From ed0192bc644f3553d64a5cb461bdd0b1fbae3fdf Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Thu, 17 Mar 2022 15:03:03 +0100 Subject: s390/maccess: rework absolute lowcore accessors Macro mem_assign_absolute() is able to access the whole memory, but is only used and makes sense when updating the absolute lowcore. Instead, introduce get_abs_lowcore() and put_abs_lowcore() macros that limit access to absolute lowcore addresses only. Suggested-by: Heiko Carstens Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik --- arch/s390/include/asm/processor.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'arch/s390/include') diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 84ec63145325..eee8d96fb38e 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -319,11 +319,18 @@ extern void (*s390_base_pgm_handler_fn)(struct pt_regs *regs); extern int memcpy_real(void *, unsigned long, size_t); extern void memcpy_absolute(void *, void *, size_t); -#define mem_assign_absolute(dest, val) do { \ - __typeof__(dest) __tmp = (val); \ - \ - BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \ - memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \ +#define put_abs_lowcore(member, x) do { \ + unsigned long __abs_address = offsetof(struct lowcore, member); \ + __typeof__(((struct lowcore *)0)->member) __tmp = (x); \ + \ + memcpy_absolute(__va(__abs_address), &__tmp, sizeof(__tmp)); \ +} while (0) + +#define get_abs_lowcore(x, member) do { \ + unsigned long __abs_address = offsetof(struct lowcore, member); \ + __typeof__(((struct lowcore *)0)->member) *__ptr = &(x); \ + \ + memcpy_absolute(__ptr, __va(__abs_address), sizeof(*__ptr)); \ } while (0) extern int s390_isolate_bp(void); -- cgit