xref: /linux/net/xdp/xsk_buff_pool.c (revision a0285236ab93fdfdd1008afaa04561d142d6c276)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/netdevice.h>
4 #include <net/netdev_lock.h>
5 #include <net/xsk_buff_pool.h>
6 #include <net/xdp_sock.h>
7 #include <net/xdp_sock_drv.h>
8 
9 #include "xsk_queue.h"
10 #include "xdp_umem.h"
11 #include "xsk.h"
12 
13 void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
14 {
15 	unsigned long flags;
16 
17 	if (!xs->tx)
18 		return;
19 
20 	spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
21 	list_add_rcu(&xs->tx_list, &pool->xsk_tx_list);
22 	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
23 }
24 
25 void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
26 {
27 	unsigned long flags;
28 
29 	if (!xs->tx)
30 		return;
31 
32 	spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
33 	list_del_rcu(&xs->tx_list);
34 	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
35 }
36 
37 void xp_destroy(struct xsk_buff_pool *pool)
38 {
39 	if (!pool)
40 		return;
41 
42 	kvfree(pool->tx_descs);
43 	kvfree(pool->heads);
44 	kvfree(pool);
45 }
46 
47 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
48 {
49 	pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
50 				  GFP_KERNEL);
51 	if (!pool->tx_descs)
52 		return -ENOMEM;
53 
54 	return 0;
55 }
56 
57 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
58 						struct xdp_umem *umem)
59 {
60 	bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
61 	struct xsk_buff_pool *pool;
62 	struct xdp_buff_xsk *xskb;
63 	u32 i, entries;
64 
65 	entries = unaligned ? umem->chunks : 0;
66 	pool = kvzalloc(struct_size(pool, free_heads, entries),	GFP_KERNEL);
67 	if (!pool)
68 		goto out;
69 
70 	pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
71 	if (!pool->heads)
72 		goto out;
73 
74 	if (xs->tx)
75 		if (xp_alloc_tx_descs(pool, xs))
76 			goto out;
77 
78 	pool->chunk_mask = ~((u64)umem->chunk_size - 1);
79 	pool->addrs_cnt = umem->size;
80 	pool->heads_cnt = umem->chunks;
81 	pool->free_heads_cnt = umem->chunks;
82 	pool->headroom = umem->headroom;
83 	pool->chunk_size = umem->chunk_size;
84 	pool->chunk_shift = ffs(umem->chunk_size) - 1;
85 	pool->unaligned = unaligned;
86 	pool->frame_len = umem->chunk_size - umem->headroom -
87 		XDP_PACKET_HEADROOM;
88 	pool->umem = umem;
89 	pool->addrs = umem->addrs;
90 	pool->tx_metadata_len = umem->tx_metadata_len;
91 	pool->tx_sw_csum = umem->flags & XDP_UMEM_TX_SW_CSUM;
92 	INIT_LIST_HEAD(&pool->free_list);
93 	INIT_LIST_HEAD(&pool->xskb_list);
94 	INIT_LIST_HEAD(&pool->xsk_tx_list);
95 	spin_lock_init(&pool->xsk_tx_list_lock);
96 	spin_lock_init(&pool->cq_lock);
97 	refcount_set(&pool->users, 1);
98 
99 	pool->fq = xs->fq_tmp;
100 	pool->cq = xs->cq_tmp;
101 
102 	for (i = 0; i < pool->free_heads_cnt; i++) {
103 		xskb = &pool->heads[i];
104 		xskb->pool = pool;
105 		xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
106 		INIT_LIST_HEAD(&xskb->list_node);
107 		if (pool->unaligned)
108 			pool->free_heads[i] = xskb;
109 		else
110 			xp_init_xskb_addr(xskb, pool, (u64)i * pool->chunk_size);
111 	}
112 
113 	return pool;
114 
115 out:
116 	xp_destroy(pool);
117 	return NULL;
118 }
119 
120 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
121 {
122 	u32 i;
123 
124 	for (i = 0; i < pool->heads_cnt; i++)
125 		pool->heads[i].xdp.rxq = rxq;
126 }
127 EXPORT_SYMBOL(xp_set_rxq_info);
128 
129 void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc)
130 {
131 	u32 i;
132 
133 	for (i = 0; i < pool->heads_cnt; i++) {
134 		struct xdp_buff_xsk *xskb = &pool->heads[i];
135 
136 		memcpy(xskb->cb + desc->off, desc->src, desc->bytes);
137 	}
138 }
139 EXPORT_SYMBOL(xp_fill_cb);
140 
141 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
142 {
143 	struct netdev_bpf bpf;
144 	int err;
145 
146 	ASSERT_RTNL();
147 
148 	if (pool->umem->zc) {
149 		bpf.command = XDP_SETUP_XSK_POOL;
