1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2021 Maciej W. Rozycki |
4 | */ |
5 | |
6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7 | |
8 | #include <linux/init.h> |
9 | #include <linux/ktime.h> |
10 | #include <linux/module.h> |
11 | #include <linux/printk.h> |
12 | #include <linux/time64.h> |
13 | #include <linux/types.h> |
14 | |
15 | #include <asm/div64.h> |
16 | |
17 | #define TEST_DIV64_N_ITER 1024 |
18 | |
19 | static const u64 test_div64_dividends[] = { |
20 | 0x00000000ab275080, |
21 | 0x0000000fe73c1959, |
22 | 0x000000e54c0a74b1, |
23 | 0x00000d4398ff1ef9, |
24 | 0x0000a18c2ee1c097, |
25 | 0x00079fb80b072e4a, |
26 | 0x0072db27380dd689, |
27 | 0x0842f488162e2284, |
28 | 0xf66745411d8ab063, |
29 | }; |
30 | #define SIZE_DIV64_DIVIDENDS ARRAY_SIZE(test_div64_dividends) |
31 | |
32 | #define TEST_DIV64_DIVISOR_0 0x00000009 |
33 | #define TEST_DIV64_DIVISOR_1 0x0000007c |
34 | #define TEST_DIV64_DIVISOR_2 0x00000204 |
35 | #define TEST_DIV64_DIVISOR_3 0x0000cb5b |
36 | #define TEST_DIV64_DIVISOR_4 0x00010000 |
37 | #define TEST_DIV64_DIVISOR_5 0x0008a880 |
38 | #define TEST_DIV64_DIVISOR_6 0x003fd3ae |
39 | #define TEST_DIV64_DIVISOR_7 0x0b658fac |
40 | #define TEST_DIV64_DIVISOR_8 0xdc08b349 |
41 | |
42 | static const u32 test_div64_divisors[] = { |
43 | TEST_DIV64_DIVISOR_0, |
44 | TEST_DIV64_DIVISOR_1, |
45 | TEST_DIV64_DIVISOR_2, |
46 | TEST_DIV64_DIVISOR_3, |
47 | TEST_DIV64_DIVISOR_4, |
48 | TEST_DIV64_DIVISOR_5, |
49 | TEST_DIV64_DIVISOR_6, |
50 | TEST_DIV64_DIVISOR_7, |
51 | TEST_DIV64_DIVISOR_8, |
52 | }; |
53 | #define SIZE_DIV64_DIVISORS ARRAY_SIZE(test_div64_divisors) |
54 | |
55 | static const struct { |
56 | u64 quotient; |
57 | u32 remainder; |
58 | } test_div64_results[SIZE_DIV64_DIVISORS][SIZE_DIV64_DIVIDENDS] = { |
59 | { |
60 | { 0x0000000013045e47, 0x00000001 }, |
61 | { 0x000000000161596c, 0x00000030 }, |
62 | { 0x000000000054e9d4, 0x00000130 }, |
63 | { 0x000000000000d776, 0x0000278e }, |
64 | { 0x000000000000ab27, 0x00005080 }, |
65 | { 0x00000000000013c4, 0x0004ce80 }, |
66 | { 0x00000000000002ae, 0x001e143c }, |
67 | { 0x000000000000000f, 0x0033e56c }, |
68 | { 0x0000000000000000, 0xab275080 }, |
69 | }, { |
70 | { 0x00000001c45c02d1, 0x00000000 }, |
71 | { 0x0000000020d5213c, 0x00000049 }, |
72 | { 0x0000000007e3d65f, 0x000001dd }, |
73 | { 0x0000000000140531, 0x000065ee }, |
74 | { 0x00000000000fe73c, 0x00001959 }, |
75 | { 0x000000000001d637, 0x0004e5d9 }, |
76 | { 0x0000000000003fc9, 0x000713bb }, |
77 | { 0x0000000000000165, 0x029abe7d }, |
78 | { 0x0000000000000012, 0x6e9f7e37 }, |
79 | }, { |
80 | { 0x000000197a3a0cf7, 0x00000002 }, |
81 | { 0x00000001d9632e5c, 0x00000021 }, |
82 | { 0x0000000071c28039, 0x000001cd }, |
83 | { 0x000000000120a844, 0x0000b885 }, |
84 | { 0x0000000000e54c0a, 0x000074b1 }, |
85 | { 0x00000000001a7bb3, 0x00072331 }, |
86 | { 0x00000000000397ad, 0x0002c61b }, |
87 | { 0x000000000000141e, 0x06ea2e89 }, |
88 | { 0x000000000000010a, 0xab002ad7 }, |
89 | }, { |
