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5
6#include <linux/bpf.h>
7#include <linux/filter.h>
8#include <linux/types.h>
9#include <linux/mm.h>
10#include <linux/netdevice.h>
11#include <linux/slab.h>
12#include <linux/idr.h>
13#include <linux/rhashtable.h>
14#include <linux/bug.h>
15#include <net/page_pool.h>
16
17#include <net/xdp.h>
18#include <net/xdp_priv.h>
19#include <trace/events/xdp.h>
20#include <net/xdp_sock_drv.h>
21
22#define REG_STATE_NEW 0x0
23#define REG_STATE_REGISTERED 0x1
24#define REG_STATE_UNREGISTERED 0x2
25#define REG_STATE_UNUSED 0x3
26
27static DEFINE_IDA(mem_id_pool);
28static DEFINE_MUTEX(mem_id_lock);
29#define MEM_ID_MAX 0xFFFE
30#define MEM_ID_MIN 1
31static int mem_id_next = MEM_ID_MIN;
32
33static bool mem_id_init;
34static struct rhashtable *mem_id_ht;
35
36static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
37{
38 const u32 *k = data;
39 const u32 key = *k;
40
41 BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id)
42 != sizeof(u32));
43
44
45 return key;
46}
47
48static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,
49 const void *ptr)
50{
51 const struct xdp_mem_allocator *xa = ptr;
52 u32 mem_id = *(u32 *)arg->key;
53
54 return xa->mem.id != mem_id;
55}
56
57static const struct rhashtable_params mem_id_rht_params = {
58 .nelem_hint = 64,
59 .head_offset = offsetof(struct xdp_mem_allocator, node),
60 .key_offset = offsetof(struct xdp_mem_allocator, mem.id),
61 .key_len = sizeof_field(struct xdp_mem_allocator, mem.id),
62 .max_size = MEM_ID_MAX,
63 .min_size = 8,
64 .automatic_shrinking = true,
65 .hashfn = xdp_mem_id_hashfn,
66 .obj_cmpfn = xdp_mem_id_cmp,
67};
68
69static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
70{
71 struct xdp_mem_allocator *xa;
72
73 xa = container_of(rcu, struct xdp_mem_allocator, rcu);
74
75
76 ida_simple_remove(&mem_id_pool, xa->mem.id);
77
78 kfree(xa);
79}
80
81static void mem_xa_remove(struct xdp_mem_allocator *xa)
82{
83 trace_mem_disconnect(xa);
84
85 if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
86 call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
87}
88
89static void mem_allocator_disconnect(void *allocator)
90{
91 struct xdp_mem_allocator *xa;
92 struct rhashtable_iter iter;
93
94 mutex_lock(&mem_id_lock);
95
96 rhashtable_walk_enter(mem_id_ht, &iter);
97 do {
98 rhashtable_walk_start(&iter);
99
100 while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) {
101 if (xa->allocator == allocator)
102 mem_xa_remove(xa);
103 }
104
105 rhashtable_walk_stop(&iter);
106
107 } while (xa == ERR_PTR(-EAGAIN));
108 rhashtable_walk_exit(&iter);
109
110 mutex_unlock(&mem_id_lock);
111}
112
113void xdp_unreg_mem_model(struct xdp_mem_info *mem)
114{
115 struct xdp_mem_allocator *xa;
116 int type = mem->type;
117 int id = mem->id;
118
119
120 mem->id = 0;
121 mem->type = 0;
122
123 if (id == 0)
124 return;
125
126 if (type == MEM_TYPE_PAGE_POOL) {
127 rcu_read_lock();
128 xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
129 page_pool_destroy(xa->page_pool);
130 rcu_read_unlock();
131 }
132}
133EXPORT_SYMBOL_GPL(xdp_unreg_mem_model);
134
135void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
136{
137 if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
138 WARN(1, "Missing register, driver bug");
139 return;
140 }
141
142 xdp_unreg_mem_model(&xdp_rxq->mem);
143}
144EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);
145
146void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
147{
148
149 if (xdp_rxq->reg_state == REG_STATE_UNUSED)
150 return;
151
152 xdp_rxq_info_unreg_mem_model(xdp_rxq);
153
154 xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
155 xdp_rxq->dev = NULL;
156}
157EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
158
159static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
160{
161 memset(xdp_rxq, 0, sizeof(*xdp_rxq));
162}
163
164
165int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
166 struct net_device *dev, u32 queue_index, unsigned int napi_id)
167{
168 if (!dev) {
169 WARN(1, "Missing net_device from driver");
170 return -ENODEV;
171 }
172
173 if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
174 WARN(1, "Driver promised not to register this");
175 return -EINVAL;
176 }
177
178 if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
179 WARN(1, "Missing unregister, handled but fix driver");
180 xdp_rxq_info_unreg(xdp_rxq);
181 }
182
183
184 xdp_rxq_info_init(xdp_rxq);
185 xdp_rxq->dev = dev;
186 xdp_rxq->queue_index = queue_index;
187 xdp_rxq->napi_id = napi_id;
188
189 xdp_rxq->reg_state = REG_STATE_REGISTERED;
190 return 0;
191}
192EXPORT_SYMBOL_GPL(xdp_rxq_info_reg);
193
194void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
195{
196 xdp_rxq->reg_state = REG_STATE_UNUSED;
197}
198EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
199
200bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
201{
202 return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
203}
204EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);
205
206static int __mem_id_init_hash_table(void)
207{
208 struct rhashtable *rht;
209 int ret;
210
211 if (unlikely(mem_id_init))
212 return 0;
213
214 rht = kzalloc(sizeof(*rht), GFP_KERNEL);
215 if (!rht)
216 return -ENOMEM;
217
218 ret = rhashtable_init(rht, &mem_id_rht_params);
219 if (ret < 0) {
220 kfree(rht);
221 return ret;
222 }
223 mem_id_ht = rht;
224 smp_mb();
225 mem_id_init = true;
226
227 return 0;
228}
229
230
231
232
233
234
235static int __mem_id_cyclic_get(gfp_t gfp)
236{
237 int retries = 1;
238 int id;
239
240again:
241 id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp);
242 if (id < 0) {
243 if (id == -ENOSPC) {
244
245 if (retries--) {
246 mem_id_next = MEM_ID_MIN;
247 goto again;
248 }
249 }
250 return id;
251 }
252 mem_id_next = id + 1;
253
254 return id;
255}
256
257static bool __is_supported_mem_type(enum xdp_mem_type type)
258{
259 if (type == MEM_TYPE_PAGE_POOL)
260 return is_page_pool_compiled_in();
261
262 if (type >= MEM_TYPE_MAX)
263 return false;
264
265 return true;
266}
267
268static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem,
269 enum xdp_mem_type type,
270 void *allocator)
271{
272 struct xdp_mem_allocator *xdp_alloc;
273 gfp_t gfp = GFP_KERNEL;
274 int id, errno, ret;
275 void *ptr;
276
277 if (!__is_supported_mem_type(type))
278 return ERR_PTR(-EOPNOTSUPP);
279
280 mem->type = type;
281
282 if (!allocator) {
283 if (type == MEM_TYPE_PAGE_POOL)
284 return ERR_PTR(-EINVAL);
285 return NULL;
286 }
287
288
289 if (!mem_id_init) {
290 mutex_lock(&mem_id_lock);
291 ret = __mem_id_init_hash_table();
292 mutex_unlock(&mem_id_lock);
293 if (ret < 0) {
294 WARN_ON(1);
295 return ERR_PTR(ret);
296 }
297 }
298
299 xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
300 if (!xdp_alloc)
301 return ERR_PTR(-ENOMEM);
302
303 mutex_lock(&mem_id_lock);
304 id = __mem_id_cyclic_get(gfp);
305 if (id < 0) {
306 errno = id;
307 goto err;
308 }
309 mem->id = id;
310 xdp_alloc->mem = *mem;
311 xdp_alloc->allocator = allocator;
312
313
314 ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
315 if (IS_ERR(ptr)) {
316 ida_simple_remove(&mem_id_pool, mem->id);
317 mem->id = 0;
318 errno = PTR_ERR(ptr);
319 goto err;
320 }
321
322 if (type == MEM_TYPE_PAGE_POOL)
323 page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem);
324
325 mutex_unlock(&mem_id_lock);
326
327 return xdp_alloc;
328err:
329 mutex_unlock(&mem_id_lock);
