Commit | Line | Data |
---|---|---|
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 | 12 | |
a9ca9f9c | 13 | #include <net/page_pool/helpers.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> | |
8d29c703 | 19 | #include <linux/mm.h> /* for put_page() */ |
c07aea3e | 20 | #include <linux/poison.h> |
f3c5264f | 21 | #include <linux/ethtool.h> |
8c48eea3 | 22 | #include <linux/netdevice.h> |
ff7d6b27 | 23 | |
32c28f7e JDB |
24 | #include <trace/events/page_pool.h> |
25 | ||
f17c6964 JK |
26 | #include "page_pool_priv.h" |
27 | ||
c3f812ce JL |
28 | #define DEFER_TIME (msecs_to_jiffies(1000)) |
29 | #define DEFER_WARN_INTERVAL (60 * HZ) | |
30 | ||
aaf153ae | 31 | #define BIAS_MAX (LONG_MAX >> 1) |
53e0961d | 32 | |
8610037e JD |
33 | #ifdef CONFIG_PAGE_POOL_STATS |
34 | /* alloc_stat_inc is intended to be used in softirq context */ | |
35 | #define alloc_stat_inc(pool, __stat) (pool->alloc_stats.__stat++) | |
ad6fa1e1 JD |
36 | /* recycle_stat_inc is safe to use when preemption is possible. */ |
37 | #define recycle_stat_inc(pool, __stat) \ | |
38 | do { \ | |
39 | struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \ | |
40 | this_cpu_inc(s->__stat); \ | |
41 | } while (0) | |
6b95e338 | 42 | |
590032a4 LB |
43 | #define recycle_stat_add(pool, __stat, val) \ |
44 | do { \ | |
45 | struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \ | |
46 | this_cpu_add(s->__stat, val); \ | |
47 | } while (0) | |
48 | ||
f3c5264f LB |
49 | static const char pp_stats[][ETH_GSTRING_LEN] = { |
50 | "rx_pp_alloc_fast", | |
51 | "rx_pp_alloc_slow", | |
52 | "rx_pp_alloc_slow_ho", | |
53 | "rx_pp_alloc_empty", | |
54 | "rx_pp_alloc_refill", | |
55 | "rx_pp_alloc_waive", | |
56 | "rx_pp_recycle_cached", | |
57 | "rx_pp_recycle_cache_full", | |
58 | "rx_pp_recycle_ring", | |
59 | "rx_pp_recycle_ring_full", | |
60 | "rx_pp_recycle_released_ref", | |
61 | }; | |
62 | ||
82e896d9 JK |
63 | /** |
64 | * page_pool_get_stats() - fetch page pool stats | |
65 | * @pool: pool from which page was allocated | |
66 | * @stats: struct page_pool_stats to fill in | |
67 | * | |
68 | * Retrieve statistics about the page_pool. This API is only available | |
69 | * if the kernel has been configured with ``CONFIG_PAGE_POOL_STATS=y``. | |
70 | * A pointer to a caller allocated struct page_pool_stats structure | |
71 | * is passed to this API which is filled in. The caller can then report | |
72 | * those stats to the user (perhaps via ethtool, debugfs, etc.). | |
73 | */ | |
d49010ad | 74 | bool page_pool_get_stats(const struct page_pool *pool, |
6b95e338 JD |
75 | struct page_pool_stats *stats) |
76 | { | |
77 | int cpu = 0; | |
78 | ||
79 | if (!stats) | |
80 | return false; | |
81 | ||
f3c5264f LB |
82 | /* The caller is responsible to initialize stats. */ |
83 | stats->alloc_stats.fast += pool->alloc_stats.fast; | |
84 | stats->alloc_stats.slow += pool->alloc_stats.slow; | |
85 | stats->alloc_stats.slow_high_order += pool->alloc_stats.slow_high_order; | |
86 | stats->alloc_stats.empty += pool->alloc_stats.empty; | |
87 | stats->alloc_stats.refill += pool->alloc_stats.refill; | |
88 | stats->alloc_stats.waive += pool->alloc_stats.waive; | |
6b95e338 JD |
89 | |
90 | for_each_possible_cpu(cpu) { | |
91 | const struct page_pool_recycle_stats *pcpu = | |
92 | per_cpu_ptr(pool->recycle_stats, cpu); | |
93 | ||
94 | stats->recycle_stats.cached += pcpu->cached; | |
95 | stats->recycle_stats.cache_full += pcpu->cache_full; | |
96 | stats->recycle_stats.ring += pcpu->ring; | |
97 | stats->recycle_stats.ring_full += pcpu->ring_full; | |
98 | stats->recycle_stats.released_refcnt += pcpu->released_refcnt; | |
99 | } | |
100 | ||
101 | return true; | |
102 | } | |
103 | EXPORT_SYMBOL(page_pool_get_stats); | |
f3c5264f LB |
104 | |
105 | u8 *page_pool_ethtool_stats_get_strings(u8 *data) | |
106 | { | |
107 | int i; | |
108 | ||
109 | for (i = 0; i < ARRAY_SIZE(pp_stats); i++) { | |
110 | memcpy(data, pp_stats[i], ETH_GSTRING_LEN); | |
111 | data += ETH_GSTRING_LEN; | |
112 | } | |
113 | ||
114 | return data; | |
115 | } | |
116 | EXPORT_SYMBOL(page_pool_ethtool_stats_get_strings); | |
117 | ||
118 | int page_pool_ethtool_stats_get_count(void) | |
119 | { | |
120 | return ARRAY_SIZE(pp_stats); | |
121 | } | |
122 | EXPORT_SYMBOL(page_pool_ethtool_stats_get_count); | |
123 | ||
124 | u64 *page_pool_ethtool_stats_get(u64 *data, void *stats) | |
125 | { | |
126 | struct page_pool_stats *pool_stats = stats; | |
127 | ||
128 | *data++ = pool_stats->alloc_stats.fast; | |
129 | *data++ = pool_stats->alloc_stats.slow; | |
130 | *data++ = pool_stats->alloc_stats.slow_high_order; | |
131 | *data++ = pool_stats->alloc_stats.empty; | |
132 | *data++ = pool_stats->alloc_stats.refill; | |
133 | *data++ = pool_stats->alloc_stats.waive; | |
134 | *data++ = pool_stats->recycle_stats.cached; | |
