include/asm-mn10300/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
  75 99:
  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 */