i965g: add lots of error checks and early returns

Any allocation that may fail should be checked, and propogate the
error upwards.  At the highest level we will flush batch and retry.

This is an alternate strategy to what the original DRI driver did of
attempting to flush batch from the lowest levels (eg inside
BEGIN_BATCH).  The trouble with that strategy was that flushes could
occur at unexpected times, and additionally there was a need for a
wierd notification mechanism to propogate the 'lost context' state
back up to higher levels.

Propogating the errors directly gives us a lot of flexibility how to
deal with these states, at the expense of a lot more checking in the
code.

Will add some sanity checks later to make sure that out-of-memory
conditions are properly escalated and not lost halfway up the stack.

1 files changed, 61 insertions, 54 deletions

diff --git a/src/gallium/drivers/i965/brw_state_cache.c b/src/gallium/drivers/i965/brw_state_cache.c
index cbd1f02d77..f8369d31ec 100644
--- a/src/gallium/drivers/i965/brw_state_cache.c
+++ b/src/gallium/drivers/i965/brw_state_cache.c
@@ -109,9 +109,8 @@ update_cache_last(struct brw_cache *cache, enum brw_cache_id cache_id,
    if (bo == cache->last_bo[cache_id])
       return; /* no change */
 
-   cache->sws->bo_unreference(cache->last_bo[cache_id]);
-   cache->last_bo[cache_id] = bo;
-   cache->sws->bo_reference(cache->last_bo[cache_id]);
+   bo_reference( &cache->last_bo[cache_id],  bo );
+
    cache->brw->state.dirty.cache |= 1 << cache_id;
 }
 
@@ -174,14 +173,15 @@ rehash(struct brw_cache *cache)
 /**
  * Returns the buffer object matching cache_id and key, or NULL.
  */
-struct brw_winsys_buffer *
+boolean
 brw_search_cache(struct brw_cache *cache,
                  enum brw_cache_id cache_id,
                  const void *key,
                  GLuint key_size,
                  struct brw_winsys_buffer **reloc_bufs, 
 		 GLuint nr_reloc_bufs,
-                 void *aux_return)
+                 void *aux_return,
+                 struct brw_winsys_buffer **bo_out)
 {
    struct brw_cache_item *item;
    GLuint hash = hash_key(key, key_size, reloc_bufs, nr_reloc_bufs);
@@ -189,20 +189,20 @@ brw_search_cache(struct brw_cache *cache,
    item = search_cache(cache, cache_id, hash, key, key_size,
 		       reloc_bufs, nr_reloc_bufs);
 
-   if (item == NULL)
-      return NULL;
-
-   if (aux_return)
-      *(void **)aux_return = (void *)((char *)item->key + item->key_size);
-
-   update_cache_last(cache, cache_id, item->bo);
-
-   cache->sws->bo_reference(item->bo);
-   return item->bo;
+   if (item) {
+      if (aux_return)
+         *(void **)aux_return = (void *)((char *)item->key + item->key_size);
+      
+      update_cache_last(cache, cache_id, item->bo);
+      bo_reference(bo_out, item->bo);
+      return TRUE;
+   }
+   
+   return FALSE;      
 }
 
 
-struct brw_winsys_buffer *
+enum pipe_error
 brw_upload_cache( struct brw_cache *cache,
 		  enum brw_cache_id cache_id,
 		  const void *key,
@@ -212,14 +212,15 @@ brw_upload_cache( struct brw_cache *cache,
 		  const void *data,
 		  GLuint data_size,
 		  const void *aux,
-		  void *aux_return )
+		  void *aux_return,
+                  struct brw_winsys_buffer **bo_out)
 {
    struct brw_cache_item *item = CALLOC_STRUCT(brw_cache_item);
    GLuint hash = hash_key(key, key_size, reloc_bufs, nr_reloc_bufs);
    GLuint relocs_size = nr_reloc_bufs * sizeof(struct brw_winsys_buffer *);
    GLuint aux_size = cache->aux_size[cache_id];
+   enum pipe_error ret;
    void *tmp;
-   struct brw_winsys_buffer *bo;
    int i;
 
    /* Create the buffer object to contain the data.  For now, use a
@@ -227,9 +228,12 @@ brw_upload_cache( struct brw_cache *cache,
     * may want to take advantage of hardware distinctions between
     * these various entities.
     */
-   bo = cache->sws->bo_alloc(cache->sws,
-                             cache->buffer_type,
-			     data_size, 1 << 6);
+   ret = cache->sws->bo_alloc(cache->sws,
+                              cache->buffer_type,
+                              data_size, 1 << 6, 
+                              bo_out);
+   if (ret)
+      return ret;
 
 
    /* Set up the memory containing the key, aux_data, and reloc_bufs */
@@ -240,7 +244,7 @@ brw_upload_cache( struct brw_cache *cache,
    memcpy((char *)tmp + key_size + aux_size, reloc_bufs, relocs_size);
    for (i = 0; i < nr_reloc_bufs; i++) {
       if (reloc_bufs[i] != NULL)
-	 cache->sws->bo_reference(reloc_bufs[i]);
+         p_atomic_inc(&reloc_bufs[i]->reference.count);
    }
 
    item->cache_id = cache_id;
@@ -249,9 +253,7 @@ brw_upload_cache( struct brw_cache *cache,
    item->key_size = key_size;
    item->reloc_bufs = (struct brw_winsys_buffer **)((char *)tmp + key_size + aux_size);
    item->nr_reloc_bufs = nr_reloc_bufs;
-
-   item->bo = bo;
-   cache->sws->bo_reference(bo);
+   bo_reference( &item->bo, *bo_out );
    item->data_size = data_size;
 
    if (cache->n_items > cache->size * 1.5)
@@ -273,28 +275,28 @@ brw_upload_cache( struct brw_cache *cache,
 		   data_size, cache_id);
 
