[PATCH 1/1] io_uring/zcrx: move zcrx uapi into separate header

[PATCH 1/1] io_uring/zcrx: move zcrx uapi into separate header

[Pavel Begunkov]

Split out zcrx uapi into a separate file. It'll be easier to manage it
this way, and that reduces the size of a not so small io_uring.h. Since
there are users that expect that zcrx definitions come with io_uring.h,
it includes the new file.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---

Depends on the patch that added querying zcrx features


 include/uapi/linux/io_uring.h      |  96 +------------------------
 include/uapi/linux/io_uring/zcrx.h | 108 +++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+), 94 deletions(-)
 create mode 100644 include/uapi/linux/io_uring/zcrx.h

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 6750c383a2ab..7a70ec70ff04 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -10,6 +10,8 @@
 
 #include <linux/fs.h>
 #include <linux/types.h>
+#include <linux/io_uring/zcrx.h>
+
 /*
  * this file is shared with liburing and that has to autodetect
  * if linux/time_types.h is available or not, it can
@@ -1049,100 +1051,6 @@ struct io_timespec {
 	__u64		tv_nsec;
 };
 
-/* Zero copy receive refill queue entry */
-struct io_uring_zcrx_rqe {
-	__u64	off;
-	__u32	len;
-	__u32	__pad;
-};
-
-struct io_uring_zcrx_cqe {
-	__u64	off;
-	__u64	__pad;
-};
-
-/* The bit from which area id is encoded into offsets */
-#define IORING_ZCRX_AREA_SHIFT	48
-#define IORING_ZCRX_AREA_MASK	(~(((__u64)1 << IORING_ZCRX_AREA_SHIFT) - 1))
-
-struct io_uring_zcrx_offsets {
-	__u32	head;
-	__u32	tail;
-	__u32	rqes;
-	__u32	__resv2;
-	__u64	__resv[2];
-};
-
-enum io_uring_zcrx_area_flags {
-	IORING_ZCRX_AREA_DMABUF		= 1,
-};
-
-struct io_uring_zcrx_area_reg {
-	__u64	addr;
-	__u64	len;
-	__u64	rq_area_token;
-	__u32	flags;
-	__u32	dmabuf_fd;
-	__u64	__resv2[2];
-};
-
-enum zcrx_reg_flags {
-	ZCRX_REG_IMPORT	= 1,
-};
-
-enum zcrx_features {
-	/*
-	 * The user can ask for the desired rx page size by passing the
-	 * value in struct io_uring_zcrx_ifq_reg::rx_buf_len.
-	 */
-	ZCRX_FEATURE_RX_PAGE_SIZE	= 1 << 0,
-};
-
-/*
- * Argument for IORING_REGISTER_ZCRX_IFQ
- */
-struct io_uring_zcrx_ifq_reg {
-	__u32	if_idx;
-	__u32	if_rxq;
-	__u32	rq_entries;
-	__u32	flags;
-
-	__u64	area_ptr; /* pointer to struct io_uring_zcrx_area_reg */
-	__u64	region_ptr; /* struct io_uring_region_desc * */
-
-	struct io_uring_zcrx_offsets offsets;
-	__u32	zcrx_id;
-	__u32	rx_buf_len;
-	__u64	__resv[3];
-};
-
-enum zcrx_ctrl_op {
-	ZCRX_CTRL_FLUSH_RQ,
-	ZCRX_CTRL_EXPORT,
-
-	__ZCRX_CTRL_LAST,
-};
-
-struct zcrx_ctrl_flush_rq {
-	__u64		__resv[6];
-};
-
-struct zcrx_ctrl_export {
-	__u32		zcrx_fd;
-	__u32 		__resv1[11];
-};
-
-struct zcrx_ctrl {
-	__u32	zcrx_id;
-	__u32	op; /* see enum zcrx_ctrl_op */
-	__u64	__resv[2];
-
-	union {
-		struct zcrx_ctrl_export		zc_export;
-		struct zcrx_ctrl_flush_rq	zc_flush;
-	};
-};
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/uapi/linux/io_uring/zcrx.h b/include/uapi/linux/io_uring/zcrx.h
new file mode 100644
index 000000000000..3163a4b8aeb0
--- /dev/null
+++ b/include/uapi/linux/io_uring/zcrx.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
+/*
+ * Header file for the io_uring zerocopy receive (zcrx) interface.
+ *
+ * Copyright (C) 2026 Pavel Begunkov
+ * Copyright (C) 2026 David Wei
+ * Copyright (C) Meta Platforms, Inc.
+ */
+#ifndef LINUX_IO_ZCRX_H
+#define LINUX_IO_ZCRX_H
+
+#include <linux/types.h>
+
+/* Zero copy receive refill queue entry */
+struct io_uring_zcrx_rqe {
+	__u64	off;
+	__u32	len;
+	__u32	__pad;
+};
+
+struct io_uring_zcrx_cqe {
+	__u64	off;
+	__u64	__pad;
+};
+
+/* The bit from which area id is encoded into offsets */
+#define IORING_ZCRX_AREA_SHIFT	48
+#define IORING_ZCRX_AREA_MASK	(~(((__u64)1 << IORING_ZCRX_AREA_SHIFT) - 1))
+
+struct io_uring_zcrx_offsets {
+	__u32	head;
+	__u32	tail;
+	__u32	rqes;
+	__u32	__resv2;
+	__u64	__resv[2];
+};
+
+enum io_uring_zcrx_area_flags {
+	IORING_ZCRX_AREA_DMABUF		= 1,
+};
+
+struct io_uring_zcrx_area_reg {
+	__u64	addr;
+	__u64	len;
+	__u64	rq_area_token;
+	__u32	flags;
+	__u32	dmabuf_fd;
+	__u64	__resv2[2];
+};
+
+enum zcrx_reg_flags {
+	ZCRX_REG_IMPORT	= 1,
+};
+
+enum zcrx_features {
+	/*
+	 * The user can ask for the desired rx page size by passing the
+	 * value in struct io_uring_zcrx_ifq_reg::rx_buf_len.
+	 */
+	ZCRX_FEATURE_RX_PAGE_SIZE	= 1 << 0,
+};
+
+/*
+ * Argument for IORING_REGISTER_ZCRX_IFQ
+ */
+struct io_uring_zcrx_ifq_reg {
+	__u32	if_idx;
+	__u32	if_rxq;
+	__u32	rq_entries;
+	__u32	flags;
+
+	__u64	area_ptr; /* pointer to struct io_uring_zcrx_area_reg */
+	__u64	region_ptr; /* struct io_uring_region_desc * */
+
+	struct io_uring_zcrx_offsets offsets;
+	__u32	zcrx_id;
+	__u32	rx_buf_len;
+	__u64	__resv[3];
+};
+
+enum zcrx_ctrl_op {
+	ZCRX_CTRL_FLUSH_RQ,
+	ZCRX_CTRL_EXPORT,
+
+	__ZCRX_CTRL_LAST,
+};
+
+struct zcrx_ctrl_flush_rq {
+	__u64		__resv[6];
+};
+
+struct zcrx_ctrl_export {
+	__u32		zcrx_fd;
+	__u32 		__resv1[11];
+};
+
+struct zcrx_ctrl {
+	__u32	zcrx_id;
+	__u32	op; /* see enum zcrx_ctrl_op */
+	__u64	__resv[2];
+
+	union {
+		struct zcrx_ctrl_export		zc_export;
+		struct zcrx_ctrl_flush_rq	zc_flush;
+	};
+};
+
+#endif /* LINUX_IO_ZCRX_H */
-- 
2.52.0