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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>#include <linux/ktime.h>#include <linux/module.h>#include <linux/printk.h>#include <linux/time64.h>#include <linux/types.h>
#include <asm/div64.h>
#define TEST_DIV64_N_ITER 1024
static const u64 test_div64_dividends[] = { 0x00000000ab275080, 0x0000000fe73c1959, 0x000000e54c0a74b1, 0x00000d4398ff1ef9, 0x0000a18c2ee1c097, 0x00079fb80b072e4a, 0x0072db27380dd689, 0x0842f488162e2284, 0xf66745411d8ab063, 0xfffffffffffffffb, 0xfffffffffffffffc, 0xffffffffffffffff,};#define SIZE_DIV64_DIVIDENDS ARRAY_SIZE(test_div64_dividends)
#define TEST_DIV64_DIVISOR_0 0x00000009#define TEST_DIV64_DIVISOR_1 0x0000007c#define TEST_DIV64_DIVISOR_2 0x00000204#define TEST_DIV64_DIVISOR_3 0x0000cb5b#define TEST_DIV64_DIVISOR_4 0x00010000#define TEST_DIV64_DIVISOR_5 0x0008a880#define TEST_DIV64_DIVISOR_6 0x003fd3ae#define TEST_DIV64_DIVISOR_7 0x0b658fac#define TEST_DIV64_DIVISOR_8 0x80000001#define TEST_DIV64_DIVISOR_9 0xdc08b349#define TEST_DIV64_DIVISOR_A 0xfffffffe#define TEST_DIV64_DIVISOR_B 0xffffffff
static const u32 test_div64_divisors[] = { TEST_DIV64_DIVISOR_0, TEST_DIV64_DIVISOR_1, TEST_DIV64_DIVISOR_2, TEST_DIV64_DIVISOR_3, TEST_DIV64_DIVISOR_4, TEST_DIV64_DIVISOR_5, TEST_DIV64_DIVISOR_6, TEST_DIV64_DIVISOR_7, TEST_DIV64_DIVISOR_8, TEST_DIV64_DIVISOR_9, TEST_DIV64_DIVISOR_A, TEST_DIV64_DIVISOR_B,};#define SIZE_DIV64_DIVISORS ARRAY_SIZE(test_div64_divisors)
static const struct { u64 quotient; u32 remainder;} test_div64_results[SIZE_DIV64_DIVIDENDS][SIZE_DIV64_DIVISORS] = { { { 0x0000000013045e47, 0x00000001 }, { 0x000000000161596c, 0x00000030 }, { 0x000000000054e9d4, 0x00000130 }, { 0x000000000000d776, 0x0000278e }, { 0x000000000000ab27, 0x00005080 }, { 0x00000000000013c4, 0x0004ce80 }, { 0x00000000000002ae, 0x001e143c }, { 0x000000000000000f, 0x0033e56c }, { 0x0000000000000001, 0x2b27507f }, { 0x0000000000000000, 0xab275080 }, { 0x0000000000000000, 0xab275080 }, { 0x0000000000000000, 0xab275080 }, }, { { 0x00000001c45c02d1, 0x00000000 }, { 0x0000000020d5213c, 0x00000049 }, { 0x0000000007e3d65f, 0x000001dd }, { 0x0000000000140531, 0x000065ee }, { 0x00000000000fe73c, 0x00001959 }, { 0x000000000001d637, 0x0004e5d9 }, { 0x0000000000003fc9, 0x000713bb }, { 0x0000000000000165, 0x029abe7d }, { 0x000000000000001f, 0x673c193a }, { 0x0000000000000012, 0x6e9f7e37 }, { 0x000000000000000f, 0xe73c1977 }, { 0x000000000000000f, 0xe73c1968 }, }, { { 0x000000197a3a0cf7, 0x00000002 }, { 0x00000001d9632e5c, 0x00000021 }, { 0x0000000071c28039, 0x000001cd }, { 0x000000000120a844, 0x0000b885 }, { 0x0000000000e54c0a, 0x000074b1 }, { 0x00000000001a7bb3, 0x00072331 }, { 0x00000000000397ad, 0x0002c61b }, { 0x000000000000141e, 0x06ea2e89 }, { 0x00000000000001ca, 0x4c0a72e7 }, { 0x000000000000010a, 0xab002ad7 }, { 0x00000000000000e5, 0x4c0a767b }, { 0x00000000000000e5, 0x4c0a7596 }, }, { { 0x0000017949e37538, 0x00000001 }, { 0x0000001b62441f37, 0x00000055 }, { 0x0000000694a3391d, 0x00000085 }, { 0x0000000010b2a5d2, 0x0000a753 }, { 0x000000000d4398ff, 0x00001ef9 }, { 0x0000000001882ec6, 0x0005cbf9 }, { 0x000000000035333b, 0x0017abdf }, { 0x00000000000129f1, 0x0ab4520d }, { 0x0000000000001a87, 