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Commit | Line | Data |
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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2e0ab8ca MT |
2 | /* |
3 | * Definitions for the 'struct ptr_ring' datastructure. | |
4 | * | |
5 | * Author: | |
6 | * Michael S. Tsirkin <mst@redhat.com> | |
7 | * | |
8 | * Copyright (C) 2016 Red Hat, Inc. | |
9 | * | |
2e0ab8ca MT |
10 | * This is a limited-size FIFO maintaining pointers in FIFO order, with |
11 | * one CPU producing entries and another consuming entries from a FIFO. | |
12 | * | |
13 | * This implementation tries to minimize cache-contention when there is a | |
14 | * single producer and a single consumer CPU. | |
15 | */ | |
16 | ||
17 | #ifndef _LINUX_PTR_RING_H | |
18 | #define _LINUX_PTR_RING_H 1 | |
19 | ||
20 | #ifdef __KERNEL__ | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/cache.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/compiler.h> | |
2e0ab8ca MT |
25 | #include <linux/slab.h> |
26 | #include <asm/errno.h> | |
27 | #endif | |
28 | ||
29 | struct ptr_ring { | |
30 | int producer ____cacheline_aligned_in_smp; | |
31 | spinlock_t producer_lock; | |
fb9de970 MT |
32 | int consumer_head ____cacheline_aligned_in_smp; /* next valid entry */ |
33 | int consumer_tail; /* next entry to invalidate */ | |
2e0ab8ca MT |
34 | spinlock_t consumer_lock; |
35 | /* Shared consumer/producer data */ | |
36 | /* Read-only by both the producer and the consumer */ | |
37 | int size ____cacheline_aligned_in_smp; /* max entries in queue */ | |
fb9de970 | 38 | int batch; /* number of entries to consume in a batch */ |
2e0ab8ca MT |
39 | void **queue; |
40 | }; | |
41 | ||
42 | /* Note: callers invoking this in a loop must use a compiler barrier, | |
84328342 MT |
43 | * for example cpu_relax(). |
44 | * | |
45 | * NB: this is unlike __ptr_ring_empty in that callers must hold producer_lock: | |
46 | * see e.g. ptr_ring_full. | |
2e0ab8ca MT |
47 | */ |
48 | static inline bool __ptr_ring_full(struct ptr_ring *r) | |
49 | { | |
50 | return r->queue[r->producer]; | |
51 | } | |
52 | ||
53 | static inline bool ptr_ring_full(struct ptr_ring *r) | |
54 | { | |
5d49de53 MT |
55 | bool ret; |
56 | ||
57 | spin_lock(&r->producer_lock); | |
58 | ret = __ptr_ring_full(r); | |
59 | spin_unlock(&r->producer_lock); | |
60 | ||
61 | return ret; | |
62 | } | |
63 | ||
64 | static inline bool ptr_ring_full_irq(struct ptr_ring *r) | |
65 | { | |
66 | bool ret; | |
67 | ||
68 | spin_lock_irq(&r->producer_lock); | |
69 | ret = __ptr_ring_full(r); | |
70 | spin_unlock_irq(&r->producer_lock); | |
71 | ||
72 | return ret; | |
73 | } | |
74 | ||
75 | static inline bool ptr_ring_full_any(struct ptr_ring *r) | |
76 | { | |
77 | unsigned long flags; | |
78 | bool ret; | |
79 | ||
80 | spin_lock_irqsave(&r->producer_lock, flags); | |
81 | ret = __ptr_ring_full(r); | |
82 | spin_unlock_irqrestore(&r->producer_lock, flags); | |
83 | ||
84 | return ret; | |
85 | } | |
86 | ||
87 | static inline bool ptr_ring_full_bh(struct ptr_ring *r) | |
88 | { | |
89 | bool ret; | |
90 | ||
91 | spin_lock_bh(&r->producer_lock); | |
92 | ret = __ptr_ring_full(r); | |
93 | spin_unlock_bh(&r->producer_lock); | |
94 | ||
95 | return ret; | |
2e0ab8ca MT |
96 | } |
97 | ||
98 | /* Note: callers invoking this in a loop must use a compiler barrier, | |
