xref: /spdk/lib/env_ocf/ocf_env.h (revision 6569a0ea0630b45bb83582ac2893cda584375dc4)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 
35 #ifndef __LIBOCF_ENV_H__
36 #define __LIBOCF_ENV_H__
37 
38 #ifndef _GNU_SOURCE
39 #define _GNU_SOURCE
40 #endif
41 #ifndef __USE_GNU
42 #define __USE_GNU
43 #endif
44 
45 #include <linux/limits.h>
46 #include <linux/stddef.h>
47 
48 #include "spdk/stdinc.h"
49 #include "spdk/likely.h"
50 #include "spdk/env.h"
51 #include "spdk/util.h"
52 #include "spdk_internal/log.h"
53 
54 #include "ocf_env_list.h"
55 #include "ocf/ocf_err.h"
56 
57 typedef uint8_t u8;
58 typedef uint16_t u16;
59 typedef uint32_t u32;
60 typedef uint64_t u64;
61 
62 typedef uint64_t sector_t;
63 
64 #define __packed __attribute__((packed))
65 #define __aligned(x) __attribute__((aligned(x)))
66 
67 /* linux sector 512-bytes */
68 #define ENV_SECTOR_SHIFT	9
69 #define ENV_SECTOR_SIZE (1<<ENV_SECTOR_SHIFT)
70 #define BYTES_TO_SECTOR(x)	((x) >> ENV_SECTOR_SHIFT)
71 
72 /* *** MEMORY MANAGEMENT *** */
73 
74 #define ENV_MEM_NORMAL	0
75 #define ENV_MEM_NOIO	0
76 #define ENV_MEM_ATOMIC	0
77 
78 #define likely spdk_likely
79 #define unlikely spdk_unlikely
80 
81 #define min(x, y) MIN(x, y)
82 #ifndef MIN
83 #define MIN(x, y) spdk_min(x, y)
84 #endif
85 
86 #define ARRAY_SIZE(x) SPDK_COUNTOF(x)
87 
88 /* LOGGING */
89 #define ENV_PRIu64 PRIu64
90 
91 #define ENV_WARN(cond, fmt, args...) ({ \
92 		if (spdk_unlikely((uintptr_t)(cond))) \
93 			SPDK_NOTICELOG("WARNING" fmt, ##args); \
94 	})
95 
96 #define ENV_WARN_ON(cond) ({ \
97 	if (spdk_unlikely((uintptr_t)(cond))) \
98 		SPDK_NOTICELOG("WARNING\n"); \
99 	})
100 
101 #define ENV_BUG() ({ \
102 		SPDK_ERRLOG("BUG\n"); \
103 		assert(0); \
104 		abort(); \
105 	})
106 
107 #define ENV_BUG_ON(cond) ({ \
108 		if (spdk_unlikely((uintptr_t)(cond))) { \
109 			SPDK_ERRLOG("BUG\n"); \
110 			assert(0); \
111 			abort(); \
112 		} \
113 	})
114 
115 #define ENV_BUILD_BUG_ON(cond)		_Static_assert(!(cond), "static "\
116 					"assertion failure")
117 
118 #define container_of(ptr, type, member) SPDK_CONTAINEROF(ptr, type, member)
119 
120 static inline void *env_malloc(size_t size, int flags)
121 {
122 	return spdk_malloc(size, 0, NULL, SPDK_ENV_LCORE_ID_ANY,
123 			   SPDK_MALLOC_DMA);
124 }
125 
126 static inline void *env_zalloc(size_t size, int flags)
127 {
128 	return spdk_zmalloc(size, 0, NULL, SPDK_ENV_LCORE_ID_ANY,
129 			    SPDK_MALLOC_DMA);
130 }
131 
132 static inline void env_free(const void *ptr)
133 {
134 	return spdk_free((void *)ptr);
135 }
136 
137 static inline void *env_vmalloc(size_t size)
138 {
139 	return spdk_malloc(size, 0, NULL, SPDK_ENV_LCORE_ID_ANY,
140 			   SPDK_MALLOC_DMA);
141 }
142 
143 static inline void *env_vzalloc(size_t size)
144 {
145 	/* TODO: raw_ram init can request huge amount of memory to store
146 	 * hashtable in it. need to ensure that allocation succedds */
147 	return spdk_zmalloc(size, 0, NULL, SPDK_ENV_LCORE_ID_ANY,
148 			    SPDK_MALLOC_DMA);
149 }
150 
151 static inline void *env_vzalloc_flags(size_t size, int flags)
152 {
153 	return env_vzalloc(size);
154 }
155 
156 static inline void *env_secure_alloc(size_t size)
157 {
158 	return spdk_zmalloc(size, 0, NULL, SPDK_ENV_LCORE_ID_ANY,
