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Diffstat (limited to 'arch/m32r/include/asm/switch_to.h')
| -rw-r--r-- | arch/m32r/include/asm/switch_to.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/m32r/include/asm/switch_to.h b/arch/m32r/include/asm/switch_to.h new file mode 100644 index 000000000000..4b262f7a8fe9 --- /dev/null +++ b/arch/m32r/include/asm/switch_to.h @@ -0,0 +1,51 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto + * Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org> + */ +#ifndef _ASM_M32R_SWITCH_TO_H +#define _ASM_M32R_SWITCH_TO_H + +/* + * switch_to(prev, next) should switch from task `prev' to `next' + * `prev' will never be the same as `next'. + * + * `next' and `prev' should be struct task_struct, but it isn't always defined + */ + +#if defined(CONFIG_FRAME_POINTER) || \ + !defined(CONFIG_SCHED_OMIT_FRAME_POINTER) +#define M32R_PUSH_FP " push fp\n" +#define M32R_POP_FP " pop fp\n" +#else +#define M32R_PUSH_FP "" +#define M32R_POP_FP "" +#endif + +#define switch_to(prev, next, last) do { \ + __asm__ __volatile__ ( \ + " seth lr, #high(1f) \n" \ + " or3 lr, lr, #low(1f) \n" \ + " st lr, @%4 ; store old LR \n" \ + " ld lr, @%5 ; load new LR \n" \ + M32R_PUSH_FP \ + " st sp, @%2 ; store old SP \n" \ + " ld sp, @%3 ; load new SP \n" \ + " push %1 ; store `prev' on new stack \n" \ + " jmp lr \n" \ + " .fillinsn \n" \ + "1: \n" \ + " pop %0 ; restore `__last' from new stack \n" \ + M32R_POP_FP \ + : "=r" (last) \ + : "0" (prev), \ + "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \ + "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \ + : "memory", "lr" \ + ); \ +} while(0) + +#endif /* _ASM_M32R_SWITCH_TO_H */ |