drm/etnaviv: move ww_acquire_ctx out of submit object

The acquire_ctx is special in that it needs to be released from the same
thread as has been used to initialize it. This collides with the intention to
extend the submit lifetime beyond the gem_submit function with potentially
other threads doing the final cleanup.

Move the ww_acquire_ctx to the function local stack as suggested in the
documentation.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -102,7 +102,6 @@ struct etnaviv_gem_submit_bo {
  */
 struct etnaviv_gem_submit {
 	struct etnaviv_gpu *gpu;
-	struct ww_acquire_ctx ticket;
 	struct dma_fence *out_fence, *in_fence;
 	u32 flags;
 	unsigned int nr_bos;

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -44,8 +44,6 @@ static struct etnaviv_gem_submit *submit_create(struct drm_device *dev,
 
 	submit->gpu = gpu;
 
-	ww_acquire_init(&submit->ticket, &reservation_ww_class);
-
 	return submit;
 }
 
@@ -107,7 +105,8 @@ static void submit_unlock_object(struct etnaviv_gem_submit *submit, int i)
 	}
 }
 
-static int submit_lock_objects(struct etnaviv_gem_submit *submit)
+static int submit_lock_objects(struct etnaviv_gem_submit *submit,
+		struct ww_acquire_ctx *ticket)
 {
 	int contended, slow_locked = -1, i, ret = 0;
 
@@ -122,7 +121,7 @@ static int submit_lock_objects(struct etnaviv_gem_submit *submit)
 
 		if (!(submit->bos[i].flags & BO_LOCKED)) {
 			ret = ww_mutex_lock_interruptible(&etnaviv_obj->resv->lock,
-					&submit->ticket);
+							  ticket);
 			if (ret == -EALREADY)
 				DRM_ERROR("BO at index %u already on submit list\n",
 					  i);
@@ -132,7 +131,7 @@ static int submit_lock_objects(struct etnaviv_gem_submit *submit)
 		}
 	}
 
-	ww_acquire_done(&submit->ticket);
+	ww_acquire_done(ticket);
 
 	return 0;
 
@@ -150,7 +149,7 @@ static int submit_lock_objects(struct etnaviv_gem_submit *submit)
 
 		/* we lost out in a seqno race, lock and retry.. */
 		ret = ww_mutex_lock_slow_interruptible(&etnaviv_obj->resv->lock,
-				&submit->ticket);
+						       ticket);
 		if (!ret) {
 			submit->bos[contended].flags |= BO_LOCKED;
 			slow_locked = contended;
@@ -361,7 +360,6 @@ static void submit_cleanup(struct etnaviv_gem_submit *submit)
 		drm_gem_object_put_unlocked(&etnaviv_obj->base);
 	}
 
-	ww_acquire_fini(&submit->ticket);
 	if (submit->in_fence)
 		dma_fence_put(submit->in_fence);
 	if (submit->out_fence)
@@ -381,6 +379,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct etnaviv_cmdbuf *cmdbuf;
 	struct etnaviv_gpu *gpu;
 	struct sync_file *sync_file = NULL;
+	struct ww_acquire_ctx ticket;
 	int out_fence_fd = -1;
 	void *stream;
 	int ret;
@@ -466,10 +465,12 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		}
 	}
 
+	ww_acquire_init(&ticket, &reservation_ww_class);
+
 	submit = submit_create(dev, gpu, args->nr_bos);
 	if (!submit) {
 		ret = -ENOMEM;
-		goto err_submit_cmds;
+		goto err_submit_ww_acquire;
 	}
 
 	submit->flags = args->flags;
@@ -478,7 +479,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 	if (ret)
 		goto err_submit_objects;
 
-	ret = submit_lock_objects(submit);
+	ret = submit_lock_objects(submit, &ticket);
 	if (ret)
 		goto err_submit_objects;
 
@@ -545,6 +546,9 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 err_submit_objects:
 	submit_cleanup(submit);
 
+err_submit_ww_acquire:
+	ww_acquire_fini(&ticket);
+
 err_submit_cmds:
 	if (ret && (out_fence_fd >= 0))
 		put_unused_fd(out_fence_fd);