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