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-rw-r--r--arch/m68k/platform/68000/entry.S261
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diff --git a/arch/m68k/platform/68000/entry.S b/arch/m68k/platform/68000/entry.S
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1/*
2 * linux/arch/m68knommu/platform/68328/entry.S
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file README.legal in the main directory of this archive
8 * for more details.
9 *
10 * Linux/m68k support by Hamish Macdonald
11 */
12
13#include <linux/linkage.h>
14#include <asm/thread_info.h>
15#include <asm/unistd.h>
16#include <asm/errno.h>
17#include <asm/setup.h>
18#include <asm/segment.h>
19#include <asm/traps.h>
20#include <asm/asm-offsets.h>
21#include <asm/entry.h>
22
23.text
24
25.globl system_call
26.globl resume
27.globl ret_from_exception
28.globl ret_from_signal
29.globl sys_call_table
30.globl ret_from_interrupt
31.globl bad_interrupt
32.globl inthandler1
33.globl inthandler2
34.globl inthandler3
35.globl inthandler4
36.globl inthandler5
37.globl inthandler6
38.globl inthandler7
39
40badsys:
41 movel #-ENOSYS,%sp@(PT_OFF_D0)
42 jra ret_from_exception
43
44do_trace:
45 movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/
46 subql #4,%sp
47 SAVE_SWITCH_STACK
48 jbsr syscall_trace_enter
49 RESTORE_SWITCH_STACK
50 addql #4,%sp
51 movel %sp@(PT_OFF_ORIG_D0),%d1
52 movel #-ENOSYS,%d0
53 cmpl #NR_syscalls,%d1
54 jcc 1f
55 lsl #2,%d1
56 lea sys_call_table, %a0
57 jbsr %a0@(%d1)
58
591: movel %d0,%sp@(PT_OFF_D0) /* save the return value */
60 subql #4,%sp /* dummy return address */
61 SAVE_SWITCH_STACK
62 jbsr syscall_trace_leave
63
64ret_from_signal:
65 RESTORE_SWITCH_STACK
66 addql #4,%sp
67 jra ret_from_exception
68
69ENTRY(system_call)
70 SAVE_ALL_SYS
71
72 /* save top of frame*/
73 pea %sp@
74 jbsr set_esp0
75 addql #4,%sp
76
77 movel %sp@(PT_OFF_ORIG_D0),%d0
78
79 movel %sp,%d1 /* get thread_info pointer */
80 andl #-THREAD_SIZE,%d1
81 movel %d1,%a2
82 btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
83 jne do_trace
84 cmpl #NR_syscalls,%d0
85 jcc badsys
86 lsl #2,%d0
87 lea sys_call_table,%a0
88 movel %a0@(%d0), %a0
89 jbsr %a0@
90 movel %d0,%sp@(PT_OFF_D0) /* save the return value*/
91
92ret_from_exception:
93 btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/
94 jeq Luser_return /* if so, skip resched, signals*/
95
96Lkernel_return:
97 RESTORE_ALL
98
99Luser_return:
100 /* only allow interrupts when we are really the last one on the*/
101 /* kernel stack, otherwise stack overflow can occur during*/
102 /* heavy interrupt load*/
103 andw #ALLOWINT,%sr
104
105 movel %sp,%d1 /* get thread_info pointer */
106 andl #-THREAD_SIZE,%d1
107 movel %d1,%a2
1081:
109 move %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */
110 jne Lwork_to_do
111 RESTORE_ALL
112
113Lwork_to_do:
114 movel %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */
115 btst #TIF_NEED_RESCHED,%d1
116 jne reschedule
117
118Lsignal_return:
119 subql #4,%sp /* dummy return address*/
120 SAVE_SWITCH_STACK
121 pea %sp@(SWITCH_STACK_SIZE)
122 bsrw do_notify_resume
123 addql #4,%sp
124 RESTORE_SWITCH_STACK
125 addql #4,%sp
126 jra 1b
127
128/*
129 * This is the main interrupt handler, responsible for calling process_int()
130 */
131inthandler1:
132 SAVE_ALL_INT
133 movew %sp@(PT_OFF_FORMATVEC), %d0
