Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
/*
 * Copyright (c) 2011-2014, Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief Misc utilities
 *
 * Misc utilities usable by the kernel and application code.
 */

#ifndef ZEPHYR_INCLUDE_SYS_UTIL_H_
#define ZEPHYR_INCLUDE_SYS_UTIL_H_

#include <zephyr/sys/util_macro.h>
#include <zephyr/toolchain.h>

/* needs to be outside _ASMLANGUAGE so 'true' and 'false' can turn
 * into '1' and '0' for asm or linker scripts
 */
#include <stdbool.h>

#ifndef _ASMLANGUAGE

#include <zephyr/types.h>
#include <stddef.h>
#include <stdint.h>

/** @brief Number of bits that make up a type */
#define NUM_BITS(t) (sizeof(t) * 8)

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup sys-util Utility Functions
 * @ingroup utilities
 * @{
 */

/** @brief Cast @p x, a pointer, to an unsigned integer. */
#define POINTER_TO_UINT(x) ((uintptr_t) (x))
/** @brief Cast @p x, an unsigned integer, to a <tt>void*</tt>. */
#define UINT_TO_POINTER(x) ((void *) (uintptr_t) (x))
/** @brief Cast @p x, a pointer, to a signed integer. */
#define POINTER_TO_INT(x)  ((intptr_t) (x))
/** @brief Cast @p x, a signed integer, to a <tt>void*</tt>. */
#define INT_TO_POINTER(x)  ((void *) (intptr_t) (x))

#if !(defined(__CHAR_BIT__) && defined(__SIZEOF_LONG__) && defined(__SIZEOF_LONG_LONG__))
#	error Missing required predefined macros for BITS_PER_LONG calculation
#endif

/** Number of bits in a long int. */
#define BITS_PER_LONG	(__CHAR_BIT__ * __SIZEOF_LONG__)

/** Number of bits in a long long int. */
#define BITS_PER_LONG_LONG	(__CHAR_BIT__ * __SIZEOF_LONG_LONG__)

/**
 * @brief Create a contiguous bitmask starting at bit position @p l
 *        and ending at position @p h.
 */
#define GENMASK(h, l) \
	(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))

/**
 * @brief Create a contiguous 64-bit bitmask starting at bit position @p l
 *        and ending at position @p h.
 */
#define GENMASK64(h, l) \
	(((~0ULL) - (1ULL << (l)) + 1) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))

/** @brief Extract the Least Significant Bit from @p value. */
#define LSB_GET(value) ((value) & -(value))

/**
 * @brief Extract a bitfield element from @p value corresponding to
 *	  the field mask @p mask.
 */
#define FIELD_GET(mask, value)  (((value) & (mask)) / LSB_GET(mask))

/**
 * @brief Prepare a bitfield element using @p value with @p mask representing
 *	  its field position and width. The result should be combined
 *	  with other fields using a logical OR.
 */
#define FIELD_PREP(mask, value) (((value) * LSB_GET(mask)) & (mask))

/** @brief 0 if @p cond is true-ish; causes a compile error otherwise. */
#define ZERO_OR_COMPILE_ERROR(cond) ((int) sizeof(char[1 - 2 * !(cond)]) - 1)

#if defined(__cplusplus)

/* The built-in function used below for type checking in C is not
 * supported by GNU C++.
 */
#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))

#else /* __cplusplus */

/**
 * @brief Zero if @p array has an array type, a compile error otherwise
 *
 * This macro is available only from C, not C++.
 */
#define IS_ARRAY(array) \
	ZERO_OR_COMPILE_ERROR( \
		!__builtin_types_compatible_p(__typeof__(array), \
					      __typeof__(&(array)[0])))

/**
 * @brief Number of elements in the given @p array
 *
 * In C++, due to language limitations, this will accept as @p array
 * any type that implements <tt>operator[]</tt>. The results may not be
 * particularly meaningful in this case.
 *
 * In C, passing a pointer as @p array causes a compile error.
 */
#define ARRAY_SIZE(array) \
	((size_t) (IS_ARRAY(array) + (sizeof(array) / sizeof((array)[0]))))

