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Niklas Söderlund 4f5901f5a6 linux/kernel.h: fix DIV_ROUND_CLOSEST to support negative divisors
While working on a thermal driver I encounter a scenario where the
divisor could be negative, instead of adding local code to handle this I
though I first try to add support for this in DIV_ROUND_CLOSEST.

Add support to DIV_ROUND_CLOSEST for negative divisors if both dividend
and divisor variable types are signed.  This should not alter current
behavior for users of the macro as previously negative divisors where
not supported.

Before:

DIV_ROUND_CLOSEST(  59,  4) =  15
DIV_ROUND_CLOSEST(  59, -4) = -14
DIV_ROUND_CLOSEST( -59,  4) = -15
DIV_ROUND_CLOSEST( -59, -4) =  14

After:

DIV_ROUND_CLOSEST(  59,  4) =  15
DIV_ROUND_CLOSEST(  59, -4) = -15
DIV_ROUND_CLOSEST( -59,  4) = -15
DIV_ROUND_CLOSEST( -59, -4) =  15

[akpm@linux-foundation.org: fix comment, per Guenter]
Link: http://lkml.kernel.org/r/20161222102217.29011-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:57 -08:00
arch m68k: replace gcc specific macros with ones from compiler.h 2017-02-24 17:46:56 -08:00
block block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get() 2017-02-22 16:41:27 -08:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto crypto: xts - Add ECB dependency 2017-02-23 20:11:06 +08:00
Documentation zram: extend zero pages to same element pages 2017-02-24 17:46:56 -08:00
drivers mm balloon: umount balloon_mnt when removing vb device 2017-02-24 17:46:56 -08:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs procfs: use an enum for possible hidepid values 2017-02-24 17:46:56 -08:00
include linux/kernel.h: fix DIV_ROUND_CLOSEST to support negative divisors 2017-02-24 17:46:57 -08:00
init Merge branch 'akpm' (patches from Andrew) 2017-02-22 19:29:24 -08:00
ipc userfaultfd: non-cooperative: add event for memory unmaps 2017-02-24 17:46:55 -08:00
kernel kernel/ksysfs.c: add __ro_after_init to bin_attribute structure 2017-02-24 17:46:56 -08:00
lib lib/find_bit.c: micro-optimise find_next_*_bit 2017-02-24 17:46:57 -08:00
mm kasan: drain quarantine of memcg slab objects 2017-02-24 17:46:56 -08:00
net bpf: Fix bpf_xdp_event_output 2017-02-23 13:53:42 -05:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
scripts Merge branch 'akpm' (patches from Andrew) 2017-02-22 19:29:24 -08:00
security mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
sound mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
tools lib/find_bit.c: micro-optimise find_next_*_bit 2017-02-24 17:46:57 -08:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf 2017-02-24 17:46:54 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add codeaurora.org names for nameless email commits 2017-01-10 18:31:55 -08:00
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS Less anger inducing pull request for 4.11 2017-02-23 18:58:18 -08:00
Makefile A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.