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s390/facilities: optimize test_facility() 

test_facility() can be optimized for bits which must be set anyway,
due to the check in head.S. This removes a couple of superfluous
runtime checks.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2015-11-24 13:48:27 +01:00 committed by Martin Schwidefsky
parent 185edd4431
commit 6ab6c31a54
1 changed files with 6 additions and 0 deletions
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6
arch/s390/include/asm/facility.h
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@ -34,6 +34,12 @@ static inline int __test_facility(unsigned long nr, void *facilities)
*/
static inline int test_facility(unsigned long nr)
{
unsigned long facilities_als[] = { FACILITIES_ALS };
if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
if (__test_facility(nr, &facilities_als))
return 1;
}
return __test_facility(nr, &S390_lowcore.stfle_fac_list);
}