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
xp_add_xsk(struct xsk_buff_pool * pool,struct xdp_sock * xs)11 void 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
xp_del_xsk(struct xsk_buff_pool * pool,struct xdp_sock * xs)23 void 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
xp_destroy(struct xsk_buff_pool * pool)35 void 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
xp_alloc_tx_descs(struct xsk_buff_pool * pool,struct xdp_sock * xs)45 int 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
xp_create_and_assign_umem(struct xdp_sock * xs,struct xdp_umem * umem)55 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
56 struct xdp_umem *umem)
57 {
58 struct xsk_buff_pool *pool;
59 struct xdp_buff_xsk *xskb;
60 u32 i;
61
62 pool = kvzalloc(struct_size(pool, free_heads, umem->chunks),
63 GFP_KERNEL);
64 if (!pool)
65 goto out;
66
67 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
68 if (!pool->heads)
69 goto out;
70
71 if (xs->tx)
72 if (xp_alloc_tx_descs(pool, xs))
73 goto out;
74
75 pool->chunk_mask = ~((u64)umem->chunk_size - 1);
76 pool->addrs_cnt = umem->size;
77 pool->heads_cnt = umem->chunks;
78 pool->free_heads_cnt = umem->chunks;
79 pool->headroom = umem->headroom;
80 pool->chunk_size = umem->chunk_size;
81 pool->unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
82 pool->frame_len = umem->chunk_size - umem->headroom -
83 XDP_PACKET_HEADROOM;
84 pool->umem = umem;
85 pool->addrs = umem->addrs;
86 INIT_LIST_HEAD(&pool->free_list);
87 INIT_LIST_HEAD(&pool->xsk_tx_list);
88 spin_lock_init(&pool->xsk_tx_list_lock);
89 spin_lock_init(&pool->cq_lock);
90 refcount_set(&pool->users, 1);
91
92 pool->fq = xs->fq_tmp;
93 pool->cq = xs->cq_tmp;
94
95 for (i = 0; i < pool->free_heads_cnt; i++) {
96 xskb = &pool->heads[i];
97 xskb->pool = pool;
98 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
99 pool->free_heads[i] = xskb;
100 }
101
102 return pool;
103
104 out:
105 xp_destroy(pool);
106 return NULL;
107 }
108
xp_set_rxq_info(struct xsk_buff_pool * pool,struct xdp_rxq_info * rxq)109 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
110 {
111 u32 i;
112
113 for (i = 0; i < pool->heads_cnt; i++)
114 pool->heads[i].xdp.rxq = rxq;
115 }
116 EXPORT_SYMBOL(xp_set_rxq_info);
117
xp_disable_drv_zc(struct xsk_buff_pool * pool)118 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
119 {
120 struct netdev_bpf bpf;
121 int err;
122
123 ASSERT_RTNL();
124
125 if (pool->umem->zc) {
126 bpf.command = XDP_SETUP_XSK_POOL;
127 bpf.xsk.pool = NULL;
128 bpf.xsk.queue_id = pool->queue_id;
129
130 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
131
132 if (err)
133 WARN(1, "Failed to disable zero-copy!\n");
134 }
135 }
136
xp_assign_dev(struct xsk_buff_pool * pool,struct net_device * netdev,u16 queue_id,u16 flags)137 int xp_assign_dev(struct xsk_buff_pool *pool,
138 struct net_device *netdev, u16 queue_id, u16 flags)
139 {
140 bool force_zc, force_copy;
141 struct netdev_bpf bpf;
142 int err = 0;
143
144 ASSERT_RTNL();
145
146 force_zc = flags & XDP_ZEROCOPY;
147 force_copy = flags & XDP_COPY;
148
149 if (force_zc && force_copy)
150 return -EINVAL;
151
152 if (xsk_get_pool_from_qid(netdev, queue_id))
153 return -EBUSY;
154
155 pool->netdev = netdev;
156 pool->queue_id = queue_id;
157 err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
158 if (err)
159 return err;
160
161 if (flags & XDP_USE_NEED_WAKEUP)
162 pool->uses_need_wakeup = true;
163 /* Tx needs to be explicitly woken up the first time. Also
164 * for supporting drivers that do not implement this
165 * feature. They will always have to call sendto() or poll().
