| #ifndef _ASM_POWERPC_MEMBARRIER_H |
| #define _ASM_POWERPC_MEMBARRIER_H |
| |
| static inline void membarrier_arch_switch_mm(struct mm_struct *prev, |
| struct mm_struct *next, |
| struct task_struct *tsk) |
| { |
| /* |
| * Only need the full barrier when switching between processes. |
| * Barrier when switching from kernel to userspace is not |
| * required here, given that it is implied by mmdrop(). Barrier |
| * when switching from userspace to kernel is not needed after |
| * store to rq->curr. |
| */ |
| if (IS_ENABLED(CONFIG_SMP) && |
| likely(!(atomic_read(&next->membarrier_state) & |
| (MEMBARRIER_STATE_PRIVATE_EXPEDITED | |
| MEMBARRIER_STATE_GLOBAL_EXPEDITED)) || !prev)) |
| return; |
| |
| /* |
| * The membarrier system call requires a full memory barrier |
| * after storing to rq->curr, before going back to user-space. |
| */ |
| smp_mb(); |
| } |
| |
| #endif /* _ASM_POWERPC_MEMBARRIER_H */ |
