Commit 035af94b authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/zcrx: grab a net device 



Zerocopy receive needs a net device to bind to its rx queue and dma map
buffers. As a preparation to following patches, resolve a net device
from the if_idx parameter with no functional changes otherwise.

Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarDavid Wei <dw@davidwei.uk>
Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20250215000947.789731-4-dw@davidwei.uk


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent cf96310c

io_uring/zcrx.c

+28 −0
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 
#include <linux/errno.h>

#include <linux/mm.h>

#include <linux/io_uring.h>

#include <linux/netdevice.h>

#include <linux/rtnetlink.h>



#include <uapi/linux/io_uring.h>
@@ -128,13 +130,28 @@ static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) 


	ifq->if_rxq = -1;

	ifq->ctx = ctx;

	spin_lock_init(&ifq->lock);

	return ifq;

}



static void io_zcrx_drop_netdev(struct io_zcrx_ifq *ifq)

{

	spin_lock(&ifq->lock);

	if (ifq->netdev) {

		netdev_put(ifq->netdev, &ifq->netdev_tracker);

		ifq->netdev = NULL;

	}

	spin_unlock(&ifq->lock);

}



static void io_zcrx_ifq_free(struct io_zcrx_ifq *ifq)

{

	io_zcrx_drop_netdev(ifq);



	if (ifq->area)

		io_zcrx_free_area(ifq->area);

	if (ifq->dev)

		put_device(ifq->dev);



	io_free_rbuf_ring(ifq);

	kfree(ifq);
@@ -195,6 +212,17 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx, 
	ifq->rq_entries = reg.rq_entries;

	ifq->if_rxq = reg.if_rxq;



	ret = -ENODEV;

	ifq->netdev = netdev_get_by_index(current->nsproxy->net_ns, reg.if_idx,

					  &ifq->netdev_tracker, GFP_KERNEL);

	if (!ifq->netdev)

		goto err;



	ifq->dev = ifq->netdev->dev.parent;

	if (!ifq->dev)

		return -EOPNOTSUPP;

	get_device(ifq->dev);



	reg.offsets.rqes = sizeof(struct io_uring);

	reg.offsets.head = offsetof(struct io_uring, head);

	reg.offsets.tail = offsetof(struct io_uring, tail);

io_uring/zcrx.h

+5 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <linux/io_uring_types.h>

#include <net/page_pool/types.h>

#include <net/net_trackers.h>



struct io_zcrx_area {

	struct net_iov_area	nia;
@@ -27,6 +28,10 @@ struct io_zcrx_ifq { 
	u32				rq_entries;



	u32				if_rxq;

	struct device			*dev;

	struct net_device		*netdev;

	netdevice_tracker		netdev_tracker;

	spinlock_t			lock;

};



#if defined(CONFIG_IO_URING_ZCRX)