1 | /* SPDX-License-Identifier: GPL-2.0-or-later |
2 | * |
3 | * entry.S -- non-mmu 68000 interrupt and exception entry points |
4 | * |
5 | * Copyright (C) 1991, 1992 Linus Torvalds |
6 | * |
7 | * Linux/m68k support by Hamish Macdonald |
8 | */ |
9 | |
10 | #include <linux/linkage.h> |
11 | #include <asm/thread_info.h> |
12 | #include <asm/unistd.h> |
13 | #include <asm/errno.h> |
14 | #include <asm/setup.h> |
15 | #include <asm/traps.h> |
16 | #include <asm/asm-offsets.h> |
17 | #include <asm/entry.h> |
18 | |
19 | .text |
20 | |
21 | .globl system_call |
22 | .globl resume |
23 | .globl ret_from_exception |
24 | .globl sys_call_table |
25 | .globl bad_interrupt |
26 | .globl inthandler1 |
27 | .globl inthandler2 |
28 | .globl inthandler3 |
29 | .globl inthandler4 |
30 | .globl inthandler5 |
31 | .globl inthandler6 |
32 | .globl inthandler7 |
33 | |
34 | badsys: |
35 | movel #-ENOSYS,%sp@(PT_OFF_D0) |
36 | jra ret_from_exception |
37 | |
38 | do_trace: |
39 | movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ |
40 | subql #4,%sp |
41 | SAVE_SWITCH_STACK |
42 | jbsr syscall_trace_enter |
43 | RESTORE_SWITCH_STACK |
44 | addql #4,%sp |
45 | addql #1,%d0 |
46 | jeq ret_from_exception |
47 | movel %sp@(PT_OFF_ORIG_D0),%d1 |
48 | movel #-ENOSYS,%d0 |
49 | cmpl #NR_syscalls,%d1 |
50 | jcc 1f |
51 | lsl #2,%d1 |
52 | lea sys_call_table, %a0 |
53 | jbsr %a0@(%d1) |
54 | |
55 | 1: movel %d0,%sp@(PT_OFF_D0) /* save the return value */ |
56 | subql #4,%sp /* dummy return address */ |
57 | SAVE_SWITCH_STACK |
58 | jbsr syscall_trace_leave |
59 | RESTORE_SWITCH_STACK |
60 | addql #4,%sp |
61 | jra ret_from_exception |
62 | |
63 | ENTRY(system_call) |
64 | SAVE_ALL_SYS |
65 | |
66 | /* save top of frame*/ |
67 | pea %sp@ |
68 | jbsr set_esp0 |
69 | addql #4,%sp |
70 | |
71 | movel %sp@(PT_OFF_ORIG_D0),%d0 |
72 | |
73 | movel %sp,%d1 /* get thread_info pointer */ |
74 | andl #-THREAD_SIZE,%d1 |
75 | movel %d1,%a2 |
76 | btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) |
77 | jne do_trace |
78 | cmpl #NR_syscalls,%d0 |
79 | jcc badsys |
80 | lsl #2,%d0 |
81 | lea sys_call_table,%a0 |
82 | movel %a0@(%d0), %a0 |
83 | jbsr %a0@ |
84 | movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ |
85 | |
86 | ret_from_exception: |
87 | btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ |
88 | jeq Luser_return /* if so, skip resched, signals*/ |
89 | |
90 | Lkernel_return: |
91 | RESTORE_ALL |
92 | |
93 | Luser_return: |
94 | /* only allow interrupts when we are really the last one on the*/ |
95 | /* kernel stack, otherwise stack overflow can occur during*/ |
96 | /* heavy interrupt load*/ |
97 | andw #ALLOWINT,%sr |
98 | |
99 | movel %sp,%d1 /* get thread_info pointer */ |
100 | andl #-THREAD_SIZE,%d1 |
101 | movel %d1,%a2 |
102 | 1: |
103 | move %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ |
104 | jne Lwork_to_do |
105 | RESTORE_ALL |
106 | |
107 | Lwork_to_do: |
108 | movel %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */ |
109 | btst #TIF_NEED_RESCHED,%d1 |
110 | jne reschedule |
111 | |
112 | Lsignal_return: |
113 | subql #4,%sp /* dummy return address*/ |
114 | SAVE_SWITCH_STACK |
115 | pea %sp@(SWITCH_STACK_SIZE) |
116 | bsrw do_notify_resume |
117 | addql #4,%sp |
118 | RESTORE_SWITCH_STACK |
119 | addql #4,%sp |
120 | jra 1b |
121 | |
122 | /* |
123 | * This is the main interrupt handler, responsible for calling process_int() |
124 | */ |
125 | inthandler1: |
126 | SAVE_ALL_INT |
127 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
128 | and #0x3ff, %d0 |
129 | |
130 | movel %sp,%sp@- |
