Commit | Line | Data |
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ddc64d0a | 1 | // SPDX-License-Identifier: GPL-2.0-only |
aecd67b6 JDB |
2 | /* net/core/xdp.c |
3 | * | |
4 | * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. | |
aecd67b6 | 5 | */ |
05296620 JK |
6 | #include <linux/bpf.h> |
7 | #include <linux/filter.h> | |
aecd67b6 JDB |
8 | #include <linux/types.h> |
9 | #include <linux/mm.h> | |
05296620 | 10 | #include <linux/netdevice.h> |
8d5d8852 JDB |
11 | #include <linux/slab.h> |
12 | #include <linux/idr.h> | |
13 | #include <linux/rhashtable.h> | |
57d0a1c1 | 14 | #include <net/page_pool.h> |
aecd67b6 JDB |
15 | |
16 | #include <net/xdp.h> | |
f033b688 JDB |
17 | #include <net/xdp_priv.h> /* struct xdp_mem_allocator */ |
18 | #include <trace/events/xdp.h> | |
aecd67b6 JDB |
19 | |
20 | #define REG_STATE_NEW 0x0 | |
21 | #define REG_STATE_REGISTERED 0x1 | |
22 | #define REG_STATE_UNREGISTERED 0x2 | |
23 | #define REG_STATE_UNUSED 0x3 | |
24 | ||
8d5d8852 JDB |
25 | static DEFINE_IDA(mem_id_pool); |
26 | static DEFINE_MUTEX(mem_id_lock); | |
27 | #define MEM_ID_MAX 0xFFFE | |
28 | #define MEM_ID_MIN 1 | |
29 | static int mem_id_next = MEM_ID_MIN; | |
30 | ||
31 | static bool mem_id_init; /* false */ | |
32 | static struct rhashtable *mem_id_ht; | |
33 | ||
8d5d8852 JDB |
34 | static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed) |
35 | { | |
36 | const u32 *k = data; | |
37 | const u32 key = *k; | |
38 | ||
39 | BUILD_BUG_ON(FIELD_SIZEOF(struct xdp_mem_allocator, mem.id) | |
40 | != sizeof(u32)); | |
41 | ||
9f9a7077 N |
42 | /* Use cyclic increasing ID as direct hash key */ |
43 | return key; | |
8d5d8852 JDB |
44 | } |
45 | ||
46 | static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg, | |
47 | const void *ptr) | |
48 | { | |
49 | const struct xdp_mem_allocator *xa = ptr; | |
50 | u32 mem_id = *(u32 *)arg->key; | |
51 | ||
52 | return xa->mem.id != mem_id; | |
53 | } | |
54 | ||
55 | static const struct rhashtable_params mem_id_rht_params = { | |
56 | .nelem_hint = 64, | |
57 | .head_offset = offsetof(struct xdp_mem_allocator, node), | |
58 | .key_offset = offsetof(struct xdp_mem_allocator, mem.id), | |
59 | .key_len = FIELD_SIZEOF(struct xdp_mem_allocator, mem.id), | |
60 | .max_size = MEM_ID_MAX, | |
61 | .min_size = 8, | |
62 | .automatic_shrinking = true, | |
63 | .hashfn = xdp_mem_id_hashfn, | |
64 | .obj_cmpfn = xdp_mem_id_cmp, | |
65 | }; | |
66 | ||
67 | static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) | |
68 | { | |
69 | struct xdp_mem_allocator *xa; | |
70 | ||
71 | xa = container_of(rcu, struct xdp_mem_allocator, rcu); | |
72 | ||
73 | /* Allow this ID to be reused */ | |
74 | ida_simple_remove(&mem_id_pool, xa->mem.id); | |
75 | ||
8d5d8852 JDB |
76 | kfree(xa); |
77 | } | |
78 | ||
c3f812ce | 79 | static void mem_xa_remove(struct xdp_mem_allocator *xa) |
99c07c43 | 80 | { |
c3f812ce | 81 | trace_mem_disconnect(xa); |
99c07c43 JDB |
82 | |
83 | mutex_lock(&mem_id_lock); | |
84 | ||
c3f812ce | 85 | if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) |
99c07c43 JDB |
86 | call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); |
87 | ||
88 | mutex_unlock(&mem_id_lock); | |
99c07c43 JDB |
89 | } |
90 | ||
c3f812ce JL |
91 | static void mem_allocator_disconnect(void *allocator) |
92 | { | |
93 | struct xdp_mem_allocator *xa; | |
94 | struct rhashtable_iter iter; | |
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); | |
99c07c43 | 106 | |