5d49de53 | 99 | * for example cpu_relax(). Callers must hold producer_lock. |
a8ceb5db MT |
100 | * Callers are responsible for making sure pointer that is being queued |
101 | * points to a valid data. | |
2e0ab8ca MT |
102 | */ |
103 | static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) | |
104 | { | |
982fb490 | 105 | if (unlikely(!r->size) || r->queue[r->producer]) |
2e0ab8ca MT |
106 | return -ENOSPC; |
107 | ||
a8ceb5db MT |
108 | /* Make sure the pointer we are storing points to a valid data. */ |
109 | /* Pairs with smp_read_barrier_depends in __ptr_ring_consume. */ | |
110 | smp_wmb(); | |
111 | ||
a07d29c6 | 112 | WRITE_ONCE(r->queue[r->producer++], ptr); |
2e0ab8ca MT |
113 | if (unlikely(r->producer >= r->size)) |
114 | r->producer = 0; | |
115 | return 0; | |
116 | } | |
117 | ||
e7169530 MT |
118 | /* |
119 | * Note: resize (below) nests producer lock within consumer lock, so if you | |
120 | * consume in interrupt or BH context, you must disable interrupts/BH when | |
121 | * calling this. | |
122 | */ | |
2e0ab8ca MT |
123 | static inline int ptr_ring_produce(struct ptr_ring *r, void *ptr) |
124 | { | |
125 | int ret; | |
126 | ||
127 | spin_lock(&r->producer_lock); | |
128 | ret = __ptr_ring_produce(r, ptr); | |
129 | spin_unlock(&r->producer_lock); | |
130 | ||
131 | return ret; | |
132 | } | |
133 | ||
134 | static inline int ptr_ring_produce_irq(struct ptr_ring *r, void *ptr) | |
135 | { | |
136 | int ret; | |
137 | ||
138 | spin_lock_irq(&r->producer_lock); | |
139 | ret = __ptr_ring_produce(r, ptr); | |
140 | spin_unlock_irq(&r->producer_lock); | |
141 | ||
142 | return ret; | |
143 | } | |
144 | ||
145 | static inline int ptr_ring_produce_any(struct ptr_ring *r, void *ptr) | |
146 | { | |
147 | unsigned long flags; | |
148 | int ret; | |
149 | ||
150 | spin_lock_irqsave(&r->producer_lock, flags); | |
151 | ret = __ptr_ring_produce(r, ptr); | |
152 | spin_unlock_irqrestore(&r->producer_lock, flags); | |
153 | ||
154 | return ret; | |
155 | } | |
156 | ||
157 | static inline int ptr_ring_produce_bh(struct ptr_ring *r, void *ptr) | |
158 | { | |
159 | int ret; | |
160 | ||
161 | spin_lock_bh(&r->producer_lock); | |
162 | ret = __ptr_ring_produce(r, ptr); | |
163 | spin_unlock_bh(&r->producer_lock); | |
164 | ||
165 | return ret; | |
166 | } | |
167 | ||
2e0ab8ca MT |
168 | static inline void *__ptr_ring_peek(struct ptr_ring *r) |
169 | { | |
982fb490 | 170 | if (likely(r->size)) |
a07d29c6 | 171 | return READ_ONCE(r->queue[r->consumer_head]); |
982fb490 | 172 | return NULL; |
2e0ab8ca MT |
173 | } |
174 | ||
8619d384 MT |
175 | /* |
176 | * Test ring empty status without taking any locks. | |
177 | * | |
178 | * NB: This is only safe to call if ring is never resized. | |
179 | * | |
180 | * However, if some other CPU consumes ring entries at the same time, the value | |
181 | * returned is not guaranteed to be correct. | |
182 | * | |
183 | * In this case - to avoid incorrectly detecting the ring | |
184 | * as empty - the CPU consuming the ring entries is responsible | |
185 | * for either consuming all ring entries until the ring is empty, | |
186 | * or synchronizing with some other CPU and causing it to | |
187 | * re-test __ptr_ring_empty and/or consume the ring enteries | |
188 | * after the synchronization point. | |
189 | * | |
190 | * Note: callers invoking this in a loop must use a compiler barrier, | |
