s390: fine-tune stack switch helper
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 10 Apr 2019 13:48:43 +0000 (15:48 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Thu, 11 Apr 2019 11:36:45 +0000 (13:36 +0200)
commit7aa0055e06475f7b486c0673bc59c6478bc055fa
tree646db629e908e27a0e133d612733cd643503a9f2
parente24e4712efad737ca09ff299276737331cd021d9
s390: fine-tune stack switch helper

The CALL_ON_STACK helper currently does not work with clang and for
calls without arguments. It does not initialize r2 although the constraint
is "+&d". Rework the CALL_FMT_x and the CALL_ON_STACK macros to work
with clang and produce optimal code in all cases.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/include/asm/processor.h