diff options
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/include/asm/rwonce.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/s390/include/asm/rwonce.h b/arch/s390/include/asm/rwonce.h new file mode 100644 index 000000000000..91fc24520e82 --- /dev/null +++ b/arch/s390/include/asm/rwonce.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_S390_RWONCE_H +#define __ASM_S390_RWONCE_H + +#include <linux/compiler_types.h> + +/* + * Use READ_ONCE_ALIGNED_128() for 128-bit block concurrent (atomic) read + * accesses. Note that x must be 128-bit aligned, otherwise a specification + * exception is generated. + */ +#define READ_ONCE_ALIGNED_128(x) \ +({ \ + union { \ + typeof(x) __x; \ + __uint128_t val; \ + } __u; \ + \ + BUILD_BUG_ON(sizeof(x) != 16); \ + asm volatile( \ + " lpq %[val],%[_x]\n" \ + : [val] "=d" (__u.val) \ + : [_x] "QS" (x) \ + : "memory"); \ + __u.__x; \ +}) + +#include <asm-generic/rwonce.h> + +#endif /* __ASM_S390_RWONCE_H */ |