150 		bpf.xsk.pool = NULL;
151 		bpf.xsk.queue_id = pool->queue_id;
152 
153 		err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
154 
155 		if (err)
156 			WARN(1, "Failed to disable zero-copy!\n");
157 	}
158 }
159 
160 #define NETDEV_XDP_ACT_ZC	(NETDEV_XDP_ACT_BASIC |		\
161 				 NETDEV_XDP_ACT_REDIRECT |	\
162 				 NETDEV_XDP_ACT_XSK_ZEROCOPY)
163 
164 int xp_assign_dev(struct xsk_buff_pool *pool,
165 		  struct net_device *netdev, u16 queue_id, u16 flags)
166 {
167 	bool force_zc, force_copy;
168 	struct netdev_bpf bpf;
169 	int err = 0;
170 
171 	ASSERT_RTNL();
172 
173 	force_zc = flags & XDP_ZEROCOPY;
174 	force_copy = flags & XDP_COPY;
175 
176 	if (force_zc && force_copy)
177 		return -EINVAL;
178 
179 	if (xsk_get_pool_from_qid(netdev, queue_id))
180 		return -EBUSY;
181 
182 	pool->netdev = netdev;
183 	pool->queue_id = queue_id;
184 	err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
185 	if (err)
186 		return err;
187 
188 	if (flags & XDP_USE_SG)
189 		pool->umem->flags |= XDP_UMEM_SG_FLAG;
190 
191 	if (flags & XDP_USE_NEED_WAKEUP)
192 		pool->uses_need_wakeup = true;
193 	/* Tx needs to be explicitly woken up the first time.  Also
194 	 * for supporting drivers that do not implement this
195 	 * feature. They will always have to call sendto() or poll().
196 	 */
197 	pool->cached_need_wakeup = XDP_WAKEUP_TX;
198 
199 	dev_hold(netdev);
200 
201 	if (force_copy)
202 		/* For copy-mode, we are done. */
203 		return 0;
204 
205 	if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {
206 		err = -EOPNOTSUPP;
207 		goto err_unreg_pool;
208 	}
209 
210 	if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) {
211 		err = -EOPNOTSUPP;
212 		goto err_unreg_pool;
213 	}
214 
215 	if (dev_get_min_mp_channel_count(netdev)) {
216 		err = -EBUSY;
217 		goto err_unreg_pool;
218 	}
219 
220 	bpf.command = XDP_SETUP_XSK_POOL;
221 	bpf.xsk.pool = pool;
222 	bpf.xsk.queue_id = queue_id;
223 
224 	netdev_ops_assert_locked(netdev);
225 	err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
226 	if (err)
227 		goto err_unreg_pool;
228 
229 	if (!pool->dma_pages) {
230 		WARN(1, "Driver did not DMA map zero-copy buffers");
231 		err = -EINVAL;
232 		goto err_unreg_xsk;
233 	}
234 	pool->umem->zc = true;
235 	pool->xdp_zc_max_segs = netdev->xdp_zc_max_segs;
236 	return 0;
237 
238 err_unreg_xsk:
239 	xp_disable_drv_zc(pool);
240 err_unreg_pool:
241 	if (!force_zc)
242 		err = 0; /* fallback to copy mode */
243 	if (err) {
244 		xsk_clear_pool_at_qid(netdev, queue_id);
245 		dev_put(netdev);
246 	}
247 	return err;
248 }
249 
250 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
251 			 struct net_device *dev, u16 queue_id)
252 {
253 	u16 flags;
254 	struct xdp_umem *umem = umem_xs->umem;
255 
256 	/* One fill and completion ring required for each queue id. */
257 	if (!pool->fq || !pool->cq)
258 		return -EINVAL;
259 
260 	flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
261 	if (umem_xs->pool->uses_need_wakeup)
262 		flags |= XDP_USE_NEED_WAKEUP;
263 
264 	return xp_assign_dev(pool, dev, queue_id, flags);
265 }
266 
267 void xp_clear_dev(struct xsk_buff_pool *pool)
268 {
269 	struct net_device *netdev = pool->netdev;
270 
271 	if (!pool->netdev)
272 		return;
273 
274 	netdev_lock_ops(netdev);
275 	xp_disable_drv_zc(pool);
276 	xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
277 	pool->netdev = NULL;
278 	netdev_unlock_ops(netdev);
279 	dev_put(netdev);
280 }
281 
282 static void xp_release_deferred(struct work_struct *work)
283 {
284 	struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
285 						  work);
286 
287 	rtnl_lock();
288 	xp_clear_dev(pool);
289 	rtnl_unlock();
290 
291 	if (pool->fq) {
292 		xskq_destroy(pool->fq);
293 		pool->fq = NULL;
294 	}
295 
296 	if (pool->cq) {
297 		xskq_destroy(pool->cq);
298 		pool->cq = NULL;
299 	}
300 
301 	xdp_put_umem(pool->umem, false);
302 	xp_destroy(pool);
303 }
304 
