tu: Implement VK_EXT_attachment_feedback_loop_layout

Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18064>

docs/features.txt

@@ -532,6 +532,7 @@ Khronos extensions that are not part of any Vulkan version:
   VK_KHR_win32_surface                                  DONE (dzn, lvp)
   VK_KHR_xcb_surface                                    DONE (anv, dzn, lvp, radv, tu, v3dv, vn)
   VK_KHR_xlib_surface                                   DONE (anv, dzn, lvp, radv, tu, v3dv, vn)
+  VK_EXT_attachment_feedback_loop_layout                DONE (radv, tu)
   VK_EXT_border_color_swizzle                           DONE (anv, lvp, tu, radv/gfx10+)
   VK_EXT_buffer_device_address                          DONE (anv/gen8+, radv)
   VK_EXT_calibrated_timestamps                          DONE (anv, lvp, radv, vn)

src/freedreno/vulkan/tu_cmd_buffer.c

@@ -2561,6 +2561,25 @@ tu_CmdBindPipeline(VkCommandBuffer commandBuffer,
    cmd->state.dirty |= TU_CMD_DIRTY_DESC_SETS_LOAD | TU_CMD_DIRTY_SHADER_CONSTS |
                        TU_CMD_DIRTY_LRZ | TU_CMD_DIRTY_VS_PARAMS;
 
+   if (pipeline->feedback_loop_may_involve_textures) {
+      /* VK_EXT_attachment_feedback_loop_layout allows feedback loop to involve
+       * not only input attachments but also sampled images or image resources.
+       * But we cannot just patch gmem for image in the descriptors.
+       *
+       * At the moment, in context of DXVK, it is expected that only a few
+       * drawcalls in a frame would use feedback loop and they would be wrapped
+       * in their own renderpasses, so it should be ok to force sysmem.
+       *
+       * However, there are two further possible optimizations if need would
+       * arise for other translation layer:
+       * - Tiling could be enabled if we ensure that there is no barrier in
+       *   the renderpass;
+       * - Check that both pipeline and attachments agree that feedback loop
+       *   is needed.
+       */
+      cmd->state.rp.disable_gmem = true;
+   }
+
    struct tu_cs *cs = &cmd->draw_cs;
 
    /* note: this also avoids emitting draw states before renderpass clears,

src/freedreno/vulkan/tu_device.c

@@ -213,6 +213,7 @@ get_device_extensions(const struct tu_physical_device *device,
       .EXT_pipeline_creation_feedback = true,
       .EXT_pipeline_creation_cache_control = true,
       .EXT_vertex_input_dynamic_state = true,
+      .EXT_attachment_feedback_loop_layout = true,
 #ifndef TU_USE_KGSL
       .EXT_physical_device_drm = true,
 #endif
@@ -926,6 +927,12 @@ tu_GetPhysicalDeviceFeatures2(VkPhysicalDevice physicalDevice,
          features->nonSeamlessCubeMap = true;
          break;
       }
+      case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ATTACHMENT_FEEDBACK_LOOP_LAYOUT_FEATURES_EXT: {
+         VkPhysicalDeviceAttachmentFeedbackLoopLayoutFeaturesEXT *features =
+            (VkPhysicalDeviceAttachmentFeedbackLoopLayoutFeaturesEXT*)ext;
+         features->attachmentFeedbackLoopLayout = true;
+         break;
+      }
 
       default:
          break;

src/freedreno/vulkan/tu_pipeline.c

@@ -270,6 +270,7 @@ struct tu_pipeline_builder
    bool subpass_raster_order_attachment_access;
    bool subpass_feedback_loop_color;
    bool subpass_feedback_loop_ds;
+   bool feedback_loop_may_involve_textures;
 };
 
 static bool
@@ -3438,6 +3439,9 @@ tu_pipeline_builder_parse_rasterization(struct tu_pipeline_builder *builder,
    const VkPipelineRasterizationStateCreateInfo *rast_info =
       builder->create_info->pRasterizationState;
 
+   pipeline->feedback_loop_may_involve_textures =
+      builder->feedback_loop_may_involve_textures;
+
    enum a6xx_polygon_mode mode = tu6_polygon_mode(rast_info->polygonMode);
 
    builder->depth_clip_disable = rast_info->depthClampEnable;
@@ -4053,6 +4057,15 @@ tu_pipeline_builder_init_graphics(
       }
    }
 
+   if (builder->create_info->flags & VK_PIPELINE_CREATE_COLOR_ATTACHMENT_FEEDBACK_LOOP_BIT_EXT) {
+      builder->subpass_feedback_loop_color = true;
+      builder->feedback_loop_may_involve_textures = true;
+   }
+
+   if (builder->create_info->flags & VK_PIPELINE_CREATE_DEPTH_STENCIL_ATTACHMENT_FEEDBACK_LOOP_BIT_EXT) {
+      builder->subpass_feedback_loop_ds = true;
+      builder->feedback_loop_may_involve_textures = true;
+   }
 
    if (builder->rasterizer_discard) {
       builder->samples = VK_SAMPLE_COUNT_1_BIT;

src/freedreno/vulkan/tu_pipeline.h

@@ -191,6 +191,7 @@ struct tu_pipeline
    /* In other words - framebuffer fetch support */
    bool raster_order_attachment_access;
    bool subpass_feedback_loop_ds;
+   bool feedback_loop_may_involve_textures;
 
    bool z_negative_one_to_one;