xdp_sock_drv.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/* Interface for implementing AF_XDP zero-copy support in drivers.
  3 * Copyright(c) 2020 Intel Corporation.
  4 */
  5
  6#ifndef _LINUX_XDP_SOCK_DRV_H
  7#define _LINUX_XDP_SOCK_DRV_H
  8
  9#include <net/xdp_sock.h>
 10#include <net/xsk_buff_pool.h>
 11
 12#define XDP_UMEM_MIN_CHUNK_SHIFT 11
 13#define XDP_UMEM_MIN_CHUNK_SIZE (1 << XDP_UMEM_MIN_CHUNK_SHIFT)
 14
 15#define NETDEV_XDP_ACT_XSK	(NETDEV_XDP_ACT_BASIC |		\
 16				 NETDEV_XDP_ACT_REDIRECT |	\
 17				 NETDEV_XDP_ACT_XSK_ZEROCOPY)
 18
 19struct xsk_cb_desc {
 20	void *src;
 21	u8 off;
 22	u8 bytes;
 23};
 24
 25#ifdef CONFIG_XDP_SOCKETS
 26
 27void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries);
 28bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc);
 29u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max);
 30void xsk_tx_release(struct xsk_buff_pool *pool);
 31struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
 32					    u16 queue_id);
 33void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool);
 34void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool);
 35void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool);
 36void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool);
 37bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool);
 38
 39static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool)
 40{
 41	return XDP_PACKET_HEADROOM + pool->headroom;
 42}
 43
 44static inline u32 xsk_pool_get_tailroom(bool mbuf)
 45{
 46	return mbuf ? SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) : 0;
 47}
 48
 49static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool)
 50{
 51	return pool->chunk_size;
 52}
 53
 54static inline u32 __xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
 55{
 56	return xsk_pool_get_chunk_size(pool) - xsk_pool_get_headroom(pool);
 57}
 58
 59static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
 60{
 61	u32 frame_size =  __xsk_pool_get_rx_frame_size(pool);
 62	struct xdp_umem *umem = pool->umem;
 63	bool mbuf;
 64
 65	/* Reserve tailroom only for zero-copy pools that opted into
 66	 * multi-buffer. The reserved area is used for skb_shared_info,
 67	 * matching the XDP core's xdp_data_hard_end() layout.
 68	 */
 69	mbuf = pool->dev && (umem->flags & XDP_UMEM_SG_FLAG);
 70	frame_size -= xsk_pool_get_tailroom(mbuf);
 71
 72	return ALIGN_DOWN(frame_size, 128);
 73}
 74
 75static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool *pool)
 76{
 77	return pool->unaligned ? 0 : xsk_pool_get_chunk_size(pool);
 78}
 79
 80static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
 81					 struct xdp_rxq_info *rxq)
 82{
 83	xp_set_rxq_info(pool, rxq);
 84}
 85
 86static inline void xsk_pool_fill_cb(struct xsk_buff_pool *pool,
 87				    struct xsk_cb_desc *desc)
 88{
 89	xp_fill_cb(pool, desc);
 90}
 91
 92static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool,
 93				      unsigned long attrs)
 94{
 95	xp_dma_unmap(pool, attrs);
 96}
 97
 98static inline int xsk_pool_dma_map(struct xsk_buff_pool *pool,
 99				   struct device *dev, unsigned long attrs)
100{
101	struct xdp_umem *umem = pool->umem;
102
103	return xp_dma_map(pool, dev, attrs, umem->pgs, umem->npgs);
104}
105
106static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
107{
108	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
109
110	return xp_get_dma(xskb);
111}
112
113static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
114{
115	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
116
117	return xp_get_frame_dma(xskb);
118}
119
