xref: /linux/arch/m68k/include/asm/div64.h (revision 668a920208fffaf5308aabd304f7568d6815169b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _M68K_DIV64_H
3 #define _M68K_DIV64_H
4 
5 #ifdef CONFIG_CPU_HAS_NO_MULDIV64
6 #include <asm-generic/div64.h>
7 #else
8 
9 #include <linux/types.h>
10 
11 /* n = n / base; return rem; */
12 
13 #define do_div(n, base) ({					\
14 	union {							\
15 		unsigned long n32[2];				\
16 		unsigned long long n64;				\
17 	} __n;							\
18 	unsigned long __rem, __upper;				\
19 	unsigned long __base = (base);				\
20 								\
21 	__n.n64 = (n);						\
22 	if ((__upper = __n.n32[0])) {				\
23 		asm ("divul.l %2,%1:%0"				\
24 		     : "=d" (__n.n32[0]), "=d" (__upper)	\
25 		     : "d" (__base), "0" (__n.n32[0]));		\
26 	}							\
27 	asm ("divu.l %2,%1:%0"					\
28 	     : "=d" (__n.n32[1]), "=d" (__rem)			\
29 	     : "d" (__base), "1" (__upper), "0" (__n.n32[1]));	\
30 	(n) = __n.n64;						\
31 	__rem;							\
32 })
33 
34 /* defining this stops the unused helper function from being built */
35 #define __div64_32 __div64_32
36 
37 #endif /* CONFIG_CPU_HAS_NO_MULDIV64 */
38 
39 #endif /* _M68K_DIV64_H */
40