+static void
+radv_render_pass_add_subpass_dep(struct radv_render_pass *pass,
+ const VkSubpassDependency2 *dep)
+{
+ uint32_t src = dep->srcSubpass;
+ uint32_t dst = dep->dstSubpass;
+
+ /* Ignore subpass self-dependencies as they allow the app to call
+ * vkCmdPipelineBarrier() inside the render pass and the driver should
+ * only do the barrier when called, not when starting the render pass.
+ */
+ if (src == dst)
+ return;
+
+ /* Accumulate all ingoing external dependencies to the first subpass. */
+ if (src == VK_SUBPASS_EXTERNAL)
+ dst = 0;
+
+ if (dst == VK_SUBPASS_EXTERNAL) {
+ if (dep->dstStageMask != VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT)
+ pass->end_barrier.src_stage_mask |= dep->srcStageMask;
+ pass->end_barrier.src_access_mask |= dep->srcAccessMask;
+ pass->end_barrier.dst_access_mask |= dep->dstAccessMask;
+ } else {
+ if (dep->dstStageMask != VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT)
+ pass->subpasses[dst].start_barrier.src_stage_mask |= dep->srcStageMask;
+ pass->subpasses[dst].start_barrier.src_access_mask |= dep->srcAccessMask;
+ pass->subpasses[dst].start_barrier.dst_access_mask |= dep->dstAccessMask;
+ }
+}
+
+static bool
+radv_pass_has_layout_transitions(const struct radv_render_pass *pass)
+{
+ for (unsigned i = 0; i < pass->subpass_count; i++) {
+ const struct radv_subpass *subpass = &pass->subpasses[i];
+ for (unsigned j = 0; j < subpass->attachment_count; j++) {
+ const uint32_t a = subpass->attachments[j].attachment;
+ if (a == VK_ATTACHMENT_UNUSED)
+ continue;
+
+ uint32_t initial_layout = pass->attachments[a].initial_layout;
+ uint32_t stencil_initial_layout = pass->attachments[a].stencil_initial_layout;
+ uint32_t final_layout = pass->attachments[a].final_layout;
+ uint32_t stencil_final_layout = pass->attachments[a].stencil_final_layout;
+
+ if (subpass->attachments[j].layout != initial_layout ||
+ subpass->attachments[j].layout != stencil_initial_layout ||
+ subpass->attachments[j].layout != final_layout ||
+ subpass->attachments[j].layout != stencil_final_layout)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static void
+radv_render_pass_add_implicit_deps(struct radv_render_pass *pass,
+ bool has_ingoing_dep, bool has_outgoing_dep)
+{
+ /* From the Vulkan 1.0.39 spec:
+ *
+ * If there is no subpass dependency from VK_SUBPASS_EXTERNAL to the
+ * first subpass that uses an attachment, then an implicit subpass
+ * dependency exists from VK_SUBPASS_EXTERNAL to the first subpass it is
+ * used in. The implicit subpass dependency only exists if there
+ * exists an automatic layout transition away from initialLayout.
+ * The subpass dependency operates as if defined with the
+ * following parameters:
+ *
+ * VkSubpassDependency implicitDependency = {
+ * .srcSubpass = VK_SUBPASS_EXTERNAL;
+ * .dstSubpass = firstSubpass; // First subpass attachment is used in
+ * .srcStageMask = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
+ * .dstStageMask = VK_PIPELINE_STAGE_ALL_COMMANDS_BIT;
+ * .srcAccessMask = 0;
+ * .dstAccessMask = VK_ACCESS_INPUT_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
+ * VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
+ * .dependencyFlags = 0;
+ * };
+ *
+ * Similarly, if there is no subpass dependency from the last subpass
+ * that uses an attachment to VK_SUBPASS_EXTERNAL, then an implicit
+ * subpass dependency exists from the last subpass it is used in to
+ * VK_SUBPASS_EXTERNAL. The implicit subpass dependency only exists
+ * if there exists an automatic layout transition into finalLayout.
+ * The subpass dependency operates as if defined with the following
+ * parameters:
+ *
+ * VkSubpassDependency implicitDependency = {
+ * .srcSubpass = lastSubpass; // Last subpass attachment is used in
+ * .dstSubpass = VK_SUBPASS_EXTERNAL;
+ * .srcStageMask = VK_PIPELINE_STAGE_ALL_COMMANDS_BIT;
+ * .dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
+ * .srcAccessMask = VK_ACCESS_INPUT_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
+ * VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT |
+ * VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
+ * .dstAccessMask = 0;
+ * .dependencyFlags = 0;
+ * };
+ */
+
+ /* Implicit subpass dependencies only make sense if automatic layout
+ * transitions are performed.
+ */
+ if (!radv_pass_has_layout_transitions(pass))
+ return;
+
+ if (!has_ingoing_dep) {
+ const VkSubpassDependency2KHR implicit_ingoing_dep = {
+ .srcSubpass = VK_SUBPASS_EXTERNAL,
+ .dstSubpass = 0,
+ .srcStageMask = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
+ .dstStageMask = VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
+ .srcAccessMask = 0,
+ .dstAccessMask = VK_ACCESS_INPUT_ATTACHMENT_READ_BIT |
+ VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
+ VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
+ VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT |
+ VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT,
+ .dependencyFlags = 0,
+ };
+
+ radv_render_pass_add_subpass_dep(pass, &implicit_ingoing_dep);
+ }
+
+ if (!has_outgoing_dep) {
+ const VkSubpassDependency2KHR implicit_outgoing_dep = {
+ .srcSubpass = 0,
+ .dstSubpass = VK_SUBPASS_EXTERNAL,
+ .srcStageMask = VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
+ .dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
+ .srcAccessMask = VK_ACCESS_INPUT_ATTACHMENT_READ_BIT |
+ VK_ACCESS_COLOR_ATTACHMENT_READ_BIT |
+ VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
+ VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT |
+ VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT,
+ .dstAccessMask = 0,
+ .dependencyFlags = 0,
+ };
+
+ radv_render_pass_add_subpass_dep(pass, &implicit_outgoing_dep);
+ }
+}
+