191 | * for example cpu_relax(). | |
192 | */ | |
5d49de53 | 193 | static inline bool __ptr_ring_empty(struct ptr_ring *r) |
2e0ab8ca | 194 | { |
a259df36 MT |
195 | if (likely(r->size)) |
196 | return !r->queue[READ_ONCE(r->consumer_head)]; | |
197 | return true; | |
2e0ab8ca MT |
198 | } |
199 | ||
5d49de53 MT |
200 | static inline bool ptr_ring_empty(struct ptr_ring *r) |
201 | { | |
202 | bool ret; | |
203 | ||
204 | spin_lock(&r->consumer_lock); | |
205 | ret = __ptr_ring_empty(r); | |
206 | spin_unlock(&r->consumer_lock); | |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
211 | static inline bool ptr_ring_empty_irq(struct ptr_ring *r) | |
212 | { | |
213 | bool ret; | |
214 | ||
215 | spin_lock_irq(&r->consumer_lock); | |
216 | ret = __ptr_ring_empty(r); | |
217 | spin_unlock_irq(&r->consumer_lock); | |
218 | ||
219 | return ret; | |
220 | } | |
221 | ||
222 | static inline bool ptr_ring_empty_any(struct ptr_ring *r) | |
223 | { | |
224 | unsigned long flags; | |
225 | bool ret; | |
226 | ||
227 | spin_lock_irqsave(&r->consumer_lock, flags); | |
228 | ret = __ptr_ring_empty(r); | |
229 | spin_unlock_irqrestore(&r->consumer_lock, flags); | |
230 | ||
231 | return ret; | |
232 | } | |
233 | ||
234 | static inline bool ptr_ring_empty_bh(struct ptr_ring *r) | |
235 | { | |
236 | bool ret; | |
237 | ||
238 | spin_lock_bh(&r->consumer_lock); | |
239 | ret = __ptr_ring_empty(r); | |
240 | spin_unlock_bh(&r->consumer_lock); | |
241 | ||
242 | return ret; | |
243 | } | |
244 | ||
2e0ab8ca MT |
245 | /* Must only be called after __ptr_ring_peek returned !NULL */ |
246 | static inline void __ptr_ring_discard_one(struct ptr_ring *r) | |
247 | { | |
fb9de970 MT |
248 | /* Fundamentally, what we want to do is update consumer |
249 | * index and zero out the entry so producer can reuse it. | |
250 | * Doing it naively at each consume would be as simple as: | |
406de755 MT |
251 | * consumer = r->consumer; |
252 | * r->queue[consumer++] = NULL; | |
253 | * if (unlikely(consumer >= r->size)) | |
254 | * consumer = 0; | |
255 | * r->consumer = consumer; | |
fb9de970 MT |
256 | * but that is suboptimal when the ring is full as producer is writing |
257 | * out new entries in the same cache line. Defer these updates until a | |
258 | * batch of entries has been consumed. | |
259 | */ | |
406de755 MT |
260 | /* Note: we must keep consumer_head valid at all times for __ptr_ring_empty |
261 | * to work correctly. | |
262 | */ | |
263 | int consumer_head = r->consumer_head; | |
264 | int head = consumer_head++; | |
fb9de970 MT |
265 | |
266 | /* Once we have processed enough entries invalidate them in | |
267 | * the ring all at once so producer can reuse their space in the ring. | |
268 | * We also do this when we reach end of the ring - not mandatory | |
269 | * but helps keep the implementation simple. | |
270 | */ | |
406de755 MT |
271 | if (unlikely(consumer_head - r->consumer_tail >= r->batch || |
272 | consumer_head >= r->size)) { | |
fb9de970 MT |
273 | /* Zero out entries in the reverse order: this way we touch the |
274 | * cache line that producer might currently be reading the last; | |
275 | * producer won't make progress and touch other cache lines | |
276 | * besides the first one until we write out all entries. | |
277 | */ | |
278 | while (likely(head >= r->consumer_tail)) | |
