[RFC net-next 10/15] xsk: Add RX helpers for page-pool drivers
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From: Björn Töpel <bjorn@kernel.org>
Date: 2026-10-02 19:01:52
Also in:
bpf, io-uring, linux-doc, lkml
Subsystem:
networking [general], the rest, xdp sockets (af_xdp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Magnus Karlsson, Maciej Fijalkowski
A driver that uses an XSK pool as its page-pool provider must know whether the pool on a queue is the installed provider, or only registered on the queue. It also needs the scatter-gather setting of the pool. Add xsk_get_pool_from_rxq(), which returns the pool only while it is the queue's installed provider, and xsk_pool_uses_sg(). Name the 128-byte RX frame alignment XSK_RX_FRAME_SIZE_ALIGN. Add !CONFIG_XDP_SOCKETS stubs for the new helpers and for two frame-size helpers that had none, so drivers need no #ifdefs. Signed-off-by: Björn Töpel <bjorn@kernel.org> --- include/net/xdp_sock_drv.h | 46 +++++++++++++++++++++++++++++++++++++- net/xdp/xsk_buff_pool.c | 2 +- 2 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index b9288f5dd48b..28461e675b8e 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h@@ -6,6 +6,7 @@ #ifndef _LINUX_XDP_SOCK_DRV_H #define _LINUX_XDP_SOCK_DRV_H +#include <net/netdev_rx_queue.h> #include <net/xdp_sock.h> #include <net/xsk_buff_pool.h>
@@ -13,6 +14,7 @@ struct netlink_ext_ack; #define XDP_UMEM_MIN_CHUNK_SHIFT 11 #define XDP_UMEM_MIN_CHUNK_SIZE (1 << XDP_UMEM_MIN_CHUNK_SHIFT) +#define XSK_RX_FRAME_SIZE_ALIGN 128 #define NETDEV_XDP_ACT_XSK (NETDEV_XDP_ACT_BASIC | \ NETDEV_XDP_ACT_REDIRECT | \
@@ -34,12 +36,33 @@ int xsk_pool_setup_page_pool(struct net_device *dev, struct xsk_buff_pool *pool, u16 queue_id, struct netlink_ext_ack *extack); struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, u16 queue_id); + +/* Return the XSK pool only while it is the installed RX memory provider. */ +static inline struct xsk_buff_pool * +xsk_get_pool_from_rxq(struct net_device *dev, u16 queue_id) +{ + struct netdev_rx_queue *rxq; + struct xsk_buff_pool *pool; + + if (queue_id >= dev->real_num_rx_queues) + return NULL; + + rxq = __netif_get_rx_queue(dev, queue_id); + pool = rxq->pool; + return pool == rxq->mp_params.mp_priv ? pool : NULL; +} + void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool); void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool); void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool); void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool); bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool); +static inline bool xsk_pool_uses_sg(struct xsk_buff_pool *pool) +{ + return pool->umem->flags & XDP_UMEM_SG_FLAG; +} + static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool) { return XDP_PACKET_HEADROOM + pool->headroom;
@@ -73,7 +96,7 @@ static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) mbuf = pool->dev && (umem->flags & XDP_UMEM_SG_FLAG); frame_size -= xsk_pool_get_tailroom(mbuf); - return ALIGN_DOWN(frame_size, 128); + return ALIGN_DOWN(frame_size, XSK_RX_FRAME_SIZE_ALIGN); } static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool *pool)
@@ -388,6 +411,12 @@ xsk_get_pool_from_qid(struct net_device *dev, u16 queue_id) return NULL; } +static inline struct xsk_buff_pool * +xsk_get_pool_from_rxq(struct net_device *dev, u16 queue_id) +{ + return NULL; +} + static inline void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) { }
@@ -409,16 +438,31 @@ static inline bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) return false; } +static inline bool xsk_pool_uses_sg(struct xsk_buff_pool *pool) +{ + return false; +} + static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool) { return 0; } +static inline u32 xsk_pool_get_tailroom(bool mbuf) +{ + return 0; +} + static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool) { return 0; } +static inline u32 __xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) +{ + return 0; +} + static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) { return 0;
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index e25347f8c208..9c32fb165533 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c@@ -261,7 +261,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool, */ frame_size = __xsk_pool_get_rx_frame_size(pool) - xsk_pool_get_tailroom(mbuf); - frame_size = ALIGN_DOWN(frame_size, 128); + frame_size = ALIGN_DOWN(frame_size, XSK_RX_FRAME_SIZE_ALIGN); if (needed > frame_size * segs) { err = -EINVAL;
--
2.55.0