From: Dragos Tatulea <dtatulea@nvidia.com>
Date: Wed, 27 Aug 2025 14:39:56 +0000 (+0300)
Subject: io_uring/zcrx: add support for custom DMA devices
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=59b8b32ac8d469958936fcea781c7f58e3d64742;p=users%2Fhch%2Fmisc.git

io_uring/zcrx: add support for custom DMA devices

Use the new API for getting a DMA device for a specific netdev queue.

This patch will allow io_uring zero-copy rx to work with devices
where the DMA device is not stored in the parent device. mlx5 SFs
are an example of such a device.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/20250827144017.1529208-4-dtatulea@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index e5ff49f3425e..319eddfd30e0 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -12,6 +12,7 @@
 #include <net/page_pool/helpers.h>
 #include <net/page_pool/memory_provider.h>
 #include <net/netlink.h>
+#include <net/netdev_queues.h>
 #include <net/netdev_rx_queue.h>
 #include <net/tcp.h>
 #include <net/rps.h>
@@ -599,7 +600,7 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx,
 		goto err;
 	}
 
-	ifq->dev = ifq->netdev->dev.parent;
+	ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, ifq->if_rxq);
 	if (!ifq->dev) {
 		ret = -EOPNOTSUPP;
 		goto err;