Commit | Line | Data |
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ff7d6b27 JDB |
1 | /* SPDX-License-Identifier: GPL-2.0 |
2 | * | |
3 | * page_pool.c | |
4 | * Author: Jesper Dangaard Brouer <netoptimizer@brouer.com> | |
5 | * Copyright (C) 2016 Red Hat, Inc. | |
6 | */ | |
32c28f7e | 7 | |
ff7d6b27 JDB |
8 | #include <linux/types.h> |
9 | #include <linux/kernel.h> | |
10 | #include <linux/slab.h> | |
f71fec47 | 11 | #include <linux/device.h> |
ff7d6b27 JDB |
12 | |
13 | #include <net/page_pool.h> | |
78862447 LB |
14 | #include <net/xdp.h> |
15 | ||
ff7d6b27 JDB |
16 | #include <linux/dma-direction.h> |
17 | #include <linux/dma-mapping.h> | |
18 | #include <linux/page-flags.h> | |
19 | #include <linux/mm.h> /* for __put_page() */ | |
20 | ||
32c28f7e JDB |
21 | #include <trace/events/page_pool.h> |
22 | ||
c3f812ce JL |
23 | #define DEFER_TIME (msecs_to_jiffies(1000)) |
24 | #define DEFER_WARN_INTERVAL (60 * HZ) | |
25 | ||
ff7d6b27 JDB |
26 | static int page_pool_init(struct page_pool *pool, |
27 | const struct page_pool_params *params) | |
28 | { | |
29 | unsigned int ring_qsize = 1024; /* Default */ | |
30 | ||
31 | memcpy(&pool->p, params, sizeof(pool->p)); | |
32 | ||
33 | /* Validate only known flags were used */ | |
34 | if (pool->p.flags & ~(PP_FLAG_ALL)) | |
35 | return -EINVAL; | |
36 | ||
37 | if (pool->p.pool_size) | |
38 | ring_qsize = pool->p.pool_size; | |
39 | ||
40 | /* Sanity limit mem that can be pinned down */ | |
41 | if (ring_qsize > 32768) | |
42 | return -E2BIG; | |
43 | ||
44 | /* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL. | |
45 | * DMA_BIDIRECTIONAL is for allowing page used for DMA sending, | |
46 | * which is the XDP_TX use-case. | |
47 | */ | |
798dda81 DK |
48 | if (pool->p.flags & PP_FLAG_DMA_MAP) { |
49 | if ((pool->p.dma_dir != DMA_FROM_DEVICE) && | |
50 | (pool->p.dma_dir != DMA_BIDIRECTIONAL)) | |
51 | return -EINVAL; | |
52 | } | |
ff7d6b27 | 53 | |
e68bc756 LB |
54 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) { |
55 | /* In order to request DMA-sync-for-device the page | |
56 | * needs to be mapped | |
57 | */ | |
58 | if (!(pool->p.flags & PP_FLAG_DMA_MAP)) | |
59 | return -EINVAL; | |
60 | ||
61 | if (!pool->p.max_len) | |
62 | return -EINVAL; | |
63 | ||
64 | /* pool->p.offset has to be set according to the address | |
65 | * offset used by the DMA engine to start copying rx data | |
66 | */ | |
67 | } | |
68 | ||
ff7d6b27 JDB |
69 | if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0) |
70 | return -ENOMEM; | |
71 | ||
99c07c43 JDB |
72 | atomic_set(&pool->pages_state_release_cnt, 0); |
73 | ||
1da4bbef IK |
74 | /* Driver calling page_pool_create() also call page_pool_destroy() */ |
75 | refcount_set(&pool->user_cnt, 1); | |
76 | ||
f71fec47 JDB |
77 | if (pool->p.flags & PP_FLAG_DMA_MAP) |
78 | get_device(pool->p.dev); | |
79 | ||
ff7d6b27 JDB |
80 | return 0; |
81 | } | |
82 | ||
83 | struct page_pool *page_pool_create(const struct page_pool_params *params) | |
84 | { | |
85 | struct page_pool *pool; | |
873343e7 | 86 | int err; |
ff7d6b27 JDB |
87 | |
88 | pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, params->nid); | |
89 | if (!pool) | |
90 | return ERR_PTR(-ENOMEM); | |
91 | ||
92 | err = page_pool_init(pool, params); | |
93 | if (err < 0) { | |
94 | pr_warn("%s() gave up with errno %d\n", __func__, err); | |
95 | kfree(pool); | |
