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1 | /* -*- mode: asm -*- |
2 | * | |
3 | * linux/arch/m68k/kernel/entry.S | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | * | |
7 | * This file is subject to the terms and conditions of the GNU General Public | |
8 | * License. See the file README.legal in the main directory of this archive | |
9 | * for more details. | |
10 | * | |
11 | * Linux/m68k support by Hamish Macdonald | |
12 | * | |
13 | * 68060 fixes by Jesper Skov | |
14 | * | |
15 | */ | |
16 | ||
17 | /* | |
18 | * entry.S contains the system-call and fault low-level handling routines. | |
19 | * This also contains the timer-interrupt handler, as well as all interrupts | |
20 | * and faults that can result in a task-switch. | |
21 | * | |
22 | * NOTE: This code handles signal-recognition, which happens every time | |
23 | * after a timer-interrupt and after each system call. | |
24 | * | |
25 | */ | |
26 | ||
27 | /* | |
28 | * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so | |
29 | * all pointers that used to be 'current' are now entry | |
30 | * number 0 in the 'current_set' list. | |
31 | * | |
32 | * 6/05/00 RZ: addedd writeback completion after return from sighandler | |
33 | * for 68040 | |
34 | */ | |
35 | ||
36 | #include <linux/linkage.h> | |
37 | #include <asm/errno.h> | |
38 | #include <asm/setup.h> | |
39 | #include <asm/segment.h> | |
40 | #include <asm/traps.h> | |
41 | #include <asm/unistd.h> | |
42 | #include <asm/asm-offsets.h> | |
43 | #include <asm/entry.h> | |
44 | ||
45 | .globl system_call, buserr, trap, resume | |
46 | .globl sys_call_table | |
20ecc91c | 47 | .globl __sys_fork, __sys_clone, __sys_vfork |
09f90f66 | 48 | .globl bad_interrupt |
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49 | .globl auto_irqhandler_fixup |
50 | .globl user_irqvec_fixup | |
51 | ||
52 | .text | |
20ecc91c | 53 | ENTRY(__sys_fork) |
14be4252 | 54 | SAVE_SWITCH_STACK |
20ecc91c AV |
55 | jbsr sys_fork |
56 | lea %sp@(24),%sp | |
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57 | rts |
58 | ||
20ecc91c | 59 | ENTRY(__sys_clone) |
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60 | SAVE_SWITCH_STACK |
61 | pea %sp@(SWITCH_STACK_SIZE) | |
62 | jbsr m68k_clone | |
20ecc91c | 63 | lea %sp@(28),%sp |
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64 | rts |
65 | ||
20ecc91c | 66 | ENTRY(__sys_vfork) |
14be4252 | 67 | SAVE_SWITCH_STACK |
20ecc91c AV |
68 | jbsr sys_vfork |
69 | lea %sp@(24),%sp | |
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70 | rts |
71 | ||
72 | ENTRY(sys_sigreturn) | |
73 | SAVE_SWITCH_STACK | |
a9551799 GU |
74 | movel %sp,%sp@- | switch_stack pointer |
75 | pea %sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer | |
14be4252 | 76 | jbsr do_sigreturn |
a9551799 | 77 | addql #8,%sp |
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78 | RESTORE_SWITCH_STACK |
79 | rts | |
80 | ||
81 | ENTRY(sys_rt_sigreturn) | |
82 | SAVE_SWITCH_STACK | |
a9551799 GU |
83 | movel %sp,%sp@- | switch_stack pointer |
84 | pea %sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer | |
14be4252 | 85 | jbsr do_rt_sigreturn |
a9551799 | 86 | addql #8,%sp |
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87 | RESTORE_SWITCH_STACK |
88 | rts | |
89 | ||
90 | ENTRY(buserr) | |
91 | SAVE_ALL_INT | |
92 | GET_CURRENT(%d0) | |
93 | movel %sp,%sp@- | stack frame pointer argument | |
94 | jbsr buserr_c | |
95 | addql #4,%sp | |
96 | jra ret_from_exception | |
97 | ||
98 | ENTRY(trap) | |
99 | SAVE_ALL_INT | |
100 | GET_CURRENT(%d0) | |
101 | movel %sp,%sp@- | stack frame pointer argument | |
102 | jbsr trap_c | |
103 | addql #4,%sp | |
104 | jra ret_from_exception | |
105 | ||
106 | | After a fork we jump here directly from resume, | |