305 void xp_get_pool(struct xsk_buff_pool *pool)
306 {
307 	refcount_inc(&pool->users);
308 }
309 
310 bool xp_put_pool(struct xsk_buff_pool *pool)
311 {
312 	if (!pool)
313 		return false;
314 
315 	if (refcount_dec_and_test(&pool->users)) {
316 		INIT_WORK(&pool->work, xp_release_deferred);
317 		schedule_work(&pool->work);
318 		return true;
319 	}
320 
321 	return false;
322 }
323 
324 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
325 {
326 	struct xsk_dma_map *dma_map;
327 
328 	list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
329 		if (dma_map->netdev == pool->netdev)
330 			return dma_map;
331 	}
332 
333 	return NULL;
334 }
335 
336 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
337 					     u32 nr_pages, struct xdp_umem *umem)
338 {
339 	struct xsk_dma_map *dma_map;
340 
341 	dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
342 	if (!dma_map)
343 		return NULL;
344 
345 	dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
346 	if (!dma_map->dma_pages) {
347 		kfree(dma_map);
348 		return NULL;
349 	}
350 
351 	dma_map->netdev = netdev;
352 	dma_map->dev = dev;
353 	dma_map->dma_pages_cnt = nr_pages;
354 	refcount_set(&dma_map->users, 1);
355 	list_add(&dma_map->list, &umem->xsk_dma_list);
356 	return dma_map;
357 }
358 
359 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
360 {
361 	list_del(&dma_map->list);
362 	kvfree(dma_map->dma_pages);
363 	kfree(dma_map);
364 }
365 
366 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
367 {
368 	dma_addr_t *dma;
369 	u32 i;
370 
371 	for (i = 0; i < dma_map->dma_pages_cnt; i++) {
372 		dma = &dma_map->dma_pages[i];
373 		if (*dma) {
374 			*dma &= ~XSK_NEXT_PG_CONTIG_MASK;
375 			dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
376 					     DMA_BIDIRECTIONAL, attrs);
377 			*dma = 0;
378 		}
379 	}
380 
381 	xp_destroy_dma_map(dma_map);
382 }
383 
384 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
385 {
386 	struct xsk_dma_map *dma_map;
387 
388 	if (!pool->dma_pages)
389 		return;
390 
391 	dma_map = xp_find_dma_map(pool);
392 	if (!dma_map) {
393 		WARN(1, "Could not find dma_map for device");
394 		return;
395 	}
396 
397 	if (refcount_dec_and_test(&dma_map->users))
398 		__xp_dma_unmap(dma_map, attrs);
399 
400 	kvfree(pool->dma_pages);
401 	pool->dma_pages = NULL;
402 	pool->dma_pages_cnt = 0;
403 	pool->dev = NULL;
404 }
405 EXPORT_SYMBOL(xp_dma_unmap);
406 
407 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
408 {
409 	u32 i;
410 
411 	for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
412 		if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
413 			dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
414 		else
415 			dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
416 	}
417 }
418 
419 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
420 {
421 	if (!pool->unaligned) {
422 		u32 i;
423 
424 		for (i = 0; i < pool->heads_cnt; i++) {
425 			struct xdp_buff_xsk *xskb = &pool->heads[i];
426 			u64 orig_addr;
427 
428 			orig_addr = xskb->xdp.data_hard_start - pool->addrs - pool->headroom;
429 			xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, orig_addr);
430 		}
431 	}
432 
433 	pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
434 	if (!pool->dma_pages)
435 		return -ENOMEM;
436 
437 	pool->dev = dma_map->dev;
438 	pool->dma_pages_cnt = dma_map->dma_pages_cnt;
439 	memcpy(pool->dma_pages, dma_map->dma_pages,
440 	       pool->dma_pages_cnt * sizeof(*pool->dma_pages));
441 
442 	return 0;
443 }
444 
445 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
446 	       unsigned long attrs, struct page **pages, u32 nr_pages)
447 {
448 	struct xsk_dma_map *dma_map;
449 	dma_addr_t dma;
450 	int err;
451 	u32 i;
452 
453 	dma_map = xp_find_dma_map(pool);
454 	if (dma_map) {
455 		err = xp_init_dma_info(pool, dma_map);
456 		if (err)
457 			return err;
458 
459 		refcount_inc(&dma_map->users);
