drm/vc4: Try even harder to succeed at allocations (wait for GPU).

Signed-off-by: Eric Anholt <eric@anholt.net>

3 files changed, 50 insertions, 20 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
index b6169d3a93c1..e4f14aa8ca9f 100644
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -125,6 +125,7 @@ vc4_bo_create(struct drm_device *dev, size_t unaligned_size)
 	uint32_t size = roundup(unaligned_size, PAGE_SIZE);
 	uint32_t page_index = bo_page_index(size);
 	struct drm_gem_cma_object *cma_obj;
+	int pass;
 
 	if (size == 0)
 		return NULL;
@@ -142,15 +143,35 @@ vc4_bo_create(struct drm_device *dev, size_t unaligned_size)
 	}
 
 	/* Otherwise, make a new BO. */
-	cma_obj = drm_gem_cma_create(dev, size);
-	if (IS_ERR(cma_obj)) {
-		/* If we've run out of CMA memory, kill the cache of
-		 * CMA allocations we've got laying around and try again.
-		 */
-		vc4_bo_cache_purge(dev);
+	for (pass = 0; ; pass++) {
 		cma_obj = drm_gem_cma_create(dev, size);
-		if (IS_ERR(cma_obj))
+		if (!IS_ERR(cma_obj))
+			break;
+
+		switch (pass) {
+		case 0:
+			/*
+			 * If we've run out of CMA memory, kill the cache of
+			 * CMA allocations we've got laying around and try again.
+			 */
+			vc4_bo_cache_purge(dev);
+			break;
+		case 1:
+			/*
+			 * Getting desperate, so try to wait for any
+			 * previous rendering to finish, free its
+			 * unreferenced BOs to the cache, and then
+			 * free the cache.
+			 */
+			vc4_wait_for_seqno(dev, vc4->emit_seqno, ~0ull);
+			vc4_job_handle_completed(vc4);
+			vc4_bo_cache_purge(dev);
+			break;
+		case 3:
+			DRM_ERROR("Failed to allocate from CMA:\n");
+			vc4_bo_stats_dump();
 			return NULL;
+		}
 	}
 
 	bo_stats.num_allocated++;
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 6b3e07cf8443..bc4384e3d4cb 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -387,6 +387,9 @@ int vc4_wait_seqno_ioctl(struct drm_device *dev, void *data,
 int vc4_wait_bo_ioctl(struct drm_device *dev, void *data,
 		      struct drm_file *file_priv);
 void vc4_submit_next_job(struct drm_device *dev);
+int vc4_wait_for_seqno(struct drm_device *dev, uint64_t seqno,
+		       uint64_t timeout_ns);
+void vc4_job_handle_completed(struct vc4_dev *vc4);
 
 /* vc4_hdmi.c */
 void vc4_hdmi_register(void);
diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index 7bb446cc1f40..54fe0b83421b 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -117,7 +117,7 @@ submit_cl(struct drm_device *dev, uint32_t thread, uint32_t start, uint32_t end)
 	barrier();
 }
 
-static int
+int
 vc4_wait_for_seqno(struct drm_device *dev, uint64_t seqno, uint64_t timeout_ns)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
@@ -477,21 +477,11 @@ vc4_complete_exec(struct vc4_exec_info *exec)
 	kfree(exec);
 }
 
-/* Scheduled when any job has been completed, this walks the list of
- * jobs that had completed and unrefs their BOs and frees their exec
- * structs.
- */
-static void
-vc4_job_done_work(struct work_struct *work)
+void
+vc4_job_handle_completed(struct vc4_dev *vc4)
 {
-	struct vc4_dev *vc4 =
-		container_of(work, struct vc4_dev, job_done_work);
-	struct drm_device *dev = vc4->dev;
 	unsigned long irqflags;
 
-	/* Need the struct lock for drm_gem_object_unreference(). */
-	mutex_lock(&dev->struct_mutex);
-
 	spin_lock_irqsave(&vc4->job_lock, irqflags);
 	while (!list_empty(&vc4->job_done_list)) {
 		struct vc4_exec_info *exec =
@@ -505,6 +495,22 @@ vc4_job_done_work(struct work_struct *work)
 	}
 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
 
+}
+
+/* Scheduled when any job has been completed, this walks the list of
+ * jobs that had completed and unrefs their BOs and frees their exec
+ * structs.
+ */
+static void
+vc4_job_done_work(struct work_struct *work)
+{
+	struct vc4_dev *vc4 =
+		container_of(work, struct vc4_dev, job_done_work);
+	struct drm_device *dev = vc4->dev;
+
+	/* Need the struct lock for drm_gem_object_unreference(). */
+	mutex_lock(&dev->struct_mutex);
+	vc4_job_handle_completed(vc4);
 	mutex_unlock(&dev->struct_mutex);
 }