1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_ARM_SWITCH_TO_H 3 #define __ASM_ARM_SWITCH_TO_H 4 5 #include <linux/thread_info.h> 6 #include <asm/smp_plat.h> 7 8 /* 9 * For v7 SMP cores running a preemptible kernel we may be pre-empted 10 * during a TLB maintenance operation, so execute an inner-shareable dsb 11 * to ensure that the maintenance completes in case we migrate to another 12 * CPU. 13 */ 14 #if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7) 15 #define __complete_pending_tlbi() dsb(ish) 16 #else 17 #define __complete_pending_tlbi() 18 #endif 19 20 /* 21 * switch_to(prev, next) should switch from task `prev' to `next' 22 * `prev' will never be the same as `next'. schedule() itself 23 * contains the memory barrier to tell GCC not to cache `current'. 24 */ 25 extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *); 26 27 #define switch_to(prev,next,last) \ 28 do { \ 29 __complete_pending_tlbi(); \ 30 if (IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO) || is_smp()) \ 31 __this_cpu_write(__entry_task, next); \ 32 last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \ 33 } while (0) 34 35 #endif /* __ASM_ARM_SWITCH_TO_H */ 36