drm/vc4: Remove BOs seqnos

`bo->seqno`, `bo->write_seqno`, and `exec->bin_dep_seqno` are leftovers
from a time when VC4 didn't support DMA Reservation Objects. Before DMA
Resv was introduced, tracking the correspondence between BOs and jobs
through the job's seqno made sense.

However, this is no longer needed, as VC4 now supports DMA Reservation
Objects and attaches the "job done" fence to the BOs. Therefore, remove
the BOs seqnos in favor of using DMA Resv Objects.

Signed-off-by: Maíra Canal <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Reviewed-by: Melissa Wen <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/vc4/vc4_crtc.c

···
 	struct drm_framebuffer *fb;
 	struct drm_framebuffer *old_fb;
 	struct drm_pending_vblank_event *event;
-
-	union {
-		struct dma_fence_cb fence;
-		struct vc4_seqno_cb seqno;
-	} cb;
+	struct dma_fence_cb cb;
 };
 
 /* Called when the V3D execution for the BO being flipped to is done, so that
···
 	kfree(flip_state);
 }
 
-static void vc4_async_page_flip_seqno_complete(struct vc4_seqno_cb *cb)
+static void vc4_async_page_flip_complete_with_cleanup(struct dma_fence *fence,
+						      struct dma_fence_cb *cb)
 {
 	struct vc4_async_flip_state *flip_state =
-		container_of(cb, struct vc4_async_flip_state, cb.seqno);
+		container_of(cb, struct vc4_async_flip_state, cb);
 	struct vc4_bo *bo = NULL;
 
 	if (flip_state->old_fb) {
···
 	}
 
 	vc4_async_page_flip_complete(flip_state);
+	dma_fence_put(fence);
 
 	/*
 	 * Decrement the BO usecnt in order to keep the inc/dec
···
 					       struct dma_fence_cb *cb)
 {
 	struct vc4_async_flip_state *flip_state =
-		container_of(cb, struct vc4_async_flip_state, cb.fence);
+		container_of(cb, struct vc4_async_flip_state, cb);
 
 	vc4_async_page_flip_complete(flip_state);
 	dma_fence_put(fence);
···
 {
 	struct drm_framebuffer *fb = flip_state->fb;
 	struct drm_gem_dma_object *dma_bo = drm_fb_dma_get_gem_obj(fb, 0);
+	dma_fence_func_t async_page_flip_complete_function;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct dma_fence *fence;
 	int ret;
 
-	if (vc4->gen == VC4_GEN_4) {
-		struct vc4_bo *bo = to_vc4_bo(&dma_bo->base);
-
-		return vc4_queue_seqno_cb(dev, &flip_state->cb.seqno, bo->seqno,
-					  vc4_async_page_flip_seqno_complete);
-	}
+	if (vc4->gen == VC4_GEN_4)
+		async_page_flip_complete_function = vc4_async_page_flip_complete_with_cleanup;
+	else
+		async_page_flip_complete_function = vc4_async_page_flip_fence_complete;
 
 	ret = dma_resv_get_singleton(dma_bo->base.resv, DMA_RESV_USAGE_READ, &fence);
 	if (ret)
···
 
 	/* If there's no fence, complete the page flip immediately */
 	if (!fence) {
-		vc4_async_page_flip_fence_complete(fence, &flip_state->cb.fence);
+		async_page_flip_complete_function(fence, &flip_state->cb);
 		return 0;
 	}
 
 	/* If the fence has already been completed, complete the page flip */
-	if (dma_fence_add_callback(fence, &flip_state->cb.fence,
-				   vc4_async_page_flip_fence_complete))
-		vc4_async_page_flip_fence_complete(fence, &flip_state->cb.fence);
+	if (dma_fence_add_callback(fence, &flip_state->cb,
+				   async_page_flip_complete_function))
+		async_page_flip_complete_function(fence, &flip_state->cb);
 
 	return 0;
 }

drivers/gpu/drm/vc4/vc4_drv.h

···
 	 */
 	struct vc4_perfmon *active_perfmon;
 
-	/* List of struct vc4_seqno_cb for callbacks to be made from a
-	 * workqueue when the given seqno is passed.
-	 */
-	struct list_head seqno_cb_list;
-
 	/* The memory used for storing binner tile alloc, tile state,
 	 * and overflow memory allocations.  This is freed when V3D
 	 * powers down.
···
 struct vc4_bo {
 	struct drm_gem_dma_object base;
 
-	/* seqno of the last job to render using this BO. */
-	uint64_t seqno;
-
-	/* seqno of the last job to use the RCL to write to this BO.
-	 *
-	 * Note that this doesn't include binner overflow memory
-	 * writes.
-	 */
-	uint64_t write_seqno;
-
 	bool t_format;
 
 	/* List entry for the BO's position in either
···
 
 #define to_vc4_fence(_fence)					\
 	container_of_const(_fence, struct vc4_fence, base)
-
-struct vc4_seqno_cb {
-	struct work_struct work;
-	uint64_t seqno;
-	void (*func)(struct vc4_seqno_cb *cb);
-};
 
 struct vc4_v3d {
 	struct vc4_dev *vc4;
···
 	/* Sequence number for this bin/render job. */
 	uint64_t seqno;
 
-	/* Latest write_seqno of any BO that binning depends on. */
-	uint64_t bin_dep_seqno;
-
 	struct dma_fence *fence;
 
