tx.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/* Copyright (C) 2024-2025 Intel Corporation */
  3
  4#ifndef __LIBETH_TX_H
  5#define __LIBETH_TX_H
  6
  7#include <linux/skbuff.h>
  8
  9#include <net/libeth/types.h>
 10
 11/* Tx buffer completion */
 12
 13/**
 14 * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion
 15 * @LIBETH_SQE_EMPTY: unused/empty OR XDP_TX/XSk frame, no action required
 16 * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required
 17 * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree()
 18 * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA
 19 * @LIBETH_SQE_SKB: &sk_buff, unmap and napi_consume_skb(), update stats
 20 * @__LIBETH_SQE_XDP_START: separator between skb and XDP types
 21 * @LIBETH_SQE_XDP_TX: &skb_shared_info, libeth_xdp_return_buff_bulk(), stats
 22 * @LIBETH_SQE_XDP_XMIT: &xdp_frame, unmap and xdp_return_frame_bulk(), stats
 23 * @LIBETH_SQE_XDP_XMIT_FRAG: &xdp_frame frag, only unmap DMA
 24 * @LIBETH_SQE_XSK_TX: &libeth_xdp_buff on XSk queue, xsk_buff_free(), stats
 25 * @LIBETH_SQE_XSK_TX_FRAG: &libeth_xdp_buff frag on XSk queue, xsk_buff_free()
 26 */
 27enum libeth_sqe_type {
 28	LIBETH_SQE_EMPTY		= 0U,
 29	LIBETH_SQE_CTX,
 30	LIBETH_SQE_SLAB,
 31	LIBETH_SQE_FRAG,
 32	LIBETH_SQE_SKB,
 33
 34	__LIBETH_SQE_XDP_START,
 35	LIBETH_SQE_XDP_TX		= __LIBETH_SQE_XDP_START,
 36	LIBETH_SQE_XDP_XMIT,
 37	LIBETH_SQE_XDP_XMIT_FRAG,
 38	LIBETH_SQE_XSK_TX,
 39	LIBETH_SQE_XSK_TX_FRAG,
 40};
 41
 42/**
 43 * struct libeth_sqe - represents a Send Queue Element / Tx buffer
 44 * @type: type of the buffer, see the enum above
 45 * @rs_idx: index of the last buffer from the batch this one was sent in
 46 * @raw: slab buffer to free via kfree()
 47 * @skb: &sk_buff to consume
 48 * @sinfo: skb shared info of an XDP_TX frame
 49 * @xdpf: XDP frame from ::ndo_xdp_xmit()
 50 * @xsk: XSk Rx frame from XDP_TX action
 51 * @dma: DMA address to unmap
 52 * @len: length of the mapped region to unmap
 53 * @nr_frags: number of frags in the frame this buffer belongs to
 54 * @packets: number of physical packets sent for this frame
 55 * @bytes: number of physical bytes sent for this frame
 56 * @priv: driver-private scratchpad
 57 */
 58struct libeth_sqe {
 59	enum libeth_sqe_type		type:32;
 60	u32				rs_idx;
 61
 62	union {
 63		void				*raw;
 64		struct sk_buff			*skb;
 65		struct skb_shared_info		*sinfo;
 66		struct xdp_frame		*xdpf;
 67		struct libeth_xdp_buff		*xsk;
 68	};
 69
 70	DEFINE_DMA_UNMAP_ADDR(dma);
 71	DEFINE_DMA_UNMAP_LEN(len);
 72
 73	u32				nr_frags;
 74	u32				packets;
 75	u32				bytes;
 76
 77	unsigned long			priv;
 78} __aligned_largest;
 79
 80/**
 81 * LIBETH_SQE_CHECK_PRIV - check the driver's private SQE data
 82 * @p: type or name of the object the driver wants to fit into &libeth_sqe
 83 *
 84 * Make sure the driver's private data fits into libeth_sqe::priv. To be used
 85 * right after its declaration.
 86 */
 87#define LIBETH_SQE_CHECK_PRIV(p)					  \
 88	static_assert(sizeof(p) <= sizeof_field(struct libeth_sqe, priv))
 89
 90/**
 91 * struct libeth_cq_pp - completion queue poll params
 92 * @dev: &device to perform DMA unmapping
 93 * @bq: XDP frame bulk to combine return operations
 94 * @ss: onstack NAPI stats to fill
 95 * @xss: onstack XDPSQ NAPI stats to fill
 96 * @xdp_tx: number of XDP-not-XSk frames processed
 97 * @napi: whether it's called from the NAPI context
 98 *
 99 * libeth uses this structure to access objects needed for performing full
100 * Tx complete operation without passing lots of arguments and change the
101 * prototypes each time a new one is added.
102 */
103struct libeth_cq_pp {
104	struct device			*dev;
105	struct xdp_frame_bulk		*bq;
106
107	union {
108		struct libeth_sq_napi_stats	*ss;
109		struct libeth_xdpsq_napi_stats	*xss;
110	};
111	u32				xdp_tx;
112
113	bool				napi;
114};
115
116/**
117 * libeth_tx_complete - perform Tx completion for one SQE
118 * @sqe: SQE to complete
119 * @cp: poll params
120 *
121 * Do Tx complete for all the types of buffers, incl. freeing, unmapping,
122 * updating the stats etc.
123 */
124static inline void libeth_tx_complete(struct libeth_sqe *sqe,
125				      const struct libeth_cq_pp *cp)
126{
127	switch (sqe->type) {
128	case LIBETH_SQE_EMPTY:
129		return;
130	case LIBETH_SQE_SKB:
131	case LIBETH_SQE_FRAG:
132	case LIBETH_SQE_SLAB:
133		dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma),
134			       dma_unmap_len(sqe, len), DMA_TO_DEVICE);
135		break;
136	default:
137		break;
138	}
139
140	switch (sqe->type) {
141	case LIBETH_SQE_SKB:
142		cp->ss->packets += sqe->packets;
143		cp->ss->bytes += sqe->bytes;
144
145		napi_consume_skb(sqe->skb, cp->napi);
146		break;
147	case LIBETH_SQE_SLAB:
148		kfree(sqe->raw);
149		break;
150	default:
151		break;
152	}
153
154	sqe->type = LIBETH_SQE_EMPTY;
155}
156
157void libeth_tx_complete_any(struct libeth_sqe *sqe, struct libeth_cq_pp *cp);
158
159#endif /* __LIBETH_TX_H */