[S390] __div64_31 broken for CONFIG_MARCH_G5
commit4fa81ed27781a12f6303b9263056635ae74e3e21
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 18 Mar 2009 12:27:32 +0000 (18 13:27 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 18 Mar 2009 12:28:12 +0000 (18 13:28 +0100)
treefab8df760ab6a01b9051c67b914c6e6b208607ba
parentee568b25ee9e160b32d1aef73d8b2ee9c05d34db
[S390] __div64_31 broken for CONFIG_MARCH_G5

The implementation of __div64_31 for G5 machines is broken. The comments
in __div64_31 are correct, only the code does not do what the comments
say. The part "If the remainder has overflown subtract base and increase
the quotient" is only partially realized, the base is subtracted correctly
but the quotient is only increased if the dividend had the last bit set.
Using the correct instruction fixes the problem.

Cc: stable@kernel.org
Reported-by: Frans Pop <elendil@planet.nl>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/lib/div64.c