279 | r->queue[head--] = NULL; | |
406de755 | 280 | r->consumer_tail = consumer_head; |
fb9de970 | 281 | } |
406de755 MT |
282 | if (unlikely(consumer_head >= r->size)) { |
283 | consumer_head = 0; | |
fb9de970 MT |
284 | r->consumer_tail = 0; |
285 | } | |
a259df36 MT |
286 | /* matching READ_ONCE in __ptr_ring_empty for lockless tests */ |
287 | WRITE_ONCE(r->consumer_head, consumer_head); | |
2e0ab8ca MT |
288 | } |
289 | ||
290 | static inline void *__ptr_ring_consume(struct ptr_ring *r) | |
291 | { | |
292 | void *ptr; | |
293 | ||
e3f9f417 AP |
294 | /* The READ_ONCE in __ptr_ring_peek guarantees that anyone |
295 | * accessing data through the pointer is up to date. Pairs | |
296 | * with smp_wmb in __ptr_ring_produce. | |
297 | */ | |
2e0ab8ca MT |
298 | ptr = __ptr_ring_peek(r); |
299 | if (ptr) | |
300 | __ptr_ring_discard_one(r); | |
301 | ||
302 | return ptr; | |
303 | } | |
304 | ||
728fc8d5 JW |
305 | static inline int __ptr_ring_consume_batched(struct ptr_ring *r, |
306 | void **array, int n) | |
307 | { | |
308 | void *ptr; | |
309 | int i; | |
310 | ||
311 | for (i = 0; i < n; i++) { | |
312 | ptr = __ptr_ring_consume(r); | |
313 | if (!ptr) | |
314 | break; | |
315 | array[i] = ptr; | |
316 | } | |
317 | ||
318 | return i; | |
319 | } | |
320 | ||
e7169530 MT |
321 | /* |
322 | * Note: resize (below) nests producer lock within consumer lock, so if you | |
323 | * call this in interrupt or BH context, you must disable interrupts/BH when | |
324 | * producing. | |
325 | */ | |
2e0ab8ca MT |
326 | static inline void *ptr_ring_consume(struct ptr_ring *r) |
327 | { | |
328 | void *ptr; | |
329 | ||
330 | spin_lock(&r->consumer_lock); | |
331 | ptr = __ptr_ring_consume(r); | |
332 | spin_unlock(&r->consumer_lock); | |
333 | ||
334 | return ptr; | |
335 | } | |
336 | ||
337 | static inline void *ptr_ring_consume_irq(struct ptr_ring *r) | |
338 | { | |
339 | void *ptr; | |
340 | ||
341 | spin_lock_irq(&r->consumer_lock); | |
342 | ptr = __ptr_ring_consume(r); | |
343 | spin_unlock_irq(&r->consumer_lock); | |
344 | ||
345 | return ptr; | |
346 | } | |
347 | ||
348 | static inline void *ptr_ring_consume_any(struct ptr_ring *r) | |
349 | { | |
350 | unsigned long flags; | |
351 | void *ptr; | |
352 | ||
353 | spin_lock_irqsave(&r->consumer_lock, flags); | |
354 | ptr = __ptr_ring_consume(r); | |
355 | spin_unlock_irqrestore(&r->consumer_lock, flags); | |
356 | ||
357 | return ptr; | |
358 | } | |
359 | ||
360 | static inline void *ptr_ring_consume_bh(struct ptr_ring *r) | |
361 | { | |
362 | void *ptr; | |
363 | ||
364 | spin_lock_bh(&r->consumer_lock); | |
365 | ptr = __ptr_ring_consume(r); | |
366 | spin_unlock_bh(&r->consumer_lock); | |
367 | ||
368 | return ptr; | |
369 | } | |
370 | ||
728fc8d5 JW |
371 | static inline int ptr_ring_consume_batched(struct ptr_ring *r, |
372 | void **array, int n) | |
373 | { | |
374 | int ret; | |
375 | ||
376 | spin_lock(&r->consumer_lock); | |
377 | ret = __ptr_ring_consume_batched(r, array, n); | |
378 | spin_unlock(&r->consumer_lock); | |
379 | ||
380 | return ret; | |
381 | } | |
382 | ||
383 | static inline int ptr_ring_consume_batched_irq(struct ptr_ring *r, | |
384 | void **array, int n) | |
385 | { | |
386 | int ret; | |
387 | ||
388 | spin_lock_irq(&r->consumer_lock); | |
389 | ret = __ptr_ring_consume_batched(r, array, n); | |
390 | spin_unlock_irq(&r->consumer_lock); | |
