xref: /openbmc/linux/arch/arm/include/asm/switch_to.h (revision e15a5365)
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 
7 /*
8  * For v7 SMP cores running a preemptible kernel we may be pre-empted
9  * during a TLB maintenance operation, so execute an inner-shareable dsb
10  * to ensure that the maintenance completes in case we migrate to another
11  * CPU.
12  */
13 #if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
14 #define __complete_pending_tlbi()	dsb(ish)
15 #else
16 #define __complete_pending_tlbi()
17 #endif
18 
19 /*
20  * switch_to(prev, next) should switch from task `prev' to `next'
21  * `prev' will never be the same as `next'.  schedule() itself
22  * contains the memory barrier to tell GCC not to cache `current'.
23  */
24 extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
25 
26 #define switch_to(prev,next,last)					\
27 do {									\
28 	__complete_pending_tlbi();					\
29 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
30 } while (0)
31 
32 #endif /* __ASM_ARM_SWITCH_TO_H */
33