xref: /openbmc/linux/drivers/md/bcache/util.h (revision 1b86db5f)
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/errno.h>
8 #include <linux/kernel.h>
9 #include <linux/sched/clock.h>
10 #include <linux/llist.h>
11 #include <linux/ratelimit.h>
12 #include <linux/vmalloc.h>
13 #include <linux/workqueue.h>
14 #include <linux/crc64.h>
15 
16 #include "closure.h"
17 
18 struct closure;
19 
20 #ifdef CONFIG_BCACHE_DEBUG
21 
22 #define EBUG_ON(cond)			BUG_ON(cond)
23 #define atomic_dec_bug(v)	BUG_ON(atomic_dec_return(v) < 0)
24 #define atomic_inc_bug(v, i)	BUG_ON(atomic_inc_return(v) <= i)
25 
26 #else /* DEBUG */
27 
28 #define EBUG_ON(cond)		do { if (cond) do {} while (0); } while (0)
29 #define atomic_dec_bug(v)	atomic_dec(v)
30 #define atomic_inc_bug(v, i)	atomic_inc(v)
31 
32 #endif
33 
34 #define DECLARE_HEAP(type, name)					\
35 	struct {							\
36 		size_t size, used;					\
37 		type *data;						\
38 	} name
39 
40 #define init_heap(heap, _size, gfp)					\
41 ({									\
42 	size_t _bytes;							\
43 	(heap)->used = 0;						\
44 	(heap)->size = (_size);						\
45 	_bytes = (heap)->size * sizeof(*(heap)->data);			\
46 	(heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
47 	(heap)->data;							\
48 })
49 
50 #define free_heap(heap)							\
51 do {									\
52 	kvfree((heap)->data);						\
53 	(heap)->data = NULL;						\
54 } while (0)
55 
56 #define heap_swap(h, i, j)	swap((h)->data[i], (h)->data[j])
57 
58 #define heap_sift(h, i, cmp)						\
59 do {									\
60 	size_t _r, _j = i;						\
61 									\
62 	for (; _j * 2 + 1 < (h)->used; _j = _r) {			\
63 		_r = _j * 2 + 1;					\
64 		if (_r + 1 < (h)->used &&				\
65 		    cmp((h)->data[_r], (h)->data[_r + 1]))		\
66 			_r++;						\
67 									\
68 		if (cmp((h)->data[_r], (h)->data[_j]))			\
69 			break;						\
70 		heap_swap(h, _r, _j);					\
71 	}								\
72 } while (0)
73 
74 #define heap_sift_down(h, i, cmp)					\
75 do {									\
76 	while (i) {							\
77 		size_t p = (i - 1) / 2;					\
78 		if (cmp((h)->data[i], (h)->data[p]))			\
79 			break;						\
80 		heap_swap(h, i, p);					\
81 		i = p;							\
82 	}								\
83 } while (0)
84 
85 #define heap_add(h, d, cmp)						\
86 ({									\
87 	bool _r = !heap_full(h);					\
88 	if (_r) {							\
89 		size_t _i = (h)->used++;				\
90 		(h)->data[_i] = d;					\
91 									\
92 		heap_sift_down(h, _i, cmp);				\
93 		heap_sift(h, _i, cmp);					\
94 	}								\
95 	_r;								\
96 })
97 
98 #define heap_pop(h, d, cmp)						\
99 ({									\
100 	bool _r = (h)->used;						\
101 	if (_r) {							\
102 		(d) = (h)->data[0];					\
103 		(h)->used--;						\
104 		heap_swap(h, 0, (h)->used);				\
105 		heap_sift(h, 0, cmp);					\
106 	}								\
107 	_r;								\
108 })
109 
110 #define heap_peek(h)	((h)->used ? (h)->data[0] : NULL)
111 
112 #define heap_full(h)	((h)->used == (h)->size)
113 
114 #define DECLARE_FIFO(type, name)					\
115 	struct {							\
116 		size_t front, back, size, mask;				\
117 		type *data;						\
118 	} name
119 
120 #define fifo_for_each(c, fifo, iter)					\
121 	for (iter = (fifo)->front;					\
122 	     c = (fifo)->data[iter], iter != (fifo)->back;		\
123 	     iter = (iter + 1) & (fifo)->mask)
124 
125 #define __init_fifo(fifo, gfp)						\
126 ({									\
127 	size_t _allocated_size, _bytes;					\
