1 // SPDX-License-Identifier: GPL-2.0
3 #include <net/xsk_buff_pool.h>
4 #include <net/xdp_sock.h>
5 #include <net/xdp_sock_drv.h>
11 void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
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);
23 void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
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);
35 void xp_destroy(struct xsk_buff_pool *pool)
40 kvfree(pool->tx_descs);
45 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
47 pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
55 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
56 struct xdp_umem *umem)
58 bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
59 struct xsk_buff_pool *pool;
60 struct xdp_buff_xsk *xskb;
63 entries = unaligned ? umem->chunks : 0;
64 pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL);
68 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
73 if (xp_alloc_tx_descs(pool, xs))
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 -
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);
97 pool->fq = xs->fq_tmp;
98 pool->cq = xs->cq_tmp;
100 for (i = 0; i < pool->free_heads_cnt; i++) {
101 xskb = &pool->heads[i];
103 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
104 INIT_LIST_HEAD(&xskb->free_list_node);
105 INIT_LIST_HEAD(&xskb->xskb_list_node);
107 pool->free_heads[i] = xskb;
109 xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
119 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
123 for (i = 0; i < pool->heads_cnt; i++)
124 pool->heads[i].xdp.rxq = rxq;
126 EXPORT_SYMBOL(xp_set_rxq_info);
128 void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc)
132 for (i = 0; i < pool->heads_cnt; i++) {
133 struct xdp_buff_xsk *xskb = &pool->heads[i];
135 memcpy(xskb->cb + desc->off, desc->src, desc->bytes);
138 EXPORT_SYMBOL(xp_fill_cb);
140 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
142 struct netdev_bpf bpf;
147 if (pool->umem->zc) {
148 bpf.command = XDP_SETUP_XSK_POOL;
150 bpf.xsk.queue_id = pool->queue_id;
152 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
155 WARN(1, "Failed to disable zero-copy!\n");
159 #define NETDEV_XDP_ACT_ZC (NETDEV_XDP_ACT_BASIC | \
160 NETDEV_XDP_ACT_REDIRECT | \
161 NETDEV_XDP_ACT_XSK_ZEROCOPY)
163 int xp_assign_dev(struct xsk_buff_pool *pool,
164 struct net_device *netdev, u16 queue_id, u16 flags)
166 bool force_zc, force_copy;
167 struct netdev_bpf bpf;
172 force_zc = flags & XDP_ZEROCOPY;
173 force_copy = flags & XDP_COPY;
175 if (force_zc && force_copy)
178 if (xsk_get_pool_from_qid(netdev, queue_id))
181 pool->netdev = netdev;
182 pool->queue_id = queue_id;
183 err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
187 if (flags & XDP_USE_SG)
188 pool->umem->flags |= XDP_UMEM_SG_FLAG;
190 if (flags & XDP_USE_NEED_WAKEUP)
191 pool->uses_need_wakeup = true;
192 /* Tx needs to be explicitly woken up the first time. Also
193 * for supporting drivers that do not implement this
194 * feature. They will always have to call sendto() or poll().
196 pool->cached_need_wakeup = XDP_WAKEUP_TX;
201 /* For copy-mode, we are done. */
204 if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {
209 if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) {
214 if (dev_get_min_mp_channel_count(netdev)) {
219 bpf.command = XDP_SETUP_XSK_POOL;
221 bpf.xsk.queue_id = queue_id;
223 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
227 if (!pool->dma_pages) {
228 WARN(1, "Driver did not DMA map zero-copy buffers");
232 pool->umem->zc = true;
236 xp_disable_drv_zc(pool);
239 err = 0; /* fallback to copy mode */
241 xsk_clear_pool_at_qid(netdev, queue_id);
247 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
248 struct net_device *dev, u16 queue_id)
251 struct xdp_umem *umem = umem_xs->umem;
253 /* One fill and completion ring required for each queue id. */
254 if (!pool->fq || !pool->cq)
257 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
258 if (umem_xs->pool->uses_need_wakeup)
259 flags |= XDP_USE_NEED_WAKEUP;
261 return xp_assign_dev(pool, dev, queue_id, flags);
264 void xp_clear_dev(struct xsk_buff_pool *pool)
269 xp_disable_drv_zc(pool);
270 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
271 dev_put(pool->netdev);
275 static void xp_release_deferred(struct work_struct *work)
277 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
285 xskq_destroy(pool->fq);
290 xskq_destroy(pool->cq);
294 xdp_put_umem(pool->umem, false);
298 void xp_get_pool(struct xsk_buff_pool *pool)
300 refcount_inc(&pool->users);
303 bool xp_put_pool(struct xsk_buff_pool *pool)
308 if (refcount_dec_and_test(&pool->users)) {
309 INIT_WORK(&pool->work, xp_release_deferred);
310 schedule_work(&pool->work);
317 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
319 struct xsk_dma_map *dma_map;
321 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
322 if (dma_map->netdev == pool->netdev)
329 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
330 u32 nr_pages, struct xdp_umem *umem)
332 struct xsk_dma_map *dma_map;
334 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
338 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
339 if (!dma_map->dma_pages) {
344 dma_map->netdev = netdev;
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);
352 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
354 list_del(&dma_map->list);
355 kvfree(dma_map->dma_pages);
359 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
364 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
365 dma = &dma_map->dma_pages[i];
367 *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
368 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
369 DMA_BIDIRECTIONAL, attrs);
374 xp_destroy_dma_map(dma_map);
377 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
379 struct xsk_dma_map *dma_map;
381 if (!pool->dma_pages)
384 dma_map = xp_find_dma_map(pool);
386 WARN(1, "Could not find dma_map for device");
390 if (!refcount_dec_and_test(&dma_map->users))