159 			    SPDK_MALLOC_DMA);
160 }
161 
162 static inline void env_secure_free(const void *ptr, size_t size)
163 {
164 	return spdk_free((void *)ptr);
165 }
166 
167 static inline void env_vfree(const void *ptr)
168 {
169 	return spdk_free((void *)ptr);
170 }
171 
172 static inline uint64_t env_get_free_memory(void)
173 {
174 	/* TODO: do we need implementation for this function? */
175 	return sysconf(_SC_PAGESIZE) * sysconf(_SC_AVPHYS_PAGES);
176 }
177 
178 /* *** ALLOCATOR *** */
179 
180 #define OCF_ALLOCATOR_NAME_MAX 128
181 
182 typedef struct {
183 	struct spdk_mempool *mempool;
184 	size_t element_size;
185 } env_allocator;
186 
187 env_allocator *env_allocator_create(uint32_t size, const char *name);
188 
189 void env_allocator_destroy(env_allocator *allocator);
190 
191 void *env_allocator_new(env_allocator *allocator);
192 
193 void env_allocator_del(env_allocator *allocator, void *item);
194 
195 uint32_t env_allocator_item_count(env_allocator *allocator);
196 
197 /* *** MUTEX *** */
198 
199 typedef struct {
200 	pthread_mutex_t m;
201 } env_mutex;
202 
203 static inline int env_mutex_init(env_mutex *mutex)
204 {
205 	return !!pthread_mutex_init(&mutex->m, NULL);
206 }
207 
208 static inline void env_mutex_lock(env_mutex *mutex)
209 {
210 	ENV_BUG_ON(pthread_mutex_lock(&mutex->m));
211 }
212 
213 static inline int env_mutex_lock_interruptible(env_mutex *mutex)
214 {
215 	env_mutex_lock(mutex);
216 	return 0;
217 }
218 
219 static inline int env_mutex_trylock(env_mutex *mutex)
220 {
221 	return pthread_mutex_trylock(&mutex->m) ? -OCF_ERR_NO_LOCK : 0;
222 }
223 
224 static inline void env_mutex_unlock(env_mutex *mutex)
225 {
226 	ENV_BUG_ON(pthread_mutex_unlock(&mutex->m));
227 }
228 
229 static inline int env_mutex_is_locked(env_mutex *mutex)
230 {
231 	if (env_mutex_trylock(mutex) == 0) {
232 		env_mutex_unlock(mutex);
233 		return 0;
234 	}
235 
236 	return 1;
237 }
238 
239 static inline int env_mutex_destroy(env_mutex *mutex)
240 {
241 	if (pthread_mutex_destroy(&mutex->m)) {
242 		return 1;
243 	}
244 
245 	return 0;
246 }
247 
248 /* *** RECURSIVE MUTEX *** */
249 
250 typedef env_mutex env_rmutex;
251 
252 static inline int env_rmutex_init(env_rmutex *rmutex)
253 {
254 	pthread_mutexattr_t attr;
255 
256 	pthread_mutexattr_init(&attr);
257 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
258 	pthread_mutex_init(&rmutex->m, &attr);
259 
260 	return 0;
261 }
262 
263 static inline void env_rmutex_lock(env_rmutex *rmutex)
264 {
265 	env_mutex_lock(rmutex);
266 }
267 
268 static inline int env_rmutex_lock_interruptible(env_rmutex *rmutex)
269 {
270 	return env_mutex_lock_interruptible(rmutex);
271 }
272 
273 static inline int env_rmutex_trylock(env_rmutex *rmutex)
274 {
275 	return env_mutex_trylock(rmutex);
276 }
277 
278 static inline void env_rmutex_unlock(env_rmutex *rmutex)
279 {
280 	env_mutex_unlock(rmutex);
281 }
282 
283 static inline int env_rmutex_is_locked(env_rmutex *rmutex)
284 {
285 	return env_mutex_is_locked(rmutex);
286 }
287 
288 static inline int env_rmutex_destroy(env_rmutex *rmutex)
289 {
290 	return env_mutex_destroy(rmutex);
291 }
292 
293 /* *** RW SEMAPHORE *** */
294 typedef struct {