 	/* Last current addresses the hardware was processing when the
···
 int vc4_wait_for_seqno(struct drm_device *dev, uint64_t seqno,
 		       uint64_t timeout_ns, bool interruptible);
 void vc4_job_handle_completed(struct vc4_dev *vc4);
-int vc4_queue_seqno_cb(struct drm_device *dev,
-		       struct vc4_seqno_cb *cb, uint64_t seqno,
-		       void (*func)(struct vc4_seqno_cb *cb));
 int vc4_gem_madvise_ioctl(struct drm_device *dev, void *data,
 			  struct drm_file *file_priv);
 

drivers/gpu/drm/vc4/vc4_gem.c

···
 }
 
 static void
-vc4_update_bo_seqnos(struct vc4_exec_info *exec, uint64_t seqno)
+vc4_attach_fences(struct vc4_exec_info *exec)
 {
 	struct vc4_bo *bo;
 	unsigned i;
 
 	for (i = 0; i < exec->bo_count; i++) {
 		bo = to_vc4_bo(exec->bo[i]);
-		bo->seqno = seqno;
-
 		dma_resv_add_fence(bo->base.base.resv, exec->fence,
 				   DMA_RESV_USAGE_READ);
 	}
 
-	list_for_each_entry(bo, &exec->unref_list, unref_head) {
-		bo->seqno = seqno;
-	}
-
 	for (i = 0; i < exec->rcl_write_bo_count; i++) {
 		bo = to_vc4_bo(&exec->rcl_write_bo[i]->base);
-		bo->write_seqno = seqno;
-
 		dma_resv_add_fence(bo->base.base.resv, exec->fence,
 				   DMA_RESV_USAGE_WRITE);
 	}
···
 	if (out_sync)
 		drm_syncobj_replace_fence(out_sync, exec->fence);
 
-	vc4_update_bo_seqnos(exec, seqno);
+	vc4_attach_fences(exec);
 
 	drm_exec_fini(exec_ctx);
 
···
 			goto fail;
 	}
 
-	/* Block waiting on any previous rendering into the CS's VBO,
-	 * IB, or textures, so that pixels are actually written by the
-	 * time we try to read them.
-	 */
-	ret = vc4_wait_for_seqno(dev, exec->bin_dep_seqno, ~0ull, true);
-
 fail:
 	kvfree(temp);
 	return ret;
···
 vc4_job_handle_completed(struct vc4_dev *vc4)
 {
 	unsigned long irqflags;
-	struct vc4_seqno_cb *cb, *cb_temp;
 
 	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
 		return;
···
 		spin_lock_irqsave(&vc4->job_lock, irqflags);
 	}
 
-	list_for_each_entry_safe(cb, cb_temp, &vc4->seqno_cb_list, work.entry) {
-		if (cb->seqno <= vc4->finished_seqno) {
-			list_del_init(&cb->work.entry);
-			schedule_work(&cb->work);
-		}
-	}
-
 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
-}
-
-static void vc4_seqno_cb_work(struct work_struct *work)
-{
-	struct vc4_seqno_cb *cb = container_of(work, struct vc4_seqno_cb, work);
-
-	cb->func(cb);
-}
-
-int vc4_queue_seqno_cb(struct drm_device *dev,
-		       struct vc4_seqno_cb *cb, uint64_t seqno,
-		       void (*func)(struct vc4_seqno_cb *cb))
-{
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	unsigned long irqflags;
-
-	if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
-		return -ENODEV;
-
-	cb->func = func;
-	INIT_WORK(&cb->work, vc4_seqno_cb_work);
-
-	spin_lock_irqsave(&vc4->job_lock, irqflags);
-	if (seqno > vc4->finished_seqno) {
-		cb->seqno = seqno;
-		list_add_tail(&cb->work.entry, &vc4->seqno_cb_list);
-	} else {
-		schedule_work(&cb->work);
-	}
-	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
-
-	return 0;
 }
 
 /* Scheduled when any job has been completed, this walks the list of
···
 	INIT_LIST_HEAD(&vc4->bin_job_list);
 	INIT_LIST_HEAD(&vc4->render_job_list);
 	INIT_LIST_HEAD(&vc4->job_done_list);
-	INIT_LIST_HEAD(&vc4->seqno_cb_list);
 	spin_lock_init(&vc4->job_lock);
 
 	INIT_WORK(&vc4->hangcheck.reset_work, vc4_reset_work);

drivers/gpu/drm/vc4/vc4_validate.c

···
 	if (!ib)
 		return -EINVAL;
 
-	exec->bin_dep_seqno = max(exec->bin_dep_seqno,
-				  to_vc4_bo(&ib->base)->write_seqno);
-
 	if (offset > ib->base.size ||
 	    (ib->base.size - offset) / index_size < length) {
 		DRM_DEBUG("IB access overflow (%d + %d*%d > %zd)\n",
···
 
 	*validated_p0 = tex->dma_addr + p0;
 
-	if (is_cs) {
-		exec->bin_dep_seqno = max(exec->bin_dep_seqno,
-					  to_vc4_bo(&tex->base)->write_seqno);
-	}
-
 	return true;
  fail:
 	DRM_INFO("Texture p0 at %d: 0x%08x\n", sample->p_offset[0], p0);
···
 		uint32_t attr_size = *(uint8_t *)(pkt_u + o + 4) + 1;
 		uint32_t stride = *(uint8_t *)(pkt_u + o + 5);
 		uint32_t max_index;
-
-		exec->bin_dep_seqno = max(exec->bin_dep_seqno,
-					  to_vc4_bo(&vbo->base)->write_seqno);
 
 		if (state->addr & 0x8)
 			stride |= (*(uint32_t *)(pkt_u + 100 + i * 4)) & ~0xff;