LXR linux/arch/m32r/include/asm/switch

   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 */
  52