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_sock * umem_xs,struct net_device * dev,u16 queue_id)201 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
202 struct net_device *dev, u16 queue_id)
203 {
204 u16 flags;
205 struct xdp_umem *umem = umem_xs->umem;
206
207 /* One fill and completion ring required for each queue id. */
208 if (!pool->fq || !pool->cq)
209 return -EINVAL;
210
211 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
212 if (umem_xs->pool->uses_need_wakeup)
213 flags |= XDP_USE_NEED_WAKEUP;
214
215 return __xp_assign_dev(pool, dev, queue_id, flags);
216 }
217
xp_clear_dev(struct xsk_buff_pool * pool)218 void xp_clear_dev(struct xsk_buff_pool *pool)
219 {
220 if (!pool->netdev)
221 return;
222
223 xp_disable_drv_zc(pool);
224 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
225 dev_put(pool->netdev);
226 pool->netdev = NULL;
227 }
228
xp_release_deferred(struct work_struct * work)229 static void xp_release_deferred(struct work_struct *work)
230 {
231 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
232 work);
233
234 rtnl_lock();
235 xp_clear_dev(pool);
236 rtnl_unlock();
237
238 if (pool->fq) {
239 xskq_destroy(pool->fq);
240 pool->fq = NULL;
241 }
242
243 if (pool->cq) {
244 xskq_destroy(pool->cq);
245 pool->cq = NULL;
246 }
247
248 xdp_put_umem(pool->umem, false);
249 xp_destroy(pool);
250 }
251
xp_get_pool(struct xsk_buff_pool * pool)252 void xp_get_pool(struct xsk_buff_pool *pool)
253 {
254 refcount_inc(&pool->users);
255 }
256
xp_put_pool(struct xsk_buff_pool * pool)257 bool xp_put_pool(struct xsk_buff_pool *pool)
258 {
259 if (!pool)
260 return false;
261
262 if (refcount_dec_and_test(&pool->users)) {
263 INIT_WORK(&pool->work, xp_release_deferred);
264 schedule_work(&pool->work);
265 return true;
266 }
267
268 return false;
269 }
270
xp_find_dma_map(struct xsk_buff_pool * pool)271 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
272 {
273 struct xsk_dma_map *dma_map;
274
275 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
276 if (dma_map->netdev == pool->netdev)
277 return dma_map;
278 }
279
280 return NULL;
281 }
282
xp_create_dma_map(struct device * dev,struct net_device * netdev,u32 nr_pages,struct xdp_umem * umem)283 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
284 u32 nr_pages, struct xdp_umem *umem)
285 {
286 struct xsk_dma_map *dma_map;
287
288 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
289 if (!dma_map)
290 return NULL;
291
292 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
293 if (!dma_map->dma_pages) {
294 kfree(dma_map);
295 return NULL;
296 }
297
298 dma_map->netdev = netdev;
299 dma_map->dev = dev;
300 dma_map->dma_need_sync = false;
301 dma_map->dma_pages_cnt = nr_pages;
302 refcount_set(&dma_map->users, 1);
303 list_add(&dma_map->list, &umem->xsk_dma_list);
304 return dma_map;
305 }
306
xp_destroy_dma_map(struct xsk_dma_map * dma_map)307 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
308 {
309 list_del(&dma_map->list);
310 kvfree(dma_map->dma_pages);
311 kfree(dma_map);
312 }
313
__xp_dma_unmap(struct xsk_dma_map * dma_map,unsigned long attrs)314 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
315 {
316 dma_addr_t *dma;
317 u32 i;
318
319 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
320 dma = &dma_map->dma_pages[i];
321 if (*dma) {
322 *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
323 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
324 DMA_BIDIRECTIONAL, attrs);
325 *dma = 0;
326 }
327 }
328
329 xp_destroy_dma_map(dma_map);
330 }
331
xp_dma_unmap(struct xsk_buff_pool * pool,unsigned long attrs)332 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
333 {
334 struct xsk_dma_map *dma_map;
335
336 if (pool->dma_pages_cnt == 0)
337 return;
338
339 dma_map = xp_find_dma_map(pool);
340 if (!dma_map) {
341 WARN(1, "Could not find dma_map for device");
342 return;
343 }
344
345 if (!refcount_dec_and_test(&dma_map->users))
346 return;
347
348 __xp_dma_unmap(dma_map, attrs);
349 kvfree(pool->dma_pages);
350 pool->dma_pages_cnt = 0;
351 pool->dev = NULL;
352 }
353 EXPORT_SYMBOL(xp_dma_unmap);
354
xp_check_dma_contiguity(struct xsk_dma_map * dma_map)355 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
356 {
357 u32 i;
358
359 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
360 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
361 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
362 else
363 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
364 }
365 }
366
xp_init_dma_info(struct xsk_buff_pool * pool,struct xsk_dma_map * dma_map)367 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
368 {
369 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
370 if (!pool->dma_pages)
371 return -ENOMEM;
372
373 pool->dev = dma_map->dev;
374 pool->dma_pages_cnt = dma_map->dma_pages_cnt;
375 pool->dma_need_sync = dma_map->dma_need_sync;
376 memcpy(pool->dma_pages, dma_map->dma_pages,
377 pool->dma_pages_cnt * sizeof(*pool->dma_pages));
378
379 return 0;
380 }
381
xp_dma_map(struct xsk_buff_pool * pool,struct device * dev,unsigned long attrs,struct page ** pages,u32 nr_pages)382 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
