100 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2024 BayLibre SAS4 */5 6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt7 8#include <linux/init.h>9#include <linux/module.h>10#include <linux/printk.h>11#include <linux/math64.h>12 13typedef struct { u64 a; u64 b; u64 c; u64 result; } test_params;14 15static test_params test_values[] = {16/* this contains many edge values followed by a couple random values */17{ 0xb, 0x7, 0x3, 0x19 },18{ 0xffff0000, 0xffff0000, 0xf, 0x1110eeef00000000 },19{ 0xffffffff, 0xffffffff, 0x1, 0xfffffffe00000001 },20{ 0xffffffff, 0xffffffff, 0x2, 0x7fffffff00000000 },21{ 0x1ffffffff, 0xffffffff, 0x2, 0xfffffffe80000000 },22{ 0x1ffffffff, 0xffffffff, 0x3, 0xaaaaaaa9aaaaaaab },23{ 0x1ffffffff, 0x1ffffffff, 0x4, 0xffffffff00000000 },24{ 0xffff000000000000, 0xffff000000000000, 0xffff000000000001, 0xfffeffffffffffff },25{ 0x3333333333333333, 0x3333333333333333, 0x5555555555555555, 0x1eb851eb851eb851 },26{ 0x7fffffffffffffff, 0x2, 0x3, 0x5555555555555554 },27{ 0xffffffffffffffff, 0x2, 0x8000000000000000, 0x3 },28{ 0xffffffffffffffff, 0x2, 0xc000000000000000, 0x2 },29{ 0xffffffffffffffff, 0x4000000000000004, 0x8000000000000000, 0x8000000000000007 },30{ 0xffffffffffffffff, 0x4000000000000001, 0x8000000000000000, 0x8000000000000001 },31{ 0xffffffffffffffff, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000001 },32{ 0xfffffffffffffffe, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000000 },33{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffe, 0x8000000000000001 },34{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffd, 0x8000000000000002 },35{ 0x7fffffffffffffff, 0xffffffffffffffff, 0xc000000000000000, 0xaaaaaaaaaaaaaaa8 },36{ 0xffffffffffffffff, 0x7fffffffffffffff, 0xa000000000000000, 0xccccccccccccccca },37{ 0xffffffffffffffff, 0x7fffffffffffffff, 0x9000000000000000, 0xe38e38e38e38e38b },38{ 0x7fffffffffffffff, 0x7fffffffffffffff, 0x5000000000000000, 0xccccccccccccccc9 },39{ 0xffffffffffffffff, 0xfffffffffffffffe, 0xffffffffffffffff, 0xfffffffffffffffe },40{ 0xe6102d256d7ea3ae, 0x70a77d0be4c31201, 0xd63ec35ab3220357, 0x78f8bf8cc86c6e18 },41{ 0xf53bae05cb86c6e1, 0x3847b32d2f8d32e0, 0xcfd4f55a647f403c, 0x42687f79d8998d35 },42{ 0x9951c5498f941092, 0x1f8c8bfdf287a251, 0xa3c8dc5f81ea3fe2, 0x1d887cb25900091f },43{ 0x374fee9daa1bb2bb, 0x0d0bfbff7b8ae3ef, 0xc169337bd42d5179, 0x03bb2dbaffcbb961 },44{ 0xeac0d03ac10eeaf0, 0x89be05dfa162ed9b, 0x92bb1679a41f0e4b, 0xdc5f5cc9e270d216 },45};46 47/*48 * The above table can be verified with the following shell script:49 *50 * #!/bin/sh51 * sed -ne 's/^{ \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\) },$/\1 \2 \3 \4/p' \52 * lib/math/test_mul_u64_u64_div_u64.c |53 * while read a b c r; do54 * expected=$( printf "obase=16; ibase=16; %X * %X / %X\n" $a $b $c | bc )55 * given=$( printf "%X\n" $r )56 * if [ "$expected" = "$given" ]; then57 * echo "$a * $b / $c = $r OK"58 * else59 * echo "$a * $b / $c = $r is wrong" >&260 * echo "should be equivalent to 0x$expected" >&261 * exit 162 * fi63 * done64 */65 66static int __init test_init(void)67{68 int i;69 70 pr_info("Starting mul_u64_u64_div_u64() test\n");71 72 for (i = 0; i < ARRAY_SIZE(test_values); i++) {73 u64 a = test_values[i].a;74 u64 b = test_values[i].b;75 u64 c = test_values[i].c;76 u64 expected_result = test_values[i].result;77 u64 result = mul_u64_u64_div_u64(a, b, c);78 79 if (result != expected_result) {80 pr_err("ERROR: 0x%016llx * 0x%016llx / 0x%016llx\n", a, b, c);81 pr_err("ERROR: expected result: %016llx\n", expected_result);82 pr_err("ERROR: obtained result: %016llx\n", result);83 }84 }85 86 pr_info("Completed mul_u64_u64_div_u64() test\n");87 return 0;88}89 90static void __exit test_exit(void)91{92}93 94module_init(test_init);95module_exit(test_exit);96 97MODULE_AUTHOR("Nicolas Pitre");98MODULE_LICENSE("GPL");99MODULE_DESCRIPTION("mul_u64_u64_div_u64() test module");100