295 	pthread_rwlock_t lock;
296 } env_rwsem;
297 
298 static inline int env_rwsem_init(env_rwsem *s)
299 {
300 	return !!pthread_rwlock_init(&s->lock, NULL);
301 }
302 
303 static inline void env_rwsem_up_read(env_rwsem *s)
304 {
305 	ENV_BUG_ON(pthread_rwlock_unlock(&s->lock));
306 }
307 
308 static inline void env_rwsem_down_read(env_rwsem *s)
309 {
310 	ENV_BUG_ON(pthread_rwlock_rdlock(&s->lock));
311 }
312 
313 static inline int env_rwsem_down_read_trylock(env_rwsem *s)
314 {
315 	return pthread_rwlock_tryrdlock(&s->lock) ? -OCF_ERR_NO_LOCK : 0;
316 }
317 
318 static inline void env_rwsem_up_write(env_rwsem *s)
319 {
320 	ENV_BUG_ON(pthread_rwlock_unlock(&s->lock));
321 }
322 
323 static inline void env_rwsem_down_write(env_rwsem *s)
324 {
325 	ENV_BUG_ON(pthread_rwlock_wrlock(&s->lock));
326 }
327 
328 static inline int env_rwsem_down_write_trylock(env_rwsem *s)
329 {
330 	return pthread_rwlock_trywrlock(&s->lock) ? -OCF_ERR_NO_LOCK : 0;
331 }
332 
333 static inline int env_rwsem_is_locked(env_rwsem *s)
334 {
335 	if (env_rwsem_down_read_trylock(s) == 0) {
336 		env_rwsem_up_read(s);
337 		return 0;
338 	}
339 
340 	return 1;
341 }
342 
343 static inline int env_rwsem_down_read_interruptible(env_rwsem *s)
344 {
345 	return pthread_rwlock_rdlock(&s->lock);
346 }
347 static inline int env_rwsem_down_write_interruptible(env_rwsem *s)
348 {
349 	return pthread_rwlock_wrlock(&s->lock);
350 }
351 
352 static inline int env_rwsem_destroy(env_rwsem *s)
353 {
354 	return pthread_rwlock_destroy(&s->lock);
355 }
356 
357 /* *** ATOMIC VARIABLES *** */
358 
359 typedef int env_atomic;
360 
361 typedef long env_atomic64;
362 
363 #ifndef atomic_read
364 #define atomic_read(ptr)       (*(__typeof__(*ptr) *volatile) (ptr))
365 #endif
366 
367 #ifndef atomic_set
368 #define atomic_set(ptr, i)     ((*(__typeof__(*ptr) *volatile) (ptr)) = (i))
369 #endif
370 
371 #define atomic_inc(ptr)        ((void) __sync_fetch_and_add(ptr, 1))
372 #define atomic_dec(ptr)        ((void) __sync_fetch_and_add(ptr, -1))
373 #define atomic_add(ptr, n)     ((void) __sync_fetch_and_add(ptr, n))
374 #define atomic_sub(ptr, n)     ((void) __sync_fetch_and_sub(ptr, n))
375 
376 #define atomic_cmpxchg         __sync_val_compare_and_swap
377 
378 static inline int env_atomic_read(const env_atomic *a)
379 {
380 	return atomic_read(a);
381 }
382 
383 static inline void env_atomic_set(env_atomic *a, int i)
384 {
385 	atomic_set(a, i);
386 }
387 
388 static inline void env_atomic_add(int i, env_atomic *a)
389 {
390 	atomic_add(a, i);
391 }
392 
393 static inline void env_atomic_sub(int i, env_atomic *a)
394 {
395 	atomic_sub(a, i);
396 }
397 
398 static inline bool env_atomic_sub_and_test(int i, env_atomic *a)
399 {
400 	return __sync_sub_and_fetch(a, i) == 0;
401 }
402 
403 static inline void env_atomic_inc(env_atomic *a)
404 {
405 	atomic_inc(a);
406 }
407 
408 static inline void env_atomic_dec(env_atomic *a)
409 {
410 	atomic_dec(a);
411 }
412 
413 static inline bool env_atomic_dec_and_test(env_atomic *a)
414 {
415 	return __sync_sub_and_fetch(a, 1) == 0;
416 }
417 
418 static inline bool env_atomic_inc_and_test(env_atomic *a)
419 {
420 	return __sync_add_and_fetch(a, 1) == 0;
421 }
422 
