xref: /openbmc/u-boot/include/div64.h (revision bfc93fb4)
1 #ifndef _ASM_GENERIC_DIV64_H
2 #define _ASM_GENERIC_DIV64_H
3 /*
4  * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
5  * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
6  *
7  * The semantics of do_div() are:
8  *
9  * uint32_t do_div(uint64_t *n, uint32_t base)
10  * {
11  *	uint32_t remainder = *n % base;
12  *	*n = *n / base;
13  *	return remainder;
14  * }
15  *
16  * NOTE: macro parameter n is evaluated multiple times,
17  *       beware of side effects!
18  */
19 
20 #include <linux/types.h>
21 
22 extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
23 
24 /* The unnecessary pointer compare is there
25  * to check for type safety (n must be 64bit)
26  */
27 # define do_div(n,base) ({				\
28 	uint32_t __base = (base);			\
29 	uint32_t __rem;					\
30 	(void)(((typeof((n)) *)0) == ((uint64_t *)0));	\
31 	if (((n) >> 32) == 0) {			\
32 		__rem = (uint32_t)(n) % __base;		\
33 		(n) = (uint32_t)(n) / __base;		\
34 	} else						\
35 		__rem = __div64_32(&(n), __base);	\
36 	__rem;						\
37  })
38 
39 /* Wrapper for do_div(). Doesn't modify dividend and returns
40  * the result, not reminder.
41  */
42 static inline uint64_t lldiv(uint64_t dividend, uint32_t divisor)
43 {
44 	uint64_t __res = dividend;
45 	do_div(__res, divisor);
46 	return(__res);
47 }
48 
49 #endif /* _ASM_GENERIC_DIV64_H */
50