    /* Copy data to the buffer */
-   cache->sws->bo_subdata(bo, 
+   cache->sws->bo_subdata(item->bo, 
                           cache_id,
                           0, data_size, data);
 
-   update_cache_last(cache, cache_id, bo);
+   update_cache_last(cache, cache_id, item->bo);
 
-   return bo;
+   return PIPE_OK;
 }
 
 
 /**
  * This doesn't really work with aux data.  Use search/upload instead
  */
-struct brw_winsys_buffer *
+enum pipe_error
 brw_cache_data_sz(struct brw_cache *cache,
 		  enum brw_cache_id cache_id,
 		  const void *data,
 		  GLuint data_size,
 		  struct brw_winsys_buffer **reloc_bufs,
-		  GLuint nr_reloc_bufs)
+		  GLuint nr_reloc_bufs,
+                  struct brw_winsys_buffer **bo_out)
 {
-   struct brw_winsys_buffer *bo;
    struct brw_cache_item *item;
    GLuint hash = hash_key(data, data_size, reloc_bufs, nr_reloc_bufs);
 
@@ -302,17 +304,17 @@ brw_cache_data_sz(struct brw_cache *cache,
 		       reloc_bufs, nr_reloc_bufs);
    if (item) {
       update_cache_last(cache, cache_id, item->bo);
-      cache->sws->bo_reference(item->bo);
-      return item->bo;
-   }
 
-   bo = brw_upload_cache(cache, cache_id,
-			 data, data_size,
-			 reloc_bufs, nr_reloc_bufs,
-			 data, data_size,
-			 NULL, NULL);
+      bo_reference(bo_out, item->bo);
+      return PIPE_OK;
+   }
 
-   return bo;
+   return brw_upload_cache(cache, cache_id,
+                           data, data_size,
+                           reloc_bufs, nr_reloc_bufs,
+                           data, data_size,
+                           NULL, NULL,
+                           bo_out);
 }
 
 
@@ -323,15 +325,16 @@ brw_cache_data_sz(struct brw_cache *cache,
  * better to use, as the potentially changing offsets in the data-used-as-key
  * will result in excessive cache misses.
  */
-struct brw_winsys_buffer *
+enum pipe_error
 brw_cache_data(struct brw_cache *cache,
 	       enum brw_cache_id cache_id,
 	       const void *data,
 	       struct brw_winsys_buffer **reloc_bufs,
-	       GLuint nr_reloc_bufs)
+	       GLuint nr_reloc_bufs,
+               struct brw_winsys_buffer **bo_out)
 {
    return brw_cache_data_sz(cache, cache_id, data, cache->key_size[cache_id],
-			    reloc_bufs, nr_reloc_bufs);
+			    reloc_bufs, nr_reloc_bufs, bo_out);
 }
 
 
@@ -506,11 +509,13 @@ brw_clear_cache(struct brw_context *brw, struct brw_cache *cache)
 	 int j;
 
 	 next = c->next;
+
 	 for (j = 0; j < c->nr_reloc_bufs; j++)
-	    brw->sws->bo_unreference(c->reloc_bufs[j]);
-	 brw->sws->bo_unreference(c->bo);
-	 free((void *)c->key);
-	 free(c);
+	    bo_reference(&c->reloc_bufs[j], NULL);
+
+	 bo_reference(&c->bo, NULL);
+	 FREE((void *)c->key);
+	 FREE(c);
       }
       cache->items[i] = NULL;
    }
@@ -551,10 +556,12 @@ brw_state_cache_bo_delete(struct brw_cache *cache, struct brw_winsys_buffer *bo)
 	    *prev = c->next;
 
 	    for (j = 0; j < c->nr_reloc_bufs; j++)
-	       cache->sws->bo_unreference(c->reloc_bufs[j]);
-	    cache->sws->bo_unreference(c->bo);
-	    free((void *)c->key);
-	    free(c);
+	       bo_reference(&c->reloc_bufs[j], NULL);
+
+	    bo_reference(&c->bo, NULL);
+
+	    FREE((void *)c->key);
+	    FREE(c);
 	    cache->n_items--;
 	 } else {
 	    prev = &c->next;
@@ -590,10 +597,10 @@ brw_destroy_cache(struct brw_context *brw, struct brw_cache *cache)
 
    brw_clear_cache(brw, cache);
    for (i = 0; i < BRW_MAX_CACHE; i++) {
-      brw->sws->bo_unreference(cache->last_bo[i]);
-      free(cache->name[i]);
+      bo_reference(&cache->last_bo[i], NULL);
+      FREE(cache->name[i]);
    }
-   free(cache->items);
+   FREE(cache->items);
    cache->items = NULL;
    cache->size = 0;
 }