Commit ac357c41 authored Dec 18, 2015 by Peter Oberparleiter Committed by Martin Schwidefsky Dec 18, 2015

s390/cio: Fix incorrect xsch opcode specification



The numeric representation of the xsch instruction was incorrectly
specified, resulting in reserved fields of the instruction opcode
potentially being set to a non-zero value. While this doesn't currently
cause any problem, a future architecture might make use of these fields
so that the current specification could result in an exception or
unwanted side-effects.

Fix this by using the xsch instruction code for which support in
binutils was added in 2003.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 62e65da9

drivers/s390/cio/io_sch.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -205,7 +205,7 @@ static inline int xsch(struct subchannel_id schid)
		int ccode;

		asm volatile(
		" .insn rre,0xb2760000,%1,0\n"
		" xsch\n"
		" ipm %0\n"
		" srl %0,28"
		: "=d" (ccode)