460 		return 0;
461 	}
462 
463 	dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
464 	if (!dma_map)
465 		return -ENOMEM;
466 
467 	for (i = 0; i < dma_map->dma_pages_cnt; i++) {
468 		dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
469 					 DMA_BIDIRECTIONAL, attrs);
470 		if (dma_mapping_error(dev, dma)) {
471 			__xp_dma_unmap(dma_map, attrs);
472 			return -ENOMEM;
473 		}
474 		dma_map->dma_pages[i] = dma;
475 	}
476 
477 	if (pool->unaligned)
478 		xp_check_dma_contiguity(dma_map);
479 
480 	err = xp_init_dma_info(pool, dma_map);
481 	if (err) {
482 		__xp_dma_unmap(dma_map, attrs);
483 		return err;
484 	}
485 
486 	return 0;
487 }
488 EXPORT_SYMBOL(xp_dma_map);
489 
490 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
491 					  u64 addr)
492 {
493 	return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
494 }
495 
496 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
497 {
498 	*addr = xp_unaligned_extract_addr(*addr);
499 	if (*addr >= pool->addrs_cnt ||
500 	    *addr + pool->chunk_size > pool->addrs_cnt ||
501 	    xp_addr_crosses_non_contig_pg(pool, *addr))
502 		return false;
503 	return true;
504 }
505 
506 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
507 {
508 	*addr = xp_aligned_extract_addr(pool, *addr);
509 	return *addr < pool->addrs_cnt;
510 }
511 
512 static struct xdp_buff_xsk *xp_get_xskb(struct xsk_buff_pool *pool, u64 addr)
513 {
514 	struct xdp_buff_xsk *xskb;
515 
516 	if (pool->unaligned) {
517 		xskb = pool->free_heads[--pool->free_heads_cnt];
518 		xp_init_xskb_addr(xskb, pool, addr);
519 		if (pool->dma_pages)
520 			xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
521 	} else {
522 		xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
523 	}
524 
525 	return xskb;
526 }
527 
528 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
529 {
530 	struct xdp_buff_xsk *xskb;
531 	u64 addr;
532 	bool ok;
533 
534 	if (pool->free_heads_cnt == 0)
535 		return NULL;
536 
537 	for (;;) {
538 		if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
539 			pool->fq->queue_empty_descs++;
540 			return NULL;
541 		}
542 
543 		ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
544 		     xp_check_aligned(pool, &addr);
545 		if (!ok) {
546 			pool->fq->invalid_descs++;
547 			xskq_cons_release(pool->fq);
548 			continue;
549 		}
550 		break;
551 	}
552 
553 	xskb = xp_get_xskb(pool, addr);
554 
555 	xskq_cons_release(pool->fq);
556 	return xskb;
557 }
558 
559 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
560 {
561 	struct xdp_buff_xsk *xskb;
562 
563 	if (!pool->free_list_cnt) {
564 		xskb = __xp_alloc(pool);
565 		if (!xskb)
566 			return NULL;
567 	} else {
568 		pool->free_list_cnt--;
569 		xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
570 					list_node);
571 		list_del_init(&xskb->list_node);
572 	}
573 
574 	xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
575 	xskb->xdp.data_meta = xskb->xdp.data;
576 	xskb->xdp.flags = 0;
577 
578 	if (pool->dev)
579 		xp_dma_sync_for_device(pool, xskb->dma, pool->frame_len);
580 
581 	return &xskb->xdp;
582 }
583 EXPORT_SYMBOL(xp_alloc);
584 
585 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
586 {
587 	u32 i, cached_cons, nb_entries;
588 
589 	if (max > pool->free_heads_cnt)
590 		max = pool->free_heads_cnt;
591 	max = xskq_cons_nb_entries(pool->fq, max);
592 
593 	cached_cons = pool->fq->cached_cons;
594 	nb_entries = max;
595 	i = max;
596 	while (i--) {
597 		struct xdp_buff_xsk *xskb;
598 		u64 addr;
599 		bool ok;
600 
601 		__xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
602 
603 		ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
604 			xp_check_aligned(pool, &addr);
605 		if (unlikely(!ok)) {
606 			pool->fq->invalid_descs++;
607 			nb_entries--;
608 			continue;
609 		}
610 
611 		xskb = xp_get_xskb(pool, addr);
612 
613 		*xdp = &xskb->xdp;
614 		xdp++;
615 	}
616 
617 	xskq_cons_release_n(pool->fq, max);
