmon;
 }
@@ -110,37 +107,34 @@ void vc4_perfmon_open_file(struct vc4_file *vc4file)
 	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
 		return;
 
-	mutex_init(&vc4file->perfmon.lock);
-	idr_init_base(&vc4file->perfmon.idr, VC4_PERFMONID_MIN);
-	vc4file->dev = vc4;
+	xa_init_flags(&vc4file->perfmons, XA_FLAGS_ALLOC1);
 }
 
-static int vc4_perfmon_idr_del(int id, void *elem, void *data)
+static void vc4_perfmon_delete(struct vc4_file *vc4file,
+			       struct vc4_perfmon *perfmon)
 {
-	struct vc4_perfmon *perfmon = elem;
-	struct vc4_dev *vc4 = (struct vc4_dev *)data;
+	struct vc4_dev *vc4 = vc4file->dev;
 
 	/* If the active perfmon is being destroyed, stop it first */
 	if (perfmon == vc4->active_perfmon)
 		vc4_perfmon_stop(vc4, perfmon, false);
 
 	vc4_perfmon_put(perfmon);
-
-	return 0;
 }
 
 void vc4_perfmon_close_file(struct vc4_file *vc4file)
 {
 	struct vc4_dev *vc4 = vc4file->dev;
+	struct vc4_perfmon *perfmon;
+	unsigned long id;
 
 	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
 		return;
 
-	mutex_lock(&vc4file->perfmon.lock);
-	idr_for_each(&vc4file->perfmon.idr, vc4_perfmon_idr_del, vc4);
-	idr_destroy(&vc4file->perfmon.idr);
-	mutex_unlock(&vc4file->perfmon.lock);
-	mutex_destroy(&vc4file->perfmon.lock);
+	xa_for_each(&vc4file->perfmons, id, perfmon)
+		vc4_perfmon_delete(vc4file, perfmon);
+
+	xa_destroy(&vc4file->perfmons);
 }
 
 int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
@@ -152,6 +146,7 @@ int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
 	struct vc4_perfmon *perfmon;
 	unsigned int i;
 	int ret;
+	u32 id;
 
 	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
 		return -ENODEV;
@@ -185,17 +180,15 @@ int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
 
 	refcount_set(&perfmon->refcnt, 1);
 
-	mutex_lock(&vc4file->perfmon.lock);
-	ret = idr_alloc(&vc4file->perfmon.idr, perfmon, VC4_PERFMONID_MIN,
-			VC4_PERFMONID_MAX, GFP_KERNEL);
-	mutex_unlock(&vc4file->perfmon.lock);
-
+	ret = xa_alloc(&vc4file->perfmons, &id, perfmon, xa_limit_32b,
+		       GFP_KERNEL);
 	if (ret < 0) {
 		kfree(perfmon);
 		return ret;
 	}
 
-	req->id = ret;
+	req->id = id;
+
 	return 0;
 }
 
@@ -215,14 +208,12 @@ int vc4_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
 		return -ENODEV;
 	}
 
-	mutex_lock(&vc4file->perfmon.lock);
-	perfmon = idr_remove(&vc4file->perfmon.idr, req->id);
-	mutex_unlock(&vc4file->perfmon.lock);
-
+	perfmon = xa_erase(&vc4file->perfmons, req->id);
 	if (!perfmon)
 		return -EINVAL;
 
-	vc4_perfmon_put(perfmon);
+	vc4_perfmon_delete(vc4file, perfmon);
+
 	return 0;
 }