128 	BUG_ON(!(fifo)->size);						\
129 									\
130 	_allocated_size = roundup_pow_of_two((fifo)->size + 1);		\
131 	_bytes = _allocated_size * sizeof(*(fifo)->data);		\
132 									\
133 	(fifo)->mask = _allocated_size - 1;				\
134 	(fifo)->front = (fifo)->back = 0;				\
135 									\
136 	(fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
137 	(fifo)->data;							\
138 })
139 
140 #define init_fifo_exact(fifo, _size, gfp)				\
141 ({									\
142 	(fifo)->size = (_size);						\
143 	__init_fifo(fifo, gfp);						\
144 })
145 
146 #define init_fifo(fifo, _size, gfp)					\
147 ({									\
148 	(fifo)->size = (_size);						\
149 	if ((fifo)->size > 4)						\
150 		(fifo)->size = roundup_pow_of_two((fifo)->size) - 1;	\
151 	__init_fifo(fifo, gfp);						\
152 })
153 
154 #define free_fifo(fifo)							\
155 do {									\
156 	kvfree((fifo)->data);						\
157 	(fifo)->data = NULL;						\
158 } while (0)
159 
160 #define fifo_used(fifo)		(((fifo)->back - (fifo)->front) & (fifo)->mask)
161 #define fifo_free(fifo)		((fifo)->size - fifo_used(fifo))
162 
163 #define fifo_empty(fifo)	(!fifo_used(fifo))
164 #define fifo_full(fifo)		(!fifo_free(fifo))
165 
166 #define fifo_front(fifo)	((fifo)->data[(fifo)->front])
167 #define fifo_back(fifo)							\
168 	((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
169 
170 #define fifo_idx(fifo, p)	(((p) - &fifo_front(fifo)) & (fifo)->mask)
171 
172 #define fifo_push_back(fifo, i)						\
173 ({									\
174 	bool _r = !fifo_full((fifo));					\
175 	if (_r) {							\
176 		(fifo)->data[(fifo)->back++] = (i);			\
177 		(fifo)->back &= (fifo)->mask;				\
178 	}								\
179 	_r;								\
180 })
181 
182 #define fifo_pop_front(fifo, i)						\
183 ({									\
184 	bool _r = !fifo_empty((fifo));					\
185 	if (_r) {							\
186 		(i) = (fifo)->data[(fifo)->front++];			\
187 		(fifo)->front &= (fifo)->mask;				\
188 	}								\
189 	_r;								\
190 })
191 
192 #define fifo_push_front(fifo, i)					\
193 ({									\
194 	bool _r = !fifo_full((fifo));					\
195 	if (_r) {							\
196 		--(fifo)->front;					\
197 		(fifo)->front &= (fifo)->mask;				\
198 		(fifo)->data[(fifo)->front] = (i);			\
199 	}								\
200 	_r;								\
201 })
202 
203 #define fifo_pop_back(fifo, i)						\
204 ({									\
205 	bool _r = !fifo_empty((fifo));					\
206 	if (_r) {							\
207 		--(fifo)->back;						\
208 		(fifo)->back &= (fifo)->mask;				\
209 		(i) = (fifo)->data[(fifo)->back]			\
210 	}								\
211 	_r;								\
212 })
213 
214 #define fifo_push(fifo, i)	fifo_push_back(fifo, (i))
215 #define fifo_pop(fifo, i)	fifo_pop_front(fifo, (i))
216 
217 #define fifo_swap(l, r)							\
218 do {									\
219 	swap((l)->front, (r)->front);					\
220 	swap((l)->back, (r)->back);					\
221 	swap((l)->size, (r)->size);					\
222 	swap((l)->mask, (r)->mask);					\
223 	swap((l)->data, (r)->data);					\
224 } while (0)
225 
226 #define fifo_move(dest, src)						\
227 do {									\
228 	typeof(*((dest)->data)) _t;					\
229 	while (!fifo_full(dest) &&					\
230 	       fifo_pop(src, _t))					\
231 		fifo_push(dest, _t);					\
232 } while (0)
233 
234 /*
235  * Simple array based allocator - preallocates a number of elements and you can
236  * never allocate more than that, also has no locking.
