xref: /linux/drivers/md/bcache/util.h (revision 4e94ddfe2aab72139acb8d5372fac9e6c3f3e383)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef _BCACHE_UTIL_H
4 #define _BCACHE_UTIL_H
5 
6 #include <linux/blkdev.h>
7 #include <linux/closure.h>
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/sched/clock.h>
11 #include <linux/llist.h>
12 #include <linux/ratelimit.h>
13 #include <linux/vmalloc.h>
14 #include <linux/workqueue.h>
15 #include <linux/crc64.h>
16 
17 struct closure;
18 
19 #ifdef CONFIG_BCACHE_DEBUG
20 
21 #define EBUG_ON(cond)			BUG_ON(cond)
22 #define atomic_dec_bug(v)	BUG_ON(atomic_dec_return(v) < 0)
23 #define atomic_inc_bug(v, i)	BUG_ON(atomic_inc_return(v) <= i)
24 
25 #else /* DEBUG */
26 
27 #define EBUG_ON(cond)		do { if (cond) do {} while (0); } while (0)
28 #define atomic_dec_bug(v)	atomic_dec(v)
29 #define atomic_inc_bug(v, i)	atomic_inc(v)
30 
31 #endif
32 
33 #define DECLARE_HEAP(type, name)					\
34 	struct {							\
35 		size_t size, used;					\
36 		type *data;						\
37 	} name
38 
39 #define init_heap(heap, _size, gfp)					\
40 ({									\
41 	size_t _bytes;							\
42 	(heap)->used = 0;						\
43 	(heap)->size = (_size);						\
44 	_bytes = (heap)->size * sizeof(*(heap)->data);			\
45 	(heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
46 	(heap)->data;							\
47 })
48 
49 #define free_heap(heap)							\
50 do {									\
51 	kvfree((heap)->data);						\
52 	(heap)->data = NULL;						\
53 } while (0)
54 
55 #define heap_swap(h, i, j)	swap((h)->data[i], (h)->data[j])
56 
57 #define heap_sift(h, i, cmp)						\
58 do {									\
59 	size_t _r, _j = i;						\
60 									\
61 	for (; _j * 2 + 1 < (h)->used; _j = _r) {			\
62 		_r = _j * 2 + 1;					\
63 		if (_r + 1 < (h)->used &&				\
64 		    cmp((h)->data[_r], (h)->data[_r + 1]))		\
65 			_r++;						\
66 									\
67 		if (cmp((h)->data[_r], (h)->data[_j]))			\
68 			break;						\
69 		heap_swap(h, _r, _j);					\
70 	}								\
71 } while (0)
72 
73 #define heap_sift_down(h, i, cmp)					\
74 do {									\
75 	while (i) {							\
76 		size_t p = (i - 1) / 2;					\
77 		if (cmp((h)->data[i], (h)->data[p]))			\
78 			break;						\
79 		heap_swap(h, i, p);					\
80 		i = p;							\
81 	}								\
82 } while (0)
83 
84 #define heap_add(h, d, cmp)						\
85 ({									\
86 	bool _r = !heap_full(h);					\
87 	if (_r) {							\
88 		size_t _i = (h)->used++;				\
89 		(h)->data[_i] = d;					\
90 									\
91 		heap_sift_down(h, _i, cmp);				\
92 		heap_sift(h, _i, cmp);					\
93 	}								\
94 	_r;								\
95 })
96 
97 #define heap_pop(h, d, cmp)						\
98 ({									\
99 	bool _r = (h)->used;						\
100 	if (_r) {							\
101 		(d) = (h)->data[0];					\
102 		(h)->used--;						\
103 		heap_swap(h, 0, (h)->used);				\
104 		heap_sift(h, 0, cmp);					\
105 	}								\
106 	_r;								\
107 })
108 
109 #define heap_peek(h)	((h)->used ? (h)->data[0] : NULL)
110 
111 #define heap_full(h)	((h)->used == (h)->size)
112 
113 #define DECLARE_FIFO(type, name)					\
114 	struct {							\
115 		size_t front, back, size, mask;				\
116 		type *data;						\
117 	} name
118 
119 #define fifo_for_each(c, fifo, iter)					\
120 	for (iter = (fifo)->front;					\
121 	     c = (fifo)->data[iter], iter != (fifo)->back;		\
122 	     iter = (iter + 1) & (fifo)->mask)
123 
124 #define __init_fifo(fifo, gfp)						\
