summaryrefslogtreecommitdiffstats
path: root/arch/m68k/platform/coldfire/entry.S
blob: 27c2b001161e1d31b43bc7a2ba6640ba4ceb4139 (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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
 *  linux/arch/m68knommu/platform/5307/entry.S
 *
 *  Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
 *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
 *                      Kenneth Albanowski <kjahds@kjahds.com>,
 *  Copyright (C) 2000  Lineo Inc. (www.lineo.com)
 *  Copyright (C) 2004-2006  Macq Electronique SA. (www.macqel.com)
 *
 * Based on:
 *
 *  linux/arch/m68k/kernel/entry.S
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file README.legal in the main directory of this archive
 * for more details.
 *
 * Linux/m68k support by Hamish Macdonald
 *
 * 68060 fixes by Jesper Skov
 * ColdFire support by Greg Ungerer (gerg@snapgear.com)
 * 5307 fixes by David W. Miller
 * linux 2.4 support David McCullough <davidm@snapgear.com>
 * Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
 */

#include <linux/linkage.h>
#include <asm/unistd.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>

#ifdef CONFIG_COLDFIRE_SW_A7
/*
 *	Define software copies of the supervisor and user stack pointers.
 */
.bss
sw_ksp:
.long	0
sw_usp:
.long	0
#endif /* CONFIG_COLDFIRE_SW_A7 */

.text

.globl system_call
.globl resume
.globl ret_from_exception
.globl ret_from_signal
.globl sys_call_table
.globl inthandler
.globl fasthandler

enosys:
	mov.l	#sys_ni_syscall,%d3
	bra	1f

ENTRY(system_call)
	SAVE_ALL
	move	#0x2000,%sr		/* enable intrs again */

	cmpl	#NR_syscalls,%d0
	jcc	enosys
	lea	sys_call_table,%a0
	lsll	#2,%d0			/* movel %a0@(%d0:l:4),%d3 */
	movel	%a0@(%d0),%d3
	jeq	enosys

1:
	movel	%sp,%d2			/* get thread_info pointer */
	andl	#-THREAD_SIZE,%d2	/* at start of kernel stack */
	movel	%d2,%a0
	movel	%a0@,%a1		/* save top of frame */
	movel	%sp,%a1@(TASK_THREAD+THREAD_ESP0)
	btst	#(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
	bnes	1f

	movel	%d3,%a0
	jbsr	%a0@
	movel	%d0,%sp@(PT_OFF_D0)	/* save the return value */
	jra	ret_from_exception
1:
	movel	#-ENOSYS,%d2		/* strace needs -ENOSYS in PT_OFF_D0 */
	movel	%d2,PT_OFF_D0(%sp)	/* on syscall entry */
	subql	#4,%sp
	SAVE_SWITCH_STACK
	jbsr	syscall_trace_enter
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	movel	%d3,%a0
	jbsr	%a0@
	movel	%d0,%sp@(PT_OFF_D0)		/* save the return value */
	subql	#4,%sp			/* dummy return address */
	SAVE_SWITCH_STACK
	jbsr	syscall_trace_leave

ret_from_signal:
	RESTORE_SWITCH_STACK
	addql	#4,%sp

ret_from_exception:
	move	#0x2700,%sr		/* disable intrs */
	btst	#5,%sp@(PT_OFF_SR)	/* check if returning to kernel */
	jeq	Luser_return		/* if so, skip resched, signals */

#ifdef CONFIG_PREEMPT
	movel	%sp,%d1			/* get thread_info pointer */
	andl	#-THREAD_SIZE,%d1	/* at base of kernel stack */
	movel	%d1,%a0
	movel	%a0@(TINFO_FLAGS),%d1	/* get thread_info->flags */
	andl	#(1<<TIF_NEED_RESCHED),%d1
	jeq	Lkernel_return

	movel	%a0@(TINFO_PREEMPT),%d1
	cmpl	#0,%d1
	jne	Lkernel_return

	pea	Lkernel_return
	jmp	preempt_schedule_irq	/* preempt the kernel */
#endif

Lkernel_return:
	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		/* stk adj */
	rte

Luser_return:
	movel	%sp,%d1			/* get thread_info pointer */
	andl	#-THREAD_SIZE,%d1	/* at base of kernel stack */
	movel	%d1,%a0
	movel	%a0@(TINFO_FLAGS),%d1	/* get thread_info->flags */
	jne	Lwork_to_do		/* still work to do */

Lreturn:
	RESTORE_USER

Lwork_to_do:
	movel	%a0@(TINFO_FLAGS),%d1	/* get thread_info->flags */
	move	#0x2000,%sr		/* enable intrs again */
	btst	#TIF_NEED_RESCHED,%d1
	jne	reschedule

	/* GERG: do we need something here for TRACEing?? */

Lsignal_return:
	subql	#4,%sp			/* dummy return address */
	SAVE_SWITCH_STACK
	pea	%sp@(SWITCH_STACK_SIZE)
	jsr	do_signal
	addql	#4,%sp
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	jmp	Luser_return

/*
 * This is the generic interrupt handler (for all hardware interrupt
 * sources). Calls up to high level code to do all the work.
 */
ENTRY(inthandler)
	SAVE_ALL
	moveq	#-1,%d0
	movel	%d0,%sp@(PT_OFF_ORIG_D0)

	movew	%sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
	andl	#0x03fc,%d0		/* mask out vector only */

	movel	%sp,%sp@-		/* push regs arg */
	lsrl	#2,%d0			/* calculate real vector # */
	movel	%d0,%sp@-		/* push vector number */
	jbsr	do_IRQ			/* call high level irq handler */
	lea	%sp@(8),%sp		/* pop args off stack */

	bra	ret_from_exception

/*
 * Beware - when entering resume, prev (the current task) is
 * in a0, next (the new task) is in a1,so don't change these
 * registers until their contents are no longer needed.
 * This is always called in supervisor mode, so don't bother to save
 * and restore sr; user's process sr is actually in the stack.
 */
ENTRY(resume)
	movel	%a0, %d1			/* get prev thread in d1 */
	RDUSP
	movel	%a2,%a0@(TASK_THREAD+THREAD_USP)

	SAVE_SWITCH_STACK
	movel	%sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
	movel	%a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
	RESTORE_SWITCH_STACK

	movel	%a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
	WRUSP
	rts