linux-kernel - [PATCH 6/6] drm: Convert tile

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Message-ID: <20250818190046.157962-7-sidhartha.kumar@oracle.com>
Date: Mon, 18 Aug 2025 19:00:46 +0000
From: Sidhartha Kumar <sidhartha.kumar@...cle.com>
To: linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org
Cc: maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de,
        airlied@...il.com, simona@...ll.ch, willy@...radead.org,
        sidhartha.kumar@...cle.com
Subject: [PATCH 6/6] drm: Convert tile_idr to XArray

From: Matthew Wilcox <willy@...radead.org>

Convert tile_idr to an Xarray.

Signed-off-by: Matthew Wilcox <willy@...radead.org>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@...cle.com>
---
 drivers/gpu/drm/drm_connector.c   | 26 ++++++++++----------------
 drivers/gpu/drm/drm_mode_config.c |  3 +--
 include/drm/drm_mode_config.h     | 12 ++++++------
 3 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 48b08c9611a7..91cfe06ca199 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -3489,9 +3489,7 @@ static void drm_tile_group_free(struct kref *kref)
 	struct drm_tile_group *tg = container_of(kref, struct drm_tile_group, refcount);
 	struct drm_device *dev = tg->dev;
 
-	mutex_lock(&dev->mode_config.idr_mutex);
-	idr_remove(&dev->mode_config.tile_idr, tg->id);
-	mutex_unlock(&dev->mode_config.idr_mutex);
+	xa_erase(&dev->mode_config.tiles, tg->id);
 	kfree(tg);
 }
 
@@ -3523,19 +3521,18 @@ struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
 					       const char topology[8])
 {
 	struct drm_tile_group *tg;
-	int id;
+	unsigned long id;
 
-	mutex_lock(&dev->mode_config.idr_mutex);
-	idr_for_each_entry(&dev->mode_config.tile_idr, tg, id) {
+	xa_lock(&dev->mode_config.tiles);
+	xa_for_each(&dev->mode_config.tiles, id, tg) {
 		if (!memcmp(tg->group_data, topology, 8)) {
 			if (!kref_get_unless_zero(&tg->refcount))
 				tg = NULL;
-			mutex_unlock(&dev->mode_config.idr_mutex);
-			return tg;
+			break;
 		}
 	}
-	mutex_unlock(&dev->mode_config.idr_mutex);
-	return NULL;
+	xa_unlock(&dev->mode_config.tiles);
+	return tg;
 }
 EXPORT_SYMBOL(drm_mode_get_tile_group);
 
@@ -3564,16 +3561,13 @@ struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
 	memcpy(tg->group_data, topology, 8);
 	tg->dev = dev;
 
-	mutex_lock(&dev->mode_config.idr_mutex);
-	ret = idr_alloc(&dev->mode_config.tile_idr, tg, 1, 0, GFP_KERNEL);
-	if (ret >= 0) {
-		tg->id = ret;
-	} else {
+	ret = xa_alloc(&dev->mode_config.tiles, &tg->id, tg, xa_limit_32b,
+			GFP_KERNEL);
+	if (ret < 0) {
 		kfree(tg);
 		tg = NULL;
 	}
 
-	mutex_unlock(&dev->mode_config.idr_mutex);
 	return tg;
 }
 EXPORT_SYMBOL(drm_mode_create_tile_group);
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index b4239fd04e9d..c3d1a6d81bc7 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -438,7 +438,7 @@ int drmm_mode_config_init(struct drm_device *dev)
 	INIT_LIST_HEAD(&dev->mode_config.plane_list);
 	INIT_LIST_HEAD(&dev->mode_config.privobj_list);
 	idr_init_base(&dev->mode_config.object_idr, 1);
-	idr_init_base(&dev->mode_config.tile_idr, 1);
+	xa_init_flags(&dev->mode_config.tiles, XA_FLAGS_ALLOC1);
 	ida_init(&dev->mode_config.connector_ida);
 	spin_lock_init(&dev->mode_config.connector_list_lock);
 
@@ -577,7 +577,6 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 	}
 
 	ida_destroy(&dev->mode_config.connector_ida);
-	idr_destroy(&dev->mode_config.tile_idr);
 	idr_destroy(&dev->mode_config.object_idr);
 	drm_modeset_lock_fini(&dev->mode_config.connection_mutex);
 }
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 9e524b51a001..8412013914d9 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -392,8 +392,8 @@ struct drm_mode_config {
 	/**
 	 * @idr_mutex:
 	 *
-	 * Mutex for KMS ID allocation and management. Protects both @object_idr
-	 * and @tile_idr.
+	 * Mutex for KMS ID allocation and management. Protects the
+	 * objects in @object_idr.
 	 */
 	struct mutex idr_mutex;
 
@@ -406,12 +406,12 @@ struct drm_mode_config {
 	struct idr object_idr;
 
 	/**
-	 * @tile_idr:
+	 * @tiles:
 	 *
-	 * Use this idr for allocating new IDs for tiled sinks like use in some
-	 * high-res DP MST screens.
+	 * Use this for allocating new IDs for tiled sinks like those
+	 * used in some high-res DP MST screens.
 	 */
-	struct idr tile_idr;
+	struct xarray tiles;
 
 	/** @fb_lock: Mutex to protect fb the global @fb_list and @num_fb. */
 	struct mutex fb_lock;
-- 
2.43.0