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, 56 insertions, 41 deletions

diff --git a/src/gallium/drivers/i965/brw_vs_surface_state.c b/src/gallium/drivers/i965/brw_vs_surface_state.c
index 32fb9b2a8b..b12df0ec03 100644
--- a/src/gallium/drivers/i965/brw_vs_surface_state.c
+++ b/src/gallium/drivers/i965/brw_vs_surface_state.c
@@ -83,22 +83,23 @@ brw_update_vs_constant_surface( struct brw_context *brw,
 {
    struct brw_surface_key key;
    struct pipe_buffer *cb = brw->curr.vs_constants;
+   enum pipe_error ret;
 
    assert(surf == 0);
 
    /* If we're in this state update atom, we need to update VS constants, so
     * free the old buffer and create a new one for the new contents.
     */
-   brw->sws->bo_unreference(vp->const_buffer);
-   vp->const_buffer = brw_vs_update_constant_buffer(brw);
+   ret = brw_vs_update_constant_buffer(brw, &vp->const_buffer);
+   if (ret)
+      return ret;
 
    /* If there's no constant buffer, then no surface BO is needed to point at
     * it.
     */
-   if (vp->const_buffer == 0) {
-      drm_intel_bo_unreference(brw->vs.surf_bo[surf]);
-      brw->vs.surf_bo[surf] = NULL;
-      return;
+   if (vp->const_buffer == NULL) {
+      bo_reference(brw->vs.surf_bo[surf], NULL);
+      return PIPE_OK;
    }
 
    memset(&key, 0, sizeof(key));
@@ -118,15 +119,20 @@ brw_update_vs_constant_surface( struct brw_context *brw,
           key.width, key.height, key.depth, key.cpp, key.pitch);
    */
 
-   drm_intel_bo_unreference(brw->vs.surf_bo[surf]);
-   brw->vs.surf_bo[surf] = brw_search_cache(&brw->surface_cache,
-                                            BRW_SS_SURFACE,
-                                            &key, sizeof(key),
-                                            &key.bo, key.bo ? 1 : 0,
-                                            NULL);
-   if (brw->vs.surf_bo[surf] == NULL) {
-      brw->vs.surf_bo[surf] = brw_create_constant_surface(brw, &key);
-   }
+   if (brw_search_cache(&brw->surface_cache,
+                        BRW_SS_SURFACE,
+                        &key, sizeof(key),
+                        &key.bo, key.bo ? 1 : 0,
+                        NULL,
+                        &brw->vs.surf_bo[surf]))
+      return PIPE_OK;
+
+   ret = brw_create_constant_surface(brw, &key
+                                     &brw->vs.surf_bo[surf]);
+   if (ret)
+      return ret;
+   
+   return PIPE_OK;
 }
 #endif
 
@@ -134,18 +140,20 @@ brw_update_vs_constant_surface( struct brw_context *brw,
 /**
  * Constructs the binding table for the VS surface state.
  */
-static struct brw_winsys_buffer *
-brw_vs_get_binding_table(struct brw_context *brw)
+static enum pipe_error
+brw_vs_get_binding_table(struct brw_context *brw,
+                         struct brw_winsys_buffer **bo_out)
 {
 #if 0
-   struct brw_winsys_buffer *bind_bo;
-
-   bind_bo = brw_search_cache(&brw->surface_cache, BRW_SS_SURF_BIND,
-			      NULL, 0,
-			      brw->vs.surf_bo, BRW_VS_MAX_SURF,
-			      NULL);
-
-   if (bind_bo == NULL) {
+   if (brw_search_cache(&brw->surface_cache, BRW_SS_SURF_BIND,
+                        NULL, 0,
+                        brw->vs.surf_bo, BRW_VS_MAX_SURF,
+                        NULL,
+                        bo_out))
+   {
+      return PIPE_OK;
+   }
+   else {
       GLuint data_size = BRW_VS_MAX_SURF * sizeof(GLuint);
       uint32_t *data = malloc(data_size);
       int i;
@@ -156,11 +164,14 @@ brw_vs_get_binding_table(struct brw_context *brw)
          else
             data[i] = 0;
 
-      bind_bo = brw_upload_cache( &brw->surface_cache, BRW_SS_SURF_BIND,
-				  NULL, 0,
-				  brw->vs.surf_bo, BRW_VS_MAX_SURF,
-				  data, data_size,
-				  NULL, NULL);
+      ret = brw_upload_cache( &brw->surface_cache, BRW_SS_SURF_BIND,
+                              NULL, 0,
+                              brw->vs.surf_bo, BRW_VS_MAX_SURF,
+                              data, data_size,
+                              NULL, NULL,
+                              bo_out);
+      if (ret)
+         return ret;
 
       /* Emit binding table relocations to surface state */
       for (i = 0; i < BRW_VS_MAX_SURF; i++) {
@@ -168,18 +179,19 @@ brw_vs_get_binding_table(struct brw_context *brw)
 	    /* The presumed offsets were set in the data values for
 	     * brw_upload_cache.
 	     */
-	    drm_intel_bo_emit_reloc(bind_bo, i * 4,
-				    brw->vs.surf_bo[i], 0,
-				    BRW_USAGE_STATE);
+	    ret = sws->bo_emit_reloc(*bo_out, i * 4,
+                                     brw->vs.surf_bo[i], 0,
+                                     BRW_USAGE_STATE);
+            if (ret)
+               return ret;
 	 }
       }
 
-      free(data);
+      FREE(data);
+      return PIPE_OK;
    }
-
-   return bind_bo;
 #else
-   return NULL;
+   return PIPE_OK;
 #endif
 }
 
@@ -190,8 +202,10 @@ brw_vs_get_binding_table(struct brw_context *brw)
  * to be updated, and produces BRW_NEW_NR_VS_SURFACES for the VS unit and
  * CACHE_NEW_SURF_BIND for the binding table upload.
  */
-static int prepare_vs_surfaces(struct brw_context *brw )
+static enum pipe_error prepare_vs_surfaces(struct brw_context *brw )
 {
+   enum pipe_error ret;
+
 #if 0
    int i;
    int nr_surfaces = 0;
@@ -215,11 +229,12 @@ static int prepare_vs_surfaces(struct brw_context *brw )
     * just slightly increases our working set size.
     */
    if (brw->vs.nr_surfaces != 0) {
-      brw->sws->bo_unreference(brw->vs.bind_bo);
-      brw->vs.bind_bo = brw_vs_get_binding_table(brw);
+      ret = brw_vs_get_binding_table(brw, &brw->vs.bind_bo);
+      if (ret)
+         return ret;
    }
 
-   return 0;
+   return PIPE_OK;
 }
 
 const struct brw_tracked_state brw_vs_surfaces = {