423 static inline int env_atomic_add_return(int i, env_atomic *a)
424 {
425 	return __sync_add_and_fetch(a, i);
426 }
427 
428 static inline int env_atomic_sub_return(int i, env_atomic *a)
429 {
430 	return __sync_sub_and_fetch(a, i);
431 }
432 
433 static inline int env_atomic_inc_return(env_atomic *a)
434 {
435 	return env_atomic_add_return(1, a);
436 }
437 
438 static inline int env_atomic_dec_return(env_atomic *a)
439 {
440 	return env_atomic_sub_return(1, a);
441 }
442 
443 static inline int env_atomic_cmpxchg(env_atomic *a, int old, int new_value)
444 {
445 	return atomic_cmpxchg(a, old, new_value);
446 }
447 
448 static inline int env_atomic_add_unless(env_atomic *a, int i, int u)
449 {
450 	int c, old;
451 	c = env_atomic_read(a);
452 	for (;;) {
453 		if (spdk_unlikely(c == (u))) {
454 			break;
455 		}
456 		old = env_atomic_cmpxchg((a), c, c + (i));
457 		if (spdk_likely(old == c)) {
458 			break;
459 		}
460 		c = old;
461 	}
462 	return c != (u);
463 }
464 
465 static inline long env_atomic64_read(const env_atomic64 *a)
466 {
467 	return atomic_read(a);
468 }
469 
470 static inline void env_atomic64_set(env_atomic64 *a, long i)
471 {
472 	atomic_set(a, i);
473 }
474 
475 static inline void env_atomic64_add(long i, env_atomic64 *a)
476 {
477 	atomic_add(a, i);
478 }
479 
480 static inline void env_atomic64_sub(long i, env_atomic64 *a)
481 {
482 	atomic_sub(a, i);
483 }
484 
485 static inline void env_atomic64_inc(env_atomic64 *a)
486 {
487 	atomic_inc(a);
488 }
489 
490 static inline void env_atomic64_dec(env_atomic64 *a)
491 {
492 	atomic_dec(a);
493 }
494 
495 static inline int env_atomic64_add_return(int i, env_atomic *a)
496 {
497 	return __sync_add_and_fetch(a, i);
498 }
499 
500 static inline int env_atomic64_sub_return(int i, env_atomic *a)
501 {
502 	return __sync_sub_and_fetch(a, i);
503 }
504 
505 static inline int env_atomic64_inc_return(env_atomic *a)
506 {
507 	return env_atomic64_add_return(1, a);
508 }
509 
510 static inline int env_atomic64_dec_return(env_atomic *a)
511 {
512 	return env_atomic_sub_return(1, a);
513 }
514 
515 static inline long env_atomic64_cmpxchg(env_atomic64 *a, long old, long new)
516 {
517 	return atomic_cmpxchg(a, old, new);
518 }
519 
520 /* *** COMPLETION *** */
521 typedef struct completion {
522 	sem_t sem;
523 } env_completion;
524 
525 static inline void env_completion_init(env_completion *completion)
526 {
527 	sem_init(&completion->sem, 0, 0);
528 }
529 
530 static inline void env_completion_wait(env_completion *completion)
531 {
532 	sem_wait(&completion->sem);
533 }
534 
535 static inline void env_completion_complete(env_completion *completion)
536 {
537 	sem_post(&completion->sem);
538 }
539 
540 static inline void env_completion_destroy(env_completion *completion)
541 {
542 	sem_destroy(&completion->sem);
543 }
544 
545 /* *** SPIN LOCKS *** */
546 
547 typedef struct {
548 	pthread_spinlock_t lock;
549 } env_spinlock;
550 
551 static inline int env_spinlock_init(env_spinlock *l)
552 {
553 	return pthread_spin_init(&l->lock, 0);
554 }
555 
556 static inline int env_spinlock_trylock(env_spinlock *l)
557 {
558 	return pthread_spin_trylock(&l->lock) ? -OCF_ERR_NO_LOCK : 0;
559 }
560 
561 static inline void env_spinlock_lock(env_spinlock *l)