135 | *data++ = pool_stats->recycle_stats.cache_full; | |
136 | *data++ = pool_stats->recycle_stats.ring; | |
137 | *data++ = pool_stats->recycle_stats.ring_full; | |
138 | *data++ = pool_stats->recycle_stats.released_refcnt; | |
139 | ||
140 | return data; | |
141 | } | |
142 | EXPORT_SYMBOL(page_pool_ethtool_stats_get); | |
143 | ||
8610037e JD |
144 | #else |
145 | #define alloc_stat_inc(pool, __stat) | |
ad6fa1e1 | 146 | #define recycle_stat_inc(pool, __stat) |
590032a4 | 147 | #define recycle_stat_add(pool, __stat, val) |
8610037e JD |
148 | #endif |
149 | ||
368d3cb4 YL |
150 | static bool page_pool_producer_lock(struct page_pool *pool) |
151 | __acquires(&pool->ring.producer_lock) | |
152 | { | |
153 | bool in_softirq = in_softirq(); | |
154 | ||
155 | if (in_softirq) | |
156 | spin_lock(&pool->ring.producer_lock); | |
157 | else | |
158 | spin_lock_bh(&pool->ring.producer_lock); | |
159 | ||
160 | return in_softirq; | |
161 | } | |
162 | ||
163 | static void page_pool_producer_unlock(struct page_pool *pool, | |
164 | bool in_softirq) | |
165 | __releases(&pool->ring.producer_lock) | |
166 | { | |
167 | if (in_softirq) | |
168 | spin_unlock(&pool->ring.producer_lock); | |
169 | else | |
170 | spin_unlock_bh(&pool->ring.producer_lock); | |
171 | } | |
172 | ||
ff7d6b27 | 173 | static int page_pool_init(struct page_pool *pool, |
2b0cfa6e LB |
174 | const struct page_pool_params *params, |
175 | int cpuid) | |
ff7d6b27 JDB |
176 | { |
177 | unsigned int ring_qsize = 1024; /* Default */ | |
178 | ||
5027ec19 JK |
179 | memcpy(&pool->p, ¶ms->fast, sizeof(pool->p)); |
180 | memcpy(&pool->slow, ¶ms->slow, sizeof(pool->slow)); | |
ff7d6b27 | 181 | |
2b0cfa6e LB |
182 | pool->cpuid = cpuid; |
183 | ||
ff7d6b27 JDB |
184 | /* Validate only known flags were used */ |
185 | if (pool->p.flags & ~(PP_FLAG_ALL)) | |
186 | return -EINVAL; | |
187 | ||
188 | if (pool->p.pool_size) | |
189 | ring_qsize = pool->p.pool_size; | |
190 | ||
191 | /* Sanity limit mem that can be pinned down */ | |
192 | if (ring_qsize > 32768) | |
193 | return -E2BIG; | |
194 | ||
195 | /* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL. | |
196 | * DMA_BIDIRECTIONAL is for allowing page used for DMA sending, | |
197 | * which is the XDP_TX use-case. | |
198 | */ | |
798dda81 DK |
199 | if (pool->p.flags & PP_FLAG_DMA_MAP) { |
200 | if ((pool->p.dma_dir != DMA_FROM_DEVICE) && | |
201 | (pool->p.dma_dir != DMA_BIDIRECTIONAL)) | |
202 | return -EINVAL; | |
203 | } | |
ff7d6b27 | 204 | |
e68bc756 LB |
205 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) { |
206 | /* In order to request DMA-sync-for-device the page | |
207 | * needs to be mapped | |
208 | */ | |
209 | if (!(pool->p.flags & PP_FLAG_DMA_MAP)) | |
210 | return -EINVAL; | |
211 | ||
212 | if (!pool->p.max_len) | |
213 | return -EINVAL; | |
214 | ||
215 | /* pool->p.offset has to be set according to the address | |
216 | * offset used by the DMA engine to start copying rx data | |
217 | */ | |
218 | } | |
219 | ||
2da0cac1 JK |
220 | pool->has_init_callback = !!pool->slow.init_callback; |
221 | ||
ad6fa1e1 JD |
222 | #ifdef CONFIG_PAGE_POOL_STATS |
223 | pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats); | |
224 | if (!pool->recycle_stats) | |
225 | return -ENOMEM; | |
226 | #endif | |
227 | ||
8ffbd166 JS |
228 | if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0) { |
229 | #ifdef CONFIG_PAGE_POOL_STATS | |
230 | free_percpu(pool->recycle_stats); | |
231 | #endif | |
ff7d6b27 | 232 | return -ENOMEM; |
8ffbd166 | 233 | } |
ff7d6b27 | 234 | |
99c07c43 JDB |
235 | atomic_set(&pool->pages_state_release_cnt, 0); |
236 | ||
1da4bbef IK |
237 | /* Driver calling page_pool_create() also call page_pool_destroy() */ |
238 | refcount_set(&pool->user_cnt, 1); | |
239 | ||
f71fec47 JDB |
240 | if (pool->p.flags & PP_FLAG_DMA_MAP) |
241 | get_device(pool->p.dev); | |
242 | ||
ff7d6b27 JDB |
243 | return 0; |
244 | } | |
245 | ||
23cfaf67 JK |
246 | static void page_pool_uninit(struct page_pool *pool) |
247 | { | |
248 | ptr_ring_cleanup(&pool->ring, NULL); | |
249 | ||
250 | if (pool->p.flags & PP_FLAG_DMA_MAP) | |
251 | put_device(pool->p.dev); | |
252 | ||
253 | #ifdef CONFIG_PAGE_POOL_STATS | |
254 | free_percpu(pool->recycle_stats); | |
255 | #endif | |
256 | } | |
257 | ||
82e896d9 | 258 | /** |
2b0cfa6e | 259 | * page_pool_create_percpu() - create a page pool for a given cpu. |
82e896d9 | 260 | * @params: parameters, see struct page_pool_params |
2b0cfa6e | 261 | * @cpuid: cpu identifier |
82e896d9 | 262 | */ |
2b0cfa6e LB |
263 | struct page_pool * |
264 | page_pool_create_percpu(const struct page_pool_params *params, int cpuid) | |
ff7d6b27 JDB |
265 | { |
266 | struct page_pool *pool; | |
873343e7 | 267 | int err; |
ff7d6b27 JDB |
268 | |
