1#ifndef _ASM_POWERPC_MEMBARRIER_H
 2#define _ASM_POWERPC_MEMBARRIER_H
 3
 4static inline void membarrier_arch_switch_mm(struct mm_struct *prev,
 5					     struct mm_struct *next,
 6					     struct task_struct *tsk)
 7{
 8	/*
 9	 * Only need the full barrier when switching between processes.
10	 * Barrier when switching from kernel to userspace is not
11	 * required here, given that it is implied by mmdrop(). Barrier
12	 * when switching from userspace to kernel is not needed after
13	 * store to rq->curr.
14	 */
15	if (IS_ENABLED(CONFIG_SMP) &&
16	    likely(!(atomic_read(&next->membarrier_state) &
17		     (MEMBARRIER_STATE_PRIVATE_EXPEDITED |
18		      MEMBARRIER_STATE_GLOBAL_EXPEDITED)) || !prev))
19		return;
20
21	/*
22	 * The membarrier system call requires a full memory barrier
23	 * after storing to rq->curr, before going back to user-space.
24	 */
25	smp_mb();
26}
27
28#endif /* _ASM_POWERPC_MEMBARRIER_H */