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-rw-r--r--include/asm-x86/div64.h20
-rw-r--r--include/linux/math64.h72
-rw-r--r--lib/div64.c23
3 files changed, 113 insertions, 2 deletions
diff --git a/include/asm-x86/div64.h b/include/asm-x86/div64.h
index 0dbf8bf3ef0a..c7892cfe9ce6 100644
--- a/include/asm-x86/div64.h
+++ b/include/asm-x86/div64.h
@@ -51,6 +51,26 @@ static inline long div_ll_X_l_rem(long long divs, long div, long *rem)
51 51
52} 52}
53 53
54static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
55{
56 union {
57 u64 v64;
58 u32 v32[2];
59 } d = { dividend };
60 u32 upper;
61
62 upper = d.v32[1];
63 d.v32[1] = 0;
64 if (upper >= divisor) {
65 d.v32[1] = upper / divisor;
66 upper %= divisor;
67 }
68 asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
69 "rm" (divisor), "0" (d.v32[0]), "1" (upper));
70 return d.v64;
71}
72#define div_u64_rem div_u64_rem
73
54extern uint64_t div64_64(uint64_t dividend, uint64_t divisor); 74extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
55 75
56#else 76#else
diff --git a/include/linux/math64.h b/include/linux/math64.h
new file mode 100644
index 000000000000..6d1716641008
--- /dev/null
+++ b/include/linux/math64.h
@@ -0,0 +1,72 @@
1#ifndef _LINUX_MATH64_H
2#define _LINUX_MATH64_H
3
4#include <linux/types.h>
5#include <asm/div64.h>
6
7#if BITS_PER_LONG == 64
8
9/**
10 * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
11 *
12 * This is commonly provided by 32bit archs to provide an optimized 64bit
13 * divide.
14 */
15static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
16{
17 *remainder = dividend % divisor;
18 return dividend / divisor;
19}
20
21/**
22 * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
23 */
24static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
25{
26 *remainder = dividend % divisor;
27 return dividend / divisor;
28}
29
30#elif BITS_PER_LONG == 32
31
32#ifndef div_u64_rem
33static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
34{
35 *remainder = do_div(dividend, divisor);
36 return dividend;
37}
38#endif
39
40#ifndef div_s64_rem
41extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
42#endif
43
44#endif /* BITS_PER_LONG */
45
46/**
47 * div_u64 - unsigned 64bit divide with 32bit divisor
48 *
49 * This is the most common 64bit divide and should be used if possible,
50 * as many 32bit archs can optimize this variant better than a full 64bit
51 * divide.
52 */
53#ifndef div_u64
54static inline u64 div_u64(u64 dividend, u32 divisor)
55{
56 u32 remainder;
57 return div_u64_rem(dividend, divisor, &remainder);
58}
59#endif
60
61/**
62 * div_s64 - signed 64bit divide with 32bit divisor
63 */
64#ifndef div_s64
65static inline s64 div_s64(s64 dividend, s32 divisor)
66{
67 s32 remainder;
68 return div_s64_rem(dividend, divisor, &remainder);
69}
70#endif
71
72#endif /* _LINUX_MATH64_H */
diff --git a/lib/div64.c b/lib/div64.c
index b71cf93c529a..689bd76833fa 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -16,9 +16,8 @@
16 * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S. 16 * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
17 */ 17 */
18 18
19#include <linux/types.h>
20#include <linux/module.h> 19#include <linux/module.h>
21#include <asm/div64.h> 20#include <linux/math64.h>
22 21
23/* Not needed on 64bit architectures */ 22/* Not needed on 64bit architectures */
24#if BITS_PER_LONG == 32 23#if BITS_PER_LONG == 32
@@ -58,6 +57,26 @@ uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
58 57
59EXPORT_SYMBOL(__div64_32); 58EXPORT_SYMBOL(__div64_32);
60 59
60#ifndef div_s64_rem
61s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
62{
63 u64 quotient;
64
65 if (dividend < 0) {
66 quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
67 *remainder = -*remainder;
68 if (divisor > 0)
69 quotient = -quotient;
70 } else {
71 quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
72 if (divisor < 0)
73 quotient = -quotient;
74 }
75 return quotient;
76}
77EXPORT_SYMBOL(div_s64_rem);
78#endif
79
61/* 64bit divisor, dividend and result. dynamic precision */ 80/* 64bit divisor, dividend and result. dynamic precision */
62uint64_t div64_64(uint64_t dividend, uint64_t divisor) 81uint64_t div64_64(uint64_t dividend, uint64_t divisor)
63{ 82{