269 | pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, params->nid); | |
270 | if (!pool) | |
271 | return ERR_PTR(-ENOMEM); | |
272 | ||
2b0cfa6e | 273 | err = page_pool_init(pool, params, cpuid); |
f17c6964 JK |
274 | if (err < 0) |
275 | goto err_free; | |
276 | ||
277 | err = page_pool_list(pool); | |
278 | if (err) | |
279 | goto err_uninit; | |
1da4bbef | 280 | |
ff7d6b27 | 281 | return pool; |
f17c6964 JK |
282 | |
283 | err_uninit: | |
284 | page_pool_uninit(pool); | |
285 | err_free: | |
286 | pr_warn("%s() gave up with errno %d\n", __func__, err); | |
287 | kfree(pool); | |
288 | return ERR_PTR(err); | |
ff7d6b27 | 289 | } |
2b0cfa6e LB |
290 | EXPORT_SYMBOL(page_pool_create_percpu); |
291 | ||
292 | /** | |
293 | * page_pool_create() - create a page pool | |
294 | * @params: parameters, see struct page_pool_params | |
295 | */ | |
296 | struct page_pool *page_pool_create(const struct page_pool_params *params) | |
297 | { | |
298 | return page_pool_create_percpu(params, -1); | |
299 | } | |
ff7d6b27 JDB |
300 | EXPORT_SYMBOL(page_pool_create); |
301 | ||
458de8a9 | 302 | static void page_pool_return_page(struct page_pool *pool, struct page *page); |
44768dec JDB |
303 | |
304 | noinline | |
304db6cb | 305 | static struct page *page_pool_refill_alloc_cache(struct page_pool *pool) |
44768dec JDB |
306 | { |
307 | struct ptr_ring *r = &pool->ring; | |
308 | struct page *page; | |
309 | int pref_nid; /* preferred NUMA node */ | |
310 | ||
311 | /* Quicker fallback, avoid locks when ring is empty */ | |
8610037e JD |
312 | if (__ptr_ring_empty(r)) { |
313 | alloc_stat_inc(pool, empty); | |
44768dec | 314 | return NULL; |
8610037e | 315 | } |
44768dec JDB |
316 | |
317 | /* Softirq guarantee CPU and thus NUMA node is stable. This, | |
318 | * assumes CPU refilling driver RX-ring will also run RX-NAPI. | |
319 | */ | |
f13fc107 | 320 | #ifdef CONFIG_NUMA |
44768dec | 321 | pref_nid = (pool->p.nid == NUMA_NO_NODE) ? numa_mem_id() : pool->p.nid; |
f13fc107 JDB |
322 | #else |
323 | /* Ignore pool->p.nid setting if !CONFIG_NUMA, helps compiler */ | |
324 | pref_nid = numa_mem_id(); /* will be zero like page_to_nid() */ | |
325 | #endif | |
44768dec | 326 | |
44768dec JDB |
327 | /* Refill alloc array, but only if NUMA match */ |
328 | do { | |
329 | page = __ptr_ring_consume(r); | |
330 | if (unlikely(!page)) | |
331 | break; | |
332 | ||
333 | if (likely(page_to_nid(page) == pref_nid)) { | |
334 | pool->alloc.cache[pool->alloc.count++] = page; | |
335 | } else { | |
336 | /* NUMA mismatch; | |
337 | * (1) release 1 page to page-allocator and | |
338 | * (2) break out to fallthrough to alloc_pages_node. | |
339 | * This limit stress on page buddy alloactor. | |
340 | */ | |
458de8a9 | 341 | page_pool_return_page(pool, page); |
8610037e | 342 | alloc_stat_inc(pool, waive); |
44768dec JDB |
343 | page = NULL; |
344 | break; | |
345 | } | |
304db6cb | 346 | } while (pool->alloc.count < PP_ALLOC_CACHE_REFILL); |
44768dec JDB |
347 | |
348 | /* Return last page */ | |
8610037e | 349 | if (likely(pool->alloc.count > 0)) { |
44768dec | 350 | page = pool->alloc.cache[--pool->alloc.count]; |
8610037e JD |
351 | alloc_stat_inc(pool, refill); |
352 | } | |
44768dec | 353 | |
44768dec JDB |
354 | return page; |
355 | } | |
356 | ||
ff7d6b27 JDB |
357 | /* fast path */ |
358 | static struct page *__page_pool_get_cached(struct page_pool *pool) | |
359 | { | |
ff7d6b27 JDB |
360 | struct page *page; |
361 | ||
304db6cb LR |
362 | /* Caller MUST guarantee safe non-concurrent access, e.g. softirq */ |
363 | if (likely(pool->alloc.count)) { | |
364 | /* Fast-path */ | |
365 | page = pool->alloc.cache[--pool->alloc.count]; | |
8610037e | 366 | alloc_stat_inc(pool, fast); |
304db6cb LR |
367 | } else { |
368 | page = page_pool_refill_alloc_cache(pool); | |
ff7d6b27 JDB |
369 | } |
370 | ||
ff7d6b27 JDB |
371 | return page; |
372 | } | |
373 | ||
e68bc756 LB |
374 | static void page_pool_dma_sync_for_device(struct page_pool *pool, |
375 | struct page *page, | |
376 | unsigned int dma_sync_size) | |
377 | { | |
9ddb3c14 MWO |
378 | dma_addr_t dma_addr = page_pool_get_dma_addr(page); |
379 | ||
e68bc756 | 380 | dma_sync_size = min(dma_sync_size, pool->p.max_len); |
9ddb3c14 | 381 | dma_sync_single_range_for_device(pool->p.dev, dma_addr, |
e68bc756 LB |
382 | pool->p.offset, dma_sync_size, |
383 | pool->p.dma_dir); | |
384 | } | |
385 | ||
dfa59717 JDB |
386 | static bool page_pool_dma_map(struct page_pool *pool, struct page *page) |
387 | { | |
388 | dma_addr_t dma; | |
389 | ||
390 | /* Setup DMA mapping: use 'struct page' area for storing DMA-addr | |
391 | * since dma_addr_t can be either 32 or 64 bits and does not always fit | |
392 | * into page private data (i.e 32bit cpu with 64bit DMA caps) | |
393 | * This mapping is kept for lifetime of page, until leaving pool. | |