391 | ||
392 | return ret; | |
393 | } | |
394 | ||
395 | static inline int ptr_ring_consume_batched_any(struct ptr_ring *r, | |
396 | void **array, int n) | |
397 | { | |
398 | unsigned long flags; | |
399 | int ret; | |
400 | ||
401 | spin_lock_irqsave(&r->consumer_lock, flags); | |
402 | ret = __ptr_ring_consume_batched(r, array, n); | |
403 | spin_unlock_irqrestore(&r->consumer_lock, flags); | |
404 | ||
405 | return ret; | |
406 | } | |
407 | ||
408 | static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r, | |
409 | void **array, int n) | |
410 | { | |
411 | int ret; | |
412 | ||
413 | spin_lock_bh(&r->consumer_lock); | |
414 | ret = __ptr_ring_consume_batched(r, array, n); | |
415 | spin_unlock_bh(&r->consumer_lock); | |
416 | ||
417 | return ret; | |
418 | } | |
419 | ||
2e0ab8ca MT |
420 | /* Cast to structure type and call a function without discarding from FIFO. |
421 | * Function must return a value. | |
422 | * Callers must take consumer_lock. | |
423 | */ | |
424 | #define __PTR_RING_PEEK_CALL(r, f) ((f)(__ptr_ring_peek(r))) | |
425 | ||
426 | #define PTR_RING_PEEK_CALL(r, f) ({ \ | |
427 | typeof((f)(NULL)) __PTR_RING_PEEK_CALL_v; \ | |
428 | \ | |
429 | spin_lock(&(r)->consumer_lock); \ | |
430 | __PTR_RING_PEEK_CALL_v = __PTR_RING_PEEK_CALL(r, f); \ | |
431 | spin_unlock(&(r)->consumer_lock); \ | |
432 | __PTR_RING_PEEK_CALL_v; \ | |
433 | }) | |
434 | ||
435 | #define PTR_RING_PEEK_CALL_IRQ(r, f) ({ \ | |
436 | typeof((f)(NULL)) __PTR_RING_PEEK_CALL_v; \ | |
437 | \ | |
438 | spin_lock_irq(&(r)->consumer_lock); \ | |
439 | __PTR_RING_PEEK_CALL_v = __PTR_RING_PEEK_CALL(r, f); \ | |
440 | spin_unlock_irq(&(r)->consumer_lock); \ | |
441 | __PTR_RING_PEEK_CALL_v; \ | |
442 | }) | |
443 | ||
444 | #define PTR_RING_PEEK_CALL_BH(r, f) ({ \ | |
445 | typeof((f)(NULL)) __PTR_RING_PEEK_CALL_v; \ | |
446 | \ | |
447 | spin_lock_bh(&(r)->consumer_lock); \ | |
448 | __PTR_RING_PEEK_CALL_v = __PTR_RING_PEEK_CALL(r, f); \ | |
449 | spin_unlock_bh(&(r)->consumer_lock); \ | |
450 | __PTR_RING_PEEK_CALL_v; \ | |
451 | }) | |
452 | ||
453 | #define PTR_RING_PEEK_CALL_ANY(r, f) ({ \ | |
454 | typeof((f)(NULL)) __PTR_RING_PEEK_CALL_v; \ | |
455 | unsigned long __PTR_RING_PEEK_CALL_f;\ | |
456 | \ | |
457 | spin_lock_irqsave(&(r)->consumer_lock, __PTR_RING_PEEK_CALL_f); \ | |
458 | __PTR_RING_PEEK_CALL_v = __PTR_RING_PEEK_CALL(r, f); \ | |
459 | spin_unlock_irqrestore(&(r)->consumer_lock, __PTR_RING_PEEK_CALL_f); \ | |
460 | __PTR_RING_PEEK_CALL_v; \ | |
461 | }) | |
462 | ||
0bf7800f JW |
463 | /* Not all gfp_t flags (besides GFP_KERNEL) are allowed. See |
464 | * documentation for vmalloc for which of them are legal. | |
465 | */ | |
81fbfe8a | 466 | static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) |
5d49de53 | 467 | { |
54e02162 | 468 | if (size > KMALLOC_MAX_SIZE / sizeof(void *)) |
6e6e41c3 | 469 | return NULL; |
0bf7800f | 470 | return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO); |
5d49de53 MT |
471 | } |
472 | ||
fb9de970 MT |
473 | static inline void __ptr_ring_set_size(struct ptr_ring *r, int size) |
474 | { | |
475 | r->size = size; | |
476 | r->batch = SMP_CACHE_BYTES * 2 / sizeof(*(r->queue)); | |
477 | /* We need to set batch at least to 1 to make logic | |
478 | * in __ptr_ring_discard_one work correctly. | |
479 | * Batching too much (because ring is small) would cause a lot of | |
