Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-only */
2 : /*
3 : * Fast and scalable bitmaps.
4 : *
5 : * Copyright (C) 2016 Facebook
6 : * Copyright (C) 2013-2014 Jens Axboe
7 : */
8 :
9 : #ifndef __LINUX_SCALE_BITMAP_H
10 : #define __LINUX_SCALE_BITMAP_H
11 :
12 : #include <linux/atomic.h>
13 : #include <linux/bitops.h>
14 : #include <linux/cache.h>
15 : #include <linux/list.h>
16 : #include <linux/log2.h>
17 : #include <linux/minmax.h>
18 : #include <linux/percpu.h>
19 : #include <linux/slab.h>
20 : #include <linux/smp.h>
21 : #include <linux/types.h>
22 : #include <linux/wait.h>
23 :
24 : struct seq_file;
25 :
26 : /**
27 : * struct sbitmap_word - Word in a &struct sbitmap.
28 : */
29 : struct sbitmap_word {
30 : /**
31 : * @word: word holding free bits
32 : */
33 : unsigned long word;
34 :
35 : /**
36 : * @cleared: word holding cleared bits
37 : */
38 : unsigned long cleared ____cacheline_aligned_in_smp;
39 : } ____cacheline_aligned_in_smp;
40 :
41 : /**
42 : * struct sbitmap - Scalable bitmap.
43 : *
44 : * A &struct sbitmap is spread over multiple cachelines to avoid ping-pong. This
45 : * trades off higher memory usage for better scalability.
46 : */
47 : struct sbitmap {
48 : /**
49 : * @depth: Number of bits used in the whole bitmap.
50 : */
51 : unsigned int depth;
52 :
53 : /**
54 : * @shift: log2(number of bits used per word)
55 : */
56 : unsigned int shift;
57 :
58 : /**
59 : * @map_nr: Number of words (cachelines) being used for the bitmap.
60 : */
61 : unsigned int map_nr;
62 :
63 : /**
64 : * @round_robin: Allocate bits in strict round-robin order.
65 : */
66 : bool round_robin;
67 :
68 : /**
69 : * @map: Allocated bitmap.
70 : */
71 : struct sbitmap_word *map;
72 :
73 : /*
74 : * @alloc_hint: Cache of last successfully allocated or freed bit.
75 : *
76 : * This is per-cpu, which allows multiple users to stick to different
77 : * cachelines until the map is exhausted.
78 : */
79 : unsigned int __percpu *alloc_hint;
80 : };
81 :
82 : #define SBQ_WAIT_QUEUES 8
83 : #define SBQ_WAKE_BATCH 8
84 :
85 : /**
86 : * struct sbq_wait_state - Wait queue in a &struct sbitmap_queue.
87 : */
88 : struct sbq_wait_state {
89 : /**
90 : * @wait: Wait queue.
91 : */
92 : wait_queue_head_t wait;
93 : } ____cacheline_aligned_in_smp;
94 :
95 : /**
96 : * struct sbitmap_queue - Scalable bitmap with the added ability to wait on free
97 : * bits.
98 : *
99 : * A &struct sbitmap_queue uses multiple wait queues and rolling wakeups to
100 : * avoid contention on the wait queue spinlock. This ensures that we don't hit a
101 : * scalability wall when we run out of free bits and have to start putting tasks
102 : * to sleep.
103 : */
104 : struct sbitmap_queue {
105 : /**
106 : * @sb: Scalable bitmap.
107 : */
108 : struct sbitmap sb;
109 :
110 : /**
111 : * @wake_batch: Number of bits which must be freed before we wake up any
112 : * waiters.
113 : */
114 : unsigned int wake_batch;
115 :
116 : /**
117 : * @wake_index: Next wait queue in @ws to wake up.
118 : */
119 : atomic_t wake_index;
120 :
121 : /**
122 : * @ws: Wait queues.