0x18ff0472 }, { 0x0000000000000f6e, 0x8ac0ce9b }, { 0x0000000000000d43, 0x98ff397f }, { 0x0000000000000d43, 0x98ff2c3c }, }, { { 0x000011f321a74e49, 0x00000006 }, { 0x0000014d8481d211, 0x0000005b }, { 0x0000005025cbd92d, 0x000001e3 }, { 0x00000000cb5e71e3, 0x000043e6 }, { 0x00000000a18c2ee1, 0x0000c097 }, { 0x0000000012a88828, 0x00036c97 }, { 0x000000000287f16f, 0x002c2a25 }, { 0x00000000000e2cc7, 0x02d581e3 }, { 0x0000000000014318, 0x2ee07d7f }, { 0x000000000000bbf4, 0x1ba08c03 }, { 0x000000000000a18c, 0x2ee303af }, { 0x000000000000a18c, 0x2ee26223 }, }, { { 0x0000d8db8f72935d, 0x00000005 }, { 0x00000fbd5aed7a2e, 0x00000002 }, { 0x000003c84b6ea64a, 0x00000122 }, { 0x0000000998fa8829, 0x000044b7 }, { 0x000000079fb80b07, 0x00002e4a }, { 0x00000000e16b20fa, 0x0002a14a }, { 0x000000001e940d22, 0x00353b2e }, { 0x0000000000ab40ac, 0x06fba6ba }, { 0x00000000000f3f70, 0x0af7eeda }, { 0x000000000008debd, 0x72d98365 }, { 0x0000000000079fb8, 0x0b166dba }, { 0x0000000000079fb8, 0x0b0ece02 }, }, { { 0x000cc3045b8fc281, 0x00000000 }, { 0x0000ed1f48b5c9fc, 0x00000079 }, { 0x000038fb9c63406a, 0x000000e1 }, { 0x000000909705b825, 0x00000a62 }, { 0x00000072db27380d, 0x0000d689 }, { 0x0000000d43fce827, 0x00082b09 }, { 0x00000001ccaba11a, 0x0037e8dd }, { 0x000000000a13f729, 0x0566dffd }, { 0x0000000000e5b64e, 0x3728203b }, { 0x000000000085a14b, 0x23d36726 }, { 0x000000000072db27, 0x38f38cd7 }, { 0x000000000072db27, 0x3880b1b0 }, }, { { 0x00eafeb9c993592b, 0x00000001 }, { 0x00110e5befa9a991, 0x00000048 }, { 0x00041947b4a1d36a, 0x000000dc }, { 0x00000a6679327311, 0x0000c079 }, { 0x00000842f488162e, 0x00002284 }, { 0x000000f4459740fc, 0x00084484 }, { 0x0000002122c47bf9, 0x002ca446 }, { 0x00000000b9936290, 0x004979c4 }, { 0x000000001085e910, 0x05a83974 }, { 0x00000000099ca89d, 0x9db446bf }, { 0x000000000842f488, 0x26b40b94 }, { 0x000000000842f488, 0x1e71170c }, }, { { 0x1b60cece589da1d2, 0x00000001 }, { 0x01fcb42be1453f5b, 0x0000004f }, { 0x007a3f2457df0749, 0x0000013f }, { 0x0001363130e3ec7b, 0x000017aa }, { 0x0000f66745411d8a, 0x0000b063 }, { 0x00001c757dfab350, 0x00048863 }, { 0x000003dc4979c652, 0x00224ea7 }, { 0x000000159edc3144, 0x06409ab3 }, { 0x00000001ecce8a7e, 0x30bc25e5 }, { 0x000000011eadfee3, 0xa99c48a8 }, { 0x00000000f6674543, 0x0a593ae9 }, { 0x00000000f6674542, 0x13f1f5a5 }, }, { { 0x1c71c71c71c71c71, 0x00000002 }, { 0x0210842108421084, 0x0000000b }, { 0x007f01fc07f01fc0, 0x000000fb }, { 0x00014245eabf1f9a, 0x0000a63d }, { 0x0000ffffffffffff, 0x0000fffb }, { 0x00001d913cecc509, 0x0007937b }, { 0x00000402c70c678f, 0x0005bfc9 }, { 0x00000016766cb70b, 0x045edf97 }, { 0x00000001fffffffb, 0x80000000 }, { 0x0000000129d84b3a, 0xa2e8fe71 }, { 0x0000000100000001, 0xfffffffd }, { 0x0000000100000000, 0xfffffffb }, }, { { 0x1c71c71c71c71c71, 0x00000003 }, { 0x0210842108421084, 0x0000000c }, { 0x007f01fc07f01fc0, 0x000000fc }, { 0x00014245eabf1f9a, 0x0000a63e }, { 0x0000ffffffffffff, 0x0000fffc }, { 0x00001d913cecc509, 0x0007937c }, { 0x00000402c70c678f, 0x0005bfca }, { 0x00000016766cb70b, 0x045edf98 }, { 0x00000001fffffffc, 0x00000000 }, { 0x0000000129d84b3a, 0xa2e8fe72 }, { 0x0000000100000002, 0x00000000 }, { 0x0000000100000000, 0xfffffffc }, }, { { 0x1c71c71c71c71c71, 0x00000006 }, { 0x0210842108421084, 0x0000000f }, { 0x007f01fc07f01fc0, 0x000000ff }, { 0x00014245eabf1f9a, 0x0000a641 }, { 0x0000ffffffffffff, 0x0000ffff }, { 0x00001d913cecc509, 0x0007937f }, { 0x00000402c70c678f, 0x0005bfcd }, { 0x00000016766cb70b, 0x045edf9b }, { 0x00000001fffffffc, 0x00000003 }, { 0x0000000129d84b3a, 0xa2e8fe75 }, { 0x0000000100000002, 0x00000003 }, { 0x0000000100000001, 0x00000000 }, },};