#endif /* __cplusplus */

/**
 * @brief Whether @p ptr is an element of @p array
 *
 * This macro can be seen as a slightly stricter version of @ref PART_OF_ARRAY
 * in that it also ensures that @p ptr is aligned to an array-element boundary
 * of @p array.
 *
 * In C, passing a pointer as @p array causes a compile error.
 *
 * @param array the array in question
 * @param ptr the pointer to check
 *
 * @return 1 if @p ptr is part of @p array, 0 otherwise
 */
#define IS_ARRAY_ELEMENT(array, ptr)                                                               \
	((ptr) && POINTER_TO_UINT(array) <= POINTER_TO_UINT(ptr) &&                          \
	 POINTER_TO_UINT(ptr) < POINTER_TO_UINT(&(array)[ARRAY_SIZE(array)]) &&                    \
	 (POINTER_TO_UINT(ptr) - POINTER_TO_UINT(array)) % sizeof((array)[0]) == 0)

/**
 * @brief Index of @p ptr within @p array
 *
 * With `CONFIG_ASSERT=y`, this macro will trigger a runtime assertion
 * when @p ptr does not fall into the range of @p array or when @p ptr
 * is not aligned to an array-element boundary of @p array.
 *
 * In C, passing a pointer as @p array causes a compile error.
 *
 * @param array the array in question
 * @param ptr pointer to an element of @p array
 *
 * @return the array index of @p ptr within @p array, on success
 */
#define ARRAY_INDEX(array, ptr)                                                                    \
	({                                                                                         \
		__ASSERT_NO_MSG(IS_ARRAY_ELEMENT(array, ptr));                                     \
		(__typeof__((array)[0]) *)(ptr) - (array);                                         \
	})

/**
 * @brief Check if a pointer @p ptr lies within @p array.
 *
 * In C but not C++, this causes a compile error if @p array is not an array
 * (e.g. if @p ptr and @p array are mixed up).
 *
 * @param array an array
 * @param ptr a pointer
 * @return 1 if @p ptr is part of @p array, 0 otherwise
 */
#define PART_OF_ARRAY(array, ptr)                                                                  \
	((ptr) && POINTER_TO_UINT(array) <= POINTER_TO_UINT(ptr) &&                                \
	 POINTER_TO_UINT(ptr) < POINTER_TO_UINT(&(array)[ARRAY_SIZE(array)]))

/**
 * @brief Array-index of @p ptr within @p array, rounded down
 *
 * This macro behaves much like @ref ARRAY_INDEX with the notable
 * difference that it accepts any @p ptr in the range of @p array rather than
 * exclusively a @p ptr aligned to an array-element boundary of @p array.
 *
 * With `CONFIG_ASSERT=y`, this macro will trigger a runtime assertion
 * when @p ptr does not fall into the range of @p array.
 *
 * In C, passing a pointer as @p array causes a compile error.
 *
 * @param array the array in question
 * @param ptr pointer to an element of @p array
 *
 * @return the array index of @p ptr within @p array, on success
 */
#define ARRAY_INDEX_FLOOR(array, ptr)                                                              \
	({                                                                                         \
		__ASSERT_NO_MSG(PART_OF_ARRAY(array, ptr));                                        \
		(POINTER_TO_UINT(ptr) - POINTER_TO_UINT(array)) / sizeof((array)[0]);              \
	})

/**
 * @brief Iterate over members of an array using an index variable
 *
 * @param array the array in question
 * @param idx name of array index variable
 */
#define ARRAY_FOR_EACH(array, idx) for (size_t idx = 0; (idx) < ARRAY_SIZE(array); ++(idx))

/**
 * @brief Iterate over members of an array using a pointer
 *
 * @param array the array in question
 * @param ptr pointer to an element of @p array
 */
#define ARRAY_FOR_EACH_PTR(array, ptr)                                                             \
	for (__typeof__(*(array)) *ptr = (array); (size_t)((ptr) - (array)) < ARRAY_SIZE(array);   \
	     ++(ptr))

/**
 * @brief Validate if two entities have a compatible type
 *
 * @param a the first entity to be compared
 * @param b the second entity to be compared
 * @return 1 if the two elements are compatible, 0 if they are not
 */
#define SAME_TYPE(a, b) __builtin_types_compatible_p(__typeof__(a), __typeof__(b))

/**
 * @brief Validate CONTAINER_OF parameters, only applies to C mode.
 */
#ifndef __cplusplus
#define CONTAINER_OF_VALIDATE(ptr, type, field)               \
	BUILD_ASSERT(SAME_TYPE(*(ptr), ((type *)0)->field) || \
		     SAME_TYPE(*(ptr), void),                 \
		     "pointer type mismatch in CONTAINER_OF");
#else
#define CONTAINER_OF_VALIDATE(ptr, type, field)
#endif

