1 /* MN10300 task switching definitions 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 #ifndef _ASM_SWITCH_TO_H 12 #define _ASM_SWITCH_TO_H 13 14 #include <asm/barrier.h> 15 16 struct task_struct; 17 struct thread_struct; 18 19 #if !defined(CONFIG_LAZY_SAVE_FPU) 20 struct fpu_state_struct; 21 extern asmlinkage void fpu_save(struct fpu_state_struct *); 22 #define switch_fpu(prev, next) \ 23 do { \ 24 if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) { \ 25 (prev)->thread.fpu_flags &= ~THREAD_HAS_FPU; \ 26 (prev)->thread.uregs->epsw &= ~EPSW_FE; \ 27 fpu_save(&(prev)->thread.fpu_state); \ 28 } \ 29 } while (0) 30 #else 31 #define switch_fpu(prev, next) do {} while (0) 32 #endif 33 34 /* context switching is now performed out-of-line in switch_to.S */ 35 extern asmlinkage 36 struct task_struct *__switch_to(struct thread_struct *prev, 37 struct thread_struct *next, 38 struct task_struct *prev_task); 39 40 #define switch_to(prev, next, last) \ 41 do { \ 42 switch_fpu(prev, next); \ 43 current->thread.wchan = (u_long) __builtin_return_address(0); \ 44 (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \ 45 mb(); \ 46 current->thread.wchan = 0; \ 47 } while (0) 48 49 #endif /* _ASM_SWITCH_TO_H */ 50