etnaviv: Use only DRAW_INSTANCED on GC3000+

The blob does this, as DRAW_INSTANCED can replace fully all the other
draw commands. It is also required to handle integer vertex formats.
The other path is only there for compatibility and might go away (or at
least rot to become buggy due to dis-use) in newer hardware.

As a by-effect this changes the behavior for GC3000-, by no longer using
the index offset for DRAW_INDEXED but instead adding it to INDEX_ADDR.
This should make no difference.

Preparation for GC7000 support.

Signed-off-by: Wladimir J. van der Laan <laanwj@gmail.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

src/gallium/drivers/etnaviv/etnaviv_context.c

@@ -188,6 +188,8 @@ etna_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info)
          BUG("Index buffer upload failed.");
          return;
       }
+      /* Add start to index offset, when rendering indexed */
+      index_offset += info->start * info->index_size;
 
       ctx->index_buffer.FE_INDEX_STREAM_BASE_ADDR.bo = etna_resource(indexbuf)->bo;
       ctx->index_buffer.FE_INDEX_STREAM_BASE_ADDR.offset = index_offset;
@@ -273,10 +275,16 @@ etna_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info)
    /* First, sync state, then emit DRAW_PRIMITIVES or DRAW_INDEXED_PRIMITIVES */
    etna_emit_state(ctx);
 
-   if (info->index_size)
-      etna_draw_indexed_primitives(ctx->stream, draw_mode, info->start, prims, info->index_bias);
-   else
-      etna_draw_primitives(ctx->stream, draw_mode, info->start, prims);
+   if (ctx->specs.halti >= 2) {
+      /* On HALTI2+ (GC3000 and higher) only use instanced drawing commands, as the blob does */
+      etna_draw_instanced(ctx->stream, info->index_size, draw_mode, 1,
+         info->count, info->index_size ? info->index_bias : info->start);
+   } else {
+      if (info->index_size)
+         etna_draw_indexed_primitives(ctx->stream, draw_mode, 0, prims, info->index_bias);
+      else
+         etna_draw_primitives(ctx->stream, draw_mode, info->start, prims);
+   }
 
    if (DBG_ENABLED(ETNA_DBG_DRAW_STALL)) {
       /* Stall the FE after every draw operation.  This allows better

src/gallium/drivers/etnaviv/etnaviv_emit.h

@@ -117,6 +117,27 @@ etna_draw_indexed_primitives(struct etna_cmd_stream *stream,
    etna_cmd_stream_emit(stream, 0);
 }
 
+/* important: this takes a vertex count, not a primitive count */
+static inline void
+etna_draw_instanced(struct etna_cmd_stream *stream,
+                    uint32_t indexed, uint32_t primitive_type,
+                    uint32_t instance_count,
+                    uint32_t vertex_count, uint32_t offset)
+{
+   etna_cmd_stream_reserve(stream, 3 + 1);
+   etna_cmd_stream_emit(stream,
+      VIV_FE_DRAW_INSTANCED_HEADER_OP_DRAW_INSTANCED |
+      COND(indexed, VIV_FE_DRAW_INSTANCED_HEADER_INDEXED) |
+      VIV_FE_DRAW_INSTANCED_HEADER_TYPE(primitive_type) |
+      VIV_FE_DRAW_INSTANCED_HEADER_INSTANCE_COUNT_LO(instance_count & 0xffff));
+   etna_cmd_stream_emit(stream,
+      VIV_FE_DRAW_INSTANCED_COUNT_INSTANCE_COUNT_HI(instance_count >> 16) |
+      VIV_FE_DRAW_INSTANCED_COUNT_VERTEX_COUNT(vertex_count));
+   etna_cmd_stream_emit(stream,
+      VIV_FE_DRAW_INSTANCED_START_INDEX(offset));
+   etna_cmd_stream_emit(stream, 0);
+}
+
 void
 etna_emit_state(struct etna_context *ctx);