diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-12 14:22:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-12 14:22:25 -0700 |
commit | 56b24d1bbcff213dc9e1625eea5b8e13bb50feb8 (patch) | |
tree | 888f40d5c2b77f3d839a14f9781e418b9d48c22a /arch/s390/include/asm/timex.h | |
parent | 5a45a5a881aeb82ce31dd1886afe04146965df23 (diff) | |
parent | 8bd49ac86677ca43d64f08c45864e438283d6a76 (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
- four patches to get the new cputime code in shape for s390
- add the new statx system call
- a few bug fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: wire up statx system call
KVM: s390: Fix guest migration for huge guests resulting in panic
s390/ipl: always use load normal for CCW-type re-IPL
s390/timex: micro optimization for tod_to_ns
s390/cputime: provide archicture specific cputime_to_nsecs
s390/cputime: reset all accounting fields on fork
s390/cputime: remove last traces of cputime_t
s390: fix in-kernel program checks
s390/crypt: fix missing unlock in ctr_paes_crypt on error path
Diffstat (limited to 'arch/s390/include/asm/timex.h')
-rw-r--r-- | arch/s390/include/asm/timex.h | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index 354344dcc198..118535123f34 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -206,20 +206,16 @@ static inline unsigned long long get_tod_clock_monotonic(void) * ns = (todval * 125) >> 9; * * In order to avoid an overflow with the multiplication we can rewrite this. - * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits) + * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits) * we end up with * - * ns = ((2^32 * th + tl) * 125 ) >> 9; - * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9); + * ns = ((2^9 * th + tl) * 125 ) >> 9; + * -> ns = (th * 125) + ((tl * 125) >> 9); * */ static inline unsigned long long tod_to_ns(unsigned long long todval) { - unsigned long long ns; - - ns = ((todval >> 32) << 23) * 125; - ns += ((todval & 0xffffffff) * 125) >> 9; - return ns; + return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9); } #endif |