237  *
238  * Handy because if you know you only need a fixed number of elements you don't
239  * have to worry about memory allocation failure, and sometimes a mempool isn't
240  * what you want.
241  *
242  * We treat the free elements as entries in a singly linked list, and the
243  * freelist as a stack - allocating and freeing push and pop off the freelist.
244  */
245 
246 #define DECLARE_ARRAY_ALLOCATOR(type, name, size)			\
247 	struct {							\
248 		type	*freelist;					\
249 		type	data[size];					\
250 	} name
251 
252 #define array_alloc(array)						\
253 ({									\
254 	typeof((array)->freelist) _ret = (array)->freelist;		\
255 									\
256 	if (_ret)							\
257 		(array)->freelist = *((typeof((array)->freelist) *) _ret);\
258 									\
259 	_ret;								\
260 })
261 
262 #define array_free(array, ptr)						\
263 do {									\
264 	typeof((array)->freelist) _ptr = ptr;				\
265 									\
266 	*((typeof((array)->freelist) *) _ptr) = (array)->freelist;	\
267 	(array)->freelist = _ptr;					\
268 } while (0)
269 
270 #define array_allocator_init(array)					\
271 do {									\
272 	typeof((array)->freelist) _i;					\
273 									\
274 	BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));	\
275 	(array)->freelist = NULL;					\
276 									\
277 	for (_i = (array)->data;					\
278 	     _i < (array)->data + ARRAY_SIZE((array)->data);		\
279 	     _i++)							\
280 		array_free(array, _i);					\
281 } while (0)
282 
283 #define array_freelist_empty(array)	((array)->freelist == NULL)
284 
285 #define ANYSINT_MAX(t)							\
286 	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
287 
288 int bch_strtoint_h(const char *cp, int *res);
289 int bch_strtouint_h(const char *cp, unsigned int *res);
290 int bch_strtoll_h(const char *cp, long long *res);
291 int bch_strtoull_h(const char *cp, unsigned long long *res);
292 
bch_strtol_h(const char * cp,long * res)293 static inline int bch_strtol_h(const char *cp, long *res)
294 {
295 #if BITS_PER_LONG == 32
296 	return bch_strtoint_h(cp, (int *) res);
297 #else
298 	return bch_strtoll_h(cp, (long long *) res);
299 #endif
300 }
301 
bch_strtoul_h(const char * cp,long * res)302 static inline int bch_strtoul_h(const char *cp, long *res)
303 {
304 #if BITS_PER_LONG == 32
305 	return bch_strtouint_h(cp, (unsigned int *) res);
306 #else
307 	return bch_strtoull_h(cp, (unsigned long long *) res);
308 #endif
309 }
310 
311 #define strtoi_h(cp, res)						\
312 	(__builtin_types_compatible_p(typeof(*res), int)		\
313 	? bch_strtoint_h(cp, (void *) res)				\
314 	: __builtin_types_compatible_p(typeof(*res), long)		\
315 	? bch_strtol_h(cp, (void *) res)				\
316 	: __builtin_types_compatible_p(typeof(*res), long long)		\
317 	? bch_strtoll_h(cp, (void *) res)				\
318 	: __builtin_types_compatible_p(typeof(*res), unsigned int)	\
319 	? bch_strtouint_h(cp, (void *) res)				\
320 	: __builtin_types_compatible_p(typeof(*res), unsigned long)	\
321 	? bch_strtoul_h(cp, (void *) res)				\
322 	: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
323 	? bch_strtoull_h(cp, (void *) res) : -EINVAL)
324 
325 #define strtoul_safe(cp, var)						\
326 ({									\
327 	unsigned long _v;						\
328 	int _r = kstrtoul(cp, 10, &_v);					\
329 	if (!_r)							\
330 		var = _v;						\
331 	_r;								\
332 })
333 
334 #define strtoul_safe_clamp(cp, var, min, max)				\
335 ({									\
336 	unsigned long _v;						\
337 	int _r = kstrtoul(cp, 10, &_v);					\
338 	if (!_r)							\
339 		var = clamp_t(typeof(var), _v, min, max);		\
340 	_r;								\
341 })
342 