96 | return ERR_PTR(err); | |
97 | } | |
1da4bbef | 98 | |
ff7d6b27 JDB |
99 | return pool; |
100 | } | |
101 | EXPORT_SYMBOL(page_pool_create); | |
102 | ||
458de8a9 | 103 | static void page_pool_return_page(struct page_pool *pool, struct page *page); |
44768dec JDB |
104 | |
105 | noinline | |
304db6cb | 106 | static struct page *page_pool_refill_alloc_cache(struct page_pool *pool) |
44768dec JDB |
107 | { |
108 | struct ptr_ring *r = &pool->ring; | |
109 | struct page *page; | |
110 | int pref_nid; /* preferred NUMA node */ | |
111 | ||
112 | /* Quicker fallback, avoid locks when ring is empty */ | |
113 | if (__ptr_ring_empty(r)) | |
114 | return NULL; | |
115 | ||
116 | /* Softirq guarantee CPU and thus NUMA node is stable. This, | |
117 | * assumes CPU refilling driver RX-ring will also run RX-NAPI. | |
118 | */ | |
f13fc107 | 119 | #ifdef CONFIG_NUMA |
44768dec | 120 | pref_nid = (pool->p.nid == NUMA_NO_NODE) ? numa_mem_id() : pool->p.nid; |
f13fc107 JDB |
121 | #else |
122 | /* Ignore pool->p.nid setting if !CONFIG_NUMA, helps compiler */ | |
123 | pref_nid = numa_mem_id(); /* will be zero like page_to_nid() */ | |
124 | #endif | |
44768dec JDB |
125 | |
126 | /* Slower-path: Get pages from locked ring queue */ | |
127 | spin_lock(&r->consumer_lock); | |
128 | ||
129 | /* Refill alloc array, but only if NUMA match */ | |
130 | do { | |
131 | page = __ptr_ring_consume(r); | |
132 | if (unlikely(!page)) | |
133 | break; | |
134 | ||
135 | if (likely(page_to_nid(page) == pref_nid)) { | |
136 | pool->alloc.cache[pool->alloc.count++] = page; | |
137 | } else { | |
138 | /* NUMA mismatch; | |
139 | * (1) release 1 page to page-allocator and | |
140 | * (2) break out to fallthrough to alloc_pages_node. | |
141 | * This limit stress on page buddy alloactor. | |
142 | */ | |
458de8a9 | 143 | page_pool_return_page(pool, page); |
44768dec JDB |
144 | page = NULL; |
145 | break; | |
146 | } | |
304db6cb | 147 | } while (pool->alloc.count < PP_ALLOC_CACHE_REFILL); |
44768dec JDB |
148 | |
149 | /* Return last page */ | |
150 | if (likely(pool->alloc.count > 0)) | |
151 | page = pool->alloc.cache[--pool->alloc.count]; | |
152 | ||
153 | spin_unlock(&r->consumer_lock); | |
154 | return page; | |
155 | } | |
156 | ||
ff7d6b27 JDB |
157 | /* fast path */ |
158 | static struct page *__page_pool_get_cached(struct page_pool *pool) | |
159 | { | |
ff7d6b27 JDB |
160 | struct page *page; |
161 | ||
304db6cb LR |
162 | /* Caller MUST guarantee safe non-concurrent access, e.g. softirq */ |
163 | if (likely(pool->alloc.count)) { | |
164 | /* Fast-path */ | |
165 | page = pool->alloc.cache[--pool->alloc.count]; | |
166 | } else { | |
167 | page = page_pool_refill_alloc_cache(pool); | |
ff7d6b27 JDB |
168 | } |
169 | ||
ff7d6b27 JDB |
170 | return page; |
171 | } | |
172 | ||
e68bc756 LB |
173 | static void page_pool_dma_sync_for_device(struct page_pool *pool, |
174 | struct page *page, | |
175 | unsigned int dma_sync_size) | |
176 | { | |
177 | dma_sync_size = min(dma_sync_size, pool->p.max_len); | |
178 | dma_sync_single_range_for_device(pool->p.dev, page->dma_addr, | |
179 | pool->p.offset, dma_sync_size, | |
180 | pool->p.dma_dir); | |
181 | } | |
182 | ||
dfa59717 JDB |
183 | static bool page_pool_dma_map(struct page_pool *pool, struct page *page) |
184 | { | |
185 | dma_addr_t dma; | |
186 | ||
187 | /* Setup DMA mapping: use 'struct page' area for storing DMA-addr | |