/**
 * @brief Get a pointer to a structure containing the element
 *
 * Example:
 *
 *	struct foo {
 *		int bar;
 *	};
 *
 *	struct foo my_foo;
 *	int *ptr = &my_foo.bar;
 *
 *	struct foo *container = CONTAINER_OF(ptr, struct foo, bar);
 *
 * Above, @p container points at @p my_foo.
 *
 * @param ptr pointer to a structure element
 * @param type name of the type that @p ptr is an element of
 * @param field the name of the field within the struct @p ptr points to
 * @return a pointer to the structure that contains @p ptr
 */
#define CONTAINER_OF(ptr, type, field)                               \
	({                                                           \
		CONTAINER_OF_VALIDATE(ptr, type, field)              \
		((type *)(((char *)(ptr)) - offsetof(type, field))); \
	})

/**
 * @brief Concatenate input arguments
 *
 * Concatenate provided tokens into a combined token during the preprocessor pass.
 * This can be used to, for ex., build an identifier out of multiple parts,
 * where one of those parts may be, for ex, a number, another macro, or a macro argument.
 *
 * @param ... Tokens to concatencate
 *
 * @return Concatenated token.
 */
#define CONCAT(...) \
	UTIL_CAT(_CONCAT_, NUM_VA_ARGS_LESS_1(__VA_ARGS__))(__VA_ARGS__)

/**
 * @brief Value of @p x rounded up to the next multiple of @p align.
 */
#define ROUND_UP(x, align)                                   \
	((((unsigned long)(x) + ((unsigned long)(align) - 1)) / \
	  (unsigned long)(align)) * (unsigned long)(align))

/**
 * @brief Value of @p x rounded down to the previous multiple of @p align.
 */
#define ROUND_DOWN(x, align)                                 \
	(((unsigned long)(x) / (unsigned long)(align)) * (unsigned long)(align))

/** @brief Value of @p x rounded up to the next word boundary. */
#define WB_UP(x) ROUND_UP(x, sizeof(void *))

/** @brief Value of @p x rounded down to the previous word boundary. */
#define WB_DN(x) ROUND_DOWN(x, sizeof(void *))

/**
 * @brief Divide and round up.
 *
 * Example:
 * @code{.c}
 * DIV_ROUND_UP(1, 2); // 1
 * DIV_ROUND_UP(3, 2); // 2
 * @endcode
 *
 * @param n Numerator.
 * @param d Denominator.
 *
 * @return The result of @p n / @p d, rounded up.
 */
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))

/**
 * @brief Divide and round to the nearest integer.
 *
 * Example:
 * @code{.c}
 * DIV_ROUND_CLOSEST(5, 2); // 3
 * DIV_ROUND_CLOSEST(5, -2); // -3
 * DIV_ROUND_CLOSEST(5, 3); // 2
 * @endcode
 *
 * @param n Numerator.
 * @param d Denominator.
 *
 * @return The result of @p n / @p d, rounded to the nearest integer.
 */
#define DIV_ROUND_CLOSEST(n, d)	\
	((((n) < 0) ^ ((d) < 0)) ? ((n) - ((d) / 2)) / (d) : \
	((n) + ((d) / 2)) / (d))

/**
 * @brief Ceiling function applied to @p numerator / @p divider as a fraction.
 * @deprecated Use DIV_ROUND_UP() instead.
 */
#define ceiling_fraction(numerator, divider) __DEPRECATED_MACRO \
	DIV_ROUND_UP(numerator, divider)

#ifndef MAX
/**
 * @brief Obtain the maximum of two values.
 *
 * @note Arguments are evaluated twice. Use Z_MAX for a GCC-only, single
 * evaluation version
 *
 * @param a First value.
 * @param b Second value.
 *
 * @returns Maximum value of @p a and @p b.
 */
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif

#ifndef MIN
/**
 * @brief Obtain the minimum of two values.
 *
 * @note Arguments are evaluated twice. Use Z_MIN for a GCC-only, single
 * evaluation version
 *
 * @param a First value.
 * @param b Second value.
 *
 * @returns Minimum value of @p a and @p b.
 */
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif

#ifndef CLAMP
/**
 * @brief Clamp a value to a given range.
 *
 * @note Arguments are evaluated multiple times. Use Z_CLAMP for a GCC-only,
 * single evaluation version.
 *
 * @param val Value to be clamped.
 * @param low Lowest allowed value (inclusive).
 * @param high Highest allowed value (inclusive).
 *
 * @returns Clamped value.
 */
#define CLAMP(val, low, high) (((val) <= (low)) ? (low) : MIN(val, high))
#endif