c3f812ce JL |
107 | } while (xa == ERR_PTR(-EAGAIN)); |
108 | rhashtable_walk_exit(&iter); | |
109 | } | |
110 | ||
111 | static void mem_id_disconnect(int id) | |
99c07c43 | 112 | { |
c3f812ce | 113 | struct xdp_mem_allocator *xa; |
d956a048 | 114 | |
c3f812ce | 115 | mutex_lock(&mem_id_lock); |
99c07c43 | 116 | |
c3f812ce JL |
117 | xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params); |
118 | if (!xa) { | |
119 | mutex_unlock(&mem_id_lock); | |
120 | WARN(1, "Request remove non-existing id(%d), driver bug?", id); | |
99c07c43 | 121 | return; |
c3f812ce | 122 | } |
99c07c43 | 123 | |
c3f812ce | 124 | trace_mem_disconnect(xa); |
d956a048 | 125 | |
c3f812ce JL |
126 | if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) |
127 | call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); | |
d956a048 | 128 | |
c3f812ce | 129 | mutex_unlock(&mem_id_lock); |
99c07c43 JDB |
130 | } |
131 | ||
dce5bd61 | 132 | void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) |
8d5d8852 JDB |
133 | { |
134 | struct xdp_mem_allocator *xa; | |
135 | int id = xdp_rxq->mem.id; | |
8d5d8852 | 136 | |
dce5bd61 BT |
137 | if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { |
138 | WARN(1, "Missing register, driver bug"); | |
139 | return; | |
140 | } | |
141 | ||
8d5d8852 JDB |
142 | if (id == 0) |
143 | return; | |
144 | ||
c3f812ce JL |
145 | if (xdp_rxq->mem.type == MEM_TYPE_ZERO_COPY) |
146 | return mem_id_disconnect(id); | |
8d5d8852 | 147 | |
c3f812ce JL |
148 | if (xdp_rxq->mem.type == MEM_TYPE_PAGE_POOL) { |
149 | rcu_read_lock(); | |
150 | xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params); | |
151 | page_pool_destroy(xa->page_pool); | |
152 | rcu_read_unlock(); | |
99c07c43 | 153 | } |
8d5d8852 | 154 | } |
dce5bd61 | 155 | EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model); |
8d5d8852 | 156 | |
aecd67b6 JDB |
157 | void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq) |
158 | { | |
159 | /* Simplify driver cleanup code paths, allow unreg "unused" */ | |
160 | if (xdp_rxq->reg_state == REG_STATE_UNUSED) | |
161 | return; | |
162 | ||
163 | WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG"); | |
164 | ||
dce5bd61 | 165 | xdp_rxq_info_unreg_mem_model(xdp_rxq); |
8d5d8852 | 166 | |
aecd67b6 JDB |
167 | xdp_rxq->reg_state = REG_STATE_UNREGISTERED; |
168 | xdp_rxq->dev = NULL; | |
8d5d8852 JDB |
169 | |
170 | /* Reset mem info to defaults */ | |
171 | xdp_rxq->mem.id = 0; | |
172 | xdp_rxq->mem.type = 0; | |
aecd67b6 JDB |
173 | } |
174 | EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg); | |
175 | ||
176 | static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq) | |
177 | { | |
178 | memset(xdp_rxq, 0, sizeof(*xdp_rxq)); | |
179 | } | |
180 | ||
181 | /* Returns 0 on success, negative on failure */ | |
182 | int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, | |
183 | struct net_device *dev, u32 queue_index) | |
184 | { | |
185 | if (xdp_rxq->reg_state == REG_STATE_UNUSED) { | |
186 | WARN(1, "Driver promised not to register this"); | |
187 | return -EINVAL; | |
188 | } | |
189 | ||
190 | if (xdp_rxq->reg_state == REG_STATE_REGISTERED) { | |
191 | WARN(1, "Missing unregister, handled but fix driver"); | |
192 | xdp_rxq_info_unreg(xdp_rxq); | |
193 | } | |
194 | ||
195 | if (!dev) { | |
196 | WARN(1, "Missing net_device from driver"); | |
197 | return -ENODEV; | |
198 | } | |
199 | ||
200 | /* State either UNREGISTERED or NEW */ | |
201 | xdp_rxq_info_init(xdp_rxq); | |