383 unsigned long attrs, struct page **pages, u32 nr_pages)
384 {
385 struct xsk_dma_map *dma_map;
386 dma_addr_t dma;
387 int err;
388 u32 i;
389
390 dma_map = xp_find_dma_map(pool);
391 if (dma_map) {
392 err = xp_init_dma_info(pool, dma_map);
393 if (err)
394 return err;
395
396 refcount_inc(&dma_map->users);
397 return 0;
398 }
399
400 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
401 if (!dma_map)
402 return -ENOMEM;
403
404 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
405 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
406 DMA_BIDIRECTIONAL, attrs);
407 if (dma_mapping_error(dev, dma)) {
408 __xp_dma_unmap(dma_map, attrs);
409 return -ENOMEM;
410 }
411 if (dma_need_sync(dev, dma))
412 dma_map->dma_need_sync = true;
413 dma_map->dma_pages[i] = dma;
414 }
415
416 if (pool->unaligned)
417 xp_check_dma_contiguity(dma_map);
418
419 err = xp_init_dma_info(pool, dma_map);
420 if (err) {
421 __xp_dma_unmap(dma_map, attrs);
422 return err;
423 }
424
425 return 0;
426 }
427 EXPORT_SYMBOL(xp_dma_map);
428
xp_addr_crosses_non_contig_pg(struct xsk_buff_pool * pool,u64 addr)429 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
430 u64 addr)
431 {
432 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
433 }
434
xp_check_unaligned(struct xsk_buff_pool * pool,u64 * addr)435 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
436 {
437 *addr = xp_unaligned_extract_addr(*addr);
438 if (*addr >= pool->addrs_cnt ||
439 *addr + pool->chunk_size > pool->addrs_cnt ||
440 xp_addr_crosses_non_contig_pg(pool, *addr))
441 return false;
442 return true;
443 }
444
xp_check_aligned(struct xsk_buff_pool * pool,u64 * addr)445 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
446 {
447 *addr = xp_aligned_extract_addr(pool, *addr);
448 return *addr < pool->addrs_cnt;
449 }
450
__xp_alloc(struct xsk_buff_pool * pool)451 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
452 {
453 struct xdp_buff_xsk *xskb;
454 u64 addr;
455 bool ok;
456
457 if (pool->free_heads_cnt == 0)
458 return NULL;
459
460 xskb = pool->free_heads[--pool->free_heads_cnt];
461
462 for (;;) {
463 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
464 pool->fq->queue_empty_descs++;
465 xp_release(xskb);
466 return NULL;
467 }
468
469 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
470 xp_check_aligned(pool, &addr);
471 if (!ok) {
472 pool->fq->invalid_descs++;
473 xskq_cons_release(pool->fq);
474 continue;
475 }
476 break;
477 }
478 xskq_cons_release(pool->fq);
479
480 xskb->orig_addr = addr;
481 xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
482 if (pool->dma_pages_cnt) {
483 xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
484 ~XSK_NEXT_PG_CONTIG_MASK) +
485 (addr & ~PAGE_MASK);
486 xskb->dma = xskb->frame_dma + pool->headroom +
487 XDP_PACKET_HEADROOM;
488 }
489 return xskb;
490 }
491
xp_alloc(struct xsk_buff_pool * pool)492 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
493 {
494 struct xdp_buff_xsk *xskb;
495
496 if (!pool->free_list_cnt) {
497 xskb = __xp_alloc(pool);
498 if (!xskb)
499 return NULL;
500 } else {
501 pool->free_list_cnt--;
502 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
503 free_list_node);
504 list_del(&xskb->free_list_node);
505 }
506
507 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
508 xskb->xdp.data_meta = xskb->xdp.data;
509
510 if (pool->dma_need_sync) {
511 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
512 pool->frame_len,
513 DMA_BIDIRECTIONAL);
514 }
515 return &xskb->xdp;
516 }
517 EXPORT_SYMBOL(xp_alloc);
518
xp_can_alloc(struct xsk_buff_pool * pool,u32 count)519 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
520 {
521 if (pool->free_list_cnt >= count)
522 return true;
523 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
524 }
525 EXPORT_SYMBOL(xp_can_alloc);
526
xp_free(struct xdp_buff_xsk * xskb)527 void xp_free(struct xdp_buff_xsk *xskb)
528 {
529 xskb->pool->free_list_cnt++;
530 list_add(&xskb->free_list_node, &xskb->pool->free_list);
531 }
532 EXPORT_SYMBOL(xp_free);
533
xp_raw_get_data(struct xsk_buff_pool * pool,u64 addr)534 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
535 {
536 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
537 return pool->addrs + addr;
538 }
539 EXPORT_SYMBOL(xp_raw_get_data);
540
xp_raw_get_dma(struct xsk_buff_pool * pool,u64 addr)541 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
542 {
543 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
544 return (pool->dma_pages[addr >> PAGE_SHIFT] &
545 ~XSK_NEXT_PG_CONTIG_MASK) +
546 (addr & ~PAGE_MASK);
547 }
548 EXPORT_SYMBOL(xp_raw_get_dma);
549
xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk * xskb)550 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
551 {
552 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
553 xskb->pool->frame_len, DMA_BIDIRECTIONAL);
554 }
555 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
556
xp_dma_sync_for_device_slow(struct xsk_buff_pool * pool,dma_addr_t dma,size_t size)557 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
558 size_t size)
559 {
560 dma_sync_single_range_for_device(pool->dev, dma, 0,
561 size, DMA_BIDIRECTIONAL);
562 }
563 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);
564