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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2418f4f2 RZ |
2 | #ifndef _LINUX_MATH64_H |
3 | #define _LINUX_MATH64_H | |
4 | ||
5 | #include <linux/types.h> | |
b874b835 | 6 | #include <vdso/math64.h> |
2418f4f2 RZ |
7 | #include <asm/div64.h> |
8 | ||
9 | #if BITS_PER_LONG == 64 | |
10 | ||
c2853c8d AS |
11 | #define div64_long(x, y) div64_s64((x), (y)) |
12 | #define div64_ul(x, y) div64_u64((x), (y)) | |
f910381a | 13 | |
2418f4f2 RZ |
14 | /** |
15 | * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder | |
078843f7 RD |
16 | * @dividend: unsigned 64bit dividend |
17 | * @divisor: unsigned 32bit divisor | |
18 | * @remainder: pointer to unsigned 32bit remainder | |
19 | * | |
20 | * Return: sets ``*remainder``, then returns dividend / divisor | |
2418f4f2 RZ |
21 | * |
22 | * This is commonly provided by 32bit archs to provide an optimized 64bit | |
23 | * divide. | |
24 | */ | |
25 | static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) | |
26 | { | |
27 | *remainder = dividend % divisor; | |
28 | return dividend / divisor; | |
29 | } | |
30 | ||
c2a9a645 | 31 | /* |
2418f4f2 | 32 | * div_s64_rem - signed 64bit divide with 32bit divisor with remainder |
078843f7 RD |
33 | * @dividend: signed 64bit dividend |
34 | * @divisor: signed 32bit divisor | |
35 | * @remainder: pointer to signed 32bit remainder | |
36 | * | |
37 | * Return: sets ``*remainder``, then returns dividend / divisor | |
2418f4f2 RZ |
38 | */ |
39 | static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) | |
40 | { | |
41 | *remainder = dividend % divisor; | |
42 | return dividend / divisor; | |
43 | } | |
44 | ||
c2a9a645 | 45 | /* |
eb18cba7 | 46 | * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder |
078843f7 RD |
47 | * @dividend: unsigned 64bit dividend |
48 | * @divisor: unsigned 64bit divisor | |
49 | * @remainder: pointer to unsigned 64bit remainder | |
50 | * | |
51 | * Return: sets ``*remainder``, then returns dividend / divisor | |
eb18cba7 MS |
52 | */ |
53 | static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) | |
54 | { | |
55 | *remainder = dividend % divisor; | |
56 | return dividend / divisor; | |
57 | } | |
58 | ||
c2a9a645 | 59 | /* |
6f6d6a1a | 60 | * div64_u64 - unsigned 64bit divide with 64bit divisor |
078843f7 RD |
61 | * @dividend: unsigned 64bit dividend |
62 | * @divisor: unsigned 64bit divisor | |
63 | * | |
64 | * Return: dividend / divisor | |
6f6d6a1a RZ |
65 | */ |
66 | static inline u64 div64_u64(u64 dividend, u64 divisor) | |
67 | { | |
68 | return dividend / divisor; | |
69 | } | |
70 | ||
c2a9a645 | 71 | /* |
658716d1 | 72 | * div64_s64 - signed 64bit divide with 64bit divisor |
078843f7 RD |
73 | * @dividend: signed 64bit dividend |
74 | * @divisor: signed 64bit divisor | |
75 | * | |
76 | * Return: dividend / divisor | |
658716d1 BB |
77 | */ |
78 | static inline s64 div64_s64(s64 dividend, s64 divisor) | |
79 | { | |
80 | return dividend / divisor; | |
81 | } | |
82 | ||
2418f4f2 RZ |
83 | #elif BITS_PER_LONG == 32 |
84 | ||
c2853c8d AS |
85 | #define div64_long(x, y) div_s64((x), (y)) |
86 | #define div64_ul(x, y) div_u64((x), (y)) | |
f910381a | 87 | |
2418f4f2 RZ |
88 | #ifndef div_u64_rem |
89 | static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) | |
90 | { | |
91 | *remainder = do_div(dividend, divisor); | |
92 | return dividend; | |
93 | } | |
94 | #endif | |
95 | ||
96 | #ifndef div_s64_rem | |