120static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool)
121{
122	return xp_alloc(pool);
123}
124
125static inline bool xsk_is_eop_desc(const struct xdp_desc *desc)
126{
127	return !xp_mb_desc(desc);
128}
129
130/* Returns as many entries as possible up to max. 0 <= N <= max. */
131static inline u32 xsk_buff_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
132{
133	return xp_alloc_batch(pool, xdp, max);
134}
135
136static inline bool xsk_buff_can_alloc(struct xsk_buff_pool *pool, u32 count)
137{
138	return xp_can_alloc(pool, count);
139}
140
141static inline void xsk_buff_free(struct xdp_buff *xdp)
142{
143	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
144	struct list_head *xskb_list = &xskb->pool->xskb_list;
145	struct xdp_buff_xsk *pos, *tmp;
146
147	if (likely(!xdp_buff_has_frags(xdp)))
148		goto out;
149
150	list_for_each_entry_safe(pos, tmp, xskb_list, list_node) {
151		list_del_init(&pos->list_node);
152		xp_free(pos);
153	}
154
155	xdp_get_shared_info_from_buff(xdp)->nr_frags = 0;
156out:
157	xp_free(xskb);
158}
159
160static inline bool xsk_buff_add_frag(struct xdp_buff *head,
161				     struct xdp_buff *xdp)
162{
163	const void *data = xdp->data;
164	struct xdp_buff_xsk *frag;
165
166	if (!__xdp_buff_add_frag(head, virt_to_netmem(data),
167				 offset_in_page(data), xdp->data_end - data,
168				 xdp->frame_sz, false))
169		return false;
170
171	frag = container_of(xdp, struct xdp_buff_xsk, xdp);
172	list_add_tail(&frag->list_node, &frag->pool->xskb_list);
173
174	return true;
175}
176
177static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
178{
179	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
180	struct xdp_buff *ret = NULL;
181	struct xdp_buff_xsk *frag;
182
183	frag = list_first_entry_or_null(&xskb->pool->xskb_list,
184					struct xdp_buff_xsk, list_node);
185	if (frag) {
186		list_del_init(&frag->list_node);
187		ret = &frag->xdp;
188	}
189
190	return ret;
191}
192
193static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
194{
195	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
196
197	list_del_init(&xskb->list_node);
198}
199
200static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
201{
202	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
203	struct xdp_buff_xsk *frag;
204
205	frag = list_first_entry(&xskb->pool->xskb_list, struct xdp_buff_xsk,
206				list_node);
207	return &frag->xdp;
208}
209
210static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)
211{
212	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
213	struct xdp_buff_xsk *frag;
214
215	frag = list_last_entry(&xskb->pool->xskb_list, struct xdp_buff_xsk,
216			       list_node);
217	return &frag->xdp;
218}
219
220static inline void xsk_buff_set_size(struct xdp_buff *xdp, u32 size)
221{
222	xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
223	xdp->data_meta = xdp->data;
224	xdp->data_end = xdp->data + size;
225	xdp->flags = 0;
226}
227
228static inline dma_addr_t xsk_buff_raw_get_dma(struct xsk_buff_pool *pool,
229					      u64 addr)
230{
231	return xp_raw_get_dma(pool, addr);
232}
233
234static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
235{
236	return xp_raw_get_data(pool, addr);
237}
238
239/**
240 * xsk_buff_raw_get_ctx - get &xdp_desc context
241 * @pool: XSk buff pool desc address belongs to
242 * @addr: desc address (from userspace)
243 *
244 * Wrapper for xp_raw_get_ctx() to be used in drivers, see its kdoc for
245 * details.
246 *
247 * Return: new &xdp_desc_ctx struct containing desc's DMA address and metadata
248 * pointer, if it is present and valid (initialized to %NULL otherwise).
