From fbe765680d1fe9d08187ea4dad5041a7955a2c3a Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 5 Jun 2012 09:59:52 +0200 Subject: s390/smp: make absolute lowcore / cpu restart parameter accesses more robust Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry64.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/s390/kernel/entry64.S') diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index d5f02e480e51..2813e831ba32 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -751,7 +751,9 @@ ENTRY(restart_int_handler) mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) - lmg %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu + lg %r1,__LC_RESTART_FN # load fn, parm & source cpu + lg %r2,__LC_RESTART_DATA + lg %r3,__LC_RESTART_SOURCE ltgr %r3,%r3 # test source cpu address jm 1f # negative -> skip source stop 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu -- cgit v1.2.3