[Mesa-dev] [PATCH v4 07/11] amdgpu: use common screen ref counting

[Rob Herring]

Use the common pipe_screen ref count. amdgpu is unique in its hashing
the dev pointer rather than the fd, so the common fd hashing cannot be
used. However, the same reference count can be used instead of the
private one. The mutex can be dropped as the pipe loader protects the
create_screen() calls.

Signed-off-by: Rob Herring <robh at kernel.org>
Cc: "Marek Olšák" <marek.olsak at amd.com>
Cc: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c | 45 ++++-----------------------
 src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h |  1 -
 2 files changed, 6 insertions(+), 40 deletions(-)

diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
index 9a04cbe..27293ac 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.c
@@ -60,8 +60,6 @@
 #define     CIK__PIPE_CONFIG__ADDR_SURF_P16_32X32_16X16  17
 
 static struct util_hash_table *dev_tab = NULL;
-pipe_static_mutex(dev_tab_mutex);
-
 static unsigned cik_get_num_tile_pipes(struct amdgpu_gpu_info *info)
 {
    unsigned mode2d = info->gb_tile_mode[CIK_TILE_MODE_COLOR_2D];
@@ -329,6 +327,7 @@ static void amdgpu_winsys_destroy(struct radeon_winsys *rws)
    pipe_mutex_destroy(ws->global_bo_list_lock);
    AddrDestroy(ws->addrlib);
    amdgpu_device_deinitialize(ws->dev);
+   util_hash_table_remove(dev_tab, ws->dev);
    FREE(rws);
 }
 
@@ -410,26 +409,6 @@ static int compare_dev(void *key1, void *key2)
 
 DEBUG_GET_ONCE_BOOL_OPTION(thread, "RADEON_THREAD", true)
 
-static bool amdgpu_winsys_unref(struct radeon_winsys *rws)
-{
-   struct amdgpu_winsys *ws = (struct amdgpu_winsys*)rws;
-   bool destroy;
-
-   /* When the reference counter drops to zero, remove the device pointer
-    * from the table.
-    * This must happen while the mutex is locked, so that
-    * amdgpu_winsys_create in another thread doesn't get the winsys
-    * from the table when the counter drops to 0. */
-   pipe_mutex_lock(dev_tab_mutex);
-
-   destroy = pipe_reference(&ws->reference, NULL);
-   if (destroy && dev_tab)
-      util_hash_table_remove(dev_tab, ws->dev);
-
-   pipe_mutex_unlock(dev_tab_mutex);
-   return destroy;
-}
-
 PUBLIC struct radeon_winsys *
 amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
 {
@@ -446,7 +425,6 @@ amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
    drmFreeVersion(version);
 
    /* Look up the winsys from the dev table. */
-   pipe_mutex_lock(dev_tab_mutex);
    if (!dev_tab)
       dev_tab = util_hash_table_create(hash_dev, compare_dev);
 
@@ -454,7 +432,6 @@ amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
     * for the same fd. */
    r = amdgpu_device_initialize(fd, &drm_major, &drm_minor, &dev);
    if (r) {
-      pipe_mutex_unlock(dev_tab_mutex);
       fprintf(stderr, "amdgpu: amdgpu_device_initialize failed.\n");
       return NULL;
    }
@@ -462,17 +439,14 @@ amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
    /* Lookup a winsys if we have already created one for this device. */
    ws = util_hash_table_get(dev_tab, dev);
    if (ws) {
-      pipe_reference(NULL, &ws->reference);
-      pipe_mutex_unlock(dev_tab_mutex);
+      pipe_reference(NULL, &ws->base.screen->reference);
       return &ws->base;
    }
 
    /* Create a new winsys. */
    ws = CALLOC_STRUCT(amdgpu_winsys);
-   if (!ws) {
-      pipe_mutex_unlock(dev_tab_mutex);
+   if (!ws)
       return NULL;
-   }
 
    ws->dev = dev;
    ws->info.drm_major = drm_major;
@@ -486,11 +460,7 @@ amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
                  (ws->info.vram_size + ws->info.gart_size) / 8,
                  amdgpu_bo_destroy, amdgpu_bo_can_reclaim);
 
-   /* init reference */
-   pipe_reference_init(&ws->reference, 1);
-
    /* Set functions. */
-   ws->base.unref = amdgpu_winsys_unref;
    ws->base.destroy = amdgpu_winsys_destroy;
    ws->base.query_info = amdgpu_winsys_query_info;
    ws->base.cs_request_feature = amdgpu_cs_request_feature;
@@ -516,21 +486,18 @@ amdgpu_winsys_create(int fd, radeon_screen_create_t screen_create)
    ws->base.screen = screen_create(&ws->base);
    if (!ws->base.screen) {
       amdgpu_winsys_destroy(&ws->base);
-      pipe_mutex_unlock(dev_tab_mutex);
       return NULL;
    }
 
    util_hash_table_set(dev_tab, dev, ws);
 
-   /* We must unlock the mutex once the winsys is fully initialized, so that
-    * other threads attempting to create the winsys from the same fd will
-    * get a fully initialized winsys and not just half-way initialized. */
-   pipe_mutex_unlock(dev_tab_mutex);
+   /* init reference */
+   pipe_reference_init(&ws->base.screen->reference, 1);
+   ws->base.screen->fd = -1;
 
    return &ws->base;
 
 fail:
-   pipe_mutex_unlock(dev_tab_mutex);
    pb_cache_deinit(&ws->bo_cache);
    FREE(ws);
    return NULL;
diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
index 8489530..b45c2d7 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
@@ -42,7 +42,6 @@ struct amdgpu_cs;
 
 struct amdgpu_winsys {
    struct radeon_winsys base;
-   struct pipe_reference reference;
    struct pb_cache bo_cache;
 
    amdgpu_device_handle dev;
-- 
2.9.2