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/include/asm/processor.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/s390/include/asm/processor.h') diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 20d0585cf90..f1700c5c888 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -348,4 +348,14 @@ extern void (*s390_base_ext_handler_fn)(void); ".previous\n" #endif +extern int memcpy_real(void *, void *, size_t); +extern void memcpy_absolute(void *, void *, size_t); + +#define mem_assign_absolute(dest, val) { \ + __typeof__(dest) __tmp = (val); \ + \ + BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \ + memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \ +} + #endif /* __ASM_S390_PROCESSOR_H */ -- cgit v1.2.3-70-g09d2