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, 52 insertions, 34 deletions

diff --git a/src/gallium/drivers/i965/brw_sf_state.c b/src/gallium/drivers/i965/brw_sf_state.c
index 31343ff245..f030f26c19 100644
--- a/src/gallium/drivers/i965/brw_sf_state.c
+++ b/src/gallium/drivers/i965/brw_sf_state.c
@@ -39,11 +39,12 @@
 #include "brw_debug.h"
 #include "brw_pipe_rast.h"
 
-static int upload_sf_vp(struct brw_context *brw)
+static enum pipe_error upload_sf_vp(struct brw_context *brw)
 {
    const struct pipe_viewport_state *vp = &brw->curr.vp;
    const struct pipe_scissor_state *scissor = &brw->curr.scissor;
    struct brw_sf_viewport sfv;
+   enum pipe_error ret;
 
    memset(&sfv, 0, sizeof(sfv));
 
@@ -61,10 +62,12 @@ static int upload_sf_vp(struct brw_context *brw)
    sfv.scissor.ymin = scissor->miny;
    sfv.scissor.ymax = scissor->maxy; /* -1 ?? */
 
-   brw->sws->bo_unreference(brw->sf.vp_bo);
-   brw->sf.vp_bo = brw_cache_data( &brw->cache, BRW_SF_VP, &sfv, NULL, 0 );
+   ret = brw_cache_data( &brw->cache, BRW_SF_VP, &sfv, NULL, 0,
+                         &brw->sf.vp_bo );
+   if (ret)
+      return ret;
 
-   return 0;
+   return PIPE_OK;
 }
 
 const struct brw_tracked_state brw_sf_vp = {
@@ -128,12 +131,13 @@ sf_unit_populate_key(struct brw_context *brw, struct brw_sf_unit_key *key)
 			   rast->point_size_max);
 }
 
-static struct brw_winsys_buffer *
+static enum pipe_error
 sf_unit_create_from_key(struct brw_context *brw, struct brw_sf_unit_key *key,
-			struct brw_winsys_buffer **reloc_bufs)
+			struct brw_winsys_buffer **reloc_bufs,
+                        struct brw_winsys_buffer **bo_out)
 {
    struct brw_sf_unit_state sf;
-   struct brw_winsys_buffer *bo;
+   enum pipe_error ret;
    int chipset_max_threads;
    memset(&sf, 0, sizeof(sf));
 
@@ -273,51 +277,65 @@ sf_unit_create_from_key(struct brw_context *brw, struct brw_sf_unit_key *key,
       sf.sf6.dest_org_hbias = 0x0;
    }
 
-   bo = brw_upload_cache(&brw->cache, BRW_SF_UNIT,
-			 key, sizeof(*key),
-			 reloc_bufs, 2,
-			 &sf, sizeof(sf),
-			 NULL, NULL);
+   ret = brw_upload_cache(&brw->cache, BRW_SF_UNIT,
+                          key, sizeof(*key),
+                          reloc_bufs, 2,
+                          &sf, sizeof(sf),
+                          NULL, NULL,
+                          bo_out);
+   if (ret)
+      return ret;
 
    /* STATE_PREFETCH command description describes this state as being
     * something loaded through the GPE (L2 ISC), so it's INSTRUCTION domain.
     */
    /* Emit SF program relocation */
-   brw->sws->bo_emit_reloc(bo,
-			   BRW_USAGE_STATE,
-			   sf.thread0.grf_reg_count << 1,
-			   offsetof(struct brw_sf_unit_state, thread0),
-			   brw->sf.prog_bo);
+   ret = brw->sws->bo_emit_reloc(*bo_out,
+                                 BRW_USAGE_STATE,
+                                 sf.thread0.grf_reg_count << 1,
+                                 offsetof(struct brw_sf_unit_state, thread0),
+                                 brw->sf.prog_bo);
+   if (ret)
+      return ret;
 
-   /* Emit SF viewport relocation */
-   brw->sws->bo_emit_reloc(bo,
-			   BRW_USAGE_STATE,
-			   sf.sf5.front_winding | (sf.sf5.viewport_transform << 1),
-			   offsetof(struct brw_sf_unit_state, sf5),
-			   brw->sf.vp_bo);
 
-   return bo;
+   /* Emit SF viewport relocation */
+   ret = brw->sws->bo_emit_reloc(*bo_out,
+                                 BRW_USAGE_STATE,
+                                 sf.sf5.front_winding | (sf.sf5.viewport_transform << 1),
+                                 offsetof(struct brw_sf_unit_state, sf5),
+                                 brw->sf.vp_bo);
+   if (ret)
+      return ret;
+   
+   return PIPE_OK;
 }
 
-static int upload_sf_unit( struct brw_context *brw )
+static enum pipe_error upload_sf_unit( struct brw_context *brw )
 {
    struct brw_sf_unit_key key;
    struct brw_winsys_buffer *reloc_bufs[2];
+   enum pipe_error ret;
 
    sf_unit_populate_key(brw, &key);
 
    reloc_bufs[0] = brw->sf.prog_bo;
    reloc_bufs[1] = brw->sf.vp_bo;
 
-   brw->sws->bo_unreference(brw->sf.state_bo);
-   brw->sf.state_bo = brw_search_cache(&brw->cache, BRW_SF_UNIT,
-				       &key, sizeof(key),
-				       reloc_bufs, 2,
-				       NULL);
-   if (brw->sf.state_bo == NULL) {
-      brw->sf.state_bo = sf_unit_create_from_key(brw, &key, reloc_bufs);
-   }
-   return 0;
+   if (brw_search_cache(&brw->cache, BRW_SF_UNIT,
+                        &key, sizeof(key),
+                        reloc_bufs, 2,
+                        NULL,
+                        &brw->sf.state_bo))
+      return PIPE_OK;
+
+
+   ret = sf_unit_create_from_key(brw, &key, reloc_bufs,
+                                 &brw->sf.state_bo);
+   if (ret)
+      return ret;
+
+   return PIPE_OK;
 }
 
 const struct brw_tracked_state brw_sf_unit = {