static inline bool test_div64_verify(u64 quotient, u32 remainder, int i, int j){ return (quotient == test_div64_results[i][j].quotient && remainder == test_div64_results[i][j].remainder);}
/* * This needs to be a macro, because we don't want to rely on the compiler * to do constant propagation, and `do_div' may take a different path for * constants, so we do want to verify that as well. */#define test_div64_one(dividend, divisor, i, j) ({ \ bool result = true; \ u64 quotient; \ u32 remainder; \ \ quotient = dividend; \ remainder = do_div(quotient, divisor); \ if (!test_div64_verify(quotient, remainder, i, j)) { \ pr_err("ERROR: %016llx / %08x => %016llx,%08x\n", \ dividend, divisor, quotient, remainder); \ pr_err("ERROR: expected value => %016llx,%08x\n",\ test_div64_results[i][j].quotient, \ test_div64_results[i][j].remainder); \ result = false; \ } \ result; \})
/* * Run calculation for the same divisor value expressed as a constant * and as a variable, so as to verify the implementation for both cases * should they be handled by different code execution paths. */static bool __init test_div64(void){ u64 dividend; int i, j;
for (i = 0; i < SIZE_DIV64_DIVIDENDS; i++) { dividend = test_div64_dividends[i]; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_0, i, 0)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_1, i, 1)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_2, i, 2)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_3, i, 3)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_4, i, 4)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_5, i, 5)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_6, i, 6)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_7, i, 7)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_8, i, 8)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_9, i, 9)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_A, i, 10)) return false; if (!test_div64_one(dividend, TEST_DIV64_DIVISOR_B, i, 11)) return false; for (j = 0; j < SIZE_DIV64_DIVISORS; j++) { if (!test_div64_one(dividend, test_div64_divisors[j], i, j)) return false; } } return true;}
static int __init test_div64_init(void){ struct timespec64 ts, ts0, ts1; int i;
pr_info("Starting 64bit/32bit division and modulo test\n"); ktime_get_ts64(&ts0);
for (i = 0; i < TEST_DIV64_N_ITER; i++) if (!test_div64()) break;
ktime_get_ts64(&ts1); ts = timespec64_sub(ts1, ts0); pr_info("Completed 64bit/32bit division and modulo test, " "%llu.%09lus elapsed\n", ts.tv_sec, ts.tv_nsec);
return 0;}
static void __exit test_div64_exit(void){}
module_init(test_div64_init);module_exit(test_div64_exit);
MODULE_AUTHOR("Maciej W. Rozycki <macro@orcam.me.uk>");MODULE_LICENSE("GPL");MODULE_DESCRIPTION("64bit/32bit division and modulo test module");