From: Rob Clark <robdclark@gmail.com>
Date: Tue, 17 Jul 2018 13:40:23 +0000 (-0400)
Subject: freedreno: hold batch references when flushing
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f2570409f90e18c290beb7375107aa4862bd1019;p=mesa.git

freedreno: hold batch references when flushing

It is possible for a batch to be freed under our feet when flushing, so
it is best to hold a reference to all of them up-front.

Signed-off-by: Rob Clark <robdclark@gmail.com>
---

diff --git a/src/gallium/drivers/freedreno/freedreno_batch_cache.c b/src/gallium/drivers/freedreno/freedreno_batch_cache.c
index 07dc1a93f07..c4640a7cfee 100644
--- a/src/gallium/drivers/freedreno/freedreno_batch_cache.c
+++ b/src/gallium/drivers/freedreno/freedreno_batch_cache.c
@@ -124,35 +124,54 @@ fd_bc_fini(struct fd_batch_cache *cache)
 	_mesa_hash_table_destroy(cache->ht, NULL);
 }
 
-void
-fd_bc_flush(struct fd_batch_cache *cache, struct fd_context *ctx)
+static void
+bc_flush(struct fd_batch_cache *cache, struct fd_context *ctx, bool deferred)
 {
-	struct hash_entry *entry;
-	struct fd_batch *last_batch = NULL;
+	/* fd_batch_flush() (and fd_batch_add_dep() which calls it indirectly)
+	 * can cause batches to be unref'd and freed under our feet, so grab
+	 * a reference to all the batches we need up-front.
+	 */
+	struct fd_batch *batches[ARRAY_SIZE(cache->batches)] = {0};
+	struct fd_batch *batch;
+	unsigned n = 0;
 
-	mtx_lock(&ctx->screen->lock);
+	fd_context_lock(ctx);
 
-	hash_table_foreach(cache->ht, entry) {
-		struct fd_batch *batch = NULL;
-		/* hold a reference since we can drop screen->lock: */
-		fd_batch_reference_locked(&batch, (struct fd_batch *)entry->data);
+	foreach_batch(batch, cache, cache->batch_mask) {
 		if (batch->ctx == ctx) {
-			mtx_unlock(&ctx->screen->lock);
-			fd_batch_reference(&last_batch, batch);
-			fd_batch_flush(batch, false, false);
-			mtx_lock(&ctx->screen->lock);
+			fd_batch_reference_locked(&batches[n++], batch);
 		}
-		fd_batch_reference_locked(&batch, NULL);
 	}
 
-	mtx_unlock(&ctx->screen->lock);
+	if (deferred) {
+		struct fd_batch *current_batch = ctx->batch;
+
+		for (unsigned i = 0; i < n; i++) {
+			if (batches[i] != current_batch) {
+				fd_batch_add_dep(current_batch, batches[i]);
+			}
+		}
+
+		fd_context_unlock(ctx);
+	} else {
+		fd_context_unlock(ctx);
+
+		for (unsigned i = 0; i < n; i++) {
+			fd_batch_flush(batches[i], false, false);
+		}
+	}
 
-	if (last_batch) {
-		fd_batch_sync(last_batch);
-		fd_batch_reference(&last_batch, NULL);
+	for (unsigned i = 0; i < n; i++) {
+		fd_batch_reference(&batches[i], NULL);
 	}
 }
 
+void
+fd_bc_flush(struct fd_batch_cache *cache, struct fd_context *ctx)
+{
+	bc_flush(cache, ctx, false);
+}
+
 /* deferred flush doesn't actually flush, but it marks every other
  * batch associated with the context as dependent on the current
  * batch.  So when the current batch gets flushed, all other batches
@@ -161,20 +180,7 @@ fd_bc_flush(struct fd_batch_cache *cache, struct fd_context *ctx)
 void
 fd_bc_flush_deferred(struct fd_batch_cache *cache, struct fd_context *ctx)
 {
-	struct fd_batch *current_batch = ctx->batch;
-	struct hash_entry *entry;
-
-	mtx_lock(&ctx->screen->lock);
-
-	hash_table_foreach(cache->ht, entry) {
-		struct fd_batch *batch = entry->data;
-		if (batch == current_batch)
-			continue;
-		if (batch->ctx == ctx)
-			fd_batch_add_dep(current_batch, batch);
-	}
-
-	mtx_unlock(&ctx->screen->lock);
+	bc_flush(cache, ctx, true);
 }
 
 void