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 #include <asm/thread_info.h>
  22
  23 #define pi break
  24
  25 #define fp a3
  26
  27 ###############################################################################
  28 #
  29 # build a stack frame from the registers
  30 # - the caller has subtracted 4 from SP before coming here
  31 #
  32 ###############################################################################
  33 .macro SAVE_ALL
  34         add     -4,sp                           # next exception frame ptr save area
  35         movm    [other],(sp)
  36         mov     usp,a1
  37         mov     a1,(sp)                         # USP in MOVM[other] dummy slot
  38         movm    [d2,d3,a2,a3,exreg0,exreg1,exother],(sp)
  39         mov     sp,fp                           # FRAME pointer in A3
  40         add     -12,sp                          # allow for calls to be made
  41
  42         # push the exception frame onto the front of the list
  43         GET_THREAD_INFO a1
  44         mov     (TI_frame,a1),a0
  45         mov     a0,(REG_NEXT,fp)
  46         mov     fp,(TI_frame,a1)
  47
  48         # disable the FPU inside the kernel
  49         and     ~EPSW_FE,epsw
  50
  51         # we may be holding current in E2
  52 #ifdef CONFIG_MN10300_CURRENT_IN_E2
  53         mov     (__current),e2
  54 #endif
  55 .endm
  56
  57 ###############################################################################
  58 #
  59 # restore the registers from a stack frame
  60 #
  61 ###############################################################################
  62 .macro RESTORE_ALL
  63         # peel back the stack to the calling frame
  64         # - this permits execve() to discard extra frames due to kernel syscalls
  65         GET_THREAD_INFO a0
  66         mov     (TI_frame,a0),fp
  67         mov     fp,sp
  68         mov     (REG_NEXT,fp),d0
  69         mov     d0,(TI_frame,a0)                # userspace has regs->next == 0
  70
  71 #ifndef CONFIG_MN10300_USING_JTAG
  72         mov     (REG_EPSW,fp),d0
  73         btst    EPSW_T,d0
  74         beq     99f
  75
  76         or      EPSW_NMID,epsw
  77         movhu   (DCR),d1
  78         or      0x0001, d1
  79         movhu   d1,(DCR)
  80
  81 99:
  82 #endif
  83         movm    (sp),[d2,d3,a2,a3,exreg0,exreg1,exother]
  84
  85         # must restore usp even if returning to kernel space,
  86         # when CONFIG_PREEMPT is enabled.
  87         mov     (sp),a1                         # USP in MOVM[other] dummy slot
  88         mov     a1,usp
  89
  90         movm    (sp),[other]
  91         add     8,sp
  92         rti
  93
  94 .endm
  95
  96
  97 #endif /* _ASM_FRAME_INC */