394 | */ | |
395 | dma = dma_map_page_attrs(pool->p.dev, page, 0, | |
396 | (PAGE_SIZE << pool->p.order), | |
8e4c62c7 JK |
397 | pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC | |
398 | DMA_ATTR_WEAK_ORDERING); | |
dfa59717 JDB |
399 | if (dma_mapping_error(pool->p.dev, dma)) |
400 | return false; | |
401 | ||
90de47f0 YL |
402 | if (page_pool_set_dma_addr(page, dma)) |
403 | goto unmap_failed; | |
dfa59717 JDB |
404 | |
405 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) | |
406 | page_pool_dma_sync_for_device(pool, page, pool->p.max_len); | |
407 | ||
408 | return true; | |
90de47f0 YL |
409 | |
410 | unmap_failed: | |
411 | WARN_ON_ONCE("unexpected DMA address, please report to netdev@"); | |
412 | dma_unmap_page_attrs(pool->p.dev, dma, | |
413 | PAGE_SIZE << pool->p.order, pool->p.dma_dir, | |
414 | DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); | |
415 | return false; | |
dfa59717 JDB |
416 | } |
417 | ||
57f05bc2 YL |
418 | static void page_pool_set_pp_info(struct page_pool *pool, |
419 | struct page *page) | |
420 | { | |
421 | page->pp = pool; | |
422 | page->pp_magic |= PP_SIGNATURE; | |
58d53d8f YL |
423 | |
424 | /* Ensuring all pages have been split into one fragment initially: | |
425 | * page_pool_set_pp_info() is only called once for every page when it | |
426 | * is allocated from the page allocator and page_pool_fragment_page() | |
427 | * is dirtying the same cache line as the page->pp_magic above, so | |
428 | * the overhead is negligible. | |
429 | */ | |
430 | page_pool_fragment_page(page, 1); | |
2da0cac1 | 431 | if (pool->has_init_callback) |
5027ec19 | 432 | pool->slow.init_callback(page, pool->slow.init_arg); |
57f05bc2 YL |
433 | } |
434 | ||
435 | static void page_pool_clear_pp_info(struct page *page) | |
436 | { | |
437 | page->pp_magic = 0; | |
438 | page->pp = NULL; | |
439 | } | |
440 | ||
be5dba25 JDB |
441 | static struct page *__page_pool_alloc_page_order(struct page_pool *pool, |
442 | gfp_t gfp) | |
ff7d6b27 JDB |
443 | { |
444 | struct page *page; | |
ff7d6b27 | 445 | |
be5dba25 | 446 | gfp |= __GFP_COMP; |
ff7d6b27 | 447 | page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); |
be5dba25 | 448 | if (unlikely(!page)) |
ff7d6b27 JDB |
449 | return NULL; |
450 | ||
be5dba25 | 451 | if ((pool->p.flags & PP_FLAG_DMA_MAP) && |
dfa59717 | 452 | unlikely(!page_pool_dma_map(pool, page))) { |
ff7d6b27 JDB |
453 | put_page(page); |
454 | return NULL; | |
455 | } | |
ff7d6b27 | 456 | |
8610037e | 457 | alloc_stat_inc(pool, slow_high_order); |
57f05bc2 | 458 | page_pool_set_pp_info(pool, page); |
c07aea3e | 459 | |
99c07c43 JDB |
460 | /* Track how many pages are held 'in-flight' */ |
461 | pool->pages_state_hold_cnt++; | |
32c28f7e | 462 | trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); |
be5dba25 JDB |
463 | return page; |
464 | } | |
465 | ||
466 | /* slow path */ | |
467 | noinline | |
468 | static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, | |
469 | gfp_t gfp) | |
470 | { | |
471 | const int bulk = PP_ALLOC_CACHE_REFILL; | |
472 | unsigned int pp_flags = pool->p.flags; | |
473 | unsigned int pp_order = pool->p.order; | |
474 | struct page *page; | |
475 | int i, nr_pages; | |
476 | ||
477 | /* Don't support bulk alloc for high-order pages */ | |
478 | if (unlikely(pp_order)) | |
479 | return __page_pool_alloc_page_order(pool, gfp); | |
480 | ||
481 | /* Unnecessary as alloc cache is empty, but guarantees zero count */ | |
482 | if (unlikely(pool->alloc.count > 0)) | |
483 | return pool->alloc.cache[--pool->alloc.count]; | |
484 | ||
485 | /* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */ | |
486 | memset(&pool->alloc.cache, 0, sizeof(void *) * bulk); | |
487 | ||
d810d367 JW |
488 | nr_pages = alloc_pages_bulk_array_node(gfp, pool->p.nid, bulk, |
489 | pool->alloc.cache); | |
be5dba25 JDB |
490 | if (unlikely(!nr_pages)) |
491 | return NULL; | |
492 | ||
493 | /* Pages have been filled into alloc.cache array, but count is zero and | |
494 | * page element have not been (possibly) DMA mapped. | |
495 | */ | |
496 | for (i = 0; i < nr_pages; i++) { | |
497 | page = pool->alloc.cache[i]; | |
498 | if ((pp_flags & PP_FLAG_DMA_MAP) && | |
499 | unlikely(!page_pool_dma_map(pool, page))) { | |
500 | put_page(page); | |
501 | continue; | |
502 | } | |
57f05bc2 YL |
503 | |
504 | page_pool_set_pp_info(pool, page); | |
be5dba25 JDB |
505 | pool->alloc.cache[pool->alloc.count++] = page; |
506 | /* Track how many pages are held 'in-flight' */ | |
507 | pool->pages_state_hold_cnt++; | |
508 | trace_page_pool_state_hold(pool, page, | |
509 | pool->pages_state_hold_cnt); | |
510 | } | |
511 | ||
512 | /* Return last page */ | |
8610037e | 513 | if (likely(pool->alloc.count > 0)) { |
be5dba25 | 514 | page = pool->alloc.cache[--pool->alloc.count]; |
