qxl: convert qxl driver to proper use for reservations

The recent addition of lockdep support to reservations and their subsequent
use by TTM showed up a number of potential problems with the way qxl was using
TTM objects.

a) it was allocating objects, and reserving them later without validating
underneath the reservation, which meant in extreme conditions the objects could
be evicted before the reservation ever used them.

b) it was reserving objects straight after allocating them, but with no
ability to back off should the reservations fail. It now allocates the necessary
objects then does a complete reservation pass on them to avoid deadlocks.

c) it had two lists per release tracking objects, unnecessary complicating
the reservation process.

This patch removes the dual object tracking, adds reservations ticket support
to the release and fence object handling. It then ports the internal fb
drawing code and the userspace facing ioctl to use the new interfaces properly,
along with cleanup up the error path handling in some codepaths.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 40 insertions, 35 deletions

diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
index 6a4106fb4c21..7e96f4f11738 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.h
+++ b/drivers/gpu/drm/qxl/qxl_drv.h
@@ -42,6 +42,9 @@
 #include <ttm/ttm_placement.h>
 #include <ttm/ttm_module.h>
 
+/* just for ttm_validate_buffer */
+#include <ttm/ttm_execbuf_util.h>
+
 #include <drm/qxl_drm.h>
 #include "qxl_dev.h"
 
@@ -118,9 +121,9 @@ struct qxl_bo {
 	uint32_t surface_id;
 	struct qxl_fence fence; /* per bo fence  - list of releases */
 	struct qxl_release *surf_create;
-	atomic_t reserve_count;
 };
 #define gem_to_qxl_bo(gobj) container_of((gobj), struct qxl_bo, gem_base)
+#define to_qxl_bo(tobj) container_of((tobj), struct qxl_bo, tbo)
 
 struct qxl_gem {
 	struct mutex		mutex;
@@ -128,12 +131,7 @@ struct qxl_gem {
 };
 
 struct qxl_bo_list {
-	struct list_head lhead;
-	struct qxl_bo *bo;
-};
-
-struct qxl_reloc_list {
-	struct list_head bos;
+	struct ttm_validate_buffer tv;
 };
 
 struct qxl_crtc {
@@ -195,10 +193,20 @@ enum {
 struct qxl_release {
 	int id;
 	int type;
-	int bo_count;
 	uint32_t release_offset;
 	uint32_t surface_release_id;
-	struct qxl_bo *bos[QXL_MAX_RES];
+	struct ww_acquire_ctx ticket;
+	struct list_head bos;
+};
+
+struct qxl_drm_chunk {
+	struct list_head head;
+	struct qxl_bo *bo;
+};
+
+struct qxl_drm_image {
+	struct qxl_bo *bo;
+	struct list_head chunk_list;
 };
 
 struct qxl_fb_image {
@@ -434,12 +442,19 @@ int qxl_mmap(struct file *filp, struct vm_area_struct *vma);
 
 /* qxl image */
 
-int qxl_image_create(struct qxl_device *qdev,
-		     struct qxl_release *release,
-		     struct qxl_bo **image_bo,
-		     const uint8_t *data,
-		     int x, int y, int width, int height,
-		     int depth, int stride);
+int qxl_image_init(struct qxl_device *qdev,
+		   struct qxl_release *release,
+		   struct qxl_drm_image *dimage,
+		   const uint8_t *data,
+		   int x, int y, int width, int height,
+		   int depth, int stride);
+int
+qxl_image_alloc_objects(struct qxl_device *qdev,
+			struct qxl_release *release,
+			struct qxl_drm_image **image_ptr,
+			int height, int stride);
+void qxl_image_free_objects(struct qxl_device *qdev, struct qxl_drm_image *dimage);
+
 void qxl_update_screen(struct qxl_device *qxl);
 
 /* qxl io operations (qxl_cmd.c) */
@@ -460,20 +475,15 @@ int qxl_ring_push(struct qxl_ring *ring, const void *new_elt, bool interruptible
 void qxl_io_flush_release(struct qxl_device *qdev);
 void qxl_io_flush_surfaces(struct qxl_device *qdev);
 
-int qxl_release_reserve(struct qxl_device *qdev,
-			struct qxl_release *release, bool no_wait);
-void qxl_release_unreserve(struct qxl_device *qdev,
-			   struct qxl_release *release);
 union qxl_release_info *qxl_release_map(struct qxl_device *qdev,
 					struct qxl_release *release);
 void qxl_release_unmap(struct qxl_device *qdev,
 		       struct qxl_release *release,
 		       union qxl_release_info *info);
-/*
- * qxl_bo_add_resource.
- *
- */
-void qxl_bo_add_resource(struct qxl_bo *main_bo, struct qxl_bo *resource);
+int qxl_release_list_add(struct qxl_release *release, struct qxl_bo *bo);
+int qxl_release_reserve_list(struct qxl_release *release, bool no_intr);
+void qxl_release_backoff_reserve_list(struct qxl_release *release);
+void qxl_release_fence_buffer_objects(struct qxl_release *release);
 
 int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
 				       enum qxl_surface_cmd_type surface_cmd_type,
@@ -482,15 +492,16 @@ int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
 int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
 			       int type, struct qxl_release **release,
 			       struct qxl_bo **rbo);
-int qxl_fence_releaseable(struct qxl_device *qdev,
-			  struct qxl_release *release);
+
 int
 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 			      uint32_t type, bool interruptible);
 int
 qxl_push_cursor_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 			     uint32_t type, bool interruptible);
-int qxl_alloc_bo_reserved(struct qxl_device *qdev, unsigned long size,
+int qxl_alloc_bo_reserved(struct qxl_device *qdev,
+			  struct qxl_release *release,
+			  unsigned long size,
 			  struct qxl_bo **_bo);
 /* qxl drawing commands */
 
@@ -511,15 +522,9 @@ void qxl_draw_copyarea(struct qxl_device *qdev,
 		       u32 sx, u32 sy,
 		       u32 dx, u32 dy);
 
-uint64_t
-qxl_release_alloc(struct qxl_device *qdev, int type,
-		  struct qxl_release **ret);
-
 void qxl_release_free(struct qxl_device *qdev,
 		      struct qxl_release *release);
-void qxl_release_add_res(struct qxl_device *qdev,
-			 struct qxl_release *release,
-			 struct qxl_bo *bo);
+
 /* used by qxl_debugfs_release */
 struct qxl_release *qxl_release_from_id_locked(struct qxl_device *qdev,
 						   uint64_t id);
@@ -562,7 +567,7 @@ void qxl_surface_evict(struct qxl_device *qdev, struct qxl_bo *surf, bool freein
 int qxl_update_surface(struct qxl_device *qdev, struct qxl_bo *surf);
 
 /* qxl_fence.c */
-int qxl_fence_add_release(struct qxl_fence *qfence, uint32_t rel_id);
+void qxl_fence_add_release_locked(struct qxl_fence *qfence, uint32_t rel_id);
 int qxl_fence_remove_release(struct qxl_fence *qfence, uint32_t rel_id);
 int qxl_fence_init(struct qxl_device *qdev, struct qxl_fence *qfence);
 void qxl_fence_fini(struct qxl_fence *qfence);