123 : */
124 : struct sbq_wait_state *ws;
125 :
126 : /*
127 : * @ws_active: count of currently active ws waitqueues
128 : */
129 : atomic_t ws_active;
130 :
131 : /**
132 : * @min_shallow_depth: The minimum shallow depth which may be passed to
133 : * sbitmap_queue_get_shallow()
134 : */
135 : unsigned int min_shallow_depth;
136 :
137 : /**
138 : * @completion_cnt: Number of bits cleared passed to the
139 : * wakeup function.
140 : */
141 : atomic_t completion_cnt;
142 :
143 : /**
144 : * @wakeup_cnt: Number of thread wake ups issued.
145 : */
146 : atomic_t wakeup_cnt;
147 : };
148 :
149 : /**
150 : * sbitmap_init_node() - Initialize a &struct sbitmap on a specific memory node.
151 : * @sb: Bitmap to initialize.
152 : * @depth: Number of bits to allocate.
153 : * @shift: Use 2^@shift bits per word in the bitmap; if a negative number if
154 : * given, a good default is chosen.
155 : * @flags: Allocation flags.
156 : * @node: Memory node to allocate on.
157 : * @round_robin: If true, be stricter about allocation order; always allocate
158 : * starting from the last allocated bit. This is less efficient
159 : * than the default behavior (false).
160 : * @alloc_hint: If true, apply percpu hint for where to start searching for
161 : * a free bit.
162 : *
163 : * Return: Zero on success or negative errno on failure.
164 : */
165 : int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
166 : gfp_t flags, int node, bool round_robin, bool alloc_hint);
167 :
168 : /* sbitmap internal helper */
169 : static inline unsigned int __map_depth(const struct sbitmap *sb, int index)
170 : {
171 0 : if (index == sb->map_nr - 1)
172 0 : return sb->depth - (index << sb->shift);
173 0 : return 1U << sb->shift;
174 : }
175 :
176 : /**
177 : * sbitmap_free() - Free memory used by a &struct sbitmap.
178 : * @sb: Bitmap to free.
179 : */
180 : static inline void sbitmap_free(struct sbitmap *sb)
181 : {
182 0 : free_percpu(sb->alloc_hint);
183 0 : kvfree(sb->map);
184 0 : sb->map = NULL;
185 : }
186 :
187 : /**
188 : * sbitmap_resize() - Resize a &struct sbitmap.
189 : * @sb: Bitmap to resize.
190 : * @depth: New number of bits to resize to.
191 : *
192 : * Doesn't reallocate anything. It's up to the caller to ensure that the new
193 : * depth doesn't exceed the depth that the sb was initialized with.
194 : */
195 : void sbitmap_resize(struct sbitmap *sb, unsigned int depth);
196 :
197 : /**
198 : * sbitmap_get() - Try to allocate a free bit from a &struct sbitmap.
199 : * @sb: Bitmap to allocate from.
200 : *
201 : * This operation provides acquire barrier semantics if it succeeds.
202 : *
203 : * Return: Non-negative allocated bit number if successful, -1 otherwise.
204 : */
205 : int sbitmap_get(struct sbitmap *sb);
206 :
207 : /**
208 : * sbitmap_get_shallow() - Try to allocate a free bit from a &struct sbitmap,
209 : * limiting the depth used from each word.
210 : * @sb: Bitmap to allocate from.
211 : * @shallow_depth: The maximum number of bits to allocate from a single word.
212 : *
213 : * This rather specific operation allows for having multiple users with
214 : * different allocation limits. E.g., there can be a high-priority class that
215 : * uses sbitmap_get() and a low-priority class that uses sbitmap_get_shallow()
216 : * with a @shallow_depth of (1 << (@sb->shift - 1)). Then, the low-priority
217 : * class can only allocate half of the total bits in the bitmap, preventing it
218 : * from starving out the high-priority class.
219 : *
220 : * Return: Non-negative allocated bit number if successful, -1 otherwise.
221 : */
222 : int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth);
223 :
224 : /**
225 : * sbitmap_any_bit_set() - Check for a set bit in a &struct sbitmap.
