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->heads);
41 kvfree(pool);
42 }
43
xp_create_and_assign_umem(struct xdp_sock * xs,struct xdp_umem * umem)44 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
45 struct xdp_umem *umem)
46 {
47 struct xsk_buff_pool *pool;
48 struct xdp_buff_xsk *xskb;
49 u32 i;
50
51 pool = kvzalloc(struct_size(pool, free_heads, umem->chunks),
52 GFP_KERNEL);
53 if (!pool)
54 goto out;
55
56 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
57 if (!pool->heads)
58 goto out;
59
60 pool->chunk_mask = ~((u64)umem->chunk_size - 1);
61 pool->addrs_cnt = umem->size;
62 pool->heads_cnt = umem->chunks;
63 pool->free_heads_cnt = umem->chunks;
64 pool->headroom = umem->headroom;
65 pool->chunk_size = umem->chunk_size;
66 pool->unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
67 pool->frame_len = umem->chunk_size - umem->headroom -
68 XDP_PACKET_HEADROOM;
69 pool->umem = umem;
70 pool->addrs = umem->addrs;
71 INIT_LIST_HEAD(&pool->free_list);
72 INIT_LIST_HEAD(&pool->xsk_tx_list);
73 spin_lock_init(&pool->xsk_tx_list_lock);
74 spin_lock_init(&pool->cq_lock);
75 refcount_set(&pool->users, 1);
76
77 pool->fq = xs->fq_tmp;
78 pool->cq = xs->cq_tmp;
79
80 for (i = 0; i < pool->free_heads_cnt; i++) {
81 xskb = &pool->heads[i];
82 xskb->pool = pool;
83 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
84 pool->free_heads[i] = xskb;
85 }
86
87 return pool;
88
89 out:
90 xp_destroy(pool);
91 return NULL;
92 }
93
xp_set_rxq_info(struct xsk_buff_pool * pool,struct xdp_rxq_info * rxq)94 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
95 {
96 u32 i;
97
98 for (i = 0; i < pool->heads_cnt; i++)
99 pool->heads[i].xdp.rxq = rxq;
100 }
101 EXPORT_SYMBOL(xp_set_rxq_info);
102
xp_disable_drv_zc(struct xsk_buff_pool * pool)103 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
104 {
105 struct netdev_bpf bpf;
106 int err;
107
108 ASSERT_RTNL();
109
110 if (pool->umem->zc) {
111 bpf.command = XDP_SETUP_XSK_POOL;
112 bpf.xsk.pool = NULL;
113 bpf.xsk.queue_id = pool->queue_id;
114
115 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
116
117 if (err)
118 WARN(1, "Failed to disable zero-copy!\n");
119 }
120 }
121
__xp_assign_dev(struct xsk_buff_pool * pool,struct net_device * netdev,u16 queue_id,u16 flags)122 static int __xp_assign_dev(struct xsk_buff_pool *pool,
123 struct net_device *netdev, u16 queue_id, u16 flags)
124 {
125 bool force_zc, force_copy;
126 struct netdev_bpf bpf;
127 int err = 0;
128
129 ASSERT_RTNL();
130
131 force_zc = flags & XDP_ZEROCOPY;
132 force_copy = flags & XDP_COPY;
133
134 if (force_zc && force_copy)
135 return -EINVAL;
136
137 if (xsk_get_pool_from_qid(netdev, queue_id))
138 return -EBUSY;
139
140 pool->netdev = netdev;
141 pool->queue_id = queue_id;
142 err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
143 if (err)
144 return err;
145
146 if (flags & XDP_USE_NEED_WAKEUP) {
147 pool->uses_need_wakeup = true;
148 /* Tx needs to be explicitly woken up the first time.
149 * Also for supporting drivers that do not implement this
150 * feature. They will always have to call sendto().