393 __xp_dma_unmap(dma_map, attrs);
394 kvfree(pool->dma_pages);
395 pool->dma_pages = NULL;
396 pool->dma_pages_cnt = 0;
399 EXPORT_SYMBOL(xp_dma_unmap);
401 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
405 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
406 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
407 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
409 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
413 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
415 if (!pool->unaligned) {
418 for (i = 0; i < pool->heads_cnt; i++) {
419 struct xdp_buff_xsk *xskb = &pool->heads[i];
421 xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
425 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
426 if (!pool->dma_pages)
429 pool->dev = dma_map->dev;
430 pool->dma_pages_cnt = dma_map->dma_pages_cnt;
431 memcpy(pool->dma_pages, dma_map->dma_pages,
432 pool->dma_pages_cnt * sizeof(*pool->dma_pages));
437 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
438 unsigned long attrs, struct page **pages, u32 nr_pages)
440 struct xsk_dma_map *dma_map;
445 dma_map = xp_find_dma_map(pool);
447 err = xp_init_dma_info(pool, dma_map);
451 refcount_inc(&dma_map->users);
455 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
459 for (i = 0; i < dma_map->dma_pages_cnt; i++) {
460 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
461 DMA_BIDIRECTIONAL, attrs);
462 if (dma_mapping_error(dev, dma)) {
463 __xp_dma_unmap(dma_map, attrs);
466 dma_map->dma_pages[i] = dma;
470 xp_check_dma_contiguity(dma_map);
472 err = xp_init_dma_info(pool, dma_map);
474 __xp_dma_unmap(dma_map, attrs);
480 EXPORT_SYMBOL(xp_dma_map);
482 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
485 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
488 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
490 *addr = xp_unaligned_extract_addr(*addr);
491 if (*addr >= pool->addrs_cnt ||
492 *addr + pool->chunk_size > pool->addrs_cnt ||
493 xp_addr_crosses_non_contig_pg(pool, *addr))
498 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
500 *addr = xp_aligned_extract_addr(pool, *addr);
501 return *addr < pool->addrs_cnt;
504 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
506 struct xdp_buff_xsk *xskb;
510 if (pool->free_heads_cnt == 0)
514 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
515 pool->fq->queue_empty_descs++;
519 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
520 xp_check_aligned(pool, &addr);
522 pool->fq->invalid_descs++;
523 xskq_cons_release(pool->fq);
529 if (pool->unaligned) {
530 xskb = pool->free_heads[--pool->free_heads_cnt];
531 xp_init_xskb_addr(xskb, pool, addr);
533 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
535 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
538 xskq_cons_release(pool->fq);
542 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
544 struct xdp_buff_xsk *xskb;
546 if (!pool->free_list_cnt) {
547 xskb = __xp_alloc(pool);
551 pool->free_list_cnt--;
552 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
554 list_del_init(&xskb->free_list_node);
557 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
558 xskb->xdp.data_meta = xskb->xdp.data;
562 xp_dma_sync_for_device(pool, xskb->dma, pool->frame_len);
566 EXPORT_SYMBOL(xp_alloc);
568 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
570 u32 i, cached_cons, nb_entries;
572 if (max > pool->free_heads_cnt)
573 max = pool->free_heads_cnt;
574 max = xskq_cons_nb_entries(pool->fq, max);
576 cached_cons = pool->fq->cached_cons;
580 struct xdp_buff_xsk *xskb;
584 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
586 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
587 xp_check_aligned(pool, &addr);
589 pool->fq->invalid_descs++;
594 if (pool->unaligned) {
595 xskb = pool->free_heads[--pool->free_heads_cnt];
596 xp_init_xskb_addr(xskb, pool, addr);
598 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
600 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
607 xskq_cons_release_n(pool->fq, max);
611 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
613 struct xdp_buff_xsk *xskb;
616 nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
620 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
621 list_del_init(&xskb->free_list_node);
626 pool->free_list_cnt -= nb_entries;
631 static u32 xp_alloc_slow(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
636 for (i = 0; i < max; i++) {
637 struct xdp_buff *buff;
639 buff = xp_alloc(pool);
649 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
651 u32 nb_entries1 = 0, nb_entries2;
653 if (unlikely(pool->dev && dma_dev_need_sync(pool->dev)))
654 return xp_alloc_slow(pool, xdp, max);
656 if (unlikely(pool->free_list_cnt)) {
657 nb_entries1 = xp_alloc_reused(pool, xdp, max);
658 if (nb_entries1 == max)
665 nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
667 pool->fq->queue_empty_descs++;
669 return nb_entries1 + nb_entries2;
671 EXPORT_SYMBOL(xp_alloc_batch);
673 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
675 u32 req_count, avail_count;
677 if (pool->free_list_cnt >= count)
680 req_count = count - pool->free_list_cnt;
681 avail_count = xskq_cons_nb_entries(pool->fq, req_count);
683 pool->fq->queue_empty_descs++;
685 return avail_count >= req_count;
687 EXPORT_SYMBOL(xp_can_alloc);
689 void xp_free(struct xdp_buff_xsk *xskb)
691 if (!list_empty(&xskb->free_list_node))
694 xskb->pool->free_list_cnt++;
695 list_add(&xskb->free_list_node, &xskb->pool->free_list);
697 EXPORT_SYMBOL(xp_free);
699 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
701 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
702 return pool->addrs + addr;
704 EXPORT_SYMBOL(xp_raw_get_data);
706 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
708 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
709 return (pool->dma_pages[addr >> PAGE_SHIFT] &
710 ~XSK_NEXT_PG_CONTIG_MASK) +
713 EXPORT_SYMBOL(xp_raw_get_dma);