97 | extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); | |
98 | #endif | |
99 | ||
eb18cba7 MS |
100 | #ifndef div64_u64_rem |
101 | extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder); | |
102 | #endif | |
103 | ||
6f6d6a1a | 104 | #ifndef div64_u64 |
f3002134 | 105 | extern u64 div64_u64(u64 dividend, u64 divisor); |
6f6d6a1a RZ |
106 | #endif |
107 | ||
658716d1 BB |
108 | #ifndef div64_s64 |
109 | extern s64 div64_s64(s64 dividend, s64 divisor); | |
110 | #endif | |
111 | ||
2418f4f2 RZ |
112 | #endif /* BITS_PER_LONG */ |
113 | ||
114 | /** | |
115 | * div_u64 - unsigned 64bit divide with 32bit divisor | |
078843f7 RD |
116 | * @dividend: unsigned 64bit dividend |
117 | * @divisor: unsigned 32bit divisor | |
2418f4f2 RZ |
118 | * |
119 | * This is the most common 64bit divide and should be used if possible, | |
120 | * as many 32bit archs can optimize this variant better than a full 64bit | |
121 | * divide. | |
122 | */ | |
123 | #ifndef div_u64 | |
124 | static inline u64 div_u64(u64 dividend, u32 divisor) | |
125 | { | |
126 | u32 remainder; | |
127 | return div_u64_rem(dividend, divisor, &remainder); | |
128 | } | |
129 | #endif | |
130 | ||
131 | /** | |
132 | * div_s64 - signed 64bit divide with 32bit divisor | |
078843f7 RD |
133 | * @dividend: signed 64bit dividend |
134 | * @divisor: signed 32bit divisor | |
2418f4f2 RZ |
135 | */ |
136 | #ifndef div_s64 | |
137 | static inline s64 div_s64(s64 dividend, s32 divisor) | |
138 | { | |
139 | s32 remainder; | |
140 | return div_s64_rem(dividend, divisor, &remainder); | |
141 | } | |
142 | #endif | |
143 | ||
f595ec96 JF |
144 | u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); |
145 | ||
9e3d6223 PZ |
146 | #ifndef mul_u32_u32 |
147 | /* | |
148 | * Many a GCC version messes this up and generates a 64x64 mult :-( | |
149 | */ | |
150 | static inline u64 mul_u32_u32(u32 a, u32 b) | |
151 | { | |
152 | return (u64)a * b; | |
153 | } | |
154 | #endif | |
155 | ||
be5e610c PZ |
156 | #if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__) |
157 | ||
158 | #ifndef mul_u64_u32_shr | |
159 | static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) | |
160 | { | |
161 | return (u64)(((unsigned __int128)a * mul) >> shift); | |
162 | } | |
163 | #endif /* mul_u64_u32_shr */ | |
164 | ||
35181e86 HZ |
165 | #ifndef mul_u64_u64_shr |
166 | static inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift) | |
167 | { | |
168 | return (u64)(((unsigned __int128)a * mul) >> shift); | |
169 | } | |
170 | #endif /* mul_u64_u64_shr */ | |
171 | ||
be5e610c PZ |
172 | #else |
173 | ||
174 | #ifndef mul_u64_u32_shr | |
175 | static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) | |
176 | { | |
177 | u32 ah, al; | |
178 | u64 ret; | |
179 | ||
180 | al = a; | |
181 | ah = a >> 32; | |
182 | ||
9e3d6223 | 183 | ret = mul_u32_u32(al, mul) >> shift; |
be5e610c | 184 | if (ah) |
9e3d6223 | 185 | ret += mul_u32_u32(ah, mul) << (32 - shift); |
be5e610c PZ |
186 | |
187 | return ret; | |
188 | } | |
189 | #endif /* mul_u64_u32_shr */ | |
190 | ||
35181e86 HZ |
191 | #ifndef mul_u64_u64_shr |
192 | static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) | |
193 | { | |
194 | union { | |
195 | u64 ll; | |
196 | struct { | |
197 | #ifdef __BIG_ENDIAN | |
198 | u32 high, low; | |
199 | #else | |
200 | u32 low, high; | |
201 | #endif | |
202 | } l; | |
203 | } rl, rm, rn, rh, a0, b0; | |
204 | u64 c; | |
205 | ||
206 | a0.ll = a; | |
207 | b0.ll = b; | |
208 | ||
9e3d6223 PZ |