166 */
167 pool->cached_need_wakeup = XDP_WAKEUP_TX;
168
169 dev_hold(netdev);
170
171 if (force_copy)
172 /* For copy-mode, we are done. */
173 return 0;
174
175 if (!netdev->netdev_ops->ndo_bpf ||
176 !netdev->netdev_ops->ndo_xsk_wakeup) {
177 err = -EOPNOTSUPP;
178 goto err_unreg_pool;
179 }
180
181 bpf.command = XDP_SETUP_XSK_POOL;
182 bpf.xsk.pool = pool;
183 bpf.xsk.queue_id = queue_id;
184
185 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
186 if (err)
187 goto err_unreg_pool;
188
189 if (!pool->dma_pages) {
190 WARN(1, "Driver did not DMA map zero-copy buffers");
191 err = -EINVAL;
192 goto err_unreg_xsk;
193 }
194 pool->umem->zc = true;
195 return 0;
196
197 err_unreg_xsk:
198 xp_disable_drv_zc(pool);
199 err_unreg_pool:
200 if (!force_zc)
201 err = 0; /* fallback to copy mode */
202 if (err) {
203 xsk_clear_pool_at_qid(netdev, queue_id);
204 dev_put(netdev);
205 }
206 return err;
207 }
208
xp_assign_dev_shared(struct xsk_buff_pool * pool,struct xdp_sock * umem_xs,struct net_device * dev,u16 queue_id)209 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
210 struct net_device *dev, u16 queue_id)
211 {
212 u16 flags;
213 struct xdp_umem *umem = umem_xs->umem;
214
215 /* One fill and completion ring required for each queue id. */
216 if (!pool->fq || !pool->cq)
217 return -EINVAL;
218
219 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
220 if (umem_xs->pool->uses_need_wakeup)
221 flags |= XDP_USE_NEED_WAKEUP;
222
223 return xp_assign_dev(pool, dev, queue_id, flags);
224 }
225
xp_clear_dev(struct xsk_buff_pool * pool)226 void xp_clear_dev(struct xsk_buff_pool *pool)
227 {
228 if (!pool->netdev)
229 return;
230
231 xp_disable_drv_zc(pool);
232 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
233 dev_put(pool->netdev);
234 pool->netdev = NULL;
235 }
236
xp_release_deferred(struct work_struct * work)237 static void xp_release_deferred(struct work_struct *work)
238 {
239 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
240 work);
241
242 rtnl_lock();
243 xp_clear_dev(pool);
244 rtnl_unlock();
245
246 if (pool->fq) {
247 xskq_destroy(pool->fq);
248 pool->fq = NULL;
249 }
250
251 if (pool->cq) {
252 xskq_destroy(pool->cq);
253 pool->cq = NULL;
254 }
255
256 xdp_put_umem(pool->umem, false);
257 xp_destroy(pool);
258 }
259
xp_get_pool(struct xsk_buff_pool * pool)260 void xp_get_pool(struct xsk_buff_pool *pool)
261 {
262 refcount_inc(&pool->users);
263 }
264
xp_put_pool(struct xsk_buff_pool * pool)265 bool xp_put_pool(struct xsk_buff_pool *pool)
266 {
267 if (!pool)
268 return false;
269
270 if (refcount_dec_and_test(&pool->users)) {
271 INIT_WORK(&pool->work, xp_release_deferred);
272 schedule_work(&pool->work);
273 return true;
274 }
275
276 return false;
277 }
278
xp_find_dma_map(struct xsk_buff_pool * pool)279 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
280 {
281 struct xsk_dma_map *dma_map;
282
283 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
284 if (dma_map->netdev == pool->netdev)
285 return dma_map;
286 }
287
288 return NULL;
289 }
290
xp_create_dma_map(struct device * dev,struct net_device * netdev,u32 nr_pages,struct xdp_umem * umem)291 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
292 u32 nr_pages, struct xdp_umem *umem)
293 {
294 struct xsk_dma_map *dma_map;
295
296 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
297 if (!dma_map)
298 return NULL;
299
300 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
301 if (!dma_map->dma_pages) {
302 kfree(dma_map);
303 return NULL;
304 }
305
306 dma_map->netdev = netdev;
307 dma_map->dev = dev;
308 dma_map->dma_need_sync = false;
309 dma_map->dma_pages_cnt = nr_pages;
310 refcount_set(&dma_map->users, 1);
311 list_add(&dma_map->list, &umem->xsk_dma_list);
312 return dma_map;
313 }
314
