aboutsummaryrefslogtreecommitdiff
path: root/arch/m68k/include/asm/entry_no.h
blob: 68611e3dbb1d41795bdaefabb158c1b37de0aa4e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
#ifndef __M68KNOMMU_ENTRY_H
#define __M68KNOMMU_ENTRY_H

#include <asm/setup.h>
#include <asm/page.h>

/*
 * Stack layout in 'ret_from_exception':
 *
 * This allows access to the syscall arguments in registers d1-d5
 *
 *	 0(sp) - d1
 *	 4(sp) - d2
 *	 8(sp) - d3
 *	 C(sp) - d4
 *	10(sp) - d5
 *	14(sp) - a0
 *	18(sp) - a1
 *	1C(sp) - a2
 *	20(sp) - d0
 *	24(sp) - orig_d0
 *	28(sp) - stack adjustment
 *	2C(sp) - [ sr              ] [ format & vector ]
 *	2E(sp) - [ pc-hiword       ] [ sr              ]
 *	30(sp) - [ pc-loword       ] [ pc-hiword       ]
 *	32(sp) - [ format & vector ] [ pc-loword       ]
 *		  ^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^
 *			M68K		  COLDFIRE
 */

#define ALLOWINT (~0x700)

#ifdef __ASSEMBLY__

#define SWITCH_STACK_SIZE (6*4+4)	/* Includes return address */

/*
 * This defines the normal kernel pt-regs layout.
 *
 * regs are a2-a6 and d6-d7 preserved by C code
 * the kernel doesn't mess with usp unless it needs to
 */

#ifdef CONFIG_COLDFIRE
#ifdef CONFIG_COLDFIRE_SW_A7
/*
 * This is made a little more tricky on older ColdFires. There is no
 * separate supervisor and user stack pointers. Need to artificially
 * construct a usp in software... When doing this we need to disable
 * interrupts, otherwise bad things will happen.
 */
.globl sw_usp
.globl sw_ksp

.macro SAVE_ALL
	move	#0x2700,%sr		/* disable intrs */
	btst	#5,%sp@(2)		/* from user? */
	bnes	6f			/* no, skip */
	movel	%sp,sw_usp		/* save user sp */
	addql	#8,sw_usp		/* remove exception */
	movel	sw_ksp,%sp		/* kernel sp */
	subql	#8,%sp			/* room for exception */
	clrl	%sp@-			/* stkadj */
	movel	%d0,%sp@-		/* orig d0 */
	movel	%d0,%sp@-		/* d0 */
	lea	%sp@(-32),%sp		/* space for 8 regs */
	moveml	%d1-%d5/%a0-%a2,%sp@
	movel	sw_usp,%a0		/* get usp */
	movel	%a0@-,%sp@(PT_OFF_PC)	/* copy exception program counter */
	movel	%a0@-,%sp@(PT_OFF_FORMATVEC)/*copy exception format/vector/sr */
	bra	7f
	6:
	clrl	%sp@-			/* stkadj */
	movel	%d0,%sp@-		/* orig d0 */
	movel	%d0,%sp@-		/* d0 */
	lea	%sp@(-32),%sp		/* space for 8 regs */
	moveml	%d1-%d5/%a0-%a2,%sp@
	7:
.endm

.macro RESTORE_USER
	move	#0x2700,%sr		/* disable intrs */
	movel	sw_usp,%a0		/* get usp */
	movel	%sp@(PT_OFF_PC),%a0@-	/* copy exception program counter */
	movel	%sp@(PT_OFF_FORMATVEC),%a0@-/*copy exception format/vector/sr */
	moveml	%sp@,%d1-%d5/%a0-%a2
	lea	%sp@(32),%sp		/* space for 8 regs */
	movel	%sp@+,%d0
	addql	#4,%sp			/* orig d0 */
	addl	%sp@+,%sp		/* stkadj */
	addql	#8,%sp			/* remove exception */
	movel	%sp,sw_ksp		/* save ksp */
	subql	#8,sw_usp		/* set exception */
	movel	sw_usp,%sp		/* restore usp */
	rte
.endm

.macro RDUSP
	movel	sw_usp,%a3
.endm

.macro WRUSP
	movel	%a3,sw_usp
.endm

#else /* !CONFIG_COLDFIRE_SW_A7 */
/*
 * Modern ColdFire parts have separate supervisor and user stack
 * pointers. Simple load and restore macros for this case.
 */
.macro SAVE_ALL
	move	#0x2700,%sr		/* disable intrs */
	clrl	%sp@-			/* stkadj */
	movel	%d0,%sp@-		/* orig d0 */
	movel	%d0,%sp@-		/* d0 */
	lea	%sp@(-32),%sp		/* space for 8 regs */
	moveml	%d1-%d5/%a0-%a2,%sp@
.endm

.macro RESTORE_USER
	moveml	%sp@,%d1-%d5/%a0-%a2
	lea	%sp@(32),%sp		/* space for 8 regs */
	movel	%sp@+,%d0
	addql	#4,%sp			/* orig d0 */
	addl	%sp@+,%sp		/* stkadj */
	rte
.endm

.macro RDUSP
	/*move	%usp,%a3*/
	.word	0x4e6b
.endm

.macro WRUSP
	/*move	%a3,%usp*/
	.word	0x4e63
.endm

#endif /* !CONFIG_COLDFIRE_SW_A7 */

.macro SAVE_SWITCH_STACK
	lea	%sp@(-24),%sp		/* 6 regs */
	moveml	%a3-%a6/%d6-%d7,%sp@
.endm

.macro RESTORE_SWITCH_STACK
	moveml	%sp@,%a3-%a6/%d6-%d7
	lea	%sp@(24),%sp		/* 6 regs */
.endm

#else /* !CONFIG_COLDFIRE */

/*
 * Standard 68k interrupt entry and exit macros.
 */
.macro SAVE_ALL
	clrl	%sp@-			/* stkadj */
	movel	%d0,%sp@-		/* orig d0 */
	movel	%d0,%sp@-		/* d0 */
	moveml	%d1-%d5/%a0-%a2,%sp@-
.endm

.macro RESTORE_ALL
	moveml	%sp@+,%a0-%a2/%d1-%d5
	movel	%sp@+,%d0
	addql	#4,%sp			/* orig d0 */
	addl	%sp@+,%sp		/* stkadj */
	rte
.endm

.macro SAVE_SWITCH_STACK
	moveml	%a3-%a6/%d6-%d7,%sp@-
.endm

.macro RESTORE_SWITCH_STACK
	moveml	%sp@+,%a3-%a6/%d6-%d7
.endm

#endif /* !COLDFIRE_SW_A7 */
#endif /* __ASSEMBLY__ */
#endif /* __M68KNOMMU_ENTRY_H */