618 	return nb_entries;
619 }
620 
621 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
622 {
623 	struct xdp_buff_xsk *xskb;
624 	u32 i;
625 
626 	nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
627 
628 	i = nb_entries;
629 	while (i--) {
630 		xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, list_node);
631 		list_del_init(&xskb->list_node);
632 
633 		*xdp = &xskb->xdp;
634 		xdp++;
635 	}
636 	pool->free_list_cnt -= nb_entries;
637 
638 	return nb_entries;
639 }
640 
641 static u32 xp_alloc_slow(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
642 			 u32 max)
643 {
644 	int i;
645 
646 	for (i = 0; i < max; i++) {
647 		struct xdp_buff *buff;
648 
649 		buff = xp_alloc(pool);
650 		if (unlikely(!buff))
651 			return i;
652 		*xdp = buff;
653 		xdp++;
654 	}
655 
656 	return max;
657 }
658 
659 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
660 {
661 	u32 nb_entries1 = 0, nb_entries2;
662 
663 	if (unlikely(pool->dev && dma_dev_need_sync(pool->dev)))
664 		return xp_alloc_slow(pool, xdp, max);
665 
666 	if (unlikely(pool->free_list_cnt)) {
667 		nb_entries1 = xp_alloc_reused(pool, xdp, max);
668 		if (nb_entries1 == max)
669 			return nb_entries1;
670 
671 		max -= nb_entries1;
672 		xdp += nb_entries1;
673 	}
674 
675 	nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
676 	if (!nb_entries2)
677 		pool->fq->queue_empty_descs++;
678 
679 	return nb_entries1 + nb_entries2;
680 }
681 EXPORT_SYMBOL(xp_alloc_batch);
682 
683 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
684 {
685 	u32 req_count, avail_count;
686 
687 	if (pool->free_list_cnt >= count)
688 		return true;
689 
690 	req_count = count - pool->free_list_cnt;
691 	avail_count = xskq_cons_nb_entries(pool->fq, req_count);
692 	if (!avail_count)
693 		pool->fq->queue_empty_descs++;
694 
695 	return avail_count >= req_count;
696 }
697 EXPORT_SYMBOL(xp_can_alloc);
698 
699 void xp_free(struct xdp_buff_xsk *xskb)
700 {
701 	if (!list_empty(&xskb->list_node))
702 		return;
703 
704 	xskb->pool->free_list_cnt++;
705 	list_add(&xskb->list_node, &xskb->pool->free_list);
706 }
707 EXPORT_SYMBOL(xp_free);
708 
709 static u64 __xp_raw_get_addr(const struct xsk_buff_pool *pool, u64 addr)
710 {
711 	return pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
712 }
713 
714 static void *__xp_raw_get_data(const struct xsk_buff_pool *pool, u64 addr)
715 {
716 	return pool->addrs + addr;
717 }
718 
719 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
720 {
721 	return __xp_raw_get_data(pool, __xp_raw_get_addr(pool, addr));
722 }
723 EXPORT_SYMBOL(xp_raw_get_data);
724 
725 static dma_addr_t __xp_raw_get_dma(const struct xsk_buff_pool *pool, u64 addr)
726 {
727 	return (pool->dma_pages[addr >> PAGE_SHIFT] &
728 		~XSK_NEXT_PG_CONTIG_MASK) +
729 		(addr & ~PAGE_MASK);
730 }
731 
732 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
733 {
734 	return __xp_raw_get_dma(pool, __xp_raw_get_addr(pool, addr));
735 }
736 EXPORT_SYMBOL(xp_raw_get_dma);
737 
738 /**
739  * xp_raw_get_ctx - get &xdp_desc context
740  * @pool: XSk buff pool desc address belongs to
741  * @addr: desc address (from userspace)
742  *
743  * Helper for getting desc's DMA address and metadata pointer, if present.
744  * Saves one call on hotpath, double calculation of the actual address,
745  * and inline checks for metadata presence and sanity.
746  *
747  * Return: new &xdp_desc_ctx struct containing desc's DMA address and metadata
748  * pointer, if it is present and valid (initialized to %NULL otherwise).
749  */
750 struct xdp_desc_ctx xp_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr)
751 {
752 	struct xdp_desc_ctx ret;
753 
754 	addr = __xp_raw_get_addr(pool, addr);
755 
756 	ret.dma = __xp_raw_get_dma(pool, addr);
757 	ret.meta = __xsk_buff_get_metadata(pool, __xp_raw_get_data(pool, addr));
758 
759 	return ret;
760 }
761 EXPORT_SYMBOL(xp_raw_get_ctx);
762