125 ({									\
126 	size_t _allocated_size, _bytes;					\
127 	BUG_ON(!(fifo)->size);						\
128 									\
129 	_allocated_size = roundup_pow_of_two((fifo)->size + 1);		\
130 	_bytes = _allocated_size * sizeof(*(fifo)->data);		\
131 									\
132 	(fifo)->mask = _allocated_size - 1;				\
133 	(fifo)->front = (fifo)->back = 0;				\
134 									\
135 	(fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
136 	(fifo)->data;							\
137 })
138 
139 #define init_fifo_exact(fifo, _size, gfp)				\
140 ({									\
141 	(fifo)->size = (_size);						\
142 	__init_fifo(fifo, gfp);						\
143 })
144 
145 #define init_fifo(fifo, _size, gfp)					\
146 ({									\
147 	(fifo)->size = (_size);						\
148 	if ((fifo)->size > 4)						\
149 		(fifo)->size = roundup_pow_of_two((fifo)->size) - 1;	\
150 	__init_fifo(fifo, gfp);						\
151 })
152 
153 #define free_fifo(fifo)							\
154 do {									\
155 	kvfree((fifo)->data);						\
156 	(fifo)->data = NULL;						\
157 } while (0)
158 
159 #define fifo_used(fifo)		(((fifo)->back - (fifo)->front) & (fifo)->mask)
160 #define fifo_free(fifo)		((fifo)->size - fifo_used(fifo))
161 
162 #define fifo_empty(fifo)	(!fifo_used(fifo))
163 #define fifo_full(fifo)		(!fifo_free(fifo))
164 
165 #define fifo_front(fifo)	((fifo)->data[(fifo)->front])
166 #define fifo_back(fifo)							\
167 	((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
168 
169 #define fifo_idx(fifo, p)	(((p) - &fifo_front(fifo)) & (fifo)->mask)
170 
171 #define fifo_push_back(fifo, i)						\
172 ({									\
173 	bool _r = !fifo_full((fifo));					\
174 	if (_r) {							\
175 		(fifo)->data[(fifo)->back++] = (i);			\
176 		(fifo)->back &= (fifo)->mask;				\
177 	}								\
178 	_r;								\
179 })
180 
181 #define fifo_pop_front(fifo, i)						\
182 ({									\
183 	bool _r = !fifo_empty((fifo));					\
184 	if (_r) {							\
185 		(i) = (fifo)->data[(fifo)->front++];			\
186 		(fifo)->front &= (fifo)->mask;				\
187 	}								\
188 	_r;								\
189 })
190 
191 #define fifo_push_front(fifo, i)					\
192 ({									\
193 	bool _r = !fifo_full((fifo));					\
194 	if (_r) {							\
195 		--(fifo)->front;					\
196 		(fifo)->front &= (fifo)->mask;				\
197 		(fifo)->data[(fifo)->front] = (i);			\
198 	}								\
199 	_r;								\
200 })
201 
202 #define fifo_pop_back(fifo, i)						\
203 ({									\
204 	bool _r = !fifo_empty((fifo));					\
205 	if (_r) {							\
206 		--(fifo)->back;						\
207 		(fifo)->back &= (fifo)->mask;				\
208 		(i) = (fifo)->data[(fifo)->back]			\
209 	}								\
210 	_r;								\
211 })
212 
213 #define fifo_push(fifo, i)	fifo_push_back(fifo, (i))
214 #define fifo_pop(fifo, i)	fifo_pop_front(fifo, (i))
215 
216 #define fifo_swap(l, r)							\
217 do {									\
218 	swap((l)->front, (r)->front);					\
219 	swap((l)->back, (r)->back);					\
220 	swap((l)->size, (r)->size);					\
221 	swap((l)->mask, (r)->mask);					\
222 	swap((l)->data, (r)->data);					\
223 } while (0)
224 
225 #define fifo_move(dest, src)						\
226 do {									\
227 	typeof(*((dest)->data)) _t;					\
228 	while (!fifo_full(dest) &&					\
229 	       fifo_pop(src, _t))					\
230 		fifo_push(dest, _t);					\
231 } while (0)
232 
233 /*
234  * Simple array based allocator - preallocates a number of elements and you can
235  * never allocate more than that, also has no locking.
