diff options
Diffstat (limited to 'lib/math/test_mul_u64_u64_div_u64.c')
| -rw-r--r-- | lib/math/test_mul_u64_u64_div_u64.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/lib/math/test_mul_u64_u64_div_u64.c b/lib/math/test_mul_u64_u64_div_u64.c new file mode 100644 index 000000000000..338d014f0c73 --- /dev/null +++ b/lib/math/test_mul_u64_u64_div_u64.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2024 BayLibre SAS + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/math64.h> + +typedef struct { u64 a; u64 b; u64 d; u64 result; uint round_up;} test_params; + +static test_params test_values[] = { +/* this contains many edge values followed by a couple random values */ +{ 0xb, 0x7, 0x3, 0x19, 1 }, +{ 0xffff0000, 0xffff0000, 0xf, 0x1110eeef00000000, 0 }, +{ 0xffffffff, 0xffffffff, 0x1, 0xfffffffe00000001, 0 }, +{ 0xffffffff, 0xffffffff, 0x2, 0x7fffffff00000000, 1 }, +{ 0x1ffffffff, 0xffffffff, 0x2, 0xfffffffe80000000, 1 }, +{ 0x1ffffffff, 0xffffffff, 0x3, 0xaaaaaaa9aaaaaaab, 0 }, +{ 0x1ffffffff, 0x1ffffffff, 0x4, 0xffffffff00000000, 1 }, +{ 0xffff000000000000, 0xffff000000000000, 0xffff000000000001, 0xfffeffffffffffff, 1 }, +{ 0x3333333333333333, 0x3333333333333333, 0x5555555555555555, 0x1eb851eb851eb851, 1 }, +{ 0x7fffffffffffffff, 0x2, 0x3, 0x5555555555555554, 1 }, +{ 0xffffffffffffffff, 0x2, 0x8000000000000000, 0x3, 1 }, +{ 0xffffffffffffffff, 0x2, 0xc000000000000000, 0x2, 1 }, +{ 0xffffffffffffffff, 0x4000000000000004, 0x8000000000000000, 0x8000000000000007, 1 }, +{ 0xffffffffffffffff, 0x4000000000000001, 0x8000000000000000, 0x8000000000000001, 1 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000001, 0 }, +{ 0xfffffffffffffffe, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000000, 1 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffe, 0x8000000000000001, 1 }, +{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffd, 0x8000000000000002, 1 }, +{ 0x7fffffffffffffff, 0xffffffffffffffff, 0xc000000000000000, 0xaaaaaaaaaaaaaaa8, 1 }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0xa000000000000000, 0xccccccccccccccca, 1 }, +{ 0xffffffffffffffff, 0x7fffffffffffffff, 0x9000000000000000, 0xe38e38e38e38e38b, 1 }, +{ 0x7fffffffffffffff, 0x7fffffffffffffff, 0x5000000000000000, 0xccccccccccccccc9, 1 }, +{ 0xffffffffffffffff, 0xfffffffffffffffe, 0xffffffffffffffff, 0xfffffffffffffffe, 0 }, +{ 0xe6102d256d7ea3ae, 0x70a77d0be4c31201, 0xd63ec35ab3220357, 0x78f8bf8cc86c6e18, 1 }, +{ 0xf53bae05cb86c6e1, 0x3847b32d2f8d32e0, 0xcfd4f55a647f403c, 0x42687f79d8998d35, 1 }, +{ 0x9951c5498f941092, 0x1f8c8bfdf287a251, 0xa3c8dc5f81ea3fe2, 0x1d887cb25900091f, 1 }, +{ 0x374fee9daa1bb2bb, 0x0d0bfbff7b8ae3ef, 0xc169337bd42d5179, 0x03bb2dbaffcbb961, 1 }, +{ 0xeac0d03ac10eeaf0, 0x89be05dfa162ed9b, 0x92bb1679a41f0e4b, 0xdc5f5cc9e270d216, 1 }, +}; + +/* + * The above table can be verified with the following shell script: + +#!/bin/sh +sed -ne 's/^{ \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\) },$/\1 \2 \3 \4 \5/p' \ + lib/math/test_mul_u64_u64_div_u64.c | +while read a b d r e; do + expected=$( printf "obase=16; ibase=16; %X * %X / %X\n" $a $b $d | bc ) + given=$( printf "%X\n" $r ) + if [ "$expected" = "$given" ]; then + echo "$a * $b / $d = $r OK" + else + echo "$a * $b / $d = $r is wrong" >&2 + echo "should be equivalent to 0x$expected" >&2 + exit 1 + fi + expected=$( printf "obase=16; ibase=16; (%X * %X + %X) / %X\n" $a $b $((d-1)) $d | bc ) + given=$( printf "%X\n" $((r + e)) ) + if [ "$expected" = "$given" ]; then + echo "$a * $b +/ $d = $(printf '%#x' $((r + e))) OK" + else + echo "$a * $b +/ $d = $(printf '%#x' $((r + e))) is wrong" >&2 + echo "should be equivalent to 0x$expected" >&2 + exit 1 + fi +done + + */ + +static u64 test_mul_u64_add_u64_div_u64(u64 a, u64 b, u64 c, u64 d); +#if __LONG_WIDTH__ >= 64 +#define TEST_32BIT_DIV +static u64 test_mul_u64_add_u64_div_u64_32bit(u64 a, u64 b, u64 c, u64 d); +#endif + +static int __init test_run(unsigned int fn_no, const char *fn_name) +{ + u64 start_time; + int errors = 0; + int tests = 0; + int i; + + start_time = ktime_get_ns(); + + for (i = 0; i < ARRAY_SIZE(test_values); i++) { + u64 a = test_values[i].a; + u64 b = test_values[i].b; + u64 d = test_values[i].d; + u64 expected_result = test_values[i].result; + u64 result, result_up; + + switch (fn_no) { + default: + result = mul_u64_u64_div_u64(a, b, d); + result_up = mul_u64_u64_div_u64_roundup(a, b, d); + break; + case 1: + result = test_mul_u64_add_u64_div_u64(a, b, 0, d); + result_up = test_mul_u64_add_u64_div_u64(a, b, d - 1, d); + break; +#ifdef TEST_32BIT_DIV + case 2: + result = test_mul_u64_add_u64_div_u64_32bit(a, b, 0, d); + result_up = test_mul_u64_add_u64_div_u64_32bit(a, b, d - 1, d); + break; +#endif + } + + tests += 2; + + if (result != expected_result) { + pr_err("ERROR: 0x%016llx * 0x%016llx / 0x%016llx\n", a, b, d); + pr_err("ERROR: expected result: %016llx\n", expected_result); + pr_err("ERROR: obtained result: %016llx\n", result); + errors++; + } + expected_result += test_values[i].round_up; + if (result_up != expected_result) { + pr_err("ERROR: 0x%016llx * 0x%016llx +/ 0x%016llx\n", a, b, d); + pr_err("ERROR: expected result: %016llx\n", expected_result); + pr_err("ERROR: obtained result: %016llx\n", result_up); + errors++; + } + } + + pr_info("Completed %s() test, %d tests, %d errors, %llu ns\n", + fn_name, tests, errors, ktime_get_ns() - start_time); + return errors; +} + +static int __init test_init(void) +{ + pr_info("Starting mul_u64_u64_div_u64() test\n"); + if (test_run(0, "mul_u64_u64_div_u64")) + return -EINVAL; + if (test_run(1, "test_mul_u64_u64_div_u64")) + return -EINVAL; +#ifdef TEST_32BIT_DIV + if (test_run(2, "test_mul_u64_u64_div_u64_32bit")) + return -EINVAL; +#endif + return 0; +} + +static void __exit test_exit(void) +{ +} + +/* Compile the generic mul_u64_add_u64_div_u64() code */ +#undef __div64_32 +#define __div64_32 __div64_32 +#define div_s64_rem div_s64_rem +#define div64_u64_rem div64_u64_rem +#define div64_u64 div64_u64 +#define div64_s64 div64_s64 +#define iter_div_u64_rem iter_div_u64_rem + +#undef mul_u64_add_u64_div_u64 +#define mul_u64_add_u64_div_u64 test_mul_u64_add_u64_div_u64 +#define test_mul_u64_add_u64_div_u64 test_mul_u64_add_u64_div_u64 + +#include "div64.c" + +#ifdef TEST_32BIT_DIV +/* Recompile the generic code for 32bit long */ +#undef test_mul_u64_add_u64_div_u64 +#define test_mul_u64_add_u64_div_u64 test_mul_u64_add_u64_div_u64_32bit +#undef BITS_PER_ITER +#define BITS_PER_ITER 16 + +#define mul_u64_u64_add_u64 mul_u64_u64_add_u64_32bit +#undef mul_u64_long_add_u64 +#undef add_u64_long +#undef mul_add + +#include "div64.c" +#endif + +module_init(test_init); +module_exit(test_exit); + +MODULE_AUTHOR("Nicolas Pitre"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("mul_u64_u64_div_u64() test module"); |