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lib: add tests for mul_u64_u64_div_u64_roundup()

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Replicate the existing mul_u64_u64_div_u64() test cases with round up. 
Update the shell script that verifies the table, remove the comment
markers so that it can be directly pasted into a shell.

Rename the divisor from 'c' to 'd' to match mul_u64_add_u64_div_u64().

It any tests fail then fail the module load with -EINVAL.

Link: https://lkml.kernel.org/r/20251105201035.64043-6-david.laight.linux@gmail.com
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Laight
2025-11-05 20:10:31 +00:00
committed by Andrew Morton
parent 6480241f31
commit 500db21917
1 changed files with 73 additions and 49 deletions
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122
lib/math/test_mul_u64_u64_div_u64.c
View File

@@ -10,61 +10,73 @@
#include <linux/printk.h>
#include <linux/math64.h>
typedef struct { u64 a; u64 b; u64 c; u64 result; } test_params;
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 },
{ 0xffff0000, 0xffff0000, 0xf, 0x1110eeef00000000 },
{ 0xffffffff, 0xffffffff, 0x1, 0xfffffffe00000001 },
{ 0xffffffff, 0xffffffff, 0x2, 0x7fffffff00000000 },
{ 0x1ffffffff, 0xffffffff, 0x2, 0xfffffffe80000000 },
{ 0x1ffffffff, 0xffffffff, 0x3, 0xaaaaaaa9aaaaaaab },
{ 0x1ffffffff, 0x1ffffffff, 0x4, 0xffffffff00000000 },
{ 0xffff000000000000, 0xffff000000000000, 0xffff000000000001, 0xfffeffffffffffff },
{ 0x3333333333333333, 0x3333333333333333, 0x5555555555555555, 0x1eb851eb851eb851 },
{ 0x7fffffffffffffff, 0x2, 0x3, 0x5555555555555554 },
{ 0xffffffffffffffff, 0x2, 0x8000000000000000, 0x3 },
{ 0xffffffffffffffff, 0x2, 0xc000000000000000, 0x2 },
{ 0xffffffffffffffff, 0x4000000000000004, 0x8000000000000000, 0x8000000000000007 },
{ 0xffffffffffffffff, 0x4000000000000001, 0x8000000000000000, 0x8000000000000001 },
{ 0xffffffffffffffff, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000001 },
{ 0xfffffffffffffffe, 0x8000000000000001, 0xffffffffffffffff, 0x8000000000000000 },
{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffe, 0x8000000000000001 },
{ 0xffffffffffffffff, 0x8000000000000001, 0xfffffffffffffffd, 0x8000000000000002 },
{ 0x7fffffffffffffff, 0xffffffffffffffff, 0xc000000000000000, 0xaaaaaaaaaaaaaaa8 },
{ 0xffffffffffffffff, 0x7fffffffffffffff, 0xa000000000000000, 0xccccccccccccccca },
{ 0xffffffffffffffff, 0x7fffffffffffffff, 0x9000000000000000, 0xe38e38e38e38e38b },
{ 0x7fffffffffffffff, 0x7fffffffffffffff, 0x5000000000000000, 0xccccccccccccccc9 },
{ 0xffffffffffffffff, 0xfffffffffffffffe, 0xffffffffffffffff, 0xfffffffffffffffe },
{ 0xe6102d256d7ea3ae, 0x70a77d0be4c31201, 0xd63ec35ab3220357, 0x78f8bf8cc86c6e18 },
{ 0xf53bae05cb86c6e1, 0x3847b32d2f8d32e0, 0xcfd4f55a647f403c, 0x42687f79d8998d35 },
{ 0x9951c5498f941092, 0x1f8c8bfdf287a251, 0xa3c8dc5f81ea3fe2, 0x1d887cb25900091f },
{ 0x374fee9daa1bb2bb, 0x0d0bfbff7b8ae3ef, 0xc169337bd42d5179, 0x03bb2dbaffcbb961 },
{ 0xeac0d03ac10eeaf0, 0x89be05dfa162ed9b, 0x92bb1679a41f0e4b, 0xdc5f5cc9e270d216 },
{ 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/^{ \+\(.*\), \+\(.*\), \+\(.*\), \+\(.*\) },$/\1 \2 \3 \4/p' \
* lib/math/test_mul_u64_u64_div_u64.c |
* while read a b c r; do
* expected=$( printf "obase=16; ibase=16; %X * %X / %X\n" $a $b $c | bc )
* given=$( printf "%X\n" $r )
* if [ "$expected" = "$given" ]; then
* echo "$a * $b / $c = $r OK"
* else
* echo "$a * $b / $c = $r is wrong" >&2
* echo "should be equivalent to 0x$expected" >&2
* exit 1
* fi
* done
#!/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 int __init test_init(void)
{
int errors = 0;
int tests = 0;
int i;
pr_info("Starting mul_u64_u64_div_u64() test\n");
@@ -72,19 +84,31 @@ static int __init test_init(void)
for (i = 0; i < ARRAY_SIZE(test_values); i++) {
u64 a = test_values[i].a;
u64 b = test_values[i].b;
u64 c = test_values[i].c;
u64 d = test_values[i].d;
u64 expected_result = test_values[i].result;
u64 result = mul_u64_u64_div_u64(a, b, c);
u64 result = mul_u64_u64_div_u64(a, b, d);
u64 result_up = mul_u64_u64_div_u64_roundup(a, b, d);
tests += 2;
if (result != expected_result) {
pr_err("ERROR: 0x%016llx * 0x%016llx / 0x%016llx\n", a, b, c);
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 mul_u64_u64_div_u64() test\n");
return 0;
pr_info("Completed mul_u64_u64_div_u64() test, %d tests, %d errors\n",
tests, errors);
return errors ? -EINVAL : 0;
}
static void __exit test_exit(void)