480 | * burstiness. Needs tuning, for now disable batching. | |
481 | */ | |
482 | if (r->batch > r->size / 2 || !r->batch) | |
483 | r->batch = 1; | |
484 | } | |
485 | ||
2e0ab8ca MT |
486 | static inline int ptr_ring_init(struct ptr_ring *r, int size, gfp_t gfp) |
487 | { | |
5d49de53 | 488 | r->queue = __ptr_ring_init_queue_alloc(size, gfp); |
2e0ab8ca MT |
489 | if (!r->queue) |
490 | return -ENOMEM; | |
491 | ||
fb9de970 MT |
492 | __ptr_ring_set_size(r, size); |
493 | r->producer = r->consumer_head = r->consumer_tail = 0; | |
2e0ab8ca MT |
494 | spin_lock_init(&r->producer_lock); |
495 | spin_lock_init(&r->consumer_lock); | |
496 | ||
497 | return 0; | |
498 | } | |
499 | ||
197a5212 MT |
500 | /* |
501 | * Return entries into ring. Destroy entries that don't fit. | |
502 | * | |
503 | * Note: this is expected to be a rare slow path operation. | |
504 | * | |
505 | * Note: producer lock is nested within consumer lock, so if you | |
506 | * resize you must make sure all uses nest correctly. | |
507 | * In particular if you consume ring in interrupt or BH context, you must | |
508 | * disable interrupts/BH when doing so. | |
509 | */ | |
510 | static inline void ptr_ring_unconsume(struct ptr_ring *r, void **batch, int n, | |
511 | void (*destroy)(void *)) | |
512 | { | |
513 | unsigned long flags; | |
514 | int head; | |
515 | ||
516 | spin_lock_irqsave(&r->consumer_lock, flags); | |
517 | spin_lock(&r->producer_lock); | |
518 | ||
519 | if (!r->size) | |
520 | goto done; | |
521 | ||
522 | /* | |
523 | * Clean out buffered entries (for simplicity). This way following code | |
524 | * can test entries for NULL and if not assume they are valid. | |
525 | */ | |
526 | head = r->consumer_head - 1; | |
527 | while (likely(head >= r->consumer_tail)) | |
528 | r->queue[head--] = NULL; | |
529 | r->consumer_tail = r->consumer_head; | |
530 | ||
531 | /* | |
532 | * Go over entries in batch, start moving head back and copy entries. | |
533 | * Stop when we run into previously unconsumed entries. | |
534 | */ | |
535 | while (n) { | |
536 | head = r->consumer_head - 1; | |
537 | if (head < 0) | |
538 | head = r->size - 1; | |
539 | if (r->queue[head]) { | |
540 | /* This batch entry will have to be destroyed. */ | |
541 | goto done; | |
542 | } | |
543 | r->queue[head] = batch[--n]; | |
a259df36 MT |
544 | r->consumer_tail = head; |
545 | /* matching READ_ONCE in __ptr_ring_empty for lockless tests */ | |
546 | WRITE_ONCE(r->consumer_head, head); | |
197a5212 MT |
547 | } |
548 | ||
549 | done: | |
550 | /* Destroy all entries left in the batch. */ | |
551 | while (n) | |
552 | destroy(batch[--n]); | |
553 | spin_unlock(&r->producer_lock); | |
554 | spin_unlock_irqrestore(&r->consumer_lock, flags); | |
555 | } | |
556 | ||
59e6ae53 MT |
557 | static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue, |
558 | int size, gfp_t gfp, | |
559 | void (*destroy)(void *)) | |
5d49de53 | 560 | { |
5d49de53 | 561 | int producer = 0; |
5d49de53 MT |
562 | void **old; |
563 | void *ptr; | |
564 | ||
e7169530 | 565 | while ((ptr = __ptr_ring_consume(r))) |
5d49de53 MT |
566 | if (producer < size) |
567 | queue[producer++] = ptr; | |
568 | else if (destroy) | |
569 | destroy(ptr); | |
570 | ||
aff6db45 CW |
571 | if (producer >= size) |
572 | producer = 0; | |
fb9de970 | 573 | __ptr_ring_set_size(r, size); |
