mirror of https://gitee.com/openkylin/linux.git
50 lines
1.5 KiB
C
50 lines
1.5 KiB
C
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/* MN10300 task switching definitions
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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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 <asm/barrier.h>
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struct task_struct;
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struct thread_struct;
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#if !defined(CONFIG_LAZY_SAVE_FPU)
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struct fpu_state_struct;
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extern asmlinkage void fpu_save(struct fpu_state_struct *);
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#define switch_fpu(prev, next) \
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do { \
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if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) { \
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(prev)->thread.fpu_flags &= ~THREAD_HAS_FPU; \
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(prev)->thread.uregs->epsw &= ~EPSW_FE; \
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fpu_save(&(prev)->thread.fpu_state); \
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} \
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} while (0)
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#else
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#define switch_fpu(prev, next) do {} while (0)
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#endif
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/* context switching is now performed out-of-line in switch_to.S */
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extern asmlinkage
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struct task_struct *__switch_to(struct thread_struct *prev,
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struct thread_struct *next,
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struct task_struct *prev_task);
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#define switch_to(prev, next, last) \
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do { \
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switch_fpu(prev, next); \
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current->thread.wchan = (u_long) __builtin_return_address(0); \
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(last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \
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mb(); \
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current->thread.wchan = 0; \
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} while (0)
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#endif /* _ASM_SWITCH_TO_H */
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