/**
 * @brief Checks if a value is within range.
 *
 * @note @p val is evaluated twice.
 *
 * @param val Value to be checked.
 * @param min Lower bound (inclusive).
 * @param max Upper bound (inclusive).
 *
 * @retval true If value is within range
 * @retval false If the value is not within range
 */
#define IN_RANGE(val, min, max) ((val) >= (min) && (val) <= (max))

/**
 * @brief Is @p x a power of two?
 * @param x value to check
 * @return true if @p x is a power of two, false otherwise
 */
static inline bool is_power_of_two(unsigned int x)
{
	return IS_POWER_OF_TWO(x);
}

/**
 * @brief Arithmetic shift right
 * @param value value to shift
 * @param shift number of bits to shift
 * @return @p value shifted right by @p shift; opened bit positions are
 *         filled with the sign bit
 */
static inline int64_t arithmetic_shift_right(int64_t value, uint8_t shift)
{
	int64_t sign_ext;

	if (shift == 0U) {
		return value;
	}

	/* extract sign bit */
	sign_ext = (value >> 63) & 1;

	/* make all bits of sign_ext be the same as the value's sign bit */
	sign_ext = -sign_ext;

	/* shift value and fill opened bit positions with sign bit */
	return (value >> shift) | (sign_ext << (64 - shift));
}

/**
 * @brief byte by byte memcpy.
 *
 * Copy `size` bytes of `src` into `dest`. This is guaranteed to be done byte by byte.
 *
 * @param dst Pointer to the destination memory.
 * @param src Pointer to the source of the data.
 * @param size The number of bytes to copy.
 */
static inline void bytecpy(void *dst, const void *src, size_t size)
{
	size_t i;

	for (i = 0; i < size; ++i) {
		((volatile uint8_t *)dst)[i] = ((volatile const uint8_t *)src)[i];
	}
}

/**
 * @brief byte by byte swap.
 *
 * Swap @a size bytes between memory regions @a a and @a b. This is
 * guaranteed to be done byte by byte.
 *
 * @param a Pointer to the the first memory region.
 * @param b Pointer to the the second memory region.
 * @param size The number of bytes to swap.
 */
static inline void byteswp(void *a, void *b, size_t size)
{
	uint8_t t;
	uint8_t *aa = (uint8_t *)a;
	uint8_t *bb = (uint8_t *)b;

	for (; size > 0; --size) {
		t = *aa;
		*aa++ = *bb;
		*bb++ = t;
	}
}

/**
 * @brief      Convert a single character into a hexadecimal nibble.
 *
 * @param c     The character to convert
 * @param x     The address of storage for the converted number.
 *
 *  @return Zero on success or (negative) error code otherwise.
 */
int char2hex(char c, uint8_t *x);

/**
 * @brief      Convert a single hexadecimal nibble into a character.
 *
 * @param c     The number to convert
 * @param x     The address of storage for the converted character.
 *
 *  @return Zero on success or (negative) error code otherwise.
 */
int hex2char(uint8_t x, char *c);

/**
 * @brief      Convert a binary array into string representation.
 *
 * @param buf     The binary array to convert
 * @param buflen  The length of the binary array to convert
 * @param hex     Address of where to store the string representation.
 * @param hexlen  Size of the storage area for string representation.
 *
 * @return     The length of the converted string, or 0 if an error occurred.
 */
size_t bin2hex(const uint8_t *buf, size_t buflen, char *hex, size_t hexlen);

/**
 * @brief      Convert a hexadecimal string into a binary array.
 *
 * @param hex     The hexadecimal string to convert
 * @param hexlen  The length of the hexadecimal string to convert.
 * @param buf     Address of where to store the binary data
 * @param buflen  Size of the storage area for binary data
 *
 * @return     The length of the binary array, or 0 if an error occurred.
 */
size_t hex2bin(const char *hex, size_t hexlen, uint8_t *buf, size_t buflen);

/**
 * @brief Convert a binary coded decimal (BCD 8421) value to binary.
 *
 * @param bcd BCD 8421 value to convert.
 *
 * @return Binary representation of input value.
 */
static inline uint8_t bcd2bin(uint8_t bcd)
{
	return ((10 * (bcd >> 4)) + (bcd & 0x0F));
}