xp_destroy_dma_map(struct xsk_dma_map * dma_map)315 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
316 {
317 list_del(&dma_map->list);
318 kvfree(dma_map->dma_pages);
319 kfree(dma_map);
320 }
321
__xp_dma_unmap(struct xsk_dma_map * dma_map,unsigned long attrs)322 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
323 {
324 dma_addr_t *dma;
325 u32 i;
326
327 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
328 dma = &dma_map->dma_pages[i];
329 if (*dma) {
330 *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
331 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
332 DMA_BIDIRECTIONAL, attrs);
333 *dma = 0;
334 }
335 }
336
337 xp_destroy_dma_map(dma_map);
338 }
339
xp_dma_unmap(struct xsk_buff_pool * pool,unsigned long attrs)340 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
341 {
342 struct xsk_dma_map *dma_map;
343
344 if (pool->dma_pages_cnt == 0)
345 return;
346
347 dma_map = xp_find_dma_map(pool);
348 if (!dma_map) {
349 WARN(1, "Could not find dma_map for device");
350 return;
351 }
352
353 if (!refcount_dec_and_test(&dma_map->users))
354 return;
355
356 __xp_dma_unmap(dma_map, attrs);
357 kvfree(pool->dma_pages);
358 pool->dma_pages_cnt = 0;
359 pool->dev = NULL;
360 }
361 EXPORT_SYMBOL(xp_dma_unmap);
362
xp_check_dma_contiguity(struct xsk_dma_map * dma_map)363 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
364 {
365 u32 i;
366
367 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
368 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
369 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
370 else
371 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
372 }
373 }
374
xp_init_dma_info(struct xsk_buff_pool * pool,struct xsk_dma_map * dma_map)375 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
376 {
377 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
378 if (!pool->dma_pages)
379 return -ENOMEM;
380
381 pool->dev = dma_map->dev;
382 pool->dma_pages_cnt = dma_map->dma_pages_cnt;
383 pool->dma_need_sync = dma_map->dma_need_sync;
384 memcpy(pool->dma_pages, dma_map->dma_pages,
385 pool->dma_pages_cnt * sizeof(*pool->dma_pages));
386
387 return 0;
388 }
389
xp_dma_map(struct xsk_buff_pool * pool,struct device * dev,unsigned long attrs,struct page ** pages,u32 nr_pages)390 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
391 unsigned long attrs, struct page **pages, u32 nr_pages)
392 {
393 struct xsk_dma_map *dma_map;
394 dma_addr_t dma;
395 int err;
396 u32 i;
397
398 dma_map = xp_find_dma_map(pool);
399 if (dma_map) {
400 err = xp_init_dma_info(pool, dma_map);
401 if (err)
402 return err;
403
404 refcount_inc(&dma_map->users);
405 return 0;
406 }
407
408 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
409 if (!dma_map)
410 return -ENOMEM;
411
412 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
413 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
414 DMA_BIDIRECTIONAL, attrs);
415 if (dma_mapping_error(dev, dma)) {
416 __xp_dma_unmap(dma_map, attrs);
417 return -ENOMEM;
418 }
419 if (dma_need_sync(dev, dma))
420 dma_map->dma_need_sync = true;
421 dma_map->dma_pages[i] = dma;
422 }
423
424 if (pool->unaligned)
425 xp_check_dma_contiguity(dma_map);
426
427 err = xp_init_dma_info(pool, dma_map);
428 if (err) {
429 __xp_dma_unmap(dma_map, attrs);
430 return err;
431 }
432
433 return 0;
434 }
435 EXPORT_SYMBOL(xp_dma_map);
436
xp_addr_crosses_non_contig_pg(struct xsk_buff_pool * pool,u64 addr)437 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
438 u64 addr)
439 {
440 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
441 }
442
xp_check_unaligned(struct xsk_buff_pool * pool,u64 * addr)443 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
444 {
445 *addr = xp_unaligned_extract_addr(*addr);
446 if (*addr >= pool->addrs_cnt ||
