LXR linux/arch/mn10300/include/asm/frame.inc

   1/* MN10300 Microcontroller core system register definitions -*- asm -*-
   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_FRAME_INC
  12#define _ASM_FRAME_INC
  13
  14#ifndef __ASSEMBLY__
  15#error not for use in C files
  16#endif
  17
  18#ifndef __ASM_OFFSETS_H__
  19#include <asm/asm-offsets.h>
  20#endif
  21
  22#define pi break
  23
  24#define fp a3
  25
  26###############################################################################
  27#
  28# build a stack frame from the registers
  29# - the caller has subtracted 4 from SP before coming here
  30#
  31###############################################################################
  32.macro SAVE_ALL
  33        add     -4,sp                           # next exception frame ptr save area
  34        movm    [other],(sp)
  35        mov     usp,a1
  36        mov     a1,(sp)                         # USP in MOVM[other] dummy slot
  37        movm    [d2,d3,a2,a3,exreg0,exreg1,exother],(sp)
  38        mov     sp,fp                           # FRAME pointer in A3
  39        add     -12,sp                          # allow for calls to be made
  40        mov     (__frame),a1
  41        mov     a1,(REG_NEXT,fp)
  42        mov     fp,(__frame)
  43
  44        and     ~EPSW_FE,epsw                   # disable the FPU inside the kernel
  45
  46        # we may be holding current in E2
  47#ifdef CONFIG_MN10300_CURRENT_IN_E2
  48        mov     (__current),e2
  49#endif
  50.endm
  51
  52###############################################################################
  53#
  54# restore the registers from a stack frame
  55#
  56###############################################################################
  57.macro RESTORE_ALL
  58        # peel back the stack to the calling frame
  59        # - this permits execve() to discard extra frames due to kernel syscalls
  60        mov     (__frame),fp
  61        mov     fp,sp
  62        mov     (REG_NEXT,fp),d0                # userspace has regs->next == 0
  63        mov     d0,(__frame)
  64
  65#ifndef CONFIG_MN10300_USING_JTAG
  66        mov     (REG_EPSW,fp),d0
  67        btst    EPSW_T,d0
  68        beq     99f
  69
  70        or      EPSW_NMID,epsw
  71        movhu   (DCR),d1
  72        or      0x0001, d1
  73        movhu   d1,(DCR)
  74
  7599:
  76#endif
  77        movm    (sp),[d2,d3,a2,a3,exreg0,exreg1,exother]
  78
  79        # must restore usp even if returning to kernel space,
  80        # when CONFIG_PREEMPT is enabled.
  81        mov     (sp),a1                         # USP in MOVM[other] dummy slot
  82        mov     a1,usp
  83
  84        movm    (sp),[other]
  85        add     8,sp
  86        rti
  87
  88.endm
  89
  90
  91#endif /* _ASM_FRAME_INC */
  92