562 {
563 	ENV_BUG_ON(pthread_spin_lock(&l->lock));
564 }
565 
566 static inline void env_spinlock_unlock(env_spinlock *l)
567 {
568 	ENV_BUG_ON(pthread_spin_unlock(&l->lock));
569 }
570 
571 #define env_spinlock_lock_irqsave(l, flags) \
572 		(void)flags; \
573 		env_spinlock_lock(l)
574 
575 #define env_spinlock_unlock_irqrestore(l, flags) \
576 		(void)flags; \
577 		env_spinlock_unlock(l)
578 
579 static inline void env_spinlock_destroy(env_spinlock *l)
580 {
581 	ENV_BUG_ON(pthread_spin_destroy(&l->lock));
582 }
583 
584 /* *** RW LOCKS *** */
585 
586 typedef struct {
587 	pthread_rwlock_t lock;
588 } env_rwlock;
589 
590 static inline void env_rwlock_init(env_rwlock *l)
591 {
592 	ENV_BUG_ON(pthread_rwlock_init(&l->lock, NULL));
593 }
594 
595 static inline void env_rwlock_read_lock(env_rwlock *l)
596 {
597 	ENV_BUG_ON(pthread_rwlock_rdlock(&l->lock));
598 }
599 
600 static inline void env_rwlock_read_unlock(env_rwlock *l)
601 {
602 	ENV_BUG_ON(pthread_rwlock_unlock(&l->lock));
603 }
604 
605 static inline void env_rwlock_write_lock(env_rwlock *l)
606 {
607 	ENV_BUG_ON(pthread_rwlock_wrlock(&l->lock));
608 }
609 
610 static inline void env_rwlock_write_unlock(env_rwlock *l)
611 {
612 	ENV_BUG_ON(pthread_rwlock_unlock(&l->lock));
613 }
614 
615 static inline void env_rwlock_destroy(env_rwlock *l)
616 {
617 	ENV_BUG_ON(pthread_rwlock_destroy(&l->lock));
618 }
619 
620 static inline void env_bit_set(int nr, volatile void *addr)
621 {
622 	char *byte = (char *)addr + (nr >> 3);
623 	char mask = 1 << (nr & 7);
624 
625 	__sync_or_and_fetch(byte, mask);
626 }
627 
628 static inline void env_bit_clear(int nr, volatile void *addr)
629 {
630 	char *byte = (char *)addr + (nr >> 3);
631 	char mask = 1 << (nr & 7);
632 
633 	mask = ~mask;
634 	__sync_and_and_fetch(byte, mask);
635 }
636 
637 static inline bool env_bit_test(int nr, const volatile unsigned long *addr)
638 {
639 	const char *byte = (char *)addr + (nr >> 3);
640 	char mask = 1 << (nr & 7);
641 
642 	return !!(*byte & mask);
643 }
644 
645 /* *** WAITQUEUE *** */
646 
647 typedef struct {
648 	sem_t sem;
649 } env_waitqueue;
650 
651 static inline void env_waitqueue_init(env_waitqueue *w)
652 {
653 	sem_init(&w->sem, 0, 0);
654 }
655 
656 static inline void env_waitqueue_wake_up(env_waitqueue *w)
657 {
658 	sem_post(&w->sem);
659 }
660 
661 #define env_waitqueue_wait(w, condition)	\
662 ({						\
663 	int __ret = 0;				\
664 	if (!(condition))			\
665 		sem_wait(&w.sem);		\
666 	__ret = __ret;				\
667 })
668 
669 /* *** SCHEDULING *** */
670 
671 /* CAS does not need this while in user-space */
672 static inline void env_schedule(void)
673 {
674 }
675 
676 #define env_cond_resched	env_schedule
677 
678 static inline int env_in_interrupt(void)
679 {
680 	return 0;
681 }
682 
683 static inline uint64_t env_get_tick_count(void)
684 {
685 	return spdk_get_ticks();
686 }
687 
688 static inline uint64_t env_ticks_to_secs(uint64_t j)
689 {
690 	return j / spdk_get_ticks_hz();
691 }
692 
693 static inline uint64_t env_ticks_to_msecs(uint64_t j)
694 {
695 	return env_ticks_to_secs(j) * 1000;
696 }
697 
698 static inline uint64_t env_ticks_to_nsecs(uint64_t j)
699 {
