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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-03-18 13:27:32 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-03-23 15:00:01 -0700
commit00d64e04909fc80db39315708a38250f38e6dda9 (patch)
tree8e28eee1345c558579be6ed42addc024624bba54
parent07d3c798afc8c28457907269fb26b000e40e8254 (diff)
S390: __div64_31 broken for CONFIG_MARCH_G5
commit 4fa81ed27781a12f6303b9263056635ae74e3e21 upstream. 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. Reported-by: Frans Pop <elendil@planet.nl> Tested-by: Frans Pop <elendil@planet.nl> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/s390/lib/div64.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/lib/div64.c b/arch/s390/lib/div64.c
index a5f8300bf3e..d9e62c0b576 100644
--- a/arch/s390/lib/div64.c
+++ b/arch/s390/lib/div64.c
@@ -61,7 +61,7 @@ static uint32_t __div64_31(uint64_t *n, uint32_t base)
" clr %0,%3\n"
" jl 0f\n"
" slr %0,%3\n"
- " alr %1,%2\n"
+ " ahi %1,1\n"
"0:\n"
: "+d" (reg2), "+d" (reg3), "=d" (tmp)
: "d" (base), "2" (1UL) : "cc" );