8610037e JD |
515 | alloc_stat_inc(pool, slow); |
516 | } else { | |
be5dba25 | 517 | page = NULL; |
8610037e | 518 | } |
32c28f7e | 519 | |
ff7d6b27 JDB |
520 | /* When page just alloc'ed is should/must have refcnt 1. */ |
521 | return page; | |
522 | } | |
523 | ||
524 | /* For using page_pool replace: alloc_pages() API calls, but provide | |
525 | * synchronization guarantee for allocation side. | |
526 | */ | |
527 | struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp) | |
528 | { | |
529 | struct page *page; | |
530 | ||
531 | /* Fast-path: Get a page from cache */ | |
532 | page = __page_pool_get_cached(pool); | |
533 | if (page) | |
534 | return page; | |
535 | ||
536 | /* Slow-path: cache empty, do real allocation */ | |
537 | page = __page_pool_alloc_pages_slow(pool, gfp); | |
538 | return page; | |
539 | } | |
540 | EXPORT_SYMBOL(page_pool_alloc_pages); | |
541 | ||
99c07c43 JDB |
542 | /* Calculate distance between two u32 values, valid if distance is below 2^(31) |
543 | * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution | |
544 | */ | |
545 | #define _distance(a, b) (s32)((a) - (b)) | |
546 | ||
7aee8429 | 547 | s32 page_pool_inflight(const struct page_pool *pool, bool strict) |
99c07c43 JDB |
548 | { |
549 | u32 release_cnt = atomic_read(&pool->pages_state_release_cnt); | |
550 | u32 hold_cnt = READ_ONCE(pool->pages_state_hold_cnt); | |
c3f812ce | 551 | s32 inflight; |
99c07c43 | 552 | |
c3f812ce | 553 | inflight = _distance(hold_cnt, release_cnt); |
99c07c43 | 554 | |
7aee8429 JK |
555 | if (strict) { |
556 | trace_page_pool_release(pool, inflight, hold_cnt, release_cnt); | |
557 | WARN(inflight < 0, "Negative(%d) inflight packet-pages", | |
558 | inflight); | |
559 | } else { | |
560 | inflight = max(0, inflight); | |
561 | } | |
99c07c43 | 562 | |
c3f812ce | 563 | return inflight; |
99c07c43 JDB |
564 | } |
565 | ||
c3f687d8 JK |
566 | static __always_inline |
567 | void __page_pool_release_page_dma(struct page_pool *pool, struct page *page) | |
ff7d6b27 | 568 | { |
1567b85e IA |
569 | dma_addr_t dma; |
570 | ||
ff7d6b27 | 571 | if (!(pool->p.flags & PP_FLAG_DMA_MAP)) |
458de8a9 IA |
572 | /* Always account for inflight pages, even if we didn't |
573 | * map them | |
574 | */ | |
c3f687d8 | 575 | return; |
ff7d6b27 | 576 | |
9ddb3c14 | 577 | dma = page_pool_get_dma_addr(page); |
458de8a9 | 578 | |
9ddb3c14 | 579 | /* When page is unmapped, it cannot be returned to our pool */ |
13f16d9d JDB |
580 | dma_unmap_page_attrs(pool->p.dev, dma, |
581 | PAGE_SIZE << pool->p.order, pool->p.dma_dir, | |
8e4c62c7 | 582 | DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); |
9ddb3c14 | 583 | page_pool_set_dma_addr(page, 0); |
c3f687d8 JK |
584 | } |
585 | ||
586 | /* Disconnects a page (from a page_pool). API users can have a need | |
587 | * to disconnect a page (from a page_pool), to allow it to be used as | |
588 | * a regular page (that will eventually be returned to the normal | |
589 | * page-allocator via put_page). | |
590 | */ | |
591 | void page_pool_return_page(struct page_pool *pool, struct page *page) | |
592 | { | |
593 | int count; | |
594 | ||
595 | __page_pool_release_page_dma(pool, page); | |
596 | ||
57f05bc2 | 597 | page_pool_clear_pp_info(page); |
c07aea3e | 598 | |
c3f812ce JL |
599 | /* This may be the last page returned, releasing the pool, so |
600 | * it is not safe to reference pool afterwards. | |
601 | */ | |
7fb9b66d | 602 | count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt); |
c3f812ce | 603 | trace_page_pool_state_release(pool, page, count); |
99c07c43 | 604 | |
ff7d6b27 JDB |
605 | put_page(page); |
606 | /* An optimization would be to call __free_pages(page, pool->p.order) | |
607 | * knowing page is not part of page-cache (thus avoiding a | |
608 | * __page_cache_release() call). | |
609 | */ | |
610 | } | |
611 | ||
458de8a9 | 612 | static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page) |
ff7d6b27 JDB |
613 | { |
614 | int ret; | |
542bcea4 QD |
615 | /* BH protection not needed if current is softirq */ |
616 | if (in_softirq()) | |
ff7d6b27 JDB |
617 | ret = ptr_ring_produce(&pool->ring, page); |
618 | else | |
619 | ret = ptr_ring_produce_bh(&pool->ring, page); | |
620 | ||
ad6fa1e1 JD |
621 | if (!ret) { |
622 | recycle_stat_inc(pool, ring); | |
623 | return true; | |
624 | } | |
625 | ||
626 | return false; | |
ff7d6b27 JDB |
627 | } |
628 | ||
629 | /* Only allow direct recycling in special circumstances, into the | |
630 | * alloc side cache. E.g. during RX-NAPI processing for XDP_DROP use-case. | |
631 | * | |
632 | * Caller must provide appropriate safe context. | |
633 | */ | |
458de8a9 | 634 | static bool page_pool_recycle_in_cache(struct page *page, |
ff7d6b27 JDB |
635 | struct page_pool *pool) |