236  *
237  * Handy because if you know you only need a fixed number of elements you don't
238  * have to worry about memory allocation failure, and sometimes a mempool isn't
239  * what you want.
240  *
241  * We treat the free elements as entries in a singly linked list, and the
242  * freelist as a stack - allocating and freeing push and pop off the freelist.
243  */
244 
245 #define DECLARE_ARRAY_ALLOCATOR(type, name, size)			\
246 	struct {							\
247 		type	*freelist;					\
248 		type	data[size];					\
249 	} name
250 
251 #define array_alloc(array)						\
252 ({									\
253 	typeof((array)->freelist) _ret = (array)->freelist;		\
254 									\
255 	if (_ret)							\
256 		(array)->freelist = *((typeof((array)->freelist) *) _ret);\
257 									\
258 	_ret;								\
259 })
260 
261 #define array_free(array, ptr)						\
262 do {									\
263 	typeof((array)->freelist) _ptr = ptr;				\
264 									\
265 	*((typeof((array)->freelist) *) _ptr) = (array)->freelist;	\
266 	(array)->freelist = _ptr;					\
267 } while (0)
268 
269 #define array_allocator_init(array)					\
270 do {									\
271 	typeof((array)->freelist) _i;					\
272 									\
273 	BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));	\
274 	(array)->freelist = NULL;					\
275 									\
276 	for (_i = (array)->data;					\
277 	     _i < (array)->data + ARRAY_SIZE((array)->data);		\
278 	     _i++)							\
279 		array_free(array, _i);					\
280 } while (0)
281 
282 #define array_freelist_empty(array)	((array)->freelist == NULL)
283 
284 #define ANYSINT_MAX(t)							\
285 	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
286 
287 int bch_strtoint_h(const char *cp, int *res);
288 int bch_strtouint_h(const char *cp, unsigned int *res);
289 int bch_strtoll_h(const char *cp, long long *res);
290 int bch_strtoull_h(const char *cp, unsigned long long *res);
291 
292 static inline int bch_strtol_h(const char *cp, long *res)
293 {
294 #if BITS_PER_LONG == 32
295 	return bch_strtoint_h(cp, (int *) res);
296 #else
297 	return bch_strtoll_h(cp, (long long *) res);
298 #endif
299 }
300 
301 static inline int bch_strtoul_h(const char *cp, long *res)
302 {
303 #if BITS_PER_LONG == 32
304 	return bch_strtouint_h(cp, (unsigned int *) res);
305 #else
306 	return bch_strtoull_h(cp, (unsigned long long *) res);
307 #endif
308 }
309 
310 #define strtoi_h(cp, res)						\
311 	(__builtin_types_compatible_p(typeof(*res), int)		\
312 	? bch_strtoint_h(cp, (void *) res)				\
313 	: __builtin_types_compatible_p(typeof(*res), long)		\
314 	? bch_strtol_h(cp, (void *) res)				\
315 	: __builtin_types_compatible_p(typeof(*res), long long)		\
316 	? bch_strtoll_h(cp, (void *) res)				\
317 	: __builtin_types_compatible_p(typeof(*res), unsigned int)	\
318 	? bch_strtouint_h(cp, (void *) res)				\
319 	: __builtin_types_compatible_p(typeof(*res), unsigned long)	\
320 	? bch_strtoul_h(cp, (void *) res)				\
321 	: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
322 	? bch_strtoull_h(cp, (void *) res) : -EINVAL)
323 
324 #define strtoul_safe(cp, var)						\
325 ({									\
326 	unsigned long _v;						\
327 	int _r = kstrtoul(cp, 10, &_v);					\
328 	if (!_r)							\
329 		var = _v;						\
330 	_r;								\
331 })
332 
333 #define strtoul_safe_clamp(cp, var, min, max)				\
334 ({									\
335 	unsigned long _v;						\
336 	int _r = kstrtoul(cp, 10, &_v);					\
337 	if (!_r)							\
338 		var = clamp_t(typeof(var), _v, min, max);		\
339 	_r;								\
340 })
341 
