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19#include <linux/export.h>
20#include <linux/kernel.h>
21#include <linux/math64.h>
22
23
24#if BITS_PER_LONG == 32
25
26uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
27{
28 uint64_t rem = *n;
29 uint64_t b = base;
30 uint64_t res, d = 1;
31 uint32_t high = rem >> 32;
32
33
34 res = 0;
35 if (high >= base) {
36 high /= base;
37 res = (uint64_t) high << 32;
38 rem -= (uint64_t) (high*base) << 32;
39 }
40
41 while ((int64_t)b > 0 && b < rem) {
42 b = b+b;
43 d = d+d;
44 }
45
46 do {
47 if (rem >= b) {
48 rem -= b;
49 res += d;
50 }
51 b >>= 1;
52 d >>= 1;
53 } while (d);
54
55 *n = res;
56 return rem;
57}
58
59EXPORT_SYMBOL(__div64_32);
60
61#ifndef div_s64_rem
62s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
63{
64 u64 quotient;
65
66 if (dividend < 0) {
67 quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
68 *remainder = -*remainder;
69 if (divisor > 0)
70 quotient = -quotient;
71 } else {
72 quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
73 if (divisor < 0)
74 quotient = -quotient;
75 }
76 return quotient;
77}
78EXPORT_SYMBOL(div_s64_rem);
79#endif
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91
92#ifndef div64_u64
93u64 div64_u64(u64 dividend, u64 divisor)
94{
95 u32 high = divisor >> 32;
96 u64 quot;
97
98 if (high == 0) {
99 quot = div_u64(dividend, divisor);
100 } else {
101 int n = 1 + fls(high);
102 quot = div_u64(dividend >> n, divisor >> n);
103
104 if (quot != 0)
105 quot--;
106 if ((dividend - quot * divisor) >= divisor)
107 quot++;
108 }
109
110 return quot;
111}
112EXPORT_SYMBOL(div64_u64);
113#endif
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118
119
120#ifndef div64_s64
121s64 div64_s64(s64 dividend, s64 divisor)
122{
123 s64 quot, t;
124
125 quot = div64_u64(abs64(dividend), abs64(divisor));
126 t = (dividend ^ divisor) >> 63;
127
128 return (quot ^ t) - t;
129}
130EXPORT_SYMBOL(div64_s64);
131#endif
132
133#endif
134
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137
138
139u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
140{
141 return __iter_div_u64_rem(dividend, divisor, remainder);
142}
143EXPORT_SYMBOL(iter_div_u64_rem);
144