188 | * since dma_addr_t can be either 32 or 64 bits and does not always fit | |
189 | * into page private data (i.e 32bit cpu with 64bit DMA caps) | |
190 | * This mapping is kept for lifetime of page, until leaving pool. | |
191 | */ | |
192 | dma = dma_map_page_attrs(pool->p.dev, page, 0, | |
193 | (PAGE_SIZE << pool->p.order), | |
194 | pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC); | |
195 | if (dma_mapping_error(pool->p.dev, dma)) | |
196 | return false; | |
197 | ||
198 | page->dma_addr = dma; | |
199 | ||
200 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) | |
201 | page_pool_dma_sync_for_device(pool, page, pool->p.max_len); | |
202 | ||
203 | return true; | |
204 | } | |
205 | ||
be5dba25 JDB |
206 | static struct page *__page_pool_alloc_page_order(struct page_pool *pool, |
207 | gfp_t gfp) | |
ff7d6b27 JDB |
208 | { |
209 | struct page *page; | |
ff7d6b27 | 210 | |
be5dba25 | 211 | gfp |= __GFP_COMP; |
ff7d6b27 | 212 | page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); |
be5dba25 | 213 | if (unlikely(!page)) |
ff7d6b27 JDB |
214 | return NULL; |
215 | ||
be5dba25 | 216 | if ((pool->p.flags & PP_FLAG_DMA_MAP) && |
dfa59717 | 217 | unlikely(!page_pool_dma_map(pool, page))) { |
ff7d6b27 JDB |
218 | put_page(page); |
219 | return NULL; | |
220 | } | |
ff7d6b27 | 221 | |
99c07c43 JDB |
222 | /* Track how many pages are held 'in-flight' */ |
223 | pool->pages_state_hold_cnt++; | |
32c28f7e | 224 | trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); |
be5dba25 JDB |
225 | return page; |
226 | } | |
227 | ||
228 | /* slow path */ | |
229 | noinline | |
230 | static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, | |
231 | gfp_t gfp) | |
232 | { | |
233 | const int bulk = PP_ALLOC_CACHE_REFILL; | |
234 | unsigned int pp_flags = pool->p.flags; | |
235 | unsigned int pp_order = pool->p.order; | |
236 | struct page *page; | |
237 | int i, nr_pages; | |
238 | ||
239 | /* Don't support bulk alloc for high-order pages */ | |
240 | if (unlikely(pp_order)) | |
241 | return __page_pool_alloc_page_order(pool, gfp); | |
242 | ||
243 | /* Unnecessary as alloc cache is empty, but guarantees zero count */ | |
244 | if (unlikely(pool->alloc.count > 0)) | |
245 | return pool->alloc.cache[--pool->alloc.count]; | |
246 | ||
247 | /* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */ | |
248 | memset(&pool->alloc.cache, 0, sizeof(void *) * bulk); | |
249 | ||
250 | nr_pages = alloc_pages_bulk_array(gfp, bulk, pool->alloc.cache); | |
251 | if (unlikely(!nr_pages)) | |
252 | return NULL; | |
253 | ||
254 | /* Pages have been filled into alloc.cache array, but count is zero and | |
255 | * page element have not been (possibly) DMA mapped. | |
256 | */ | |
257 | for (i = 0; i < nr_pages; i++) { | |
258 | page = pool->alloc.cache[i]; | |
259 | if ((pp_flags & PP_FLAG_DMA_MAP) && | |
260 | unlikely(!page_pool_dma_map(pool, page))) { | |
261 | put_page(page); | |
262 | continue; | |
263 | } | |
264 | pool->alloc.cache[pool->alloc.count++] = page; | |
265 | /* Track how many pages are held 'in-flight' */ | |
266 | pool->pages_state_hold_cnt++; | |
267 | trace_page_pool_state_hold(pool, page, | |
268 | pool->pages_state_hold_cnt); | |
269 | } | |
270 | ||
271 | /* Return last page */ | |
272 | if (likely(pool->alloc.count > 0)) | |
273 | page = pool->alloc.cache[--pool->alloc.count]; | |
274 | else | |
275 | page = NULL; | |
