zink: add launch_grid pipe_context hook for compute handling

we're reusing update_descriptors, so this is trivial

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8781>

src/gallium/drivers/zink/zink_context.c

@@ -1675,6 +1675,7 @@ zink_context_create(struct pipe_screen *pscreen, void *priv, unsigned flags)
    ctx->base.clear_texture = zink_clear_texture;
 
    ctx->base.draw_vbo = zink_draw_vbo;
+   ctx->base.launch_grid = zink_launch_grid;
    ctx->base.flush = zink_flush;
    ctx->base.memory_barrier = zink_memory_barrier;
 

src/gallium/drivers/zink/zink_context.h

@@ -259,4 +259,6 @@ zink_draw_vbo(struct pipe_context *pctx,
               const struct pipe_draw_start_count *draws,
               unsigned num_draws);
 
+void
+zink_launch_grid(struct pipe_context *pctx, const struct pipe_grid_info *info);
 #endif

src/gallium/drivers/zink/zink_draw.c

@@ -780,3 +780,29 @@ zink_draw_vbo(struct pipe_context *pctx,
    }
    batch->has_draw = true;
 }
+
+void
+zink_launch_grid(struct pipe_context *pctx, const struct pipe_grid_info *info)
+{
+   struct zink_context *ctx = zink_context(pctx);
+   struct zink_screen *screen = zink_screen(pctx->screen);
+   struct zink_batch *batch = &ctx->compute_batch;
+   struct zink_compute_program *comp_program = get_compute_program(ctx);
+   if (!comp_program)
+      return;
+
+   VkPipeline pipeline = zink_get_compute_pipeline(screen, comp_program,
+                                               &ctx->compute_pipeline_state);
+
+   update_descriptors(ctx, screen, true);
+
+
+   vkCmdBindPipeline(batch->cmdbuf, VK_PIPELINE_BIND_POINT_COMPUTE, pipeline);
+
+   if (info->indirect) {
+      vkCmdDispatchIndirect(batch->cmdbuf, zink_resource(info->indirect)->buffer, info->indirect_offset);
+      zink_batch_reference_resource_rw(batch, zink_resource(info->indirect), false);
+   } else
+      vkCmdDispatch(batch->cmdbuf, info->grid[0], info->grid[1], info->grid[2]);
+   batch->has_draw = true;
+}