447 *addr + pool->chunk_size > pool->addrs_cnt ||
448 xp_addr_crosses_non_contig_pg(pool, *addr))
449 return false;
450 return true;
451 }
452
xp_check_aligned(struct xsk_buff_pool * pool,u64 * addr)453 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
454 {
455 *addr = xp_aligned_extract_addr(pool, *addr);
456 return *addr < pool->addrs_cnt;
457 }
458
__xp_alloc(struct xsk_buff_pool * pool)459 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
460 {
461 struct xdp_buff_xsk *xskb;
462 u64 addr;
463 bool ok;
464
465 if (pool->free_heads_cnt == 0)
466 return NULL;
467
468 xskb = pool->free_heads[--pool->free_heads_cnt];
469
470 for (;;) {
471 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
472 pool->fq->queue_empty_descs++;
473 xp_release(xskb);
474 return NULL;
475 }
476
477 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
478 xp_check_aligned(pool, &addr);
479 if (!ok) {
480 pool->fq->invalid_descs++;
481 xskq_cons_release(pool->fq);
482 continue;
483 }
484 break;
485 }
486 xskq_cons_release(pool->fq);
487
488 xskb->orig_addr = addr;
489 xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
490 if (pool->dma_pages_cnt) {
491 xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
492 ~XSK_NEXT_PG_CONTIG_MASK) +
493 (addr & ~PAGE_MASK);
494 xskb->dma = xskb->frame_dma + pool->headroom +
495 XDP_PACKET_HEADROOM;
496 }
497 return xskb;
498 }
499
xp_alloc(struct xsk_buff_pool * pool)500 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
501 {
502 struct xdp_buff_xsk *xskb;
503
504 if (!pool->free_list_cnt) {
505 xskb = __xp_alloc(pool);
506 if (!xskb)
507 return NULL;
508 } else {
509 pool->free_list_cnt--;
510 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
511 free_list_node);
512 list_del(&xskb->free_list_node);
513 }
514
515 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
516 xskb->xdp.data_meta = xskb->xdp.data;
517
518 if (pool->dma_need_sync) {
519 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
520 pool->frame_len,
521 DMA_BIDIRECTIONAL);
522 }
523 return &xskb->xdp;
524 }
525 EXPORT_SYMBOL(xp_alloc);
526
xp_can_alloc(struct xsk_buff_pool * pool,u32 count)527 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
528 {
529 if (pool->free_list_cnt >= count)
530 return true;
531 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
532 }
533 EXPORT_SYMBOL(xp_can_alloc);
534
xp_free(struct xdp_buff_xsk * xskb)535 void xp_free(struct xdp_buff_xsk *xskb)
536 {
537 xskb->pool->free_list_cnt++;
538 list_add(&xskb->free_list_node, &xskb->pool->free_list);
539 }
540 EXPORT_SYMBOL(xp_free);
541
xp_raw_get_data(struct xsk_buff_pool * pool,u64 addr)542 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
543 {
544 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
545 return pool->addrs + addr;
546 }
547 EXPORT_SYMBOL(xp_raw_get_data);
548
xp_raw_get_dma(struct xsk_buff_pool * pool,u64 addr)549 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
550 {
551 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
552 return (pool->dma_pages[addr >> PAGE_SHIFT] &
553 ~XSK_NEXT_PG_CONTIG_MASK) +
554 (addr & ~PAGE_MASK);
555 }
556 EXPORT_SYMBOL(xp_raw_get_dma);
557
xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk * xskb)558 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
559 {
560 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
561 xskb->pool->frame_len, DMA_BIDIRECTIONAL);
562 }
563 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
564
xp_dma_sync_for_device_slow(struct xsk_buff_pool * pool,dma_addr_t dma,size_t size)565 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
566 size_t size)
567 {
568 dma_sync_single_range_for_device(pool->dev, dma, 0,
569 size, DMA_BIDIRECTIONAL);
570 }
571 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);
572