151 */
152 pool->cached_need_wakeup = XDP_WAKEUP_TX;
153 }
154
155 dev_hold(netdev);
156
157 if (force_copy)
158 /* For copy-mode, we are done. */
159 return 0;
160
161 if (!netdev->netdev_ops->ndo_bpf ||
162 !netdev->netdev_ops->ndo_xsk_wakeup) {
163 err = -EOPNOTSUPP;
164 goto err_unreg_pool;
165 }
166
167 bpf.command = XDP_SETUP_XSK_POOL;
168 bpf.xsk.pool = pool;
169 bpf.xsk.queue_id = queue_id;
170
171 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
172 if (err)
173 goto err_unreg_pool;
174
175 if (!pool->dma_pages) {
176 WARN(1, "Driver did not DMA map zero-copy buffers");
177 err = -EINVAL;
178 goto err_unreg_xsk;
179 }
180 pool->umem->zc = true;
181 return 0;
182
183 err_unreg_xsk:
184 xp_disable_drv_zc(pool);
185 err_unreg_pool:
186 if (!force_zc)
187 err = 0; /* fallback to copy mode */
188 if (err) {
189 xsk_clear_pool_at_qid(netdev, queue_id);
190 dev_put(netdev);
191 }
192 return err;
193 }
194
xp_assign_dev(struct xsk_buff_pool * pool,struct net_device * dev,u16 queue_id,u16 flags)195 int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
196 u16 queue_id, u16 flags)
197 {
198 return __xp_assign_dev(pool, dev, queue_id, flags);
199 }
200
xp_assign_dev_shared(struct xsk_buff_pool * pool,struct xdp_umem * umem,struct net_device * dev,u16 queue_id)201 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem,
202 struct net_device *dev, u16 queue_id)
203 {
204 u16 flags;
205
206 /* One fill and completion ring required for each queue id. */
207 if (!pool->fq || !pool->cq)
208 return -EINVAL;
209
210 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
211 if (pool->uses_need_wakeup)
212 flags |= XDP_USE_NEED_WAKEUP;
213
214 return __xp_assign_dev(pool, dev, queue_id, flags);
215 }
216
xp_clear_dev(struct xsk_buff_pool * pool)217 void xp_clear_dev(struct xsk_buff_pool *pool)
218 {
219 if (!pool->netdev)
220 return;
221
222 xp_disable_drv_zc(pool);
223 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
224 dev_put(pool->netdev);
225 pool->netdev = NULL;
226 }
227
xp_release_deferred(struct work_struct * work)228 static void xp_release_deferred(struct work_struct *work)
229 {
230 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
231 work);
232
233 rtnl_lock();
234 xp_clear_dev(pool);
235 rtnl_unlock();
236
237 if (pool->fq) {
238 xskq_destroy(pool->fq);
239 pool->fq = NULL;
240 }
241
242 if (pool->cq) {
243 xskq_destroy(pool->cq);
244 pool->cq = NULL;
245 }
246
247 xdp_put_umem(pool->umem, false);
248 xp_destroy(pool);
249 }
250
xp_get_pool(struct xsk_buff_pool * pool)251 void xp_get_pool(struct xsk_buff_pool *pool)
252 {
253 refcount_inc(&pool->users);
254 }
255
xp_put_pool(struct xsk_buff_pool * pool)256 bool xp_put_pool(struct xsk_buff_pool *pool)
257 {
258 if (!pool)
259 return false;
260
261 if (refcount_dec_and_test(&pool->users)) {
262 INIT_WORK(&pool->work, xp_release_deferred);
263 schedule_work(&pool->work);
264 return true;
265 }
266
267 return false;
268 }
269
xp_find_dma_map(struct xsk_buff_pool * pool)270 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
271 {
272 struct xsk_dma_map *dma_map;
273
274 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
275 if (dma_map->netdev == pool->netdev)
276 return dma_map;
277 }
278
279 return NULL;
280 }
281
xp_create_dma_map(struct device * dev,struct net_device * netdev,u32 nr_pages,struct xdp_umem * umem)282 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
283 u32 nr_pages, struct xdp_umem *umem)
284 {
285 struct xsk_dma_map *dma_map;
286
287 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
288 if (!dma_map)
289 return NULL;
290
291 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
292 if (!dma_map->dma_pages) {
293 kfree(dma_map);
294 return NULL;
295 }
296
297 dma_map->netdev = netdev;
298 dma_map->dev = dev;
299 dma_map->dma_need_sync = false;