330 kfree(xdp_alloc);
331 return ERR_PTR(errno);
332}
333
334int xdp_reg_mem_model(struct xdp_mem_info *mem,
335 enum xdp_mem_type type, void *allocator)
336{
337 struct xdp_mem_allocator *xdp_alloc;
338
339 xdp_alloc = __xdp_reg_mem_model(mem, type, allocator);
340 if (IS_ERR(xdp_alloc))
341 return PTR_ERR(xdp_alloc);
342 return 0;
343}
344EXPORT_SYMBOL_GPL(xdp_reg_mem_model);
345
346int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
347 enum xdp_mem_type type, void *allocator)
348{
349 struct xdp_mem_allocator *xdp_alloc;
350
351 if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
352 WARN(1, "Missing register, driver bug");
353 return -EFAULT;
354 }
355
356 xdp_alloc = __xdp_reg_mem_model(&xdp_rxq->mem, type, allocator);
357 if (IS_ERR(xdp_alloc))
358 return PTR_ERR(xdp_alloc);
359
360 if (trace_mem_connect_enabled() && xdp_alloc)
361 trace_mem_connect(xdp_alloc, xdp_rxq);
362 return 0;
363}
364
365EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
366
367
368
369
370
371
372
373static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
374 struct xdp_buff *xdp)
375{
376 struct xdp_mem_allocator *xa;
377 struct page *page;
378
379 switch (mem->type) {
380 case MEM_TYPE_PAGE_POOL:
381 rcu_read_lock();
382
383 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
384 page = virt_to_head_page(data);
385 if (napi_direct && xdp_return_frame_no_direct())
386 napi_direct = false;
387 page_pool_put_full_page(xa->page_pool, page, napi_direct);
388 rcu_read_unlock();
389 break;
390 case MEM_TYPE_PAGE_SHARED:
391 page_frag_free(data);
392 break;
393 case MEM_TYPE_PAGE_ORDER0:
394 page = virt_to_page(data);
395 put_page(page);
396 break;
397 case MEM_TYPE_XSK_BUFF_POOL:
398
399 xsk_buff_free(xdp);
400 break;
401 default:
402
403 WARN(1, "Incorrect XDP memory type (%d) usage", mem->type);
404 break;
405 }
406}
407
408void xdp_return_frame(struct xdp_frame *xdpf)
409{
410 __xdp_return(xdpf->data, &xdpf->mem, false, NULL);
411}
412EXPORT_SYMBOL_GPL(xdp_return_frame);
413
414void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
415{
416 __xdp_return(xdpf->data, &xdpf->mem, true, NULL);
417}
418EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
419
420
421
422
423
424
425
426
427
428
429
430void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq)
431{
432 struct xdp_mem_allocator *xa = bq->xa;
433
434 if (unlikely(!xa || !bq->count))
435 return;
436
437 page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count);
438
439 bq->count = 0;
440}
441EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk);
442
443
444void xdp_return_frame_bulk(struct xdp_frame *xdpf,
445 struct xdp_frame_bulk *bq)
446{
447 struct xdp_mem_info *mem = &xdpf->mem;
448 struct xdp_mem_allocator *xa;
449
450 if (mem->type != MEM_TYPE_PAGE_POOL) {
451 __xdp_return(xdpf->data, &xdpf->mem, false, NULL);
452 return;
453 }
454
455 xa = bq->xa;
456 if (unlikely(!xa)) {
457 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
458 bq->count = 0;
459 bq->xa = xa;
460 }
461
462 if (bq->count == XDP_BULK_QUEUE_SIZE)
463 xdp_flush_frame_bulk(bq);
464
465 if (unlikely(mem->id != xa->mem.id)) {
466 xdp_flush_frame_bulk(bq);
467 bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
468 }
469
470 bq->q[bq->count++] = xdpf->data;
471}
472EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);
473
474void xdp_return_buff(struct xdp_buff *xdp)
475{
476 __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
477}
478
479
480void __xdp_release_frame(void *data, struct xdp_mem_info *mem)
481{
482 struct xdp_mem_allocator *xa;
483 struct page *page;
484
485 rcu_read_lock();
486 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
487 page = virt_to_head_page(data);
488 if (xa)