209 | rl.ll = mul_u32_u32(a0.l.low, b0.l.low); |
210 | rm.ll = mul_u32_u32(a0.l.low, b0.l.high); | |
211 | rn.ll = mul_u32_u32(a0.l.high, b0.l.low); | |
212 | rh.ll = mul_u32_u32(a0.l.high, b0.l.high); | |
35181e86 HZ |
213 | |
214 | /* | |
215 | * Each of these lines computes a 64-bit intermediate result into "c", | |
216 | * starting at bits 32-95. The low 32-bits go into the result of the | |
217 | * multiplication, the high 32-bits are carried into the next step. | |
218 | */ | |
219 | rl.l.high = c = (u64)rl.l.high + rm.l.low + rn.l.low; | |
220 | rh.l.low = c = (c >> 32) + rm.l.high + rn.l.high + rh.l.low; | |
221 | rh.l.high = (c >> 32) + rh.l.high; | |
222 | ||
223 | /* | |
224 | * The 128-bit result of the multiplication is in rl.ll and rh.ll, | |
225 | * shift it right and throw away the high part of the result. | |
226 | */ | |
227 | if (shift == 0) | |
228 | return rl.ll; | |
229 | if (shift < 64) | |
230 | return (rl.ll >> shift) | (rh.ll << (64 - shift)); | |
231 | return rh.ll >> (shift & 63); | |
232 | } | |
233 | #endif /* mul_u64_u64_shr */ | |
234 | ||
be5e610c PZ |
235 | #endif |
236 | ||
381d585c HZ |
237 | #ifndef mul_u64_u32_div |
238 | static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) | |
239 | { | |
240 | union { | |
241 | u64 ll; | |
242 | struct { | |
243 | #ifdef __BIG_ENDIAN | |
244 | u32 high, low; | |
245 | #else | |
246 | u32 low, high; | |
247 | #endif | |
248 | } l; | |
249 | } u, rl, rh; | |
250 | ||
251 | u.ll = a; | |
9e3d6223 PZ |
252 | rl.ll = mul_u32_u32(u.l.low, mul); |
253 | rh.ll = mul_u32_u32(u.l.high, mul) + rl.l.high; | |
381d585c HZ |
254 | |
255 | /* Bits 32-63 of the result will be in rh.l.low. */ | |
256 | rl.l.high = do_div(rh.ll, divisor); | |
257 | ||
258 | /* Bits 0-31 of the result will be in rl.l.low. */ | |
259 | do_div(rl.ll, divisor); | |
260 | ||
261 | rl.l.high = rh.l.low; | |
262 | return rl.ll; | |
263 | } | |
264 | #endif /* mul_u64_u32_div */ | |
265 | ||
3dc167ba ON |
266 | u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div); |
267 | ||
68600f62 RG |
268 | #define DIV64_U64_ROUND_UP(ll, d) \ |
269 | ({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); }) | |
270 | ||
cb8be119 SH |
271 | /** |
272 | * DIV64_U64_ROUND_CLOSEST - unsigned 64bit divide with 64bit divisor rounded to nearest integer | |
273 | * @dividend: unsigned 64bit dividend | |
274 | * @divisor: unsigned 64bit divisor | |
275 | * | |
276 | * Divide unsigned 64bit dividend by unsigned 64bit divisor | |
277 | * and round to closest integer. | |
278 | * | |
279 | * Return: dividend / divisor rounded to nearest integer | |
280 | */ | |
281 | #define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \ | |
282 | ({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); }) | |
283 | ||
af60459a CZ |
284 | /* |
285 | * DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer | |
286 | * @dividend: signed 64bit dividend | |
287 | * @divisor: signed 32bit divisor | |
288 | * | |
289 | * Divide signed 64bit dividend by signed 32bit divisor | |
290 | * and round to closest integer. | |
291 | * | |
292 | * Return: dividend / divisor rounded to nearest integer | |
293 | */ | |
294 | #define DIV_S64_ROUND_CLOSEST(dividend, divisor)( \ | |
295 | { \ | |
296 | s64 __x = (dividend); \ | |
297 | s32 __d = (divisor); \ | |
298 | ((__x > 0) == (__d > 0)) ? \ | |
299 | div_s64((__x + (__d / 2)), __d) : \ | |
300 | div_s64((__x - (__d / 2)), __d); \ | |
301 | } \ | |
302 | ) | |
2418f4f2 | 303 | #endif /* _LINUX_MATH64_H */ |