226 : * @sb: Bitmap to check.
227 : *
228 : * Return: true if any bit in the bitmap is set, false otherwise.
229 : */
230 : bool sbitmap_any_bit_set(const struct sbitmap *sb);
231 :
232 : #define SB_NR_TO_INDEX(sb, bitnr) ((bitnr) >> (sb)->shift)
233 : #define SB_NR_TO_BIT(sb, bitnr) ((bitnr) & ((1U << (sb)->shift) - 1U))
234 :
235 : typedef bool (*sb_for_each_fn)(struct sbitmap *, unsigned int, void *);
236 :
237 : /**
238 : * __sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap.
239 : * @start: Where to start the iteration.
240 : * @sb: Bitmap to iterate over.
241 : * @fn: Callback. Should return true to continue or false to break early.
242 : * @data: Pointer to pass to callback.
243 : *
244 : * This is inline even though it's non-trivial so that the function calls to the
245 : * callback will hopefully get optimized away.
246 : */
247 0 : static inline void __sbitmap_for_each_set(struct sbitmap *sb,
248 : unsigned int start,
249 : sb_for_each_fn fn, void *data)
250 : {
251 : unsigned int index;
252 : unsigned int nr;
253 0 : unsigned int scanned = 0;
254 :
255 0 : if (start >= sb->depth)
256 0 : start = 0;
257 0 : index = SB_NR_TO_INDEX(sb, start);
258 0 : nr = SB_NR_TO_BIT(sb, start);
259 :
260 0 : while (scanned < sb->depth) {
261 : unsigned long word;
262 0 : unsigned int depth = min_t(unsigned int,
263 : __map_depth(sb, index) - nr,
264 : sb->depth - scanned);
265 :
266 0 : scanned += depth;
267 0 : word = sb->map[index].word & ~sb->map[index].cleared;
268 0 : if (!word)
269 : goto next;
270 :
271 : /*
272 : * On the first iteration of the outer loop, we need to add the
273 : * bit offset back to the size of the word for find_next_bit().
274 : * On all other iterations, nr is zero, so this is a noop.
275 : */
276 0 : depth += nr;
277 : while (1) {
278 0 : nr = find_next_bit(&word, depth, nr);
279 0 : if (nr >= depth)
280 : break;
281 0 : if (!fn(sb, (index << sb->shift) + nr, data))
282 0 : return;
283 :
284 0 : nr++;
285 : }
286 : next:
287 0 : nr = 0;
288 0 : if (++index >= sb->map_nr)
289 0 : index = 0;
290 : }
291 : }
292 :
293 : /**
294 : * sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap.
295 : * @sb: Bitmap to iterate over.
296 : * @fn: Callback. Should return true to continue or false to break early.
297 : * @data: Pointer to pass to callback.
298 : */
299 : static inline void sbitmap_for_each_set(struct sbitmap *sb, sb_for_each_fn fn,
300 : void *data)
301 : {
302 0 : __sbitmap_for_each_set(sb, 0, fn, data);
303 : }
304 :
305 : static inline unsigned long *__sbitmap_word(struct sbitmap *sb,
306 : unsigned int bitnr)
307 : {
308 0 : return &sb->map[SB_NR_TO_INDEX(sb, bitnr)].word;
309 : }
310 :
311 : /* Helpers equivalent to the operations in asm/bitops.h and linux/bitmap.h */
312 :
313 : static inline void sbitmap_set_bit(struct sbitmap *sb, unsigned int bitnr)
314 : {
315 0 : set_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
316 : }
317 :
318 : static inline void sbitmap_clear_bit(struct sbitmap *sb, unsigned int bitnr)
319 : {
320 0 : clear_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
321 : }
322 :
323 : /*
324 : * This one is special, since it doesn't actually clear the bit, rather it
325 : * sets the corresponding bit in the ->cleared mask instead. Paired with
326 : * the caller doing sbitmap_deferred_clear() if a given index is full, which
327 : * will clear the previously freed entries in the corresponding ->word.