202 | xdp_rxq->dev = dev; | |
203 | xdp_rxq->queue_index = queue_index; | |
204 | ||
205 | xdp_rxq->reg_state = REG_STATE_REGISTERED; | |
206 | return 0; | |
207 | } | |
208 | EXPORT_SYMBOL_GPL(xdp_rxq_info_reg); | |
209 | ||
210 | void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq) | |
211 | { | |
212 | xdp_rxq->reg_state = REG_STATE_UNUSED; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(xdp_rxq_info_unused); | |
c0124f32 JDB |
215 | |
216 | bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq) | |
217 | { | |
218 | return (xdp_rxq->reg_state == REG_STATE_REGISTERED); | |
219 | } | |
220 | EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg); | |
5ab073ff | 221 | |
8d5d8852 JDB |
222 | static int __mem_id_init_hash_table(void) |
223 | { | |
224 | struct rhashtable *rht; | |
225 | int ret; | |
226 | ||
227 | if (unlikely(mem_id_init)) | |
228 | return 0; | |
229 | ||
230 | rht = kzalloc(sizeof(*rht), GFP_KERNEL); | |
231 | if (!rht) | |
232 | return -ENOMEM; | |
233 | ||
234 | ret = rhashtable_init(rht, &mem_id_rht_params); | |
235 | if (ret < 0) { | |
236 | kfree(rht); | |
237 | return ret; | |
238 | } | |
239 | mem_id_ht = rht; | |
240 | smp_mb(); /* mutex lock should provide enough pairing */ | |
241 | mem_id_init = true; | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | /* Allocate a cyclic ID that maps to allocator pointer. | |
247 | * See: https://www.kernel.org/doc/html/latest/core-api/idr.html | |
248 | * | |
249 | * Caller must lock mem_id_lock. | |
250 | */ | |
251 | static int __mem_id_cyclic_get(gfp_t gfp) | |
252 | { | |
253 | int retries = 1; | |
254 | int id; | |
255 | ||
256 | again: | |
257 | id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp); | |
258 | if (id < 0) { | |
259 | if (id == -ENOSPC) { | |
260 | /* Cyclic allocator, reset next id */ | |
261 | if (retries--) { | |
262 | mem_id_next = MEM_ID_MIN; | |
263 | goto again; | |
264 | } | |
265 | } | |
266 | return id; /* errno */ | |
267 | } | |
268 | mem_id_next = id + 1; | |
269 | ||
270 | return id; | |
271 | } | |
272 | ||
57d0a1c1 JDB |
273 | static bool __is_supported_mem_type(enum xdp_mem_type type) |
274 | { | |
275 | if (type == MEM_TYPE_PAGE_POOL) | |
276 | return is_page_pool_compiled_in(); | |
277 | ||
278 | if (type >= MEM_TYPE_MAX) | |
279 | return false; | |
280 | ||
281 | return true; | |
282 | } | |
283 | ||
5ab073ff JDB |
284 | int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, |
285 | enum xdp_mem_type type, void *allocator) | |
286 | { | |
8d5d8852 JDB |
287 | struct xdp_mem_allocator *xdp_alloc; |
288 | gfp_t gfp = GFP_KERNEL; | |
289 | int id, errno, ret; | |
290 | void *ptr; | |
291 | ||
292 | if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { | |
293 | WARN(1, "Missing register, driver bug"); | |
294 | return -EFAULT; | |
295 | } | |
296 | ||
57d0a1c1 JDB |
297 | if (!__is_supported_mem_type(type)) |
298 | return -EOPNOTSUPP; | |
5ab073ff JDB |
299 | |
300 | xdp_rxq->mem.type = type; | |
301 | ||
57d0a1c1 | 302 | if (!allocator) { |
02b55e56 | 303 | if (type == MEM_TYPE_PAGE_POOL || type == MEM_TYPE_ZERO_COPY) |
57d0a1c1 | 304 | return -EINVAL; /* Setup time check page_pool req */ |
8d5d8852 | 305 | return 0; |
57d0a1c1 | 306 | } |
8d5d8852 JDB |
307 | |
308 | /* Delay init of rhashtable to save memory if feature isn't used */ | |
309 | if (!mem_id_init) { | |
310 | mutex_lock(&mem_id_lock); | |
311 | ret = __mem_id_init_hash_table(); | |
312 | mutex_unlock(&mem_id_lock); | |
