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->heads);
41	kvfree(pool);
42}
43
44struct 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
89out:
90	xp_destroy(pool);
91	return NULL;
92}
93
94void 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}
101EXPORT_SYMBOL(xp_set_rxq_info);
102
103static 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
122static 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
183err_unreg_xsk:
184	xp_disable_drv_zc(pool);
185err_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
195int 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
201int 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
218void 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
229static 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
252void xp_get_pool(struct xsk_buff_pool *pool)
253{
254	refcount_inc(&pool->users);
255}
256
257bool 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
271static 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
283static 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
307static 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
314static 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
332void 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}
353EXPORT_SYMBOL(xp_dma_unmap);
354
355static 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
367static 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
382int 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}
427EXPORT_SYMBOL(xp_dma_map);
428
429static 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
435static 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
445static 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
451static 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
492struct 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}
517EXPORT_SYMBOL(xp_alloc);
518
519bool 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}
525EXPORT_SYMBOL(xp_can_alloc);
526
527void 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}
532EXPORT_SYMBOL(xp_free);
533
534void *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}
539EXPORT_SYMBOL(xp_raw_get_data);
540
541dma_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}
548EXPORT_SYMBOL(xp_raw_get_dma);
549
550void 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}
555EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
556
557void 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}
563EXPORT_SYMBOL(xp_dma_sync_for_device_slow);
564