107 | | so that %d1 contains the previous task | |
108 | | schedule_tail now used regardless of CONFIG_SMP | |
109 | ENTRY(ret_from_fork) | |
110 | movel %d1,%sp@- | |
111 | jsr schedule_tail | |
112 | addql #4,%sp | |
113 | jra ret_from_exception | |
114 | ||
533e6903 AV |
115 | ENTRY(ret_from_kernel_thread) |
116 | | a3 contains the kernel thread payload, d7 - its argument | |
117 | movel %d1,%sp@- | |
118 | jsr schedule_tail | |
533e6903 AV |
119 | movel %d7,(%sp) |
120 | jsr %a3@ | |
121 | addql #4,%sp | |
d878d6da AV |
122 | jra ret_from_exception |
123 | ||
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124 | #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU) |
125 | ||
126 | #ifdef TRAP_DBG_INTERRUPT | |
127 | ||
128 | .globl dbginterrupt | |
129 | ENTRY(dbginterrupt) | |
130 | SAVE_ALL_INT | |
131 | GET_CURRENT(%d0) | |
132 | movel %sp,%sp@- /* stack frame pointer argument */ | |
133 | jsr dbginterrupt_c | |
134 | addql #4,%sp | |
135 | jra ret_from_exception | |
136 | #endif | |
137 | ||
138 | ENTRY(reschedule) | |
139 | /* save top of frame */ | |
140 | pea %sp@ | |
141 | jbsr set_esp0 | |
142 | addql #4,%sp | |
143 | pea ret_from_exception | |
144 | jmp schedule | |
145 | ||
146 | ENTRY(ret_from_user_signal) | |
147 | moveq #__NR_sigreturn,%d0 | |
148 | trap #0 | |
149 | ||
150 | ENTRY(ret_from_user_rt_signal) | |
151 | movel #__NR_rt_sigreturn,%d0 | |
152 | trap #0 | |
153 | ||
66d857b0 | 154 | #else |
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155 | |
156 | do_trace_entry: | |
157 | movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace | |
158 | subql #4,%sp | |
159 | SAVE_SWITCH_STACK | |
160 | jbsr syscall_trace | |
161 | RESTORE_SWITCH_STACK | |
162 | addql #4,%sp | |
163 | movel %sp@(PT_OFF_ORIG_D0),%d0 | |
164 | cmpl #NR_syscalls,%d0 | |
165 | jcs syscall | |
166 | badsys: | |
167 | movel #-ENOSYS,%sp@(PT_OFF_D0) | |
168 | jra ret_from_syscall | |
169 | ||
170 | do_trace_exit: | |
171 | subql #4,%sp | |
172 | SAVE_SWITCH_STACK | |
173 | jbsr syscall_trace | |
174 | RESTORE_SWITCH_STACK | |
175 | addql #4,%sp | |
176 | jra .Lret_from_exception | |
177 | ||
178 | ENTRY(ret_from_signal) | |
179 | movel %curptr@(TASK_STACK),%a1 | |
180 | tstb %a1@(TINFO_FLAGS+2) | |
181 | jge 1f | |
182 | jbsr syscall_trace | |
183 | 1: RESTORE_SWITCH_STACK | |
184 | addql #4,%sp | |
185 | /* on 68040 complete pending writebacks if any */ | |
186 | #ifdef CONFIG_M68040 | |
187 | bfextu %sp@(PT_OFF_FORMATVEC){#0,#4},%d0 | |
188 | subql #7,%d0 | bus error frame ? | |
189 | jbne 1f | |
190 | movel %sp,%sp@- | |
191 | jbsr berr_040cleanup | |
192 | addql #4,%sp | |
193 | 1: | |
194 | #endif | |
195 | jra .Lret_from_exception | |
196 | ||
197 | ENTRY(system_call) | |
198 | SAVE_ALL_SYS | |
199 | ||
200 | GET_CURRENT(%d1) | |
201 | movel %d1,%a1 | |
202 | ||
203 | | save top of frame | |
204 | movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0) | |
205 | ||
206 | | syscall trace? | |
207 | tstb %a1@(TINFO_FLAGS+2) | |
208 | jmi do_trace_entry | |
209 | cmpl #NR_syscalls,%d0 | |
210 | jcc badsys | |
211 | syscall: | |
212 | jbsr @(sys_call_table,%d0:l:4)@(0) | |
213 | movel %d0,%sp@(PT_OFF_D0) | save the return value | |
214 | ret_from_syscall: | |
215 | |oriw #0x0700,%sr | |
216 | movel %curptr@(TASK_STACK),%a1 | |
217 | movew %a1@(TINFO_FLAGS+2),%d0 | |
218 | jne syscall_exit_work | |
219 | 1: RESTORE_ALL | |
220 | ||
221 | syscall_exit_work: | |
222 | btst #5,%sp@(PT_OFF_SR) | check if returning to kernel | |
223 | bnes 1b | if so, skip resched, signals | |
224 | lslw #1,%d0 | |
225 | jcs do_trace_exit | |
226 | jmi do_delayed_trace | |
227 | lslw #8,%d0 | |
228 | jne do_signal_return | |
229 | pea resume_userspace | |
230 | jra schedule | |
231 | ||
232 | ||
233 | ENTRY(ret_from_exception) | |