300 dma_map->dma_pages_cnt = nr_pages;
301 refcount_set(&dma_map->users, 1);
302 list_add(&dma_map->list, &umem->xsk_dma_list);
303 return dma_map;
304 }
305
xp_destroy_dma_map(struct xsk_dma_map * dma_map)306 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
307 {
308 list_del(&dma_map->list);
309 kvfree(dma_map->dma_pages);
310 kfree(dma_map);
311 }
312
__xp_dma_unmap(struct xsk_dma_map * dma_map,unsigned long attrs)313 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
314 {
315 dma_addr_t *dma;
316 u32 i;
317
318 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
319 dma = &dma_map->dma_pages[i];
320 if (*dma) {
321 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
322 DMA_BIDIRECTIONAL, attrs);
323 *dma = 0;
324 }
325 }
326
327 xp_destroy_dma_map(dma_map);
328 }
329
xp_dma_unmap(struct xsk_buff_pool * pool,unsigned long attrs)330 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
331 {
332 struct xsk_dma_map *dma_map;
333
334 if (pool->dma_pages_cnt == 0)
335 return;
336
337 dma_map = xp_find_dma_map(pool);
338 if (!dma_map) {
339 WARN(1, "Could not find dma_map for device");
340 return;
341 }
342
343 if (!refcount_dec_and_test(&dma_map->users))
344 return;
345
346 __xp_dma_unmap(dma_map, attrs);
347 kvfree(pool->dma_pages);
348 pool->dma_pages_cnt = 0;
349 pool->dev = NULL;
350 }
351 EXPORT_SYMBOL(xp_dma_unmap);
352
xp_check_dma_contiguity(struct xsk_dma_map * dma_map)353 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
354 {
355 u32 i;
356
357 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
358 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
359 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
360 else
361 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
362 }
363 }
364
xp_init_dma_info(struct xsk_buff_pool * pool,struct xsk_dma_map * dma_map)365 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
366 {
367 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
368 if (!pool->dma_pages)
369 return -ENOMEM;
370
371 pool->dev = dma_map->dev;
372 pool->dma_pages_cnt = dma_map->dma_pages_cnt;
373 pool->dma_need_sync = dma_map->dma_need_sync;
374 memcpy(pool->dma_pages, dma_map->dma_pages,
375 pool->dma_pages_cnt * sizeof(*pool->dma_pages));
376
377 return 0;
378 }
379
xp_dma_map(struct xsk_buff_pool * pool,struct device * dev,unsigned long attrs,struct page ** pages,u32 nr_pages)380 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
381 unsigned long attrs, struct page **pages, u32 nr_pages)
382 {
383 struct xsk_dma_map *dma_map;
384 dma_addr_t dma;
385 int err;
386 u32 i;
387
388 dma_map = xp_find_dma_map(pool);
389 if (dma_map) {
390 err = xp_init_dma_info(pool, dma_map);
391 if (err)
392 return err;
393
394 refcount_inc(&dma_map->users);
395 return 0;
396 }
397
398 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
399 if (!dma_map)
400 return -ENOMEM;
401
402 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
403 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
404 DMA_BIDIRECTIONAL, attrs);
405 if (dma_mapping_error(dev, dma)) {
406 __xp_dma_unmap(dma_map, attrs);
407 return -ENOMEM;
408 }
409 if (dma_need_sync(dev, dma))
410 dma_map->dma_need_sync = true;
411 dma_map->dma_pages[i] = dma;
412 }
413
414 if (pool->unaligned)
415 xp_check_dma_contiguity(dma_map);
416
417 err = xp_init_dma_info(pool, dma_map);
418 if (err) {
419 __xp_dma_unmap(dma_map, attrs);
420 return err;
421 }
422
423 return 0;
424 }
425 EXPORT_SYMBOL(xp_dma_map);
426
xp_addr_crosses_non_contig_pg(struct xsk_buff_pool * pool,u64 addr)427 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
428 u64 addr)
429 {
430 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
431 }
432
xp_check_unaligned(struct xsk_buff_pool * pool,u64 * addr)433 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
434 {
435 *addr = xp_unaligned_extract_addr(*addr);
