vulkan: Add dmabuf sync helpers from wlroots

These helpers are obtained from the wlroots project at
https://gitlab.freedesktop.org/wlroots/wlroots/

spa/plugins/vulkan/dmabuf_linux.c

@@ -0,0 +1,127 @@
+// Copyright (c) 2023 The wlroots contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// Obtained from https://gitlab.freedesktop.org/wlroots/wlroots/
+
+/* SPDX-FileCopyrightText: Copyright © 2023 The wlroots contributors */
+/* SPDX-License-Identifier: MIT */
+
+#include <linux/dma-buf.h>
+#include <linux/version.h>
+#include <stdlib.h>
+#include <sys/utsname.h>
+#include <xf86drm.h>
+#include <errno.h>
+
+#include <spa/support/log.h>
+#include <spa/utils/result.h>
+
+#include "dmabuf.h"
+
+bool dmabuf_check_sync_file_import_export(struct spa_log *log) {
+	/* Unfortunately there's no better way to check the availability of the
+	 * IOCTL than to check the kernel version. See the discussion at:
+	 * https://lore.kernel.org/dri-devel/20220601161303.64797-1-contact@emersion.fr/
+	 */
+
+	struct utsname utsname = {0};
+	if (uname(&utsname) != 0) {
+		spa_log_warn(log, "uname failed");
+		return false;
+	}
+
+	if (strcmp(utsname.sysname, "Linux") != 0) {
+		return false;
+	}
+
+	// Trim release suffix if any, e.g. "-arch1-1"
+	for (size_t i = 0; utsname.release[i] != '\0'; i++) {
+		char ch = utsname.release[i];
+		if ((ch < '0' || ch > '9') && ch != '.') {
+			utsname.release[i] = '\0';
+			break;
+		}
+	}
+
+	char *rel = strtok(utsname.release, ".");
+	int major = atoi(rel);
+
+	int minor = 0;
+	rel = strtok(NULL, ".");
+	if (rel != NULL) {
+		minor = atoi(rel);
+	}
+
+	int patch = 0;
+	rel = strtok(NULL, ".");
+	if (rel != NULL) {
+		patch = atoi(rel);
+	}
+
+	return KERNEL_VERSION(major, minor, patch) >= KERNEL_VERSION(5, 20, 0);
+}
+
+// TODO: drop these definitions once widespread
+
+#if !defined(DMA_BUF_IOCTL_IMPORT_SYNC_FILE)
+
+struct dma_buf_import_sync_file {
+	__u32 flags;
+	__s32 fd;
+};
+
+#define DMA_BUF_IOCTL_IMPORT_SYNC_FILE _IOW(DMA_BUF_BASE, 3, struct dma_buf_import_sync_file)
+
+#endif
+
+#if !defined(DMA_BUF_IOCTL_EXPORT_SYNC_FILE)
+
+struct dma_buf_export_sync_file {
+	__u32 flags;
+	__s32 fd;
+};
+
+#define DMA_BUF_IOCTL_EXPORT_SYNC_FILE _IOWR(DMA_BUF_BASE, 2, struct dma_buf_export_sync_file)
+
+#endif
+
+bool dmabuf_import_sync_file(struct spa_log *log, int dmabuf_fd, uint32_t flags, int sync_file_fd) {
+	struct dma_buf_import_sync_file data = {
+		.flags = flags,
+		.fd = sync_file_fd,
+	};
+	if (drmIoctl(dmabuf_fd, DMA_BUF_IOCTL_IMPORT_SYNC_FILE, &data) != 0) {
+		spa_log_error(log, "drmIoctl(IMPORT_SYNC_FILE) failed with %d (%s)", errno, spa_strerror(-errno));
+		return false;
+	}
+	return true;
+}
+
+int dmabuf_export_sync_file(struct spa_log *log, int dmabuf_fd, uint32_t flags) {
+	struct dma_buf_export_sync_file data = {
+		.flags = flags,
+		.fd = -1,
+	};
+	if (drmIoctl(dmabuf_fd, DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &data) != 0) {
+		spa_log_error(log, "drmIoctl(EXPORT_SYNC_FILE) failed with %d (%s)", errno, spa_strerror(-errno));
+		return -1;
+	}
+	return data.fd;
+}