134 and #0x3ff, %d0
135
136 movel %sp,%sp@-
137 movel #65,%sp@- /* put vector # on stack*/
138 jbsr process_int /* process the IRQ*/
1393: addql #8,%sp /* pop parameters off stack*/
140 bra ret_from_interrupt
141
142inthandler2:
143 SAVE_ALL_INT
144 movew %sp@(PT_OFF_FORMATVEC), %d0
145 and #0x3ff, %d0
146
147 movel %sp,%sp@-
148 movel #66,%sp@- /* put vector # on stack*/
149 jbsr process_int /* process the IRQ*/
1503: addql #8,%sp /* pop parameters off stack*/
151 bra ret_from_interrupt
152
153inthandler3:
154 SAVE_ALL_INT
155 movew %sp@(PT_OFF_FORMATVEC), %d0
156 and #0x3ff, %d0
157
158 movel %sp,%sp@-
159 movel #67,%sp@- /* put vector # on stack*/
160 jbsr process_int /* process the IRQ*/
1613: addql #8,%sp /* pop parameters off stack*/
162 bra ret_from_interrupt
163
164inthandler4:
165 SAVE_ALL_INT
166 movew %sp@(PT_OFF_FORMATVEC), %d0
167 and #0x3ff, %d0
168
169 movel %sp,%sp@-
170 movel #68,%sp@- /* put vector # on stack*/
171 jbsr process_int /* process the IRQ*/
1723: addql #8,%sp /* pop parameters off stack*/
173 bra ret_from_interrupt
174
175inthandler5:
176 SAVE_ALL_INT
177 movew %sp@(PT_OFF_FORMATVEC), %d0
178 and #0x3ff, %d0
179
180 movel %sp,%sp@-
181 movel #69,%sp@- /* put vector # on stack*/
182 jbsr process_int /* process the IRQ*/
1833: addql #8,%sp /* pop parameters off stack*/
184 bra ret_from_interrupt
185
186inthandler6:
187 SAVE_ALL_INT
188 movew %sp@(PT_OFF_FORMATVEC), %d0
189 and #0x3ff, %d0
190
191 movel %sp,%sp@-
192 movel #70,%sp@- /* put vector # on stack*/
193 jbsr process_int /* process the IRQ*/
1943: addql #8,%sp /* pop parameters off stack*/
195 bra ret_from_interrupt
196
197inthandler7:
198 SAVE_ALL_INT
199 movew %sp@(PT_OFF_FORMATVEC), %d0
200 and #0x3ff, %d0
201
202 movel %sp,%sp@-
203 movel #71,%sp@- /* put vector # on stack*/
204 jbsr process_int /* process the IRQ*/
2053: addql #8,%sp /* pop parameters off stack*/
206 bra ret_from_interrupt
207
208inthandler:
209 SAVE_ALL_INT
210 movew %sp@(PT_OFF_FORMATVEC), %d0
211 and #0x3ff, %d0
212
213 movel %sp,%sp@-
214 movel %d0,%sp@- /* put vector # on stack*/
215 jbsr process_int /* process the IRQ*/
2163: addql #8,%sp /* pop parameters off stack*/
217 bra ret_from_interrupt
218
219ret_from_interrupt:
220 jeq 1f
2212:
222 RESTORE_ALL
2231:
224 moveb %sp@(PT_OFF_SR), %d0
225 and #7, %d0
226 jhi 2b
227
228 /* check if we need to do software interrupts */
229 jeq ret_from_exception
230
231 pea ret_from_exception
232 jra do_softirq
233
234
235/*
236 * Handler for uninitialized and spurious interrupts.
237 */
238ENTRY(bad_interrupt)
239 addql #1,irq_err_count
240 rte
241
242/*
243 * Beware - when entering resume, prev (the current task) is
244 * in a0, next (the new task) is in a1, so don't change these
245 * registers until their contents are no longer needed.
246 */
247ENTRY(resume)
248 movel %a0,%d1 /* save prev thread in d1 */
249 movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */
250 SAVE_SWITCH_STACK
251 movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
252 movel %usp,%a3 /* save usp */
253 movel %a3,%a0@(TASK_THREAD+THREAD_USP)
254
255 movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */
256 movel %a3,%usp
257 movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
258 RESTORE_SWITCH_STACK
259 movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */
260 rts
261