90 | { 0x0000017949e37538, 0x00000001 }, |
91 | { 0x0000001b62441f37, 0x00000055 }, |
92 | { 0x0000000694a3391d, 0x00000085 }, |
93 | { 0x0000000010b2a5d2, 0x0000a753 }, |
94 | { 0x000000000d4398ff, 0x00001ef9 }, |
95 | { 0x0000000001882ec6, 0x0005cbf9 }, |
96 | { 0x000000000035333b, 0x0017abdf }, |
97 | { 0x00000000000129f1, 0x0ab4520d }, |
98 | { 0x0000000000000f6e, 0x8ac0ce9b }, |
99 | }, { |
100 | { 0x000011f321a74e49, 0x00000006 }, |
101 | { 0x0000014d8481d211, 0x0000005b }, |
102 | { 0x0000005025cbd92d, 0x000001e3 }, |
103 | { 0x00000000cb5e71e3, 0x000043e6 }, |
104 | { 0x00000000a18c2ee1, 0x0000c097 }, |
105 | { 0x0000000012a88828, 0x00036c97 }, |
106 | { 0x000000000287f16f, 0x002c2a25 }, |
107 | { 0x00000000000e2cc7, 0x02d581e3 }, |
108 | { 0x000000000000bbf4, 0x1ba08c03 }, |
109 | }, { |
110 | { 0x0000d8db8f72935d, 0x00000005 }, |
111 | { 0x00000fbd5aed7a2e, 0x00000002 }, |
112 | { 0x000003c84b6ea64a, 0x00000122 }, |
113 | { 0x0000000998fa8829, 0x000044b7 }, |
114 | { 0x000000079fb80b07, 0x00002e4a }, |
115 | { 0x00000000e16b20fa, 0x0002a14a }, |
116 | { 0x000000001e940d22, 0x00353b2e }, |
117 | { 0x0000000000ab40ac, 0x06fba6ba }, |
118 | { 0x000000000008debd, 0x72d98365 }, |
119 | }, { |
120 | { 0x000cc3045b8fc281, 0x00000000 }, |
121 | { 0x0000ed1f48b5c9fc, 0x00000079 }, |
122 | { 0x000038fb9c63406a, 0x000000e1 }, |
123 | { 0x000000909705b825, 0x00000a62 }, |
124 | { 0x00000072db27380d, 0x0000d689 }, |
125 | { 0x0000000d43fce827, 0x00082b09 }, |
126 | { 0x00000001ccaba11a, 0x0037e8dd }, |
127 | { 0x000000000a13f729, 0x0566dffd }, |
128 | { 0x000000000085a14b, 0x23d36726 }, |
129 | }, { |
130 | { 0x00eafeb9c993592b, 0x00000001 }, |
131 | { 0x00110e5befa9a991, 0x00000048 }, |
132 | { 0x00041947b4a1d36a, 0x000000dc }, |
133 | { 0x00000a6679327311, 0x0000c079 }, |
134 | { 0x00000842f488162e, 0x00002284 }, |
135 | { 0x000000f4459740fc, 0x00084484 }, |
136 | { 0x0000002122c47bf9, 0x002ca446 }, |
137 | { 0x00000000b9936290, 0x004979c4 }, |
138 | { 0x00000000099ca89d, 0x9db446bf }, |
139 | }, { |
140 | { 0x1b60cece589da1d2, 0x00000001 }, |
141 | { 0x01fcb42be1453f5b, 0x0000004f }, |
142 | { 0x007a3f2457df0749, 0x0000013f }, |
143 | { 0x0001363130e3ec7b, 0x000017aa }, |
144 | { 0x0000f66745411d8a, 0x0000b063 }, |
145 | { 0x00001c757dfab350, 0x00048863 }, |
146 | { 0x000003dc4979c652, 0x00224ea7 }, |
147 | { 0x000000159edc3144, 0x06409ab3 }, |
148 | { 0x000000011eadfee3, 0xa99c48a8 }, |
149 | }, |
150 | }; |
151 | |
152 | static inline bool test_div64_verify(u64 quotient, u32 remainder, int i, int j) |
153 | { |
154 | return (quotient == test_div64_results[i][j].quotient && |
155 | remainder == test_div64_results[i][j].remainder); |
156 | } |
157 | |
158 | /* |
159 | * This needs to be a macro, because we don't want to rely on the compiler |
160 | * to do constant propagation, and `do_div' may take a different path for |
161 | * constants, so we do want to verify that as well. |
162 | */ |
163 | #define test_div64_one(dividend, divisor, i, j) ({ \ |