32c28f7e | 276 | |
ff7d6b27 JDB |
277 | /* When page just alloc'ed is should/must have refcnt 1. */ |
278 | return page; | |
279 | } | |
280 | ||
281 | /* For using page_pool replace: alloc_pages() API calls, but provide | |
282 | * synchronization guarantee for allocation side. | |
283 | */ | |
284 | struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp) | |
285 | { | |
286 | struct page *page; | |
287 | ||
288 | /* Fast-path: Get a page from cache */ | |
289 | page = __page_pool_get_cached(pool); | |
290 | if (page) | |
291 | return page; | |
292 | ||
293 | /* Slow-path: cache empty, do real allocation */ | |
294 | page = __page_pool_alloc_pages_slow(pool, gfp); | |
295 | return page; | |
296 | } | |
297 | EXPORT_SYMBOL(page_pool_alloc_pages); | |
298 | ||
99c07c43 JDB |
299 | /* Calculate distance between two u32 values, valid if distance is below 2^(31) |
300 | * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution | |
301 | */ | |
302 | #define _distance(a, b) (s32)((a) - (b)) | |
303 | ||
304 | static s32 page_pool_inflight(struct page_pool *pool) | |
305 | { | |
306 | u32 release_cnt = atomic_read(&pool->pages_state_release_cnt); | |
307 | u32 hold_cnt = READ_ONCE(pool->pages_state_hold_cnt); | |
c3f812ce | 308 | s32 inflight; |
99c07c43 | 309 | |
c3f812ce | 310 | inflight = _distance(hold_cnt, release_cnt); |
99c07c43 | 311 | |
7c9e6942 | 312 | trace_page_pool_release(pool, inflight, hold_cnt, release_cnt); |
99c07c43 JDB |
313 | WARN(inflight < 0, "Negative(%d) inflight packet-pages", inflight); |
314 | ||
c3f812ce | 315 | return inflight; |
99c07c43 JDB |
316 | } |
317 | ||
458de8a9 IA |
318 | /* Disconnects a page (from a page_pool). API users can have a need |
319 | * to disconnect a page (from a page_pool), to allow it to be used as | |
320 | * a regular page (that will eventually be returned to the normal | |
321 | * page-allocator via put_page). | |
322 | */ | |
323 | void page_pool_release_page(struct page_pool *pool, struct page *page) | |
ff7d6b27 | 324 | { |
1567b85e | 325 | dma_addr_t dma; |
c3f812ce | 326 | int count; |
1567b85e | 327 | |
ff7d6b27 | 328 | if (!(pool->p.flags & PP_FLAG_DMA_MAP)) |
458de8a9 IA |
329 | /* Always account for inflight pages, even if we didn't |
330 | * map them | |
331 | */ | |
99c07c43 | 332 | goto skip_dma_unmap; |
ff7d6b27 | 333 | |
1567b85e | 334 | dma = page->dma_addr; |
458de8a9 IA |
335 | |
336 | /* When page is unmapped, it cannot be returned our pool */ | |
13f16d9d JDB |
337 | dma_unmap_page_attrs(pool->p.dev, dma, |
338 | PAGE_SIZE << pool->p.order, pool->p.dma_dir, | |
339 | DMA_ATTR_SKIP_CPU_SYNC); | |
1567b85e | 340 | page->dma_addr = 0; |
99c07c43 | 341 | skip_dma_unmap: |
c3f812ce JL |
342 | /* This may be the last page returned, releasing the pool, so |
343 | * it is not safe to reference pool afterwards. | |
344 | */ | |
345 | count = atomic_inc_return(&pool->pages_state_release_cnt); | |
346 | trace_page_pool_state_release(pool, page, count); | |
ff7d6b27 | 347 | } |
458de8a9 | 348 | EXPORT_SYMBOL(page_pool_release_page); |
a25d50bf | 349 | |
ff7d6b27 | 350 | /* Return a page to the page allocator, cleaning up our state */ |
458de8a9 | 351 | static void page_pool_return_page(struct page_pool *pool, struct page *page) |
ff7d6b27 | 352 | { |
458de8a9 | 353 | page_pool_release_page(pool, page); |
99c07c43 | 354 | |
ff7d6b27 JDB |
355 | put_page(page); |