436 if (*addr >= pool->addrs_cnt ||
437 *addr + pool->chunk_size > pool->addrs_cnt ||
438 xp_addr_crosses_non_contig_pg(pool, *addr))
439 return false;
440 return true;
441 }
442
xp_check_aligned(struct xsk_buff_pool * pool,u64 * addr)443 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
444 {
445 *addr = xp_aligned_extract_addr(pool, *addr);
446 return *addr < pool->addrs_cnt;
447 }
448
__xp_alloc(struct xsk_buff_pool * pool)449 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
450 {
451 struct xdp_buff_xsk *xskb;
452 u64 addr;
453 bool ok;
454
455 if (pool->free_heads_cnt == 0)
456 return NULL;
457
458 xskb = pool->free_heads[--pool->free_heads_cnt];
459
460 for (;;) {
461 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
462 pool->fq->queue_empty_descs++;
463 xp_release(xskb);
464 return NULL;
465 }
466
467 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
468 xp_check_aligned(pool, &addr);
469 if (!ok) {
470 pool->fq->invalid_descs++;
471 xskq_cons_release(pool->fq);
472 continue;
473 }
474 break;
475 }
476 xskq_cons_release(pool->fq);
477
478 xskb->orig_addr = addr;
479 xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
480 if (pool->dma_pages_cnt) {
481 xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
482 ~XSK_NEXT_PG_CONTIG_MASK) +
483 (addr & ~PAGE_MASK);
484 xskb->dma = xskb->frame_dma + pool->headroom +
485 XDP_PACKET_HEADROOM;
486 }
487 return xskb;
488 }
489
xp_alloc(struct xsk_buff_pool * pool)490 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
491 {
492 struct xdp_buff_xsk *xskb;
493
494 if (!pool->free_list_cnt) {
495 xskb = __xp_alloc(pool);
496 if (!xskb)
497 return NULL;
498 } else {
499 pool->free_list_cnt--;
500 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
501 free_list_node);
502 list_del(&xskb->free_list_node);
503 }
504
505 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
506 xskb->xdp.data_meta = xskb->xdp.data;
507
508 if (pool->dma_need_sync) {
509 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
510 pool->frame_len,
511 DMA_BIDIRECTIONAL);
512 }
513 return &xskb->xdp;
514 }
515 EXPORT_SYMBOL(xp_alloc);
516
xp_can_alloc(struct xsk_buff_pool * pool,u32 count)517 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
518 {
519 if (pool->free_list_cnt >= count)
520 return true;
521 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
522 }
523 EXPORT_SYMBOL(xp_can_alloc);
524
xp_free(struct xdp_buff_xsk * xskb)525 void xp_free(struct xdp_buff_xsk *xskb)
526 {
527 xskb->pool->free_list_cnt++;
528 list_add(&xskb->free_list_node, &xskb->pool->free_list);
529 }
530 EXPORT_SYMBOL(xp_free);
531
xp_raw_get_data(struct xsk_buff_pool * pool,u64 addr)532 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
533 {
534 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
535 return pool->addrs + addr;
536 }
537 EXPORT_SYMBOL(xp_raw_get_data);
538
xp_raw_get_dma(struct xsk_buff_pool * pool,u64 addr)539 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
540 {
541 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
542 return (pool->dma_pages[addr >> PAGE_SHIFT] &
543 ~XSK_NEXT_PG_CONTIG_MASK) +
544 (addr & ~PAGE_MASK);
545 }
546 EXPORT_SYMBOL(xp_raw_get_dma);
547
xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk * xskb)548 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
549 {
550 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
551 xskb->pool->frame_len, DMA_BIDIRECTIONAL);
552 }
553 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
554
xp_dma_sync_for_device_slow(struct xsk_buff_pool * pool,dma_addr_t dma,size_t size)555 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
556 size_t size)
557 {
558 dma_sync_single_range_for_device(pool->dev, dma, 0,
559 size, DMA_BIDIRECTIONAL);
560 }
561 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);
562