249 */
250static inline struct xdp_desc_ctx
251xsk_buff_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr)
252{
253	return xp_raw_get_ctx(pool, addr);
254}
255
256#define XDP_TXMD_FLAGS_VALID ( \
257		XDP_TXMD_FLAGS_TIMESTAMP | \
258		XDP_TXMD_FLAGS_CHECKSUM | \
259		XDP_TXMD_FLAGS_LAUNCH_TIME | \
260	0)
261
262static inline bool
263xsk_buff_valid_tx_metadata(const struct xsk_tx_metadata *meta)
264{
265	return !(meta->flags & ~XDP_TXMD_FLAGS_VALID);
266}
267
268static inline struct xsk_tx_metadata *
269__xsk_buff_get_metadata(const struct xsk_buff_pool *pool, void *data)
270{
271	struct xsk_tx_metadata *meta;
272
273	if (!pool->tx_metadata_len)
274		return NULL;
275
276	meta = data - pool->tx_metadata_len;
277	if (unlikely(!xsk_buff_valid_tx_metadata(meta)))
278		return NULL; /* no way to signal the error to the user */
279
280	return meta;
281}
282
283static inline struct xsk_tx_metadata *
284xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
285{
286	return __xsk_buff_get_metadata(pool, xp_raw_get_data(pool, addr));
287}
288
289static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
290{
291	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
292
293	xp_dma_sync_for_cpu(xskb);
294}
295
296static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
297						    dma_addr_t dma,
298						    size_t size)
299{
300	xp_dma_sync_for_device(pool, dma, size);
301}
302
303#else
304
305static inline void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
306{
307}
308
309static inline bool xsk_tx_peek_desc(struct xsk_buff_pool *pool,
310				    struct xdp_desc *desc)
311{
312	return false;
313}
314
315static inline u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max)
316{
317	return 0;
318}
319
320static inline void xsk_tx_release(struct xsk_buff_pool *pool)
321{
322}
323
324static inline struct xsk_buff_pool *
325xsk_get_pool_from_qid(struct net_device *dev, u16 queue_id)
326{
327	return NULL;
328}
329
330static inline void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
331{
332}
333
334static inline void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
335{
336}
337
338static inline void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
339{
340}
341
342static inline void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
343{
344}
345
346static inline bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
347{
348	return false;
349}
350
351static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool)
352{
353	return 0;
354}
355
356static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool)
357{
358	return 0;
359}
360
361static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
362{
363	return 0;
364}
365
366static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool *pool)
367{
368	return 0;
369}
370
371static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
372					 struct xdp_rxq_info *rxq)
373{
374}
375
376static inline void xsk_pool_fill_cb(struct xsk_buff_pool *pool,
377				    struct xsk_cb_desc *desc)
378{
379}
380
381static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool,
382				      unsigned long attrs)
383{
384}
385
386static inline int xsk_pool_dma_map(struct xsk_buff_pool *pool,
387				   struct device *dev, unsigned long attrs)
388{
389	return 0;
390}
391
392static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
393{
394	return 0;
395}
396
397static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
398{
399	return 0;
400}
401
402static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool)
403{
404	return NULL;
405}
406
407static inline bool xsk_is_eop_desc(const struct xdp_desc *desc)
408{
409	return false;
410}
411
412static inline u32 xsk_buff_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
413{
414	return 0;
415}
416
417static inline bool xsk_buff_can_alloc(struct xsk_buff_pool *pool, u32 count)
418{
419	return false;
420}
421
422static inline void xsk_buff_free(struct xdp_buff *xdp)
423{
424}
425
426static inline bool xsk_buff_add_frag(struct xdp_buff *head,
427				     struct xdp_buff *xdp)
428{
429	return false;
430}
431
432static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
433{
434	return NULL;
435}
436
437static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
438{
439}
440
441static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
442{
443	return NULL;
444}
445
446static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)
447{
448	return NULL;
449}
450
451static inline void xsk_buff_set_size(struct xdp_buff *xdp, u32 size)
452{
453}
454
455static inline dma_addr_t xsk_buff_raw_get_dma(struct xsk_buff_pool *pool,
456					      u64 addr)
457{
458	return 0;
459}
460
461static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
462{
463	return NULL;
464}
465
466static inline struct xdp_desc_ctx
467xsk_buff_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr)
468{
469	return (struct xdp_desc_ctx){ };
470}
471
472static inline bool xsk_buff_valid_tx_metadata(struct xsk_tx_metadata *meta)
473{
474	return false;
475}
476
477static inline struct xsk_tx_metadata *
478__xsk_buff_get_metadata(const struct xsk_buff_pool *pool, void *data)
479{
480	return NULL;
481}
482
483static inline struct xsk_tx_metadata *
484xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
485{
486	return NULL;
487}
488
489static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
490{
491}
492
493static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
494						    dma_addr_t dma,
495						    size_t size)
496{
497}
498
499#endif /* CONFIG_XDP_SOCKETS */
500
501#endif /* _LINUX_XDP_SOCK_DRV_H */