From a377d32fdc4dd878497fabe6d338f6862c198b29 Mon Sep 17 00:00:00 2001
From: Emma Anholt <emma@anholt.net>
Date: Mon, 31 Oct 2022 13:44:29 -0700
Subject: [PATCH] vulkan/wsi: Add a test for kernel 6.0 sync file import/export
 ioctls.

We'll use this in DRM WSI to decide if we need the implicit_sync flag on
swapchain image creation.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19309>
---
 src/vulkan/wsi/wsi_common.h         |  3 ++
 src/vulkan/wsi/wsi_common_drm.c     | 78 +++++++++++++++++++++++++++++
 src/vulkan/wsi/wsi_common_private.h |  1 +
 3 files changed, 82 insertions(+)

diff --git a/src/vulkan/wsi/wsi_common.h b/src/vulkan/wsi/wsi_common.h
index 6e714debd95..e3764939292 100644
--- a/src/vulkan/wsi/wsi_common.h
+++ b/src/vulkan/wsi/wsi_common.h
@@ -122,6 +122,9 @@ struct wsi_device {
    VkPresentModeKHR override_present_mode;
    bool force_bgra8_unorm_first;
 
+   /* Cached result for wsi_drm_check_dma_buf_sync_file_import_export(). */
+   uint32_t cached_sync_file_import_export_result;
+
    /* Whether to enable adaptive sync for a swapchain if implemented and
     * available. Not all window systems might support this. */
    bool enable_adaptive_sync;
diff --git a/src/vulkan/wsi/wsi_common_drm.c b/src/vulkan/wsi/wsi_common_drm.c
index d4013ed51a4..099c3150c29 100644
--- a/src/vulkan/wsi/wsi_common_drm.c
+++ b/src/vulkan/wsi/wsi_common_drm.c
@@ -24,8 +24,10 @@
 #include "wsi_common_private.h"
 #include "wsi_common_drm.h"
 #include "util/macros.h"
+#include "util/log.h"
 #include "util/os_file.h"
 #include "util/log.h"
+#include "util/u_atomic.h"
 #include "util/xmlconfig.h"
 #include "vk_device.h"
 #include "vk_physical_device.h"
@@ -96,6 +98,82 @@ wsi_dma_buf_import_sync_file(int dma_buf_fd, int sync_file_fd)
    return VK_SUCCESS;
 }
 
+/**
+ * Returns whether we can do import/export of fences from dma-bufs.
+ *
+ * This should return success on linux 6.0+.
+ */
+static VkResult
+wsi_drm_check_dma_buf_sync_file_import_export(const struct wsi_device *wsi, VkDevice device)
+{
+   /* Not doing a mutex here -- we may race to do the check twice, but it's
+    * lockless normally.
+    */
+   uint32_t cached_result = p_atomic_read(&wsi->cached_sync_file_import_export_result);
+   if (likely(cached_result != 0))
+      return (VkResult) (cached_result + 1);
+
+   struct VkExportMemoryAllocateInfo export_info = {
+       .sType = VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO,
+       .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT,
+   };
+   struct VkMemoryAllocateInfo mem_info = {
+       .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+       .allocationSize = 4096,
+       .pNext = (void *)&export_info};
+   VkResult result;
+   VkDeviceMemory mem;
+   result = wsi->AllocateMemory(device, &mem_info, NULL, &mem);
+   if (result != VK_SUCCESS)
+   {
+      mesa_logd("wsi: failed to create memory for dma-buf sync import/export test.");
+      goto out;
+   }
+
+   int fd;
+   struct VkMemoryGetFdInfoKHR get_info = {
+       .sType = VK_STRUCTURE_TYPE_MEMORY_GET_FD_INFO_KHR,
+       .memory = mem,
+       .handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT,
+   };
+   result = wsi->GetMemoryFdKHR(device, &get_info, &fd);
+   if (result != VK_SUCCESS)
+   {
+      mesa_logd("wsi: failed to dma-buf fd for sync import/export test.");
+      goto free_mem;
+   }
+
+   int sync_file;
+   result = wsi_dma_buf_export_sync_file(fd, &sync_file);
+   if (result != VK_SUCCESS)
+   {
+      mesa_logd("wsi: failed export sync file from dma-buf fd.");
+      goto free_fd;
+   }
+
+   result = wsi_dma_buf_import_sync_file(fd, sync_file);
+   if (result != VK_SUCCESS)
+   {
+      mesa_logd("wsi: failed import sync file to dma-buf fd.");
+      goto free_sync_file;
+   }
+
+   mesa_logd("Found support for dma-buf sync import/export");
+
+free_sync_file:
+   close(sync_file);
+free_fd:
+   close(fd);
+free_mem:
+   wsi->FreeMemory(device, mem, NULL);
+out:
+   /* We can ignore const here -- this field is managed entirely by this
+    * function, in an atomic manner.
+    */
+   p_atomic_set(&((struct wsi_device *)wsi)->cached_sync_file_import_export_result, result - 1);
+   return result;
+}
+
 static VkResult
 prepare_signal_dma_buf_from_semaphore(struct wsi_swapchain *chain,
                                       const struct wsi_image *image)
diff --git a/src/vulkan/wsi/wsi_common_private.h b/src/vulkan/wsi/wsi_common_private.h
index d523202fcda..2bc24435d84 100644
--- a/src/vulkan/wsi/wsi_common_private.h
+++ b/src/vulkan/wsi/wsi_common_private.h
@@ -408,6 +408,7 @@ wsi_drm_wait_for_explicit_sync_release(struct wsi_swapchain *chain,
                                        struct wsi_image **images,
                                        uint64_t rel_timeout_ns,
                                        uint32_t *image_index);
+
 #endif
 
 struct wsi_interface {