636 | { | |
ad6fa1e1 JD |
637 | if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) { |
638 | recycle_stat_inc(pool, cache_full); | |
ff7d6b27 | 639 | return false; |
ad6fa1e1 | 640 | } |
ff7d6b27 JDB |
641 | |
642 | /* Caller MUST have verified/know (page_ref_count(page) == 1) */ | |
643 | pool->alloc.cache[pool->alloc.count++] = page; | |
ad6fa1e1 | 644 | recycle_stat_inc(pool, cached); |
ff7d6b27 JDB |
645 | return true; |
646 | } | |
647 | ||
458de8a9 IA |
648 | /* If the page refcnt == 1, this will try to recycle the page. |
649 | * if PP_FLAG_DMA_SYNC_DEV is set, we'll try to sync the DMA area for | |
650 | * the configured size min(dma_sync_size, pool->max_len). | |
651 | * If the page refcnt != 1, then the page will be returned to memory | |
652 | * subsystem. | |
653 | */ | |
78862447 LB |
654 | static __always_inline struct page * |
655 | __page_pool_put_page(struct page_pool *pool, struct page *page, | |
656 | unsigned int dma_sync_size, bool allow_direct) | |
ff7d6b27 | 657 | { |
ff4e538c JK |
658 | lockdep_assert_no_hardirq(); |
659 | ||
ff7d6b27 JDB |
660 | /* This allocator is optimized for the XDP mode that uses |
661 | * one-frame-per-page, but have fallbacks that act like the | |
662 | * regular page allocator APIs. | |
663 | * | |
664 | * refcnt == 1 means page_pool owns page, and can recycle it. | |
05656132 AL |
665 | * |
666 | * page is NOT reusable when allocated when system is under | |
667 | * some pressure. (page_is_pfmemalloc) | |
ff7d6b27 | 668 | */ |
05656132 | 669 | if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) { |
ff7d6b27 JDB |
670 | /* Read barrier done in page_ref_count / READ_ONCE */ |
671 | ||
e68bc756 LB |
672 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) |
673 | page_pool_dma_sync_for_device(pool, page, | |
674 | dma_sync_size); | |
675 | ||
542bcea4 | 676 | if (allow_direct && in_softirq() && |
78862447 LB |
677 | page_pool_recycle_in_cache(page, pool)) |
678 | return NULL; | |
ff7d6b27 | 679 | |
78862447 LB |
680 | /* Page found as candidate for recycling */ |
681 | return page; | |
ff7d6b27 JDB |
682 | } |
683 | /* Fallback/non-XDP mode: API user have elevated refcnt. | |
684 | * | |
685 | * Many drivers split up the page into fragments, and some | |
686 | * want to keep doing this to save memory and do refcnt based | |
687 | * recycling. Support this use case too, to ease drivers | |
688 | * switching between XDP/non-XDP. | |
689 | * | |
690 | * In-case page_pool maintains the DMA mapping, API user must | |
691 | * call page_pool_put_page once. In this elevated refcnt | |
692 | * case, the DMA is unmapped/released, as driver is likely | |
693 | * doing refcnt based recycle tricks, meaning another process | |
694 | * will be invoking put_page. | |
695 | */ | |
ad6fa1e1 | 696 | recycle_stat_inc(pool, released_refcnt); |
07e0c7d3 | 697 | page_pool_return_page(pool, page); |
78862447 LB |
698 | |
699 | return NULL; | |
700 | } | |
701 | ||
0a149ab7 LC |
702 | void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page, |
703 | unsigned int dma_sync_size, bool allow_direct) | |
78862447 LB |
704 | { |
705 | page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct); | |
706 | if (page && !page_pool_recycle_in_ring(pool, page)) { | |
707 | /* Cache full, fallback to free pages */ | |
ad6fa1e1 | 708 | recycle_stat_inc(pool, ring_full); |
78862447 LB |
709 | page_pool_return_page(pool, page); |
710 | } | |
ff7d6b27 | 711 | } |
0a149ab7 | 712 | EXPORT_SYMBOL(page_pool_put_unrefed_page); |
ff7d6b27 | 713 | |
82e896d9 JK |
714 | /** |
715 | * page_pool_put_page_bulk() - release references on multiple pages | |
716 | * @pool: pool from which pages were allocated | |
717 | * @data: array holding page pointers | |
718 | * @count: number of pages in @data | |
719 | * | |
720 | * Tries to refill a number of pages into the ptr_ring cache holding ptr_ring | |
721 | * producer lock. If the ptr_ring is full, page_pool_put_page_bulk() | |
722 | * will release leftover pages to the page allocator. | |
723 | * page_pool_put_page_bulk() is suitable to be run inside the driver NAPI tx | |
724 | * completion loop for the XDP_REDIRECT use case. | |
725 | * | |
726 | * Please note the caller must not use data area after running | |
727 | * page_pool_put_page_bulk(), as this function overwrites it. | |
728 | */ | |
78862447 LB |
729 | void page_pool_put_page_bulk(struct page_pool *pool, void **data, |
730 | int count) | |
731 | { | |
732 | int i, bulk_len = 0; | |
368d3cb4 | 733 | bool in_softirq; |
78862447 LB |
734 | |
735 | for (i = 0; i < count; i++) { | |
736 | struct page *page = virt_to_head_page(data[i]); | |
737 | ||
52cc6ffc | 738 | /* It is not the last user for the page frag case */ |
0a149ab7 | 739 | if (!page_pool_is_last_ref(page)) |
52cc6ffc AD |
740 | continue; |
741 | ||
