iris: make resources take a ref on the screen object

Because St creates resources from a screen and attach them onto
another we need to ensure the resources associated to a screen &
bufmgr stay around until we don't need them anymore.

Signed-off-by: Lionel Landwerlin <[email protected]>
Cc: <[email protected]>
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/1373
Reviewed-by: Adam Jackson <[email protected]>
Reviewed-by: Rafael Antognolli <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4086>

3 files changed, 37 insertions, 6 deletions

diff --git a/src/gallium/drivers/iris/iris_resource.c b/src/gallium/drivers/iris/iris_resource.c
index 50f01d350cf..40655bb4032 100644
--- a/src/gallium/drivers/iris/iris_resource.c
+++ b/src/gallium/drivers/iris/iris_resource.c
@@ -340,6 +340,8 @@ iris_resource_destroy(struct pipe_screen *screen,
    iris_resource_disable_aux(res);
 
    iris_bo_unreference(res->bo);
+   iris_pscreen_unref(res->base.screen);
+
    free(res);
 }
 
@@ -352,7 +354,7 @@ iris_alloc_resource(struct pipe_screen *pscreen,
       return NULL;
 
    res->base = *templ;
-   res->base.screen = pscreen;
+   res->base.screen = iris_pscreen_ref(pscreen);
    pipe_reference_init(&res->base.reference, 1);
 
    res->aux.possible_usages = 1 << ISL_AUX_USAGE_NONE;
diff --git a/src/gallium/drivers/iris/iris_screen.c b/src/gallium/drivers/iris/iris_screen.c
index 6afd1235f8c..0c99e3702e2 100644
--- a/src/gallium/drivers/iris/iris_screen.c
+++ b/src/gallium/drivers/iris/iris_screen.c
@@ -521,18 +521,23 @@ iris_get_timestamp(struct pipe_screen *pscreen)
    return result;
 }
 
-static void
-iris_destroy_screen(struct pipe_screen *pscreen)
+void
+iris_screen_destroy(struct iris_screen *screen)
 {
-   struct iris_screen *screen = (struct iris_screen *) pscreen;
    iris_bo_unreference(screen->workaround_bo);
-   u_transfer_helper_destroy(pscreen->transfer_helper);
+   u_transfer_helper_destroy(screen->base.transfer_helper);
    iris_bufmgr_unref(screen->bufmgr);
    disk_cache_destroy(screen->disk_cache);
    ralloc_free(screen);
 }
 
 static void
+iris_screen_unref(struct pipe_screen *pscreen)
+{
+   iris_pscreen_unref(pscreen);
+}
+
+static void
 iris_query_memory_info(struct pipe_screen *pscreen,
                        struct pipe_memory_info *info)
 {
@@ -639,6 +644,8 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
    screen->pci_id = screen->devinfo.chipset_id;
    screen->no_hw = screen->devinfo.no_hw;
 
+   p_atomic_set(&screen->refcount, 1);
+
    if (screen->devinfo.gen < 8 || screen->devinfo.is_cherryview)
       return NULL;
 
@@ -705,7 +712,7 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
    iris_init_screen_fence_functions(pscreen);
    iris_init_screen_resource_functions(pscreen);
 
-   pscreen->destroy = iris_destroy_screen;
+   pscreen->destroy = iris_screen_unref;
    pscreen->get_name = iris_get_name;
    pscreen->get_vendor = iris_get_vendor;
    pscreen->get_device_vendor = iris_get_device_vendor;
diff --git a/src/gallium/drivers/iris/iris_screen.h b/src/gallium/drivers/iris/iris_screen.h
index cd5bac9e54e..58864f7625d 100644
--- a/src/gallium/drivers/iris/iris_screen.h
+++ b/src/gallium/drivers/iris/iris_screen.h
@@ -46,6 +46,8 @@ struct gen_l3_config;
 struct iris_screen {
    struct pipe_screen base;
 
+   uint32_t refcount;
+
    /** Global slab allocator for iris_transfer_map objects */
    struct slab_parent_pool transfer_pool;
 
@@ -96,6 +98,26 @@ struct iris_screen {
 struct pipe_screen *
 iris_screen_create(int fd, const struct pipe_screen_config *config);
 
+void iris_screen_destroy(struct iris_screen *screen);
+
+UNUSED static inline struct pipe_screen *
+iris_pscreen_ref(struct pipe_screen *pscreen)
+{
+   struct iris_screen *screen = (struct iris_screen *) pscreen;
+
+   p_atomic_inc(&screen->refcount);
+   return pscreen;
+}
+
+UNUSED static inline void
+iris_pscreen_unref(struct pipe_screen *pscreen)
+{
+   struct iris_screen *screen = (struct iris_screen *) pscreen;
+
+   if (p_atomic_dec_zero(&screen->refcount))
+      iris_screen_destroy(screen);
+}
+
 bool
 iris_is_format_supported(struct pipe_screen *pscreen,
                          enum pipe_format format,