From: David Wei <dw@davidwei.uk>
Date: Thu, 13 Nov 2025 10:46:17 +0000 (+0000)
Subject: io_uring/zcrx: add io_fill_zcrx_offsets()
X-Git-Tag: v6.19-rc1~169^2~6^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0926f94ab36a6d76d07fa8f0934e65f5f66647ec;p=thirdparty%2Fkernel%2Flinux.git

io_uring/zcrx: add io_fill_zcrx_offsets()

Add a helper io_fill_zcrx_offsets() that sets the constant offsets in
struct io_uring_zcrx_offsets returned to userspace.

Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index 815992aff246d..da7e556c349ef 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -345,6 +345,13 @@ static void io_zcrx_get_niov_uref(struct net_iov *niov)
 	atomic_inc(io_get_user_counter(niov));
 }
 
+static void io_fill_zcrx_offsets(struct io_uring_zcrx_offsets *offsets)
+{
+	offsets->head = offsetof(struct io_uring, head);
+	offsets->tail = offsetof(struct io_uring, tail);
+	offsets->rqes = ALIGN(sizeof(struct io_uring), L1_CACHE_BYTES);
+}
+
 static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx,
 				 struct io_zcrx_ifq *ifq,
 				 struct io_uring_zcrx_ifq_reg *reg,
@@ -356,7 +363,8 @@ static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx,
 	void *ptr;
 	int ret;
 
-	off = ALIGN(sizeof(struct io_uring), L1_CACHE_BYTES);
+	io_fill_zcrx_offsets(&reg->offsets);
+	off = reg->offsets.rqes;
 	size = off + sizeof(struct io_uring_zcrx_rqe) * reg->rq_entries;
 	if (size > rd->size)
 		return -EINVAL;
@@ -372,9 +380,6 @@ static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx,
 	ifq->rq_ring = (struct io_uring *)ptr;
 	ifq->rqes = (struct io_uring_zcrx_rqe *)(ptr + off);
 
-	reg->offsets.head = offsetof(struct io_uring, head);
-	reg->offsets.tail = offsetof(struct io_uring, tail);
-	reg->offsets.rqes = off;
 	return 0;
 }