45 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			45 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| /*
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|  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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|  */
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| #ifndef _ASM_SWITCH_TO_H
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| #define _ASM_SWITCH_TO_H
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| 
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| #include <asm/cpu-features.h>
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| #include <asm/fpu.h>
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| #include <asm/lbt.h>
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| 
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| struct task_struct;
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| 
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| /**
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|  * __switch_to - switch execution of a task
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|  * @prev:	The task previously executed.
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|  * @next:	The task to begin executing.
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|  * @next_ti:	task_thread_info(next).
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|  * @sched_ra:	__schedule return address.
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|  * @sched_cfa:	__schedule call frame address.
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|  *
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|  * This function is used whilst scheduling to save the context of prev & load
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|  * the context of next. Returns prev.
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|  */
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| extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev,
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| 			struct task_struct *next, struct thread_info *next_ti,
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| 			void *sched_ra, void *sched_cfa);
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| 
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| /*
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|  * For newly created kernel threads switch_to() will return to
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|  * ret_from_kernel_thread, newly created user threads to ret_from_fork.
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|  * That is, everything following __switch_to() will be skipped for new threads.
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|  * So everything that matters to new threads should be placed before __switch_to().
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|  */
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| #define switch_to(prev, next, last)						\
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| do {										\
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| 	lose_fpu_inatomic(1, prev);						\
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| 	lose_lbt_inatomic(1, prev);						\
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| 	hw_breakpoint_thread_switch(next);					\
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| 	(last) = __switch_to(prev, next, task_thread_info(next),		\
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| 		 __builtin_return_address(0), __builtin_frame_address(0));	\
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| } while (0)
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| 
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| #endif /* _ASM_SWITCH_TO_H */
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