343 ssize_t bch_hprint(char *buf, int64_t v);
344 
345 bool bch_is_zero(const char *p, size_t n);
346 int bch_parse_uuid(const char *s, char *uuid);
347 
348 struct time_stats {
349 	spinlock_t	lock;
350 	/*
351 	 * all fields are in nanoseconds, averages are ewmas stored left shifted
352 	 * by 8
353 	 */
354 	uint64_t	max_duration;
355 	uint64_t	average_duration;
356 	uint64_t	average_frequency;
357 	uint64_t	last;
358 };
359 
360 void bch_time_stats_update(struct time_stats *stats, uint64_t time);
361 
local_clock_us(void)362 static inline unsigned int local_clock_us(void)
363 {
364 	return local_clock() >> 10;
365 }
366 
367 #define NSEC_PER_ns			1L
368 #define NSEC_PER_us			NSEC_PER_USEC
369 #define NSEC_PER_ms			NSEC_PER_MSEC
370 #define NSEC_PER_sec			NSEC_PER_SEC
371 
372 #define __print_time_stat(stats, name, stat, units)			\
373 	sysfs_print(name ## _ ## stat ## _ ## units,			\
374 		    div_u64((stats)->stat >> 8, NSEC_PER_ ## units))
375 
376 #define sysfs_print_time_stats(stats, name,				\
377 			       frequency_units,				\
378 			       duration_units)				\
379 do {									\
380 	__print_time_stat(stats, name,					\
381 			  average_frequency,	frequency_units);	\
382 	__print_time_stat(stats, name,					\
383 			  average_duration,	duration_units);	\
384 	sysfs_print(name ## _ ##max_duration ## _ ## duration_units,	\
385 			div_u64((stats)->max_duration,			\
386 				NSEC_PER_ ## duration_units));		\
387 									\
388 	sysfs_print(name ## _last_ ## frequency_units, (stats)->last	\
389 		    ? div_s64(local_clock() - (stats)->last,		\
390 			      NSEC_PER_ ## frequency_units)		\
391 		    : -1LL);						\
392 } while (0)
393 
394 #define sysfs_time_stats_attribute(name,				\
395 				   frequency_units,			\
396 				   duration_units)			\
397 read_attribute(name ## _average_frequency_ ## frequency_units);		\
398 read_attribute(name ## _average_duration_ ## duration_units);		\
399 read_attribute(name ## _max_duration_ ## duration_units);		\
400 read_attribute(name ## _last_ ## frequency_units)
401 
402 #define sysfs_time_stats_attribute_list(name,				\
403 					frequency_units,		\
404 					duration_units)			\
405 &sysfs_ ## name ## _average_frequency_ ## frequency_units,		\
406 &sysfs_ ## name ## _average_duration_ ## duration_units,		\
407 &sysfs_ ## name ## _max_duration_ ## duration_units,			\
408 &sysfs_ ## name ## _last_ ## frequency_units,
409 
410 #define ewma_add(ewma, val, weight, factor)				\
411 ({									\
412 	(ewma) *= (weight) - 1;						\
413 	(ewma) += (val) << factor;					\
414 	(ewma) /= (weight);						\
415 	(ewma) >> factor;						\
416 })
417 
418 struct bch_ratelimit {
419 	/* Next time we want to do some work, in nanoseconds */
420 	uint64_t		next;
421 
422 	/*
423 	 * Rate at which we want to do work, in units per second
424 	 * The units here correspond to the units passed to bch_next_delay()
425 	 */
426 	atomic_long_t		rate;
427 };
428 
bch_ratelimit_reset(struct bch_ratelimit * d)429 static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
430 {
431 	d->next = local_clock();
432 }
433 
434 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);
435 
436 #define __DIV_SAFE(n, d, zero)						\
437 ({									\
438 	typeof(n) _n = (n);						\
439 	typeof(d) _d = (d);						\
440 	_d ? _n / _d : zero;						\
441 })
442 
443 #define DIV_SAFE(n, d)	__DIV_SAFE(n, d, 0)
444 
445 #define container_of_or_null(ptr, type, member)				\
446 ({									\
447 	typeof(ptr) _ptr = ptr;						\
448 	_ptr ? container_of(_ptr, type, member) : NULL;			\
449 })
450 
451 #define RB_INSERT(root, new, member, cmp)				\
