18c2ecf20Sopenharmony_ci#ifndef _ASM_POWERPC_MEMBARRIER_H 28c2ecf20Sopenharmony_ci#define _ASM_POWERPC_MEMBARRIER_H 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_cistatic inline void membarrier_arch_switch_mm(struct mm_struct *prev, 58c2ecf20Sopenharmony_ci struct mm_struct *next, 68c2ecf20Sopenharmony_ci struct task_struct *tsk) 78c2ecf20Sopenharmony_ci{ 88c2ecf20Sopenharmony_ci /* 98c2ecf20Sopenharmony_ci * Only need the full barrier when switching between processes. 108c2ecf20Sopenharmony_ci * Barrier when switching from kernel to userspace is not 118c2ecf20Sopenharmony_ci * required here, given that it is implied by mmdrop(). Barrier 128c2ecf20Sopenharmony_ci * when switching from userspace to kernel is not needed after 138c2ecf20Sopenharmony_ci * store to rq->curr. 148c2ecf20Sopenharmony_ci */ 158c2ecf20Sopenharmony_ci if (likely(!(atomic_read(&next->membarrier_state) & 168c2ecf20Sopenharmony_ci (MEMBARRIER_STATE_PRIVATE_EXPEDITED | 178c2ecf20Sopenharmony_ci MEMBARRIER_STATE_GLOBAL_EXPEDITED)) || !prev)) 188c2ecf20Sopenharmony_ci return; 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci /* 218c2ecf20Sopenharmony_ci * The membarrier system call requires a full memory barrier 228c2ecf20Sopenharmony_ci * after storing to rq->curr, before going back to user-space. 238c2ecf20Sopenharmony_ci */ 248c2ecf20Sopenharmony_ci smp_mb(); 258c2ecf20Sopenharmony_ci} 268c2ecf20Sopenharmony_ci 278c2ecf20Sopenharmony_ci#endif /* _ASM_POWERPC_MEMBARRIER_H */ 28