From: Matthew Wilcox <willy@infradead.org>
Date: Thu, 14 Feb 2019 12:58:31 +0000 (-0500)
Subject: drm: Convert ctx_idr to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9015f06657286b78faa58636404bca991423c18f;p=users%2Fwilly%2Fxarray.git

drm: Convert ctx_idr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---

diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c
index 1f802d8e5681e..7c48cbcc2f5dc 100644
--- a/drivers/gpu/drm/drm_context.c
+++ b/drivers/gpu/drm/drm_context.c
@@ -54,8 +54,7 @@ struct drm_ctx_list {
  * \param ctx_handle context handle.
  *
  * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
- * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
- * lock.
+ * in drm_device::ctxts.
  */
 void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
 {
@@ -63,9 +62,7 @@ void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
 		return;
 
-	mutex_lock(&dev->struct_mutex);
-	idr_remove(&dev->ctx_idr, ctx_handle);
-	mutex_unlock(&dev->struct_mutex);
+	xa_erase(&dev->ctxts, ctx_handle);
 }
 
 /**
@@ -74,18 +71,17 @@ void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
  * \param dev DRM device.
  * \return (non-negative) context handle on success or a negative number on failure.
  *
- * Allocate a new idr from drm_device::ctx_idr while holding the
- * drm_device::struct_mutex lock.
+ * Allocate a new id from drm_device::ctxts.
  */
 static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
 {
-	int ret;
+	int ret, id;
 
-	mutex_lock(&dev->struct_mutex);
-	ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
-			GFP_KERNEL);
-	mutex_unlock(&dev->struct_mutex);
-	return ret;
+	ret = xa_alloc(&dev->ctxts, &id, NULL,
+			XA_LIMIT(DRM_RESERVED_CONTEXTS, INT_MAX), GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+	return id;
 }
 
 /**
@@ -93,7 +89,7 @@ static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
  *
  * \param dev DRM device.
  *
- * Initialise the drm_device::ctx_idr
+ * Initialise the drm_device::ctxts
  */
 void drm_legacy_ctxbitmap_init(struct drm_device * dev)
 {
@@ -101,7 +97,7 @@ void drm_legacy_ctxbitmap_init(struct drm_device * dev)
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
 		return;
 
-	idr_init(&dev->ctx_idr);
+	xa_init_flags(&dev->ctxts, XA_FLAGS_ALLOC);
 }
 
 /**
@@ -109,8 +105,8 @@ void drm_legacy_ctxbitmap_init(struct drm_device * dev)
  *
  * \param dev DRM device.
  *
- * Free all idr members using drm_ctx_sarea_free helper function
- * while holding the drm_device::struct_mutex lock.
+ * Free all memory used by the ctxts data structure.  Does not free the
+ * pointers in that data structures.
  */
 void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
 {
@@ -118,9 +114,7 @@ void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
 		return;
 
-	mutex_lock(&dev->struct_mutex);
-	idr_destroy(&dev->ctx_idr);
-	mutex_unlock(&dev->struct_mutex);
+	xa_destroy(&dev->ctxts);
 }
 
 /**
@@ -172,7 +166,7 @@ void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
  * \param arg user argument pointing to a drm_ctx_priv_map structure.
  * \return zero on success or a negative number on failure.
  *
- * Gets the map from drm_device::ctx_idr with the handle specified and
+ * Gets the map from drm_device::ctxts with the handle specified and
  * returns its handle.
  */
 int drm_legacy_getsareactx(struct drm_device *dev, void *data,
@@ -188,7 +182,7 @@ int drm_legacy_getsareactx(struct drm_device *dev, void *data,
 
 	mutex_lock(&dev->struct_mutex);
 
-	map = idr_find(&dev->ctx_idr, request->ctx_id);
+	map = xa_load(&dev->ctxts, request->ctx_id);
 	if (!map) {
 		mutex_unlock(&dev->struct_mutex);
 		return -EINVAL;
@@ -221,7 +215,7 @@ int drm_legacy_getsareactx(struct drm_device *dev, void *data,
  * \return zero on success or a negative number on failure.
  *
  * Searches the mapping specified in \p arg and update the entry in
- * drm_device::ctx_idr with it.
+ * drm_device::ctxts with it.
  */
 int drm_legacy_setsareactx(struct drm_device *dev, void *data,
 			   struct drm_file *file_priv)
@@ -249,7 +243,7 @@ int drm_legacy_setsareactx(struct drm_device *dev, void *data,
 	if (!map)
 		goto bad;
 
-	if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
+	if (xa_is_err(xa_store(&dev->ctxts, request->ctx_id, map, GFP_KERNEL)))
 		goto bad;
 
 	mutex_unlock(&dev->struct_mutex);
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index d3c3d087d238d..aba3ce7b1970b 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -318,7 +318,7 @@ struct drm_device {
 	struct mutex ctxlist_mutex;
 
 	/* Context handle management */
-	struct idr ctx_idr;
+	struct xarray ctxts;
 
 	/* Memory management - linked list of regions */
 	struct list_head maplist;