[PATCH 3/6] drm: Convert syncobj_idr to XArray

[Sidhartha Kumar]

From: Matthew Wilcox <wi...@infradead.org>

Remove syncobj_table_lock by converting the syncobj_idr to an XArray.

Signed-off-by: Matthew Wilcox <wi...@infradead.org>
Signed-off-by: Sidhartha Kumar <sidhartha.ku...@oracle.com>
---
 drivers/gpu/drm/drm_syncobj.c | 64 +++++++++++------------------------
 include/drm/drm_file.h        |  6 ++--
 2 files changed, 22 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 636cd83ca29e..2177a354c9f7 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -249,14 +249,12 @@ struct drm_syncobj *drm_syncobj_find(struct drm_file 
*file_private,
 {
        struct drm_syncobj *syncobj;
 
-       spin_lock(&file_private->syncobj_table_lock);
-
-       /* Check if we currently have a reference on the object */
-       syncobj = idr_find(&file_private->syncobj_idr, handle);
+       /* Get a reference on the object */
+       xa_lock(&file_private->syncobjs);
+       syncobj = xa_load(&file_private->syncobjs, handle);
        if (syncobj)
                drm_syncobj_get(syncobj);
-
-       spin_unlock(&file_private->syncobj_table_lock);
+       xa_unlock(&file_private->syncobjs);
 
        return syncobj;
 }
@@ -597,23 +595,16 @@ int drm_syncobj_get_handle(struct drm_file *file_private,
 {
        int ret;
 
-       /* take a reference to put in the idr */
+       /* take a reference to put in the XArray */
        drm_syncobj_get(syncobj);
 
-       idr_preload(GFP_KERNEL);
-       spin_lock(&file_private->syncobj_table_lock);
-       ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
-       spin_unlock(&file_private->syncobj_table_lock);
+       ret = xa_alloc(&file_private->syncobjs, handle, syncobj, xa_limit_31b,
+                       GFP_KERNEL);
 
-       idr_preload_end();
-
-       if (ret < 0) {
+       if (ret < 0)
                drm_syncobj_put(syncobj);
-               return ret;
-       }
 
-       *handle = ret;
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL(drm_syncobj_get_handle);
 
@@ -637,9 +628,7 @@ static int drm_syncobj_destroy(struct drm_file 
*file_private,
 {
        struct drm_syncobj *syncobj;
 
-       spin_lock(&file_private->syncobj_table_lock);
-       syncobj = idr_remove(&file_private->syncobj_idr, handle);
-       spin_unlock(&file_private->syncobj_table_lock);
+       syncobj = xa_erase(&file_private->syncobjs, handle);
 
        if (!syncobj)
                return -EINVAL;
@@ -725,16 +714,10 @@ static int drm_syncobj_fd_to_handle(struct drm_file 
*file_private,
        syncobj = fd_file(f)->private_data;
        drm_syncobj_get(syncobj);
 
-       idr_preload(GFP_KERNEL);
-       spin_lock(&file_private->syncobj_table_lock);
-       ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
-       spin_unlock(&file_private->syncobj_table_lock);
-       idr_preload_end();
+       ret = xa_alloc(&file_private->syncobjs, handle, syncobj, xa_limit_31b,
+                       GFP_KERNEL);
 
-       if (ret > 0) {
-               *handle = ret;
-               ret = 0;
-       } else
+       if (ret < 0)
                drm_syncobj_put(syncobj);
 
        return ret;
@@ -813,17 +796,7 @@ static int drm_syncobj_export_sync_file(struct drm_file 
*file_private,
 void
 drm_syncobj_open(struct drm_file *file_private)
 {
-       idr_init_base(&file_private->syncobj_idr, 1);
-       spin_lock_init(&file_private->syncobj_table_lock);
-}
-
-static int
-drm_syncobj_release_handle(int id, void *ptr, void *data)
-{
-       struct drm_syncobj *syncobj = ptr;
-
-       drm_syncobj_put(syncobj);
-       return 0;
+       xa_init_flags(&file_private->syncobjs, XA_FLAGS_ALLOC1);
 }
 
 /**
@@ -837,9 +810,12 @@ drm_syncobj_release_handle(int id, void *ptr, void *data)
 void
 drm_syncobj_release(struct drm_file *file_private)
 {
-       idr_for_each(&file_private->syncobj_idr,
-                    &drm_syncobj_release_handle, file_private);
-       idr_destroy(&file_private->syncobj_idr);
+       struct drm_syncobj *syncobj;
+       unsigned long index;
+
+       xa_for_each(&file_private->syncobjs, index, syncobj)
+               drm_syncobj_put(syncobj);
+       xa_destroy(&file_private->syncobjs);
 }
 
 int
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 5c3b2aa3e69d..68928554d426 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -306,10 +306,8 @@ struct drm_file {
        /** @table_lock: Protects @object_idr. */
        spinlock_t table_lock;
 
-       /** @syncobj_idr: Mapping of sync object handles to object pointers. */
-       struct idr syncobj_idr;
-       /** @syncobj_table_lock: Protects @syncobj_idr. */
-       spinlock_t syncobj_table_lock;
+       /** @syncobjs: Mapping of sync object handles to object pointers. */
+       struct xarray syncobjs;
 
        /** @filp: Pointer to the core file structure. */
        struct file *filp;
-- 
2.43.0