5d49de53 | 574 | r->producer = producer; |
fb9de970 MT |
575 | r->consumer_head = 0; |
576 | r->consumer_tail = 0; | |
5d49de53 MT |
577 | old = r->queue; |
578 | r->queue = queue; | |
579 | ||
59e6ae53 MT |
580 | return old; |
581 | } | |
582 | ||
e7169530 MT |
583 | /* |
584 | * Note: producer lock is nested within consumer lock, so if you | |
585 | * resize you must make sure all uses nest correctly. | |
586 | * In particular if you consume ring in interrupt or BH context, you must | |
587 | * disable interrupts/BH when doing so. | |
588 | */ | |
59e6ae53 MT |
589 | static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, |
590 | void (*destroy)(void *)) | |
591 | { | |
592 | unsigned long flags; | |
593 | void **queue = __ptr_ring_init_queue_alloc(size, gfp); | |
594 | void **old; | |
595 | ||
596 | if (!queue) | |
597 | return -ENOMEM; | |
598 | ||
e7169530 MT |
599 | spin_lock_irqsave(&(r)->consumer_lock, flags); |
600 | spin_lock(&(r)->producer_lock); | |
59e6ae53 MT |
601 | |
602 | old = __ptr_ring_swap_queue(r, queue, size, gfp, destroy); | |
603 | ||
e7169530 MT |
604 | spin_unlock(&(r)->producer_lock); |
605 | spin_unlock_irqrestore(&(r)->consumer_lock, flags); | |
5d49de53 | 606 | |
0bf7800f | 607 | kvfree(old); |
5d49de53 MT |
608 | |
609 | return 0; | |
610 | } | |
611 | ||
e7169530 MT |
612 | /* |
613 | * Note: producer lock is nested within consumer lock, so if you | |
614 | * resize you must make sure all uses nest correctly. | |
615 | * In particular if you consume ring in interrupt or BH context, you must | |
616 | * disable interrupts/BH when doing so. | |
617 | */ | |
81fbfe8a ED |
618 | static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, |
619 | unsigned int nrings, | |
59e6ae53 MT |
620 | int size, |
621 | gfp_t gfp, void (*destroy)(void *)) | |
622 | { | |
623 | unsigned long flags; | |
624 | void ***queues; | |
625 | int i; | |
626 | ||
81fbfe8a | 627 | queues = kmalloc_array(nrings, sizeof(*queues), gfp); |
59e6ae53 MT |
628 | if (!queues) |
629 | goto noqueues; | |
630 | ||
631 | for (i = 0; i < nrings; ++i) { | |
632 | queues[i] = __ptr_ring_init_queue_alloc(size, gfp); | |
633 | if (!queues[i]) | |
634 | goto nomem; | |
635 | } | |
636 | ||
637 | for (i = 0; i < nrings; ++i) { | |
e7169530 MT |
638 | spin_lock_irqsave(&(rings[i])->consumer_lock, flags); |
639 | spin_lock(&(rings[i])->producer_lock); | |
59e6ae53 MT |
640 | queues[i] = __ptr_ring_swap_queue(rings[i], queues[i], |
641 | size, gfp, destroy); | |
e7169530 MT |
642 | spin_unlock(&(rings[i])->producer_lock); |
643 | spin_unlock_irqrestore(&(rings[i])->consumer_lock, flags); | |
59e6ae53 MT |
644 | } |
645 | ||
646 | for (i = 0; i < nrings; ++i) | |
0bf7800f | 647 | kvfree(queues[i]); |
59e6ae53 MT |
648 | |
649 | kfree(queues); | |
650 | ||
651 | return 0; | |
652 | ||
653 | nomem: | |
654 | while (--i >= 0) | |
0bf7800f | 655 | kvfree(queues[i]); |
59e6ae53 MT |
656 | |
657 | kfree(queues); | |
658 | ||
659 | noqueues: | |
660 | return -ENOMEM; | |
661 | } | |
662 | ||
5d49de53 | 663 | static inline void ptr_ring_cleanup(struct ptr_ring *r, void (*destroy)(void *)) |
2e0ab8ca | 664 | { |
5d49de53 MT |
665 | void *ptr; |
666 | ||
667 | if (destroy) | |
668 | while ((ptr = ptr_ring_consume(r))) | |
669 | destroy(ptr); | |
0bf7800f | 670 | kvfree(r->queue); |
2e0ab8ca MT |
671 | } |
672 | ||
673 | #endif /* _LINUX_PTR_RING_H */ |