356 | /* An optimization would be to call __free_pages(page, pool->p.order) | |
357 | * knowing page is not part of page-cache (thus avoiding a | |
358 | * __page_cache_release() call). | |
359 | */ | |
360 | } | |
361 | ||
458de8a9 | 362 | static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page) |
ff7d6b27 JDB |
363 | { |
364 | int ret; | |
365 | /* BH protection not needed if current is serving softirq */ | |
366 | if (in_serving_softirq()) | |
367 | ret = ptr_ring_produce(&pool->ring, page); | |
368 | else | |
369 | ret = ptr_ring_produce_bh(&pool->ring, page); | |
370 | ||
371 | return (ret == 0) ? true : false; | |
372 | } | |
373 | ||
374 | /* Only allow direct recycling in special circumstances, into the | |
375 | * alloc side cache. E.g. during RX-NAPI processing for XDP_DROP use-case. | |
376 | * | |
377 | * Caller must provide appropriate safe context. | |
378 | */ | |
458de8a9 | 379 | static bool page_pool_recycle_in_cache(struct page *page, |
ff7d6b27 JDB |
380 | struct page_pool *pool) |
381 | { | |
382 | if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) | |
383 | return false; | |
384 | ||
385 | /* Caller MUST have verified/know (page_ref_count(page) == 1) */ | |
386 | pool->alloc.cache[pool->alloc.count++] = page; | |
387 | return true; | |
388 | } | |
389 | ||
458de8a9 IA |
390 | /* If the page refcnt == 1, this will try to recycle the page. |
391 | * if PP_FLAG_DMA_SYNC_DEV is set, we'll try to sync the DMA area for | |
392 | * the configured size min(dma_sync_size, pool->max_len). | |
393 | * If the page refcnt != 1, then the page will be returned to memory | |
394 | * subsystem. | |
395 | */ | |
78862447 LB |
396 | static __always_inline struct page * |
397 | __page_pool_put_page(struct page_pool *pool, struct page *page, | |
398 | unsigned int dma_sync_size, bool allow_direct) | |
ff7d6b27 JDB |
399 | { |
400 | /* This allocator is optimized for the XDP mode that uses | |
401 | * one-frame-per-page, but have fallbacks that act like the | |
402 | * regular page allocator APIs. | |
403 | * | |
404 | * refcnt == 1 means page_pool owns page, and can recycle it. | |
05656132 AL |
405 | * |
406 | * page is NOT reusable when allocated when system is under | |
407 | * some pressure. (page_is_pfmemalloc) | |
ff7d6b27 | 408 | */ |
05656132 | 409 | if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) { |
ff7d6b27 JDB |
410 | /* Read barrier done in page_ref_count / READ_ONCE */ |
411 | ||
e68bc756 LB |
412 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) |
413 | page_pool_dma_sync_for_device(pool, page, | |
414 | dma_sync_size); | |
415 | ||
78862447 LB |
416 | if (allow_direct && in_serving_softirq() && |
417 | page_pool_recycle_in_cache(page, pool)) | |
418 | return NULL; | |
ff7d6b27 | 419 | |
78862447 LB |
420 | /* Page found as candidate for recycling */ |
421 | return page; | |
ff7d6b27 JDB |
422 | } |
423 | /* Fallback/non-XDP mode: API user have elevated refcnt. | |
424 | * | |
425 | * Many drivers split up the page into fragments, and some | |
426 | * want to keep doing this to save memory and do refcnt based | |
427 | * recycling. Support this use case too, to ease drivers | |
428 | * switching between XDP/non-XDP. | |
429 | * | |
430 | * In-case page_pool maintains the DMA mapping, API user must | |
431 | * call page_pool_put_page once. In this elevated refcnt | |
432 | * case, the DMA is unmapped/released, as driver is likely | |