328 : */
329 : static inline void sbitmap_deferred_clear_bit(struct sbitmap *sb, unsigned int bitnr)
330 : {
331 0 : unsigned long *addr = &sb->map[SB_NR_TO_INDEX(sb, bitnr)].cleared;
332 :
333 0 : set_bit(SB_NR_TO_BIT(sb, bitnr), addr);
334 : }
335 :
336 : /*
337 : * Pair of sbitmap_get, and this one applies both cleared bit and
338 : * allocation hint.
339 : */
340 : static inline void sbitmap_put(struct sbitmap *sb, unsigned int bitnr)
341 : {
342 : sbitmap_deferred_clear_bit(sb, bitnr);
343 :
344 : if (likely(sb->alloc_hint && !sb->round_robin && bitnr < sb->depth))
345 : *raw_cpu_ptr(sb->alloc_hint) = bitnr;
346 : }
347 :
348 : static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr)
349 : {
350 0 : return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
351 : }
352 :
353 : static inline int sbitmap_calculate_shift(unsigned int depth)
354 : {
355 0 : int shift = ilog2(BITS_PER_LONG);
356 :
357 : /*
358 : * If the bitmap is small, shrink the number of bits per word so
359 : * we spread over a few cachelines, at least. If less than 4
360 : * bits, just forget about it, it's not going to work optimally
361 : * anyway.
362 : */
363 0 : if (depth >= 4) {
364 0 : while ((4U << shift) > depth)
365 0 : shift--;
366 : }
367 :
368 : return shift;
369 : }
370 :
371 : /**
372 : * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file.
373 : * @sb: Bitmap to show.
374 : * @m: struct seq_file to write to.
375 : *
376 : * This is intended for debugging. The format may change at any time.
377 : */
378 : void sbitmap_show(struct sbitmap *sb, struct seq_file *m);
379 :
380 :
381 : /**
382 : * sbitmap_weight() - Return how many set and not cleared bits in a &struct
383 : * sbitmap.
384 : * @sb: Bitmap to check.
385 : *
386 : * Return: How many set and not cleared bits set
387 : */
388 : unsigned int sbitmap_weight(const struct sbitmap *sb);
389 :
390 : /**
391 : * sbitmap_bitmap_show() - Write a hex dump of a &struct sbitmap to a &struct
392 : * seq_file.
393 : * @sb: Bitmap to show.
394 : * @m: struct seq_file to write to.
395 : *
396 : * This is intended for debugging. The output isn't guaranteed to be internally
397 : * consistent.
398 : */
399 : void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m);
400 :
401 : /**
402 : * sbitmap_queue_init_node() - Initialize a &struct sbitmap_queue on a specific
403 : * memory node.
404 : * @sbq: Bitmap queue to initialize.
405 : * @depth: See sbitmap_init_node().
406 : * @shift: See sbitmap_init_node().
407 : * @round_robin: See sbitmap_get().
408 : * @flags: Allocation flags.
409 : * @node: Memory node to allocate on.
410 : *
411 : * Return: Zero on success or negative errno on failure.
412 : */
413 : int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
414 : int shift, bool round_robin, gfp_t flags, int node);
415 :
416 : /**
417 : * sbitmap_queue_free() - Free memory used by a &struct sbitmap_queue.
418 : *
419 : * @sbq: Bitmap queue to free.
420 : */
421 0 : static inline void sbitmap_queue_free(struct sbitmap_queue *sbq)
422 : {
423 0 : kfree(sbq->ws);
424 0 : sbitmap_free(&sbq->sb);
425 0 : }
426 :
427 : /**
428 : * sbitmap_queue_recalculate_wake_batch() - Recalculate wake batch
429 : * @sbq: Bitmap queue to recalculate wake batch.
430 : * @users: Number of shares.
431 : *
432 : * Like sbitmap_queue_update_wake_batch(), this will calculate wake batch
433 : * by depth. This interface is for HCTX shared tags or queue shared tags.
