render/dmabuf: add dmabuf_import_sync_file

References: https://lore.kernel.org/dri-devel/20220506180216.2095060-1-jason@jlekstrand.net/

1 files changed, 75 insertions, 0 deletions

diff --git a/render/dmabuf_linux.c b/render/dmabuf_linux.c
new file mode 100644
index 00000000..a6bf1d42
--- /dev/null
+++ b/render/dmabuf_linux.c
@@ -0,0 +1,75 @@
+#include <linux/dma-buf.h>
+#include <linux/version.h>
+#include <stdlib.h>
+#include <sys/utsname.h>
+#include <wlr/util/log.h>
+#include <xf86drm.h>
+
+#include "render/dmabuf.h"
+
+bool dmabuf_check_sync_file_import_export(void) {
+	/* 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) {
+		wlr_log_errno(WLR_ERROR, "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
+
+bool dmabuf_import_sync_file(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) {
+		wlr_log_errno(WLR_ERROR, "drmIoctl(IMPORT_SYNC_FILE) failed");
+		return false;
+	}
+	return true;
+}