433 | * doing refcnt based recycle tricks, meaning another process | |
434 | * will be invoking put_page. | |
435 | */ | |
458de8a9 IA |
436 | /* Do not replace this with page_pool_return_page() */ |
437 | page_pool_release_page(pool, page); | |
ff7d6b27 | 438 | put_page(page); |
78862447 LB |
439 | |
440 | return NULL; | |
441 | } | |
442 | ||
443 | void page_pool_put_page(struct page_pool *pool, struct page *page, | |
444 | unsigned int dma_sync_size, bool allow_direct) | |
445 | { | |
446 | page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct); | |
447 | if (page && !page_pool_recycle_in_ring(pool, page)) { | |
448 | /* Cache full, fallback to free pages */ | |
449 | page_pool_return_page(pool, page); | |
450 | } | |
ff7d6b27 | 451 | } |
458de8a9 | 452 | EXPORT_SYMBOL(page_pool_put_page); |
ff7d6b27 | 453 | |
78862447 LB |
454 | /* Caller must not use data area after call, as this function overwrites it */ |
455 | void page_pool_put_page_bulk(struct page_pool *pool, void **data, | |
456 | int count) | |
457 | { | |
458 | int i, bulk_len = 0; | |
459 | ||
460 | for (i = 0; i < count; i++) { | |
461 | struct page *page = virt_to_head_page(data[i]); | |
462 | ||
463 | page = __page_pool_put_page(pool, page, -1, false); | |
464 | /* Approved for bulk recycling in ptr_ring cache */ | |
465 | if (page) | |
466 | data[bulk_len++] = page; | |
467 | } | |
468 | ||
469 | if (unlikely(!bulk_len)) | |
470 | return; | |
471 | ||
472 | /* Bulk producer into ptr_ring page_pool cache */ | |
473 | page_pool_ring_lock(pool); | |
474 | for (i = 0; i < bulk_len; i++) { | |
475 | if (__ptr_ring_produce(&pool->ring, data[i])) | |
476 | break; /* ring full */ | |
477 | } | |
478 | page_pool_ring_unlock(pool); | |
479 | ||
480 | /* Hopefully all pages was return into ptr_ring */ | |
481 | if (likely(i == bulk_len)) | |
482 | return; | |
483 | ||
484 | /* ptr_ring cache full, free remaining pages outside producer lock | |
485 | * since put_page() with refcnt == 1 can be an expensive operation | |
486 | */ | |
487 | for (; i < bulk_len; i++) | |
488 | page_pool_return_page(pool, data[i]); | |
489 | } | |
490 | EXPORT_SYMBOL(page_pool_put_page_bulk); | |
491 | ||
458de8a9 | 492 | static void page_pool_empty_ring(struct page_pool *pool) |
ff7d6b27 JDB |
493 | { |
494 | struct page *page; | |
495 | ||
496 | /* Empty recycle ring */ | |
4905bd9a | 497 | while ((page = ptr_ring_consume_bh(&pool->ring))) { |
ff7d6b27 JDB |
498 | /* Verify the refcnt invariant of cached pages */ |
499 | if (!(page_ref_count(page) == 1)) | |
500 | pr_crit("%s() page_pool refcnt %d violation\n", | |
501 | __func__, page_ref_count(page)); | |
502 | ||
458de8a9 | 503 | page_pool_return_page(pool, page); |
ff7d6b27 JDB |
504 | } |
505 | } | |
506 | ||
c3f812ce | 507 | static void page_pool_free(struct page_pool *pool) |
d956a048 | 508 | { |
c3f812ce JL |
509 | if (pool->disconnect) |
510 | pool->disconnect(pool); | |
e54cfd7e JDB |
511 | |
512 | ptr_ring_cleanup(&pool->ring, NULL); | |
f71fec47 JDB |
513 | |
514 | if (pool->p.flags & PP_FLAG_DMA_MAP) | |
515 | put_device(pool->p.dev); | |
516 | ||
e54cfd7e JDB |
517 | kfree(pool); |
518 | } | |
e54cfd7e | 519 | |
7c9e6942 | 520 | static void page_pool_empty_alloc_cache_once(struct page_pool *pool) |
ff7d6b27 JDB |
521 | { |
522 | struct page *page; | |
523 | ||
7c9e6942 JDB |
524 | if (pool->destroy_cnt) |
