aboutsummaryrefslogtreecommitdiff
path: root/arch/m68knommu/platform/5307/entry.S
blob: b333731b875a81de24c5ea29fee216a0c75bcfbb (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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/*
 *  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/sys.h>
#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>

.bss

sw_ksp:
.long	0

sw_usp:
.long	0

.text

.globl system_call
.globl resume
.globl ret_from_exception
.globl ret_from_signal
.globl sys_call_table
.globl ret_from_interrupt
.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@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
	bnes	1f

	movel	%d3,%a0
	jbsr	%a0@
	movel	%d0,%sp@(PT_D0)		/* save the return value */
	jra	ret_from_exception
1:
	movel	#-ENOSYS,%d2		/* strace needs -ENOSYS in PT_D0 */
	movel	%d2,PT_D0(%sp)		/* on syscall entry */
	subql	#4,%sp
	SAVE_SWITCH_STACK
	jbsr	syscall_trace
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	movel	%d3,%a0
	jbsr	%a0@
	movel	%d0,%sp@(PT_D0)		/* save the return value */
	subql	#4,%sp			/* dummy return address */
	SAVE_SWITCH_STACK
	jbsr	syscall_trace

ret_from_signal:
	RESTORE_SWITCH_STACK
	addql	#4,%sp

ret_from_exception:
	btst	#5,%sp@(PT_SR)		/* check if returning to kernel */
	jeq	Luser_return		/* if so, skip resched, signals */

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@(TI_FLAGS),%d1	/* get thread_info->flags */
	andl	#_TIF_WORK_MASK,%d1
	jne	Lwork_to_do		/* still work to do */

Lreturn:
	move	#0x2700,%sr		/* disable intrs */
	movel	sw_usp,%a0		/* get usp */
	movel	%sp@(PT_PC),%a0@-	/* copy exception program counter */
	movel	%sp@(PT_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		/* stk adj */
	addql	#8,%sp			/* remove exception */
	movel	%sp,sw_ksp		/* save ksp */
	subql	#8,sw_usp		/* set exception */
	movel	sw_usp,%sp		/* restore usp */
	rte

Lwork_to_do:
	movel	%a0@(TI_FLAGS),%d1	/* get thread_info->flags */
	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)
	clrl	%sp@-
	jsr	do_signal
	addql	#8,%sp
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	jmp	Lreturn

/*
 * This is the generic interrupt handler (for all hardware interrupt
 * sources). Calls upto high level code to do all the work.
 */
ENTRY(inthandler)
	SAVE_ALL
	moveq	#-1,%d0
	movel	%d0,%sp@(PT_ORIG_D0)

	movew	%sp@(PT_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_interrupt	/* this was fallthrough */

/*
 * This is the fast interrupt handler (for certain hardware interrupt
 * sources). Unlike the normal interrupt handler it just uses the
 * current stack (doesn't care if it is user or kernel). It also
 * doesn't bother doing the bottom half handlers.
 */
ENTRY(fasthandler)
	SAVE_LOCAL

	movew	%sp@(PT_FORMATVEC),%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 */

	RESTORE_LOCAL

ENTRY(ret_from_interrupt)
	jeq	2f
1:
	RESTORE_ALL
2:
	moveb	%sp@(PT_SR),%d0
	andl	#0x7,%d0
	jhi	1b

	/* check if we need to do software interrupts */
	movel	irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0
	jeq	ret_from_exception

	pea	ret_from_exception
	jmp	do_softirq

/*
 * 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 */

	movel	sw_usp,%d0			/* save usp */
	movel	%d0,%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 */
	movel	%a0, sw_usp
	rts