452 ({									\
453 	__label__ dup;							\
454 	struct rb_node **n = &(root)->rb_node, *parent = NULL;		\
455 	typeof(new) this;						\
456 	int res, ret = -1;						\
457 									\
458 	while (*n) {							\
459 		parent = *n;						\
460 		this = container_of(*n, typeof(*(new)), member);	\
461 		res = cmp(new, this);					\
462 		if (!res)						\
463 			goto dup;					\
464 		n = res < 0						\
465 			? &(*n)->rb_left				\
466 			: &(*n)->rb_right;				\
467 	}								\
468 									\
469 	rb_link_node(&(new)->member, parent, n);			\
470 	rb_insert_color(&(new)->member, root);				\
471 	ret = 0;							\
472 dup:									\
473 	ret;								\
474 })
475 
476 #define RB_SEARCH(root, search, member, cmp)				\
477 ({									\
478 	struct rb_node *n = (root)->rb_node;				\
479 	typeof(&(search)) this, ret = NULL;				\
480 	int res;							\
481 									\
482 	while (n) {							\
483 		this = container_of(n, typeof(search), member);		\
484 		res = cmp(&(search), this);				\
485 		if (!res) {						\
486 			ret = this;					\
487 			break;						\
488 		}							\
489 		n = res < 0						\
490 			? n->rb_left					\
491 			: n->rb_right;					\
492 	}								\
493 	ret;								\
494 })
495 
496 #define RB_GREATER(root, search, member, cmp)				\
497 ({									\
498 	struct rb_node *n = (root)->rb_node;				\
499 	typeof(&(search)) this, ret = NULL;				\
500 	int res;							\
501 									\
502 	while (n) {							\
503 		this = container_of(n, typeof(search), member);		\
504 		res = cmp(&(search), this);				\
505 		if (res < 0) {						\
506 			ret = this;					\
507 			n = n->rb_left;					\
508 		} else							\
509 			n = n->rb_right;				\
510 	}								\
511 	ret;								\
512 })
513 
514 #define RB_FIRST(root, type, member)					\
515 	container_of_or_null(rb_first(root), type, member)
516 
517 #define RB_LAST(root, type, member)					\
518 	container_of_or_null(rb_last(root), type, member)
519 
520 #define RB_NEXT(ptr, member)						\
521 	container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)
522 
523 #define RB_PREV(ptr, member)						\
524 	container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)
525 
bch_crc64(const void * p,size_t len)526 static inline uint64_t bch_crc64(const void *p, size_t len)
527 {
528 	uint64_t crc = 0xffffffffffffffffULL;
529 
530 	crc = crc64_be(crc, p, len);
531 	return crc ^ 0xffffffffffffffffULL;
532 }
533 
534 /*
535  * A stepwise-linear pseudo-exponential.  This returns 1 << (x >>
536  * frac_bits), with the less-significant bits filled in by linear
537  * interpolation.
538  *
539  * This can also be interpreted as a floating-point number format,
540  * where the low frac_bits are the mantissa (with implicit leading
541  * 1 bit), and the more significant bits are the exponent.
542  * The return value is 1.mantissa * 2^exponent.
543  *
544  * The way this is used, fract_bits is 6 and the largest possible
545  * input is CONGESTED_MAX-1 = 1023 (exponent 16, mantissa 0x1.fc),
546  * so the maximum output is 0x1fc00.
547  */
fract_exp_two(unsigned int x,unsigned int fract_bits)548 static inline unsigned int fract_exp_two(unsigned int x,
549 					 unsigned int fract_bits)
550 {
551 	unsigned int mantissa = 1 << fract_bits;	/* Implicit bit */
552 
553 	mantissa += x & (mantissa - 1);
554 	x >>= fract_bits;	/* The exponent */
555 	/* Largest intermediate value 0x7f0000 */
556 	return mantissa << x >> fract_bits;
557 }
558 
559 void bch_bio_map(struct bio *bio, void *base);
560 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);
561 
562 #endif /* _BCACHE_UTIL_H */
563