700 	return env_ticks_to_secs(j) * 1000 * 1000;
701 }
702 
703 static inline uint64_t env_ticks_to_usecs(uint64_t j)
704 {
705 	return env_ticks_to_secs(j) * 1000 * 1000 * 1000;
706 }
707 
708 static inline uint64_t env_secs_to_ticks(uint64_t j)
709 {
710 	return j * spdk_get_ticks_hz();
711 }
712 
713 /* *** STRING OPERATIONS *** */
714 
715 /* 512 KB is sufficient amount of memory for OCF operations */
716 #define ENV_MAX_MEM (512 * 1024)
717 
718 static inline int env_memset(void *dest, size_t len, uint8_t value)
719 {
720 	if (dest == NULL || len == 0) {
721 		return 1;
722 	}
723 
724 	memset(dest, value, len);
725 	return 0;
726 }
727 
728 static inline int env_memcpy(void *dest, size_t dmax, const void *src, size_t len)
729 {
730 	if (dest == NULL || src == NULL) {
731 		return 1;
732 	}
733 	if (dmax == 0 || dmax > ENV_MAX_MEM) {
734 		return 1;
735 	}
736 	if (len == 0 || len > dmax) {
737 		return 1;
738 	}
739 
740 	memcpy(dest, src, len);
741 	return 0;
742 }
743 
744 static inline int env_memcmp(const void *aptr, size_t dmax, const void *bptr, size_t len,
745 			     int *diff)
746 {
747 	if (diff == NULL || aptr == NULL || bptr == NULL) {
748 		return 1;
749 	}
750 	if (dmax == 0 || dmax > ENV_MAX_MEM) {
751 		return 1;
752 	}
753 	if (len == 0 || len > dmax) {
754 		return 1;
755 	}
756 
757 	*diff = memcmp(aptr, bptr, len);
758 	return 0;
759 }
760 
761 /* 4096 is sufficient max length for any OCF operation on string */
762 #define ENV_MAX_STR (4 * 1024)
763 
764 static inline size_t env_strnlen(const char *src, size_t dmax)
765 {
766 	return strnlen(src, dmax);
767 }
768 
769 static inline int env_strncpy(char *dest, size_t dmax, const char *src, size_t len)
770 {
771 	if (dest == NULL  || src == NULL) {
772 		return 1;
773 	}
774 	if (dmax == 0 || dmax > ENV_MAX_STR) {
775 		return 1;
776 	}
777 	if (len == 0) {
778 		return 1;
779 	}
780 	/* Just copy as many characters as we can instead of return failure */
781 	len = min(len, dmax);
782 
783 	strncpy(dest, src, len);
784 	return 0;
785 }
786 
787 #define env_strncmp(s1, slen1, s2, slen2) strncmp(s1, s2, min(slen1, slen2))
788 
789 static inline char *env_strdup(const char *src, int flags)
790 {
791 	int len;
792 	char *ret;
793 
794 	if (src == NULL) {
795 		return NULL;
796 	}
797 
798 	len = env_strnlen(src, ENV_MAX_STR) + 1;
799 	ret = env_malloc(len, flags);
800 
801 	if (env_strncpy(ret, ENV_MAX_STR, src, len)) {
802 		return NULL;
803 	} else {
804 		return ret;
805 	}
806 }
807 
808 /* *** SORTING *** */
809 
810 static inline void env_sort(void *base, size_t num, size_t size,
811 			    int (*cmp_fn)(const void *, const void *),
812 			    void (*swap_fn)(void *, void *, int size))
813 {
814 	qsort(base, num, size, cmp_fn);
815 }
816 
817 static inline void env_msleep(uint64_t n)
818 {
819 	usleep(n * 1000);
820 }
821 
822 static inline void env_touch_softlockup_wd(void)
823 {
824 }
825 
826 /* *** CRC *** */
827 
828 uint32_t env_crc32(uint32_t crc, uint8_t const *data, size_t len);
829 
830 /* EXECUTION CONTEXTS */
831 unsigned env_get_execution_context(void);
832 void env_put_execution_context(unsigned ctx);
833 unsigned env_get_execution_context_count(void);
834 
835 #endif /* __OCF_ENV_H__ */
836