/**
 * @brief Convert a binary value to binary coded decimal (BCD 8421).
 *
 * @param bin Binary value to convert.
 *
 * @return BCD 8421 representation of input value.
 */
static inline uint8_t bin2bcd(uint8_t bin)
{
	return (((bin / 10) << 4) | (bin % 10));
}

/**
 * @brief      Convert a uint8_t into a decimal string representation.
 *
 * Convert a uint8_t value into its ASCII decimal string representation.
 * The string is terminated if there is enough space in buf.
 *
 * @param buf     Address of where to store the string representation.
 * @param buflen  Size of the storage area for string representation.
 * @param value   The value to convert to decimal string
 *
 * @return     The length of the converted string (excluding terminator if
 *             any), or 0 if an error occurred.
 */
uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value);

/**
 * @brief Properly truncate a NULL-terminated UTF-8 string
 *
 * Take a NULL-terminated UTF-8 string and ensure that if the string has been
 * truncated (by setting the NULL terminator) earlier by other means, that
 * the string ends with a properly formatted UTF-8 character (1-4 bytes).
 *
 * @htmlonly
 * Example:
 *      char test_str[] = "€€€";
 *      char trunc_utf8[8];
 *
 *      printf("Original : %s\n", test_str); // €€€
 *      strncpy(trunc_utf8, test_str, sizeof(trunc_utf8));
 *      trunc_utf8[sizeof(trunc_utf8) - 1] = '\0';
 *      printf("Bad      : %s\n", trunc_utf8); // €€�
 *      utf8_trunc(trunc_utf8);
 *      printf("Truncated: %s\n", trunc_utf8); // €€
 * @endhtmlonly
 *
 * @param utf8_str NULL-terminated string
 *
 * @return Pointer to the @p utf8_str
 */
char *utf8_trunc(char *utf8_str);

/**
 * @brief Copies a UTF-8 encoded string from @p src to @p dst
 *
 * The resulting @p dst will always be NULL terminated if @p n is larger than 0,
 * and the @p dst string will always be properly UTF-8 truncated.
 *
 * @param dst The destination of the UTF-8 string.
 * @param src The source string
 * @param n   The size of the @p dst buffer. Maximum number of characters copied
 *            is @p n - 1. If 0 nothing will be done, and the @p dst will not be
 *            NULL terminated.
 *
 * @return Pointer to the @p dst
 */
char *utf8_lcpy(char *dst, const char *src, size_t n);

#define __z_log2d(x) (32 - __builtin_clz(x) - 1)
#define __z_log2q(x) (64 - __builtin_clzll(x) - 1)
#define __z_log2(x) (sizeof(__typeof__(x)) > 4 ? __z_log2q(x) : __z_log2d(x))

/**
 * @brief Compute log2(x)
 *
 * @note This macro expands its argument multiple times (to permit use
 *       in constant expressions), which must not have side effects.
 *
 * @param x An unsigned integral value to compute logarithm of (positive only)
 *
 * @return log2(x) when 1 <= x <= max(x), -1 when x < 1
 */
#define LOG2(x) ((x) < 1 ? -1 : __z_log2(x))

/**
 * @brief Compute ceil(log2(x))
 *
 * @note This macro expands its argument multiple times (to permit use
 *       in constant expressions), which must not have side effects.
 *
 * @param x An unsigned integral value
 *
 * @return ceil(log2(x)) when 1 <= x <= max(type(x)), 0 when x < 1
 */
#define LOG2CEIL(x) ((x) < 1 ?  0 : __z_log2((x)-1) + 1)

/**
 * @brief Compute next highest power of two
 *
 * Equivalent to 2^ceil(log2(x))
 *
 * @note This macro expands its argument multiple times (to permit use
 *       in constant expressions), which must not have side effects.
 *
 * @param x An unsigned integral value
 *
 * @return 2^ceil(log2(x)) or 0 if 2^ceil(log2(x)) would saturate 64-bits
 */
#define NHPOT(x) ((x) < 1 ? 1 : ((x) > (1ULL<<63) ? 0 : 1ULL << LOG2CEIL(x)))

/**
 * @brief Determine if a buffer exceeds highest address
 *
 * This macro determines if a buffer identified by a starting address @a addr
 * and length @a buflen spans a region of memory that goes beond the highest
 * possible address (thereby resulting in a pointer overflow).
 *
 * @param addr Buffer starting address
 * @param buflen Length of the buffer
 *
 * @return true if pointer overflow detected, false otherwise
 */
#define Z_DETECT_POINTER_OVERFLOW(addr, buflen)  \
	(((buflen) != 0) &&                        \
	((UINTPTR_MAX - (uintptr_t)(addr)) <= ((uintptr_t)((buflen) - 1))))