313 | if (ret < 0) { | |
314 | WARN_ON(1); | |
315 | return ret; | |
316 | } | |
317 | } | |
318 | ||
319 | xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp); | |
320 | if (!xdp_alloc) | |
321 | return -ENOMEM; | |
322 | ||
323 | mutex_lock(&mem_id_lock); | |
324 | id = __mem_id_cyclic_get(gfp); | |
325 | if (id < 0) { | |
326 | errno = id; | |
327 | goto err; | |
328 | } | |
329 | xdp_rxq->mem.id = id; | |
330 | xdp_alloc->mem = xdp_rxq->mem; | |
331 | xdp_alloc->allocator = allocator; | |
332 | ||
333 | /* Insert allocator into ID lookup table */ | |
334 | ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node); | |
335 | if (IS_ERR(ptr)) { | |
516a7593 JDB |
336 | ida_simple_remove(&mem_id_pool, xdp_rxq->mem.id); |
337 | xdp_rxq->mem.id = 0; | |
8d5d8852 JDB |
338 | errno = PTR_ERR(ptr); |
339 | goto err; | |
340 | } | |
341 | ||
1da4bbef | 342 | if (type == MEM_TYPE_PAGE_POOL) |
c3f812ce | 343 | page_pool_use_xdp_mem(allocator, mem_allocator_disconnect); |
1da4bbef | 344 | |
8d5d8852 | 345 | mutex_unlock(&mem_id_lock); |
5ab073ff | 346 | |
f033b688 | 347 | trace_mem_connect(xdp_alloc, xdp_rxq); |
5ab073ff | 348 | return 0; |
8d5d8852 JDB |
349 | err: |
350 | mutex_unlock(&mem_id_lock); | |
351 | kfree(xdp_alloc); | |
352 | return errno; | |
5ab073ff JDB |
353 | } |
354 | EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); | |
8d5d8852 | 355 | |
389ab7f0 JDB |
356 | /* XDP RX runs under NAPI protection, and in different delivery error |
357 | * scenarios (e.g. queue full), it is possible to return the xdp_frame | |
baead859 | 358 | * while still leveraging this protection. The @napi_direct boolean |
389ab7f0 JDB |
359 | * is used for those calls sites. Thus, allowing for faster recycling |
360 | * of xdp_frames/pages in those cases. | |
361 | */ | |
02b55e56 BT |
362 | static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, |
363 | unsigned long handle) | |
8d5d8852 | 364 | { |
57d0a1c1 JDB |
365 | struct xdp_mem_allocator *xa; |
366 | struct page *page; | |
367 | ||
368 | switch (mem->type) { | |
369 | case MEM_TYPE_PAGE_POOL: | |
370 | rcu_read_lock(); | |
371 | /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ | |
372 | xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); | |
373 | page = virt_to_head_page(data); | |
c3f812ce JL |
374 | napi_direct &= !xdp_return_frame_no_direct(); |
375 | page_pool_put_page(xa->page_pool, page, napi_direct); | |
57d0a1c1 JDB |
376 | rcu_read_unlock(); |
377 | break; | |
378 | case MEM_TYPE_PAGE_SHARED: | |
8d5d8852 | 379 | page_frag_free(data); |
57d0a1c1 JDB |
380 | break; |
381 | case MEM_TYPE_PAGE_ORDER0: | |
382 | page = virt_to_page(data); /* Assumes order0 page*/ | |
8d5d8852 | 383 | put_page(page); |
57d0a1c1 | 384 | break; |
02b55e56 BT |
385 | case MEM_TYPE_ZERO_COPY: |
386 | /* NB! Only valid from an xdp_buff! */ | |
387 | rcu_read_lock(); | |
388 | /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ | |
389 | xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); | |
eb91e4d4 | 390 | xa->zc_alloc->free(xa->zc_alloc, handle); |
02b55e56 | 391 | rcu_read_unlock(); |
57d0a1c1 JDB |
392 | default: |
393 | /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ | |
394 | break; | |
8d5d8852 JDB |
395 | } |
396 | } | |
c497176c BT |
397 | |
398 | void xdp_return_frame(struct xdp_frame *xdpf) | |
399 | { | |
02b55e56 | 400 | __xdp_return(xdpf->data, &xdpf->mem, false, 0); |
c497176c | 401 | } |
8d5d8852 | 402 | EXPORT_SYMBOL_GPL(xdp_return_frame); |