434 : */
435 : void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq,
436 : unsigned int users);
437 :
438 : /**
439 : * sbitmap_queue_resize() - Resize a &struct sbitmap_queue.
440 : * @sbq: Bitmap queue to resize.
441 : * @depth: New number of bits to resize to.
442 : *
443 : * Like sbitmap_resize(), this doesn't reallocate anything. It has to do
444 : * some extra work on the &struct sbitmap_queue, so it's not safe to just
445 : * resize the underlying &struct sbitmap.
446 : */
447 : void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth);
448 :
449 : /**
450 : * __sbitmap_queue_get() - Try to allocate a free bit from a &struct
451 : * sbitmap_queue with preemption already disabled.
452 : * @sbq: Bitmap queue to allocate from.
453 : *
454 : * Return: Non-negative allocated bit number if successful, -1 otherwise.
455 : */
456 : int __sbitmap_queue_get(struct sbitmap_queue *sbq);
457 :
458 : /**
459 : * __sbitmap_queue_get_batch() - Try to allocate a batch of free bits
460 : * @sbq: Bitmap queue to allocate from.
461 : * @nr_tags: number of tags requested
462 : * @offset: offset to add to returned bits
463 : *
464 : * Return: Mask of allocated tags, 0 if none are found. Each tag allocated is
465 : * a bit in the mask returned, and the caller must add @offset to the value to
466 : * get the absolute tag value.
467 : */
468 : unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags,
469 : unsigned int *offset);
470 :
471 : /**
472 : * sbitmap_queue_get_shallow() - Try to allocate a free bit from a &struct
473 : * sbitmap_queue, limiting the depth used from each word, with preemption
474 : * already disabled.
475 : * @sbq: Bitmap queue to allocate from.
476 : * @shallow_depth: The maximum number of bits to allocate from a single word.
477 : * See sbitmap_get_shallow().
478 : *
479 : * If you call this, make sure to call sbitmap_queue_min_shallow_depth() after
480 : * initializing @sbq.
481 : *
482 : * Return: Non-negative allocated bit number if successful, -1 otherwise.
483 : */
484 : int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq,
485 : unsigned int shallow_depth);
486 :
487 : /**
488 : * sbitmap_queue_get() - Try to allocate a free bit from a &struct
489 : * sbitmap_queue.
490 : * @sbq: Bitmap queue to allocate from.
491 : * @cpu: Output parameter; will contain the CPU we ran on (e.g., to be passed to
492 : * sbitmap_queue_clear()).
493 : *
494 : * Return: Non-negative allocated bit number if successful, -1 otherwise.
495 : */
496 : static inline int sbitmap_queue_get(struct sbitmap_queue *sbq,
497 : unsigned int *cpu)
498 : {
499 : int nr;
500 :
501 : *cpu = get_cpu();
502 : nr = __sbitmap_queue_get(sbq);
503 : put_cpu();
504 : return nr;
505 : }
506 :
507 : /**
508 : * sbitmap_queue_min_shallow_depth() - Inform a &struct sbitmap_queue of the
509 : * minimum shallow depth that will be used.
510 : * @sbq: Bitmap queue in question.
511 : * @min_shallow_depth: The minimum shallow depth that will be passed to
512 : * sbitmap_queue_get_shallow() or __sbitmap_queue_get_shallow().
513 : *
514 : * sbitmap_queue_clear() batches wakeups as an optimization. The batch size
515 : * depends on the depth of the bitmap. Since the shallow allocation functions
516 : * effectively operate with a different depth, the shallow depth must be taken
517 : * into account when calculating the batch size. This function must be called
518 : * with the minimum shallow depth that will be used. Failure to do so can result
519 : * in missed wakeups.
520 : */
521 : void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq,
522 : unsigned int min_shallow_depth);
523 :
524 : /**
525 : * sbitmap_queue_clear() - Free an allocated bit and wake up waiters on a
526 : * &struct sbitmap_queue.
527 : * @sbq: Bitmap to free from.
528 : * @nr: Bit number to free.