/**
 * @brief XOR n bytes
 *
 * @param dst  Destination of where to store result. Shall be @p len bytes.
 * @param src1 First source. Shall be @p len bytes.
 * @param src2 Second source. Shall be @p len bytes.
 * @param len  Number of bytes to XOR.
 */
static inline void mem_xor_n(uint8_t *dst, const uint8_t *src1, const uint8_t *src2, size_t len)
{
	while (len--) {
		*dst++ = *src1++ ^ *src2++;
	}
}

/**
 * @brief XOR 32 bits
 *
 * @param dst  Destination of where to store result. Shall be 32 bits.
 * @param src1 First source. Shall be 32 bits.
 * @param src2 Second source. Shall be 32 bits.
 */
static inline void mem_xor_32(uint8_t dst[4], const uint8_t src1[4], const uint8_t src2[4])
{
	mem_xor_n(dst, src1, src2, 4U);
}

/**
 * @brief XOR 128 bits
 *
 * @param dst  Destination of where to store result. Shall be 128 bits.
 * @param src1 First source. Shall be 128 bits.
 * @param src2 Second source. Shall be 128 bits.
 */
static inline void mem_xor_128(uint8_t dst[16], const uint8_t src1[16], const uint8_t src2[16])
{
	mem_xor_n(dst, src1, src2, 16);
}

#ifdef __cplusplus
}
#endif

/* This file must be included at the end of the !_ASMLANGUAGE guard.
 * It depends on macros defined in this file above which cannot be forward declared.
 */
#include <zephyr/sys/time_units.h>

#endif /* !_ASMLANGUAGE */

/** @brief Number of bytes in @p x kibibytes */
#ifdef _LINKER
/* This is used in linker scripts so need to avoid type casting there */
#define KB(x) ((x) << 10)
#else
#define KB(x) (((size_t)x) << 10)
#endif
/** @brief Number of bytes in @p x mebibytes */
#define MB(x) (KB(x) << 10)
/** @brief Number of bytes in @p x gibibytes */
#define GB(x) (MB(x) << 10)

/** @brief Number of Hz in @p x kHz */
#define KHZ(x) ((x) * 1000)
/** @brief Number of Hz in @p x MHz */
#define MHZ(x) (KHZ(x) * 1000)

/**
 * @brief For the POSIX architecture add a minimal delay in a busy wait loop.
 * For other architectures this is a no-op.
 *
 * In the POSIX ARCH, code takes zero simulated time to execute,
 * so busy wait loops become infinite loops, unless we
 * force the loop to take a bit of time.
 * Include this macro in all busy wait/spin loops
 * so they will also work when building for the POSIX architecture.
 *
 * @param t Time in microseconds we will busy wait
 */
#if defined(CONFIG_ARCH_POSIX)
#define Z_SPIN_DELAY(t) k_busy_wait(t)
#else
#define Z_SPIN_DELAY(t)
#endif

/**
 * @brief Wait for an expression to return true with a timeout
 *
 * Spin on an expression with a timeout and optional delay between iterations
 *
 * Commonly needed when waiting on hardware to complete an asynchronous
 * request to read/write/initialize/reset, but useful for any expression.
 *
 * @param expr Truth expression upon which to poll, e.g.: XYZREG & XYZREG_EN
 * @param timeout Timeout to wait for in microseconds, e.g.: 1000 (1ms)
 * @param delay_stmt Delay statement to perform each poll iteration
 *                   e.g.: NULL, k_yield(), k_msleep(1) or k_busy_wait(1)
 *
 * @retval expr As a boolean return, if false then it has timed out.
 */
#define WAIT_FOR(expr, timeout, delay_stmt)                                                        \
	({                                                                                         \
		uint32_t _wf_cycle_count = k_us_to_cyc_ceil32(timeout);                            \
		uint32_t _wf_start = k_cycle_get_32();                                             \
		while (!(expr) && (_wf_cycle_count > (k_cycle_get_32() - _wf_start))) {            \
			delay_stmt;                                                                \
			Z_SPIN_DELAY(10);                                                          \
		}                                                                                  \
		(expr);                                                                            \
	})

/**
 * @}
 */

#endif /* ZEPHYR_INCLUDE_SYS_UTIL_H_ */