| David Howells | c9034c3 | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 2001 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto |
| 7 | * Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org> |
| 8 | */ |
| 9 | #ifndef _ASM_M32R_SWITCH_TO_H |
| 10 | #define _ASM_M32R_SWITCH_TO_H |
| 11 | |
| 12 | /* |
| 13 | * switch_to(prev, next) should switch from task `prev' to `next' |
| 14 | * `prev' will never be the same as `next'. |
| 15 | * |
| 16 | * `next' and `prev' should be struct task_struct, but it isn't always defined |
| 17 | */ |
| 18 | |
| 19 | #if defined(CONFIG_FRAME_POINTER) || \ |
| 20 | !defined(CONFIG_SCHED_OMIT_FRAME_POINTER) |
| 21 | #define M32R_PUSH_FP " push fp\n" |
| 22 | #define M32R_POP_FP " pop fp\n" |
| 23 | #else |
| 24 | #define M32R_PUSH_FP "" |
| 25 | #define M32R_POP_FP "" |
| 26 | #endif |
| 27 | |
| 28 | #define switch_to(prev, next, last) do { \ |
| 29 | __asm__ __volatile__ ( \ |
| 30 | " seth lr, #high(1f) \n" \ |
| 31 | " or3 lr, lr, #low(1f) \n" \ |
| 32 | " st lr, @%4 ; store old LR \n" \ |
| 33 | " ld lr, @%5 ; load new LR \n" \ |
| 34 | M32R_PUSH_FP \ |
| 35 | " st sp, @%2 ; store old SP \n" \ |
| 36 | " ld sp, @%3 ; load new SP \n" \ |
| 37 | " push %1 ; store `prev' on new stack \n" \ |
| 38 | " jmp lr \n" \ |
| 39 | " .fillinsn \n" \ |
| 40 | "1: \n" \ |
| 41 | " pop %0 ; restore `__last' from new stack \n" \ |
| 42 | M32R_POP_FP \ |
| 43 | : "=r" (last) \ |
| 44 | : "0" (prev), \ |
| 45 | "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \ |
| 46 | "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \ |
| 47 | : "memory", "lr" \ |
| 48 | ); \ |
| 49 | } while(0) |
| 50 | |
| 51 | #endif /* _ASM_M32R_SWITCH_TO_H */ |