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David Howellsb920de12008-02-08 04:19:31 -08001/* 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 */