131 | movel #65,%sp@- /* put vector # on stack*/ |
132 | jbsr process_int /* process the IRQ*/ |
133 | 3: addql #8,%sp /* pop parameters off stack*/ |
134 | bra ret_from_exception |
135 | |
136 | inthandler2: |
137 | SAVE_ALL_INT |
138 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
139 | and #0x3ff, %d0 |
140 | |
141 | movel %sp,%sp@- |
142 | movel #66,%sp@- /* put vector # on stack*/ |
143 | jbsr process_int /* process the IRQ*/ |
144 | 3: addql #8,%sp /* pop parameters off stack*/ |
145 | bra ret_from_exception |
146 | |
147 | inthandler3: |
148 | SAVE_ALL_INT |
149 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
150 | and #0x3ff, %d0 |
151 | |
152 | movel %sp,%sp@- |
153 | movel #67,%sp@- /* put vector # on stack*/ |
154 | jbsr process_int /* process the IRQ*/ |
155 | 3: addql #8,%sp /* pop parameters off stack*/ |
156 | bra ret_from_exception |
157 | |
158 | inthandler4: |
159 | SAVE_ALL_INT |
160 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
161 | and #0x3ff, %d0 |
162 | |
163 | movel %sp,%sp@- |
164 | movel #68,%sp@- /* put vector # on stack*/ |
165 | jbsr process_int /* process the IRQ*/ |
166 | 3: addql #8,%sp /* pop parameters off stack*/ |
167 | bra ret_from_exception |
168 | |
169 | inthandler5: |
170 | SAVE_ALL_INT |
171 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
172 | and #0x3ff, %d0 |
173 | |
174 | movel %sp,%sp@- |
175 | movel #69,%sp@- /* put vector # on stack*/ |
176 | jbsr process_int /* process the IRQ*/ |
177 | 3: addql #8,%sp /* pop parameters off stack*/ |
178 | bra ret_from_exception |
179 | |
180 | inthandler6: |
181 | SAVE_ALL_INT |
182 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
183 | and #0x3ff, %d0 |
184 | |
185 | movel %sp,%sp@- |
186 | movel #70,%sp@- /* put vector # on stack*/ |
187 | jbsr process_int /* process the IRQ*/ |
188 | 3: addql #8,%sp /* pop parameters off stack*/ |
189 | bra ret_from_exception |
190 | |
191 | inthandler7: |
192 | SAVE_ALL_INT |
193 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
194 | and #0x3ff, %d0 |
195 | |
196 | movel %sp,%sp@- |
197 | movel #71,%sp@- /* put vector # on stack*/ |
198 | jbsr process_int /* process the IRQ*/ |
199 | 3: addql #8,%sp /* pop parameters off stack*/ |
200 | bra ret_from_exception |
201 | |
202 | inthandler: |
203 | SAVE_ALL_INT |
204 | movew %sp@(PT_OFF_FORMATVEC), %d0 |
205 | and #0x3ff, %d0 |
206 | |
207 | movel %sp,%sp@- |
208 | movel %d0,%sp@- /* put vector # on stack*/ |
209 | jbsr process_int /* process the IRQ*/ |
210 | 3: addql #8,%sp /* pop parameters off stack*/ |
211 | bra ret_from_exception |
212 | |
213 | /* |
214 | * Handler for uninitialized and spurious interrupts. |
215 | */ |
216 | ENTRY(bad_interrupt) |
217 | addql #1,irq_err_count |
218 | rte |
219 | |
220 | /* |
221 | * Beware - when entering resume, prev (the current task) is |
222 | * in a0, next (the new task) is in a1, so don't change these |
223 | * registers until their contents are no longer needed. |
224 | */ |
225 | ENTRY(resume) |
226 | movel %a0,%d1 /* save prev thread in d1 */ |
227 | movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ |
228 | SAVE_SWITCH_STACK |
229 | movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ |
230 | movel %usp,%a3 /* save usp */ |
231 | movel %a3,%a0@(TASK_THREAD+THREAD_USP) |
232 | |
233 | movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */ |
234 | movel %a3,%usp |
235 | movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ |
236 | RESTORE_SWITCH_STACK |
237 | movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ |
238 | rts |
239 | |
240 | |