78862447 LB |
742 | page = __page_pool_put_page(pool, page, -1, false); |
743 | /* Approved for bulk recycling in ptr_ring cache */ | |
744 | if (page) | |
745 | data[bulk_len++] = page; | |
746 | } | |
747 | ||
748 | if (unlikely(!bulk_len)) | |
749 | return; | |
750 | ||
751 | /* Bulk producer into ptr_ring page_pool cache */ | |
368d3cb4 | 752 | in_softirq = page_pool_producer_lock(pool); |
78862447 | 753 | for (i = 0; i < bulk_len; i++) { |
590032a4 LB |
754 | if (__ptr_ring_produce(&pool->ring, data[i])) { |
755 | /* ring full */ | |
756 | recycle_stat_inc(pool, ring_full); | |
757 | break; | |
758 | } | |
78862447 | 759 | } |
590032a4 | 760 | recycle_stat_add(pool, ring, i); |
368d3cb4 | 761 | page_pool_producer_unlock(pool, in_softirq); |
78862447 LB |
762 | |
763 | /* Hopefully all pages was return into ptr_ring */ | |
764 | if (likely(i == bulk_len)) | |
765 | return; | |
766 | ||
767 | /* ptr_ring cache full, free remaining pages outside producer lock | |
768 | * since put_page() with refcnt == 1 can be an expensive operation | |
769 | */ | |
770 | for (; i < bulk_len; i++) | |
771 | page_pool_return_page(pool, data[i]); | |
772 | } | |
773 | EXPORT_SYMBOL(page_pool_put_page_bulk); | |
774 | ||
53e0961d YL |
775 | static struct page *page_pool_drain_frag(struct page_pool *pool, |
776 | struct page *page) | |
777 | { | |
778 | long drain_count = BIAS_MAX - pool->frag_users; | |
779 | ||
780 | /* Some user is still using the page frag */ | |
0a149ab7 | 781 | if (likely(page_pool_unref_page(page, drain_count))) |
53e0961d YL |
782 | return NULL; |
783 | ||
784 | if (page_ref_count(page) == 1 && !page_is_pfmemalloc(page)) { | |
785 | if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) | |
786 | page_pool_dma_sync_for_device(pool, page, -1); | |
787 | ||
788 | return page; | |
789 | } | |
790 | ||
791 | page_pool_return_page(pool, page); | |
792 | return NULL; | |
793 | } | |
794 | ||
795 | static void page_pool_free_frag(struct page_pool *pool) | |
796 | { | |
797 | long drain_count = BIAS_MAX - pool->frag_users; | |
798 | struct page *page = pool->frag_page; | |
799 | ||
800 | pool->frag_page = NULL; | |
801 | ||
0a149ab7 | 802 | if (!page || page_pool_unref_page(page, drain_count)) |
53e0961d YL |
803 | return; |
804 | ||
805 | page_pool_return_page(pool, page); | |
806 | } | |
807 | ||
808 | struct page *page_pool_alloc_frag(struct page_pool *pool, | |
809 | unsigned int *offset, | |
810 | unsigned int size, gfp_t gfp) | |
811 | { | |
812 | unsigned int max_size = PAGE_SIZE << pool->p.order; | |
813 | struct page *page = pool->frag_page; | |
814 | ||
09d96ee5 | 815 | if (WARN_ON(size > max_size)) |
53e0961d YL |
816 | return NULL; |
817 | ||
818 | size = ALIGN(size, dma_get_cache_alignment()); | |
819 | *offset = pool->frag_offset; | |
820 | ||
821 | if (page && *offset + size > max_size) { | |
822 | page = page_pool_drain_frag(pool, page); | |
0f6deac3 JW |
823 | if (page) { |
824 | alloc_stat_inc(pool, fast); | |
53e0961d | 825 | goto frag_reset; |
0f6deac3 | 826 | } |
53e0961d YL |
827 | } |
828 | ||
829 | if (!page) { | |
830 | page = page_pool_alloc_pages(pool, gfp); | |
831 | if (unlikely(!page)) { | |
832 | pool->frag_page = NULL; | |
833 | return NULL; | |
834 | } | |
835 | ||
836 | pool->frag_page = page; | |
837 | ||
838 | frag_reset: | |
839 | pool->frag_users = 1; | |
840 | *offset = 0; | |
841 | pool->frag_offset = size; | |
52cc6ffc | 842 | page_pool_fragment_page(page, BIAS_MAX); |
53e0961d YL |
843 | return page; |
844 | } | |
845 | ||
846 | pool->frag_users++; | |
847 | pool->frag_offset = *offset + size; | |
0f6deac3 | 848 | alloc_stat_inc(pool, fast); |
53e0961d YL |
849 | return page; |
850 | } | |
851 | EXPORT_SYMBOL(page_pool_alloc_frag); | |
852 | ||
458de8a9 | 853 | static void page_pool_empty_ring(struct page_pool *pool) |
ff7d6b27 JDB |
854 | { |
855 | struct page *page; | |
856 | ||
857 | /* Empty recycle ring */ | |
4905bd9a | 858 | while ((page = ptr_ring_consume_bh(&pool->ring))) { |
ff7d6b27 JDB |
859 | /* Verify the refcnt invariant of cached pages */ |
860 | if (!(page_ref_count(page) == 1)) | |
861 | pr_crit("%s() page_pool refcnt %d violation\n", | |
862 | __func__, page_ref_count(page)); | |
863 | ||
458de8a9 | 864 | page_pool_return_page(pool, page); |
ff7d6b27 JDB |
865 | } |
866 | } | |
867 | ||
de97502e | 868 | static void __page_pool_destroy(struct page_pool *pool) |
d956a048 | 869 | { |
c3f812ce JL |
870 | if (pool->disconnect) |
871 | pool->disconnect(pool); | |
e54cfd7e | 872 | |
f17c6964 | 873 | page_pool_unlist(pool); |
23cfaf67 | 874 | page_pool_uninit(pool); |
e54cfd7e JDB |
875 | kfree(pool); |
876 | } | |
e54cfd7e | 877 | |
7c9e6942 | 878 | static void page_pool_empty_alloc_cache_once(struct page_pool *pool) |
ff7d6b27 JDB |
879 | { |
880 | struct page *page; | |