489 page_pool_release_page(xa->page_pool, page);
490 rcu_read_unlock();
491}
492EXPORT_SYMBOL_GPL(__xdp_release_frame);
493
494void xdp_attachment_setup(struct xdp_attachment_info *info,
495 struct netdev_bpf *bpf)
496{
497 if (info->prog)
498 bpf_prog_put(info->prog);
499 info->prog = bpf->prog;
500 info->flags = bpf->flags;
501}
502EXPORT_SYMBOL_GPL(xdp_attachment_setup);
503
504struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
505{
506 unsigned int metasize, totsize;
507 void *addr, *data_to_copy;
508 struct xdp_frame *xdpf;
509 struct page *page;
510
511
512 metasize = xdp_data_meta_unsupported(xdp) ? 0 :
513 xdp->data - xdp->data_meta;
514 totsize = xdp->data_end - xdp->data + metasize;
515
516 if (sizeof(*xdpf) + totsize > PAGE_SIZE)
517 return NULL;
518
519 page = dev_alloc_page();
520 if (!page)
521 return NULL;
522
523 addr = page_to_virt(page);
524 xdpf = addr;
525 memset(xdpf, 0, sizeof(*xdpf));
526
527 addr += sizeof(*xdpf);
528 data_to_copy = metasize ? xdp->data_meta : xdp->data;
529 memcpy(addr, data_to_copy, totsize);
530
531 xdpf->data = addr + metasize;
532 xdpf->len = totsize - metasize;
533 xdpf->headroom = 0;
534 xdpf->metasize = metasize;
535 xdpf->frame_sz = PAGE_SIZE;
536 xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
537
538 xsk_buff_free(xdp);
539 return xdpf;
540}
541EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);
542
543
544void xdp_warn(const char *msg, const char *func, const int line)
545{
546 WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);
547};
548EXPORT_SYMBOL_GPL(xdp_warn);
549
550int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp)
551{
552 n_skb = kmem_cache_alloc_bulk(skbuff_head_cache, gfp,
553 n_skb, skbs);
554 if (unlikely(!n_skb))
555 return -ENOMEM;
556
557 return 0;
558}
559EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk);
560
561struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
562 struct sk_buff *skb,
563 struct net_device *dev)
564{
565 unsigned int headroom, frame_size;
566 void *hard_start;
567
568
569 headroom = sizeof(*xdpf) + xdpf->headroom;
570
571
572
573
574 frame_size = xdpf->frame_sz;
575
576 hard_start = xdpf->data - headroom;
577 skb = build_skb_around(skb, hard_start, frame_size);
578 if (unlikely(!skb))
579 return NULL;
580
581 skb_reserve(skb, headroom);
582 __skb_put(skb, xdpf->len);
583 if (xdpf->metasize)
584 skb_metadata_set(skb, xdpf->metasize);
585
586
587 skb->protocol = eth_type_trans(skb, dev);
588
589
590
591
592
593
594
595
596 xdp_release_frame(xdpf);
597
598
599 xdp_scrub_frame(xdpf);
600
601 return skb;
602}
603EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);
604
605struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
606 struct net_device *dev)
607{
608 struct sk_buff *skb;
609
610 skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
611 if (unlikely(!skb))
612 return NULL;
613
614 memset(skb, 0, offsetof(struct sk_buff, tail));
615
616 return __xdp_build_skb_from_frame(xdpf, skb, dev);
617}
618EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame);
619
620struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf)
621{
622 unsigned int headroom, totalsize;
623 struct xdp_frame *nxdpf;
624 struct page *page;
625 void *addr;
626
627 headroom = xdpf->headroom + sizeof(*xdpf);
628 totalsize = headroom + xdpf->len;
629
630 if (unlikely(totalsize > PAGE_SIZE))
631 return NULL;
632 page = dev_alloc_page();
633 if (!page)
634 return NULL;
635 addr = page_to_virt(page);
636
637 memcpy(addr, xdpf, totalsize);
638
639 nxdpf = addr;
640 nxdpf->data = addr + headroom;
641 nxdpf->frame_sz = PAGE_SIZE;
642 nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
643 nxdpf->mem.id = 0;
644
645 return nxdpf;
646}
647