342 ssize_t bch_hprint(char *buf, int64_t v);
343 
344 bool bch_is_zero(const char *p, size_t n);
345 int bch_parse_uuid(const char *s, char *uuid);
346 
347 struct time_stats {
348 	spinlock_t	lock;
349 	/*
350 	 * all fields are in nanoseconds, averages are ewmas stored left shifted
351 	 * by 8
352 	 */
353 	uint64_t	max_duration;
354 	uint64_t	average_duration;
355 	uint64_t	average_frequency;
356 	uint64_t	last;
357 };
358 
359 void bch_time_stats_update(struct time_stats *stats, uint64_t time);
360 
361 static inline unsigned int local_clock_us(void)
362 {
363 	return local_clock() >> 10;
364 }
365 
366 #define NSEC_PER_ns			1L
367 #define NSEC_PER_us			NSEC_PER_USEC
368 #define NSEC_PER_ms			NSEC_PER_MSEC
369 #define NSEC_PER_sec			NSEC_PER_SEC
370 
371 #define __print_time_stat(stats, name, stat, units)			\
372 	sysfs_print(name ## _ ## stat ## _ ## units,			\
373 		    div_u64((stats)->stat >> 8, NSEC_PER_ ## units))
374 
375 #define sysfs_print_time_stats(stats, name,				\
376 			       frequency_units,				\
377 			       duration_units)				\
378 do {									\
379 	__print_time_stat(stats, name,					\
380 			  average_frequency,	frequency_units);	\
381 	__print_time_stat(stats, name,					\
382 			  average_duration,	duration_units);	\
383 	sysfs_print(name ## _ ##max_duration ## _ ## duration_units,	\
384 			div_u64((stats)->max_duration,			\
385 				NSEC_PER_ ## duration_units));		\
386 									\
387 	sysfs_print(name ## _last_ ## frequency_units, (stats)->last	\
388 		    ? div_s64(local_clock() - (stats)->last,		\
389 			      NSEC_PER_ ## frequency_units)		\
390 		    : -1LL);						\
391 } while (0)
392 
393 #define sysfs_time_stats_attribute(name,				\
394 				   frequency_units,			\
395 				   duration_units)			\
396 read_attribute(name ## _average_frequency_ ## frequency_units);		\
397 read_attribute(name ## _average_duration_ ## duration_units);		\
398 read_attribute(name ## _max_duration_ ## duration_units);		\
399 read_attribute(name ## _last_ ## frequency_units)
400 
401 #define sysfs_time_stats_attribute_list(name,				\
402 					frequency_units,		\
403 					duration_units)			\
404 &sysfs_ ## name ## _average_frequency_ ## frequency_units,		\
405 &sysfs_ ## name ## _average_duration_ ## duration_units,		\
406 &sysfs_ ## name ## _max_duration_ ## duration_units,			\
407 &sysfs_ ## name ## _last_ ## frequency_units,
408 
409 #define ewma_add(ewma, val, weight, factor)				\
410 ({									\
411 	(ewma) *= (weight) - 1;						\
412 	(ewma) += (val) << factor;					\
413 	(ewma) /= (weight);						\
414 	(ewma) >> factor;						\
415 })
416 
417 struct bch_ratelimit {
418 	/* Next time we want to do some work, in nanoseconds */
419 	uint64_t		next;
420 
421 	/*
422 	 * Rate at which we want to do work, in units per second
423 	 * The units here correspond to the units passed to bch_next_delay()
424 	 */
425 	atomic_long_t		rate;
426 };
427 
428 static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
429 {
430 	d->next = local_clock();
431 }
432 
433 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);
434 
435 #define __DIV_SAFE(n, d, zero)						\
436 ({									\
437 	typeof(n) _n = (n);						\
438 	typeof(d) _d = (d);						\
439 	_d ? _n / _d : zero;						\
440 })
441 
442 #define DIV_SAFE(n, d)	__DIV_SAFE(n, d, 0)
443 
444 #define container_of_or_null(ptr, type, member)				\
445 ({									\
446 	typeof(ptr) _ptr = ptr;						\
447 	_ptr ? container_of(_ptr, type, member) : NULL;			\
448 })
449 
450 #define RB_INSERT(root, new, member, cmp)				\