529 : * @cpu: CPU the bit was allocated on.
530 : */
531 : void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
532 : unsigned int cpu);
533 :
534 : /**
535 : * sbitmap_queue_clear_batch() - Free a batch of allocated bits
536 : * &struct sbitmap_queue.
537 : * @sbq: Bitmap to free from.
538 : * @offset: offset for each tag in array
539 : * @tags: array of tags
540 : * @nr_tags: number of tags in array
541 : */
542 : void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset,
543 : int *tags, int nr_tags);
544 :
545 : static inline int sbq_index_inc(int index)
546 : {
547 0 : return (index + 1) & (SBQ_WAIT_QUEUES - 1);
548 : }
549 :
550 : static inline void sbq_index_atomic_inc(atomic_t *index)
551 : {
552 0 : int old = atomic_read(index);
553 0 : int new = sbq_index_inc(old);
554 0 : atomic_cmpxchg(index, old, new);
555 : }
556 :
557 : /**
558 : * sbq_wait_ptr() - Get the next wait queue to use for a &struct
559 : * sbitmap_queue.
560 : * @sbq: Bitmap queue to wait on.
561 : * @wait_index: A counter per "user" of @sbq.
562 : */
563 : static inline struct sbq_wait_state *sbq_wait_ptr(struct sbitmap_queue *sbq,
564 : atomic_t *wait_index)
565 : {
566 : struct sbq_wait_state *ws;
567 :
568 0 : ws = &sbq->ws[atomic_read(wait_index)];
569 0 : sbq_index_atomic_inc(wait_index);
570 : return ws;
571 : }
572 :
573 : /**
574 : * sbitmap_queue_wake_all() - Wake up everything waiting on a &struct
575 : * sbitmap_queue.
576 : * @sbq: Bitmap queue to wake up.
577 : */
578 : void sbitmap_queue_wake_all(struct sbitmap_queue *sbq);
579 :
580 : /**
581 : * sbitmap_queue_wake_up() - Wake up some of waiters in one waitqueue
582 : * on a &struct sbitmap_queue.
583 : * @sbq: Bitmap queue to wake up.
584 : * @nr: Number of bits cleared.
585 : */
586 : void sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr);
587 :
588 : /**
589 : * sbitmap_queue_show() - Dump &struct sbitmap_queue information to a &struct
590 : * seq_file.
591 : * @sbq: Bitmap queue to show.
592 : * @m: struct seq_file to write to.
593 : *
594 : * This is intended for debugging. The format may change at any time.
595 : */
596 : void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m);
597 :
598 : struct sbq_wait {
599 : struct sbitmap_queue *sbq; /* if set, sbq_wait is accounted */
600 : struct wait_queue_entry wait;
601 : };
602 :
603 : #define DEFINE_SBQ_WAIT(name) \
604 : struct sbq_wait name = { \
605 : .sbq = NULL, \
606 : .wait = { \
607 : .private = current, \
608 : .func = autoremove_wake_function, \
609 : .entry = LIST_HEAD_INIT((name).wait.entry), \
610 : } \
611 : }
612 :
613 : /*
614 : * Wrapper around prepare_to_wait_exclusive(), which maintains some extra
615 : * internal state.
616 : */
617 : void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq,
618 : struct sbq_wait_state *ws,
619 : struct sbq_wait *sbq_wait, int state);
620 :
621 : /*
622 : * Must be paired with sbitmap_prepare_to_wait().
623 : */
624 : void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws,
625 : struct sbq_wait *sbq_wait);
626 :
627 : /*
628 : * Wrapper around add_wait_queue(), which maintains some extra internal state
629 : */
630 : void sbitmap_add_wait_queue(struct sbitmap_queue *sbq,
631 : struct sbq_wait_state *ws,
632 : struct sbq_wait *sbq_wait);
633 :
634 : /*
635 : * Must be paired with sbitmap_add_wait_queue()
636 : */
637 : void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait);
638 :
639 : #endif /* __LINUX_SCALE_BITMAP_H */
|