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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-09-06 09:39:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-09-06 09:39:47 -0700 |
| commit | c7c6bf1e8c72b94d73756d5dc4f7a6d7c4d1e290 (patch) | |
| tree | 05a749ebde9f76985f2f6ded042cf42d0a8fe588 /include | |
| parent | bd12ce8cc23a5ab7eafb1edb3f2cd311d2b89e7e (diff) | |
| parent | b6d86d3d6d6e4c9b588d81615c81b5a8292b62ed (diff) | |
| download | lwn-c7c6bf1e8c72b94d73756d5dc4f7a6d7c4d1e290.tar.gz lwn-c7c6bf1e8c72b94d73756d5dc4f7a6d7c4d1e290.zip | |
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull a hwmon fix from Guenter Roeck:
"One patch, fixing DIV_ROUND_CLOSEST to support negative dividends.
While the changes are not in the drivers/hwmon directory, the problem
primarily affects hwmon drivers, and it makes sense to push the patch
through the hwmon tree."
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
linux/kernel.h: Fix DIV_ROUND_CLOSEST to support negative dividends
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kernel.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 604382143bcf..594b419b7d20 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -82,10 +82,18 @@ __x - (__x % (y)); \ } \ ) + +/* + * Divide positive or negative dividend by positive divisor and round + * to closest integer. Result is undefined for negative divisors. + */ #define DIV_ROUND_CLOSEST(x, divisor)( \ { \ - typeof(divisor) __divisor = divisor; \ - (((x) + ((__divisor) / 2)) / (__divisor)); \ + typeof(x) __x = x; \ + typeof(divisor) __d = divisor; \ + (((typeof(x))-1) >= 0 || (__x) >= 0) ? \ + (((__x) + ((__d) / 2)) / (__d)) : \ + (((__x) - ((__d) / 2)) / (__d)); \ } \ ) |