panvk/csf: Pass a non-zero flush-id to benefit from cache flush reduction

The cache flush reduction mechanism relies on the flush ID to
conditionally eliminate cache flush requests if another cache flush
happened between the time the flush ID was retrieved and the time
the flush operation happens.

Store the current flush ID at EndCommandBuffer() time, and pass it
back to the submit ioctl().

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31230>

src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c

@@ -148,6 +148,7 @@ VKAPI_ATTR VkResult VKAPI_CALL
 panvk_per_arch(EndCommandBuffer)(VkCommandBuffer commandBuffer)
 {
    VK_FROM_HANDLE(panvk_cmd_buffer, cmdbuf, commandBuffer);
+   struct panvk_device *dev = to_panvk_device(cmdbuf->vk.base.device);
 
    emit_tls(cmdbuf);
 
@@ -162,6 +163,8 @@ panvk_per_arch(EndCommandBuffer)(VkCommandBuffer commandBuffer)
       }
    }
 
+   cmdbuf->flush_id = panthor_kmod_get_flush_id(dev->kmod.dev);
+
    return vk_command_buffer_end(&cmdbuf->vk);
 }
 

src/panfrost/vulkan/csf/panvk_vX_queue.c

@@ -251,7 +251,7 @@ init_subqueue(struct panvk_queue *queue, enum panvk_subqueue_id subqueue)
       .queue_index = subqueue,
       .stream_size = cs_root_chunk_size(&b),
       .stream_addr = cs_root_chunk_gpu_addr(&b),
-      .latest_flush = 0,
+      .latest_flush = panthor_kmod_get_flush_id(dev->kmod.dev),
       .syncs = DRM_PANTHOR_OBJ_ARRAY(1, &syncop),
    };
    struct drm_panthor_group_submit gsubmit = {
@@ -568,7 +568,7 @@ panvk_queue_submit(struct vk_queue *vk_queue, struct vk_queue_submit *submit)
             .queue_index = j,
             .stream_size = cs_root_chunk_size(&cmdbuf->state.cs[j].builder),
             .stream_addr = cs_root_chunk_gpu_addr(&cmdbuf->state.cs[j].builder),
-            .latest_flush = 0,
+            .latest_flush = cmdbuf->flush_id,
          };
       }
    }