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
17struct 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)							\
50do {									\
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)						\
58do {									\
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)					\
74do {									\
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)							\
154do {									\
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)							\
217do {									\
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)						\
226do {									\
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)						\
262do {									\
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)					\
270do {									\
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
287int bch_strtoint_h(const char *cp, int *res);
288int bch_strtouint_h(const char *cp, unsigned int *res);
289int bch_strtoll_h(const char *cp, long long *res);
290int bch_strtoull_h(const char *cp, unsigned long long *res);
291
292static 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
301static 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
342ssize_t bch_hprint(char *buf, int64_t v);
343
344bool bch_is_zero(const char *p, size_t n);
345int bch_parse_uuid(const char *s, char *uuid);
346
347struct 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
359void bch_time_stats_update(struct time_stats *stats, uint64_t time);
360
361static 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)				\
378do {									\
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)			\
396read_attribute(name ## _average_frequency_ ## frequency_units);		\
397read_attribute(name ## _average_duration_ ## duration_units);		\
398read_attribute(name ## _max_duration_ ## duration_units);		\
399read_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
417struct 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
428static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
429{
430	d->next = local_clock();
431}
432
433uint64_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;							\
471dup:									\
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
525static 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 */
547static 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
558void bch_bio_map(struct bio *bio, void *base);
559int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);
560
561#endif /* _BCACHE_UTIL_H */
562