164 | bool result = true; \ |
165 | u64 quotient; \ |
166 | u32 remainder; \ |
167 | \ |
168 | quotient = dividend; \ |
169 | remainder = do_div(quotient, divisor); \ |
170 | if (!test_div64_verify(quotient, remainder, i, j)) { \ |
171 | pr_err("ERROR: %016llx / %08x => %016llx,%08x\n", \ |
172 | dividend, divisor, quotient, remainder); \ |
173 | pr_err("ERROR: expected value => %016llx,%08x\n",\ |
174 | test_div64_results[i][j].quotient, \ |
175 | test_div64_results[i][j].remainder); \ |
176 | result = false; \ |
177 | } \ |
178 | result; \ |
179 | }) |
180 | |
181 | /* |
182 | * Run calculation for the same divisor value expressed as a constant |
183 | * and as a variable, so as to verify the implementation for both cases |
184 | * should they be handled by different code execution paths. |
185 | */ |
186 | static bool __init test_div64(void) |
187 | { |
188 | u64 dividend; |
189 | int i, j; |
190 | |
191 | for (i = 0; i < SIZE_DIV64_DIVIDENDS; i++) { |
192 | dividend = test_div64_dividends[i]; |
193 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_0, i, 0)) |
194 | return false; |
195 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_1, i, 1)) |
196 | return false; |
197 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_2, i, 2)) |
198 | return false; |
199 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_3, i, 3)) |
200 | return false; |
201 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_4, i, 4)) |
202 | return false; |
203 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_5, i, 5)) |
204 | return false; |
205 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_6, i, 6)) |
206 | return false; |
207 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_7, i, 7)) |
208 | return false; |
209 | if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_8, i, 8)) |
210 | return false; |
211 | for (j = 0; j < SIZE_DIV64_DIVISORS; j++) { |
212 | if (!test_div64_one(dividend, test_div64_divisors[j], |
213 | i, j)) |
214 | return false; |
215 | } |
216 | } |
217 | return true; |
218 | } |
219 | |
220 | static int __init test_div64_init(void) |
221 | { |
222 | struct timespec64 ts, ts0, ts1; |
223 | int i; |
224 | |
225 | pr_info("Starting 64bit/32bit division and modulo test\n" ); |
226 | ktime_get_ts64(ts: &ts0); |
227 | |
228 | for (i = 0; i < TEST_DIV64_N_ITER; i++) |
229 | if (!test_div64()) |
230 | break; |
231 | |
232 | ktime_get_ts64(ts: &ts1); |
233 | ts = timespec64_sub(lhs: ts1, rhs: ts0); |
234 | pr_info("Completed 64bit/32bit division and modulo test, " |
235 | "%llu.%09lus elapsed\n" , ts.tv_sec, ts.tv_nsec); |
236 | |
237 | return 0; |
238 | } |
239 | |
240 | static void __exit test_div64_exit(void) |
241 | { |
242 | } |
243 | |
244 | module_init(test_div64_init); |
245 | module_exit(test_div64_exit); |
246 | |
247 | MODULE_AUTHOR("Maciej W. Rozycki <macro@orcam.me.uk>" ); |
248 | MODULE_LICENSE("GPL" ); |
249 | MODULE_DESCRIPTION("64bit/32bit division and modulo test module" ); |
250 | |