881 | ||
7c9e6942 JDB |
882 | if (pool->destroy_cnt) |
883 | return; | |
884 | ||
ff7d6b27 JDB |
885 | /* Empty alloc cache, assume caller made sure this is |
886 | * no-longer in use, and page_pool_alloc_pages() cannot be | |
887 | * call concurrently. | |
888 | */ | |
889 | while (pool->alloc.count) { | |
890 | page = pool->alloc.cache[--pool->alloc.count]; | |
458de8a9 | 891 | page_pool_return_page(pool, page); |
ff7d6b27 | 892 | } |
7c9e6942 JDB |
893 | } |
894 | ||
895 | static void page_pool_scrub(struct page_pool *pool) | |
896 | { | |
897 | page_pool_empty_alloc_cache_once(pool); | |
898 | pool->destroy_cnt++; | |
ff7d6b27 JDB |
899 | |
900 | /* No more consumers should exist, but producers could still | |
901 | * be in-flight. | |
902 | */ | |
458de8a9 | 903 | page_pool_empty_ring(pool); |
c3f812ce JL |
904 | } |
905 | ||
906 | static int page_pool_release(struct page_pool *pool) | |
907 | { | |
908 | int inflight; | |
909 | ||
910 | page_pool_scrub(pool); | |
7aee8429 | 911 | inflight = page_pool_inflight(pool, true); |
c3f812ce | 912 | if (!inflight) |
de97502e | 913 | __page_pool_destroy(pool); |
c3f812ce JL |
914 | |
915 | return inflight; | |
916 | } | |
917 | ||
918 | static void page_pool_release_retry(struct work_struct *wq) | |
919 | { | |
920 | struct delayed_work *dwq = to_delayed_work(wq); | |
921 | struct page_pool *pool = container_of(dwq, typeof(*pool), release_dw); | |
be009667 | 922 | void *netdev; |
c3f812ce JL |
923 | int inflight; |
924 | ||
925 | inflight = page_pool_release(pool); | |
926 | if (!inflight) | |
927 | return; | |
928 | ||
be009667 JK |
929 | /* Periodic warning for page pools the user can't see */ |
930 | netdev = READ_ONCE(pool->slow.netdev); | |
931 | if (time_after_eq(jiffies, pool->defer_warn) && | |
932 | (!netdev || netdev == NET_PTR_POISON)) { | |
c3f812ce JL |
933 | int sec = (s32)((u32)jiffies - (u32)pool->defer_start) / HZ; |
934 | ||
be009667 JK |
935 | pr_warn("%s() stalled pool shutdown: id %u, %d inflight %d sec\n", |
936 | __func__, pool->user.id, inflight, sec); | |
c3f812ce JL |
937 | pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; |
938 | } | |
939 | ||
940 | /* Still not ready to be disconnected, retry later */ | |
941 | schedule_delayed_work(&pool->release_dw, DEFER_TIME); | |
942 | } | |
943 | ||
64693ec7 THJ |
944 | void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), |
945 | struct xdp_mem_info *mem) | |
c3f812ce JL |
946 | { |
947 | refcount_inc(&pool->user_cnt); | |
948 | pool->disconnect = disconnect; | |
64693ec7 | 949 | pool->xdp_mem_id = mem->id; |
c3f812ce JL |
950 | } |
951 | ||
56ef27e3 | 952 | static void page_pool_disable_direct_recycling(struct page_pool *pool) |
dd64b232 | 953 | { |
56ef27e3 AL |
954 | /* Disable direct recycling based on pool->cpuid. |
955 | * Paired with READ_ONCE() in napi_pp_put_page(). | |
956 | */ | |
957 | WRITE_ONCE(pool->cpuid, -1); | |
958 | ||
dd64b232 JK |
959 | if (!pool->p.napi) |
960 | return; | |
961 | ||
962 | /* To avoid races with recycling and additional barriers make sure | |
963 | * pool and NAPI are unlinked when NAPI is disabled. | |
964 | */ | |
965 | WARN_ON(!test_bit(NAPI_STATE_SCHED, &pool->p.napi->state) || | |
966 | READ_ONCE(pool->p.napi->list_owner) != -1); | |
967 | ||
968 | WRITE_ONCE(pool->p.napi, NULL); | |
969 | } | |
dd64b232 | 970 | |
c3f812ce JL |
971 | void page_pool_destroy(struct page_pool *pool) |
972 | { | |
973 | if (!pool) | |
974 | return; | |
975 | ||
976 | if (!page_pool_put(pool)) | |
977 | return; | |
978 | ||
56ef27e3 | 979 | page_pool_disable_direct_recycling(pool); |
53e0961d YL |
980 | page_pool_free_frag(pool); |
981 | ||
c3f812ce JL |
982 | if (!page_pool_release(pool)) |
983 | return; | |
984 | ||
69cb4952 | 985 | page_pool_detached(pool); |
c3f812ce JL |
986 | pool->defer_start = jiffies; |
987 | pool->defer_warn = jiffies + DEFER_WARN_INTERVAL; | |
ff7d6b27 | 988 | |
c3f812ce JL |
989 | INIT_DELAYED_WORK(&pool->release_dw, page_pool_release_retry); |
990 | schedule_delayed_work(&pool->release_dw, DEFER_TIME); | |
ff7d6b27 | 991 | } |
c3f812ce | 992 | EXPORT_SYMBOL(page_pool_destroy); |
bc836748 SM |
993 | |
994 | /* Caller must provide appropriate safe context, e.g. NAPI. */ | |
995 | void page_pool_update_nid(struct page_pool *pool, int new_nid) | |
996 | { | |
44768dec JDB |
997 | struct page *page; |
998 | ||
bc836748 SM |
999 | trace_page_pool_update_nid(pool, new_nid); |
1000 | pool->p.nid = new_nid; | |
44768dec JDB |
1001 | |
1002 | /* Flush pool alloc cache, as refill will check NUMA node */ | |
1003 | while (pool->alloc.count) { | |
1004 | page = pool->alloc.cache[--pool->alloc.count]; | |
458de8a9 | 1005 | page_pool_return_page(pool, page); |
44768dec | 1006 | } |
bc836748 SM |
1007 | } |
1008 | EXPORT_SYMBOL(page_pool_update_nid); |