1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MATH64_H
3 #define _LINUX_MATH64_H
4
5 #include <linux/types.h>
6
7 #ifdef __x86_64__
8 static inline u64 mul_u64_u64_div64(u64 a, u64 b, u64 c)
9 {
10 u64 q;
11
12 asm ("mulq %2; divq %3" : "=a" (q)
13 : "a" (a), "rm" (b), "rm" (c)
14 : "rdx");
15
16 return q;
17 }
18 #define mul_u64_u64_div64 mul_u64_u64_div64
19 #endif
20
21 #ifdef __SIZEOF_INT128__
22 static inline u64 mul_u64_u32_shr(u64 a, u32 b, unsigned int shift)
23 {
24 return (u64)(((unsigned __int128)a * b) >> shift);
25 }
26
27 #else
28
29 #ifdef __i386__
30 static inline u64 mul_u32_u32(u32 a, u32 b)
31 {
32 u32 high, low;
33
34 asm ("mull %[b]" : "=a" (low), "=d" (high)
35 : [a] "a" (a), [b] "rm" (b) );
36
37 return low | ((u64)high) << 32;
38 }
39 #else
40 static inline u64 mul_u32_u32(u32 a, u32 b)
41 {
42 return (u64)a * b;
43 }
44 #endif
45
46 static inline u64 mul_u64_u32_shr(u64 a, u32 b, unsigned int shift)
47 {
48 u32 ah, al;
49 u64 ret;
50
51 al = a;
52 ah = a >> 32;
53
54 ret = mul_u32_u32(al, b) >> shift;
55 if (ah)
56 ret += mul_u32_u32(ah, b) << (32 - shift);
57
58 return ret;
59 }
60
61 #endif /* __SIZEOF_INT128__ */
62
63 #ifndef mul_u64_u64_div64
64 static inline u64 mul_u64_u64_div64(u64 a, u64 b, u64 c)
65 {
66 u64 quot, rem;
67
68 quot = a / c;
69 rem = a % c;
70
71 return quot * b + (rem * b) / c;
72 }
73 #endif
74
75 #endif /* _LINUX_MATH64_H */
76
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