50 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			50 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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 * Copyright IBM Corp. 1999, 2009
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 *
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 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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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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#include <linux/thread_info.h>
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#include <asm/fpu/api.h>
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#include <asm/ptrace.h>
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#include <asm/guarded_storage.h>
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extern struct task_struct *__switch_to(void *, void *);
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extern void update_cr_regs(struct task_struct *task);
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static inline void save_access_regs(unsigned int *acrs)
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{
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	typedef struct { int _[NUM_ACRS]; } acrstype;
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	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
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}
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static inline void restore_access_regs(unsigned int *acrs)
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{
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	typedef struct { int _[NUM_ACRS]; } acrstype;
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	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
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}
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#define switch_to(prev, next, last) do {				\
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	/* save_fpu_regs() sets the CIF_FPU flag, which enforces	\
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	 * a restore of the floating point / vector registers as	\
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	 * soon as the next task returns to user space			\
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	 */								\
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	save_fpu_regs();						\
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	save_access_regs(&prev->thread.acrs[0]);			\
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	save_ri_cb(prev->thread.ri_cb);					\
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	save_gs_cb(prev->thread.gs_cb);					\
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	update_cr_regs(next);						\
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	restore_access_regs(&next->thread.acrs[0]);			\
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	restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);		\
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	restore_gs_cb(next->thread.gs_cb);				\
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	prev = __switch_to(prev, next);					\
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} while (0)
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#endif /* __ASM_SWITCH_TO_H */
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