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