525 | return; | |
526 | ||
ff7d6b27 JDB |
527 | /* Empty alloc cache, assume caller made sure this is |
528 | * no-longer in use, and page_pool_alloc_pages() cannot be | |
529 | * call concurrently. | |
530 | */ | |
531 | while (pool->alloc.count) { | |
532 | page = pool->alloc.cache[--pool->alloc.count]; | |
458de8a9 | 533 | page_pool_return_page(pool, page); |
ff7d6b27 | 534 | } |
7c9e6942 JDB |
535 | } |
536 | ||
537 | static void page_pool_scrub(struct page_pool *pool) | |
538 | { | |
539 | page_pool_empty_alloc_cache_once(pool); | |
540 | pool->destroy_cnt++; | |
ff7d6b27 JDB |
541 | |
542 | /* No more consumers should exist, but producers could still | |
543 | * be in-flight. | |
544 | */ | |
458de8a9 | 545 | page_pool_empty_ring(pool); |
c3f812ce JL |
546 | } |
547 | ||
548 | static int page_pool_release(struct page_pool *pool) | |
549 | { | |
550 | int inflight; | |
551 | ||
552 | page_pool_scrub(pool); | |
553 | inflight = page_pool_inflight(pool); | |
554 | if (!inflight) | |
555 | page_pool_free(pool); | |
556 | ||
557 | return inflight; | |
558 | } | |
559 | ||
560 | static void page_pool_release_retry(struct work_struct *wq) | |
561 | { | |
562 | struct delayed_work *dwq = to_delayed_work(wq); | |
563 | struct page_pool *pool = container_of(dwq, typeof(*pool), release_dw); | |
564 | int inflight; | |
565 | ||
566 | inflight = page_pool_release(pool); | |
567 | if (!inflight) | |
568 | return; | |
569 | ||
570 | /* Periodic warning */ | |
571 | if (time_after_eq(jiffies, pool->defer_warn)) { | |
572 | int sec = (s32)((u32)jiffies - (u32)pool->defer_start) / HZ; | |
573 | ||
574 | pr_warn("%s() stalled pool shutdown %d inflight %d sec\n", | |
575 | __func__, inflight, sec); | |
576 | pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; | |
577 | } | |
578 | ||
579 | /* Still not ready to be disconnected, retry later */ | |
580 | schedule_delayed_work(&pool->release_dw, DEFER_TIME); | |
581 | } | |
582 | ||
583 | void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *)) | |
584 | { | |
585 | refcount_inc(&pool->user_cnt); | |
586 | pool->disconnect = disconnect; | |
587 | } | |
588 | ||
589 | void page_pool_destroy(struct page_pool *pool) | |
590 | { | |
591 | if (!pool) | |
592 | return; | |
593 | ||
594 | if (!page_pool_put(pool)) | |
595 | return; | |
596 | ||
597 | if (!page_pool_release(pool)) | |
598 | return; | |
599 | ||
600 | pool->defer_start = jiffies; | |
601 | pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; | |
ff7d6b27 | 602 | |
c3f812ce JL |
603 | INIT_DELAYED_WORK(&pool->release_dw, page_pool_release_retry); |
604 | schedule_delayed_work(&pool->release_dw, DEFER_TIME); | |
ff7d6b27 | 605 | } |
c3f812ce | 606 | EXPORT_SYMBOL(page_pool_destroy); |
bc836748 SM |
607 | |
608 | /* Caller must provide appropriate safe context, e.g. NAPI. */ | |
609 | void page_pool_update_nid(struct page_pool *pool, int new_nid) | |
610 | { | |
44768dec JDB |
611 | struct page *page; |
612 | ||
bc836748 SM |
613 | trace_page_pool_update_nid(pool, new_nid); |
614 | pool->p.nid = new_nid; | |
44768dec JDB |
615 | |
616 | /* Flush pool alloc cache, as refill will check NUMA node */ | |
617 | while (pool->alloc.count) { | |
618 | page = pool->alloc.cache[--pool->alloc.count]; | |
458de8a9 | 619 | page_pool_return_page(pool, page); |
44768dec | 620 | } |
bc836748 SM |
621 | } |
622 | EXPORT_SYMBOL(page_pool_update_nid); |