451 ({									\
452 	__label__ dup;							\
453 	struct rb_node **n = &(root)->rb_node, *parent = NULL;		\
454 	typeof(new) this;						\
455 	int res, ret = -1;						\
456 									\
457 	while (*n) {							\
458 		parent = *n;						\
459 		this = container_of(*n, typeof(*(new)), member);	\
460 		res = cmp(new, this);					\
461 		if (!res)						\
462 			goto dup;					\
463 		n = res < 0						\
464 			? &(*n)->rb_left				\
465 			: &(*n)->rb_right;				\
466 	}								\
467 									\
468 	rb_link_node(&(new)->member, parent, n);			\
469 	rb_insert_color(&(new)->member, root);				\
470 	ret = 0;							\
471 dup:									\
472 	ret;								\
473 })
474 
475 #define RB_SEARCH(root, search, member, cmp)				\
476 ({									\
477 	struct rb_node *n = (root)->rb_node;				\
478 	typeof(&(search)) this, ret = NULL;				\
479 	int res;							\
480 									\
481 	while (n) {							\
482 		this = container_of(n, typeof(search), member);		\
483 		res = cmp(&(search), this);				\
484 		if (!res) {						\
485 			ret = this;					\
486 			break;						\
487 		}							\
488 		n = res < 0						\
489 			? n->rb_left					\
490 			: n->rb_right;					\
491 	}								\
492 	ret;								\
493 })
494 
495 #define RB_GREATER(root, search, member, cmp)				\
496 ({									\
497 	struct rb_node *n = (root)->rb_node;				\
498 	typeof(&(search)) this, ret = NULL;				\
499 	int res;							\
500 									\
501 	while (n) {							\
502 		this = container_of(n, typeof(search), member);		\
503 		res = cmp(&(search), this);				\
504 		if (res < 0) {						\
505 			ret = this;					\
506 			n = n->rb_left;					\
507 		} else							\
508 			n = n->rb_right;				\
509 	}								\
510 	ret;								\
511 })
512 
513 #define RB_FIRST(root, type, member)					\
514 	container_of_or_null(rb_first(root), type, member)
515 
516 #define RB_LAST(root, type, member)					\
517 	container_of_or_null(rb_last(root), type, member)
518 
519 #define RB_NEXT(ptr, member)						\
520 	container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)
521 
522 #define RB_PREV(ptr, member)						\
523 	container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)
524 
525 static inline uint64_t bch_crc64(const void *p, size_t len)
526 {
527 	uint64_t crc = 0xffffffffffffffffULL;
528 
529 	crc = crc64_be(crc, p, len);
530 	return crc ^ 0xffffffffffffffffULL;
531 }
532 
533 /*
534  * A stepwise-linear pseudo-exponential.  This returns 1 << (x >>
535  * frac_bits), with the less-significant bits filled in by linear
536  * interpolation.
537  *
538  * This can also be interpreted as a floating-point number format,
539  * where the low frac_bits are the mantissa (with implicit leading
540  * 1 bit), and the more significant bits are the exponent.
541  * The return value is 1.mantissa * 2^exponent.
542  *
543  * The way this is used, fract_bits is 6 and the largest possible
544  * input is CONGESTED_MAX-1 = 1023 (exponent 16, mantissa 0x1.fc),
545  * so the maximum output is 0x1fc00.
546  */
547 static inline unsigned int fract_exp_two(unsigned int x,
548 					 unsigned int fract_bits)
549 {
550 	unsigned int mantissa = 1 << fract_bits;	/* Implicit bit */
551 
552 	mantissa += x & (mantissa - 1);
553 	x >>= fract_bits;	/* The exponent */
554 	/* Largest intermediate value 0x7f0000 */
555 	return mantissa << x >> fract_bits;
556 }
557 
558 void bch_bio_map(struct bio *bio, void *base);
559 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);
560 
561 #endif /* _BCACHE_UTIL_H */
562