c497176c | 403 | |
389ab7f0 JDB |
404 | void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) |
405 | { | |
02b55e56 | 406 | __xdp_return(xdpf->data, &xdpf->mem, true, 0); |
389ab7f0 JDB |
407 | } |
408 | EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); | |
409 | ||
c497176c BT |
410 | void xdp_return_buff(struct xdp_buff *xdp) |
411 | { | |
02b55e56 | 412 | __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle); |
c497176c BT |
413 | } |
414 | EXPORT_SYMBOL_GPL(xdp_return_buff); | |
05296620 | 415 | |
6bf071bf JDB |
416 | /* Only called for MEM_TYPE_PAGE_POOL see xdp.h */ |
417 | void __xdp_release_frame(void *data, struct xdp_mem_info *mem) | |
418 | { | |
419 | struct xdp_mem_allocator *xa; | |
420 | struct page *page; | |
421 | ||
422 | rcu_read_lock(); | |
423 | xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); | |
424 | page = virt_to_head_page(data); | |
425 | if (xa) | |
426 | page_pool_release_page(xa->page_pool, page); | |
427 | rcu_read_unlock(); | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(__xdp_release_frame); | |
430 | ||
05296620 JK |
431 | int xdp_attachment_query(struct xdp_attachment_info *info, |
432 | struct netdev_bpf *bpf) | |
433 | { | |
434 | bpf->prog_id = info->prog ? info->prog->aux->id : 0; | |
435 | bpf->prog_flags = info->prog ? info->flags : 0; | |
436 | return 0; | |
437 | } | |
438 | EXPORT_SYMBOL_GPL(xdp_attachment_query); | |
439 | ||
440 | bool xdp_attachment_flags_ok(struct xdp_attachment_info *info, | |
441 | struct netdev_bpf *bpf) | |
442 | { | |
443 | if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) { | |
444 | NL_SET_ERR_MSG(bpf->extack, | |
445 | "program loaded with different flags"); | |
446 | return false; | |
447 | } | |
448 | return true; | |
449 | } | |
450 | EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok); | |
451 | ||
452 | void xdp_attachment_setup(struct xdp_attachment_info *info, | |
453 | struct netdev_bpf *bpf) | |
454 | { | |
455 | if (info->prog) | |
456 | bpf_prog_put(info->prog); | |
457 | info->prog = bpf->prog; | |
458 | info->flags = bpf->flags; | |
459 | } | |
460 | EXPORT_SYMBOL_GPL(xdp_attachment_setup); | |
b0d1beef BT |
461 | |
462 | struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp) | |
463 | { | |
72962167 | 464 | unsigned int metasize, totsize; |
b0d1beef BT |
465 | void *addr, *data_to_copy; |
466 | struct xdp_frame *xdpf; | |
467 | struct page *page; | |
468 | ||
469 | /* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */ | |
470 | metasize = xdp_data_meta_unsupported(xdp) ? 0 : | |
471 | xdp->data - xdp->data_meta; | |
b0d1beef BT |
472 | totsize = xdp->data_end - xdp->data + metasize; |
473 | ||
474 | if (sizeof(*xdpf) + totsize > PAGE_SIZE) | |
475 | return NULL; | |
476 | ||
477 | page = dev_alloc_page(); | |
478 | if (!page) | |
479 | return NULL; | |
480 | ||
481 | addr = page_to_virt(page); | |
482 | xdpf = addr; | |
483 | memset(xdpf, 0, sizeof(*xdpf)); | |
484 | ||
485 | addr += sizeof(*xdpf); | |
486 | data_to_copy = metasize ? xdp->data_meta : xdp->data; | |
487 | memcpy(addr, data_to_copy, totsize); | |
488 | ||
489 | xdpf->data = addr + metasize; | |
490 | xdpf->len = totsize - metasize; | |
491 | xdpf->headroom = 0; | |
492 | xdpf->metasize = metasize; | |
493 | xdpf->mem.type = MEM_TYPE_PAGE_ORDER0; | |
494 | ||
495 | xdp_return_buff(xdp); | |
496 | return xdpf; | |
497 | } | |
498 | EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame); |