234 | .Lret_from_exception: | |
235 | btst #5,%sp@(PT_OFF_SR) | check if returning to kernel | |
236 | bnes 1f | if so, skip resched, signals | |
237 | | only allow interrupts when we are really the last one on the | |
238 | | kernel stack, otherwise stack overflow can occur during | |
239 | | heavy interrupt load | |
240 | andw #ALLOWINT,%sr | |
241 | ||
242 | resume_userspace: | |
243 | movel %curptr@(TASK_STACK),%a1 | |
244 | moveb %a1@(TINFO_FLAGS+3),%d0 | |
245 | jne exit_work | |
246 | 1: RESTORE_ALL | |
247 | ||
248 | exit_work: | |
249 | | save top of frame | |
250 | movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0) | |
251 | lslb #1,%d0 | |
252 | jne do_signal_return | |
253 | pea resume_userspace | |
254 | jra schedule | |
255 | ||
256 | ||
257 | do_signal_return: | |
258 | |andw #ALLOWINT,%sr | |
259 | subql #4,%sp | dummy return address | |
260 | SAVE_SWITCH_STACK | |
261 | pea %sp@(SWITCH_STACK_SIZE) | |
262 | bsrl do_notify_resume | |
263 | addql #4,%sp | |
264 | RESTORE_SWITCH_STACK | |
265 | addql #4,%sp | |
266 | jbra resume_userspace | |
267 | ||
268 | do_delayed_trace: | |
269 | bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR | |
270 | pea 1 | send SIGTRAP | |
271 | movel %curptr,%sp@- | |
272 | pea LSIGTRAP | |
273 | jbsr send_sig | |
274 | addql #8,%sp | |
275 | addql #4,%sp | |
276 | jbra resume_userspace | |
277 | ||
278 | ||
279 | /* This is the main interrupt handler for autovector interrupts */ | |
280 | ||
281 | ENTRY(auto_inthandler) | |
282 | SAVE_ALL_INT | |
283 | GET_CURRENT(%d0) | |
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284 | | put exception # in d0 |
285 | bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0 | |
286 | subw #VEC_SPUR,%d0 | |
287 | ||
288 | movel %sp,%sp@- | |
289 | movel %d0,%sp@- | put vector # on stack | |
290 | auto_irqhandler_fixup = . + 2 | |
291 | jsr do_IRQ | process the IRQ | |
292 | addql #8,%sp | pop parameters off stack | |
09f90f66 | 293 | jra ret_from_exception |
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294 | |
295 | /* Handler for user defined interrupt vectors */ | |
296 | ||
297 | ENTRY(user_inthandler) | |
298 | SAVE_ALL_INT | |
299 | GET_CURRENT(%d0) | |
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300 | | put exception # in d0 |
301 | bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0 | |
302 | user_irqvec_fixup = . + 2 | |
303 | subw #VEC_USER,%d0 | |
304 | ||
305 | movel %sp,%sp@- | |
306 | movel %d0,%sp@- | put vector # on stack | |
307 | jsr do_IRQ | process the IRQ | |
308 | addql #8,%sp | pop parameters off stack | |
09f90f66 | 309 | jra ret_from_exception |
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310 | |
311 | /* Handler for uninitialized and spurious interrupts */ | |
312 | ||
313 | ENTRY(bad_inthandler) | |
314 | SAVE_ALL_INT | |
315 | GET_CURRENT(%d0) | |
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316 | |
317 | movel %sp,%sp@- | |
318 | jsr handle_badint | |
319 | addql #4,%sp | |
09f90f66 | 320 | jra ret_from_exception |
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321 | |
322 | resume: | |
323 | /* | |
324 | * Beware - when entering resume, prev (the current task) is | |
325 | * in a0, next (the new task) is in a1,so don't change these | |
326 | * registers until their contents are no longer needed. | |
327 | */ | |
328 | ||
329 | /* save sr */ | |
330 | movew %sr,%a0@(TASK_THREAD+THREAD_SR) | |
331 | ||
332 | /* save fs (sfc,%dfc) (may be pointing to kernel memory) */ | |
333 | movec %sfc,%d0 | |
334 | movew %d0,%a0@(TASK_THREAD+THREAD_FS) | |
335 | ||
336 | /* save usp */ | |
337 | /* it is better to use a movel here instead of a movew 8*) */ | |
338 | movec %usp,%d0 | |
339 | movel %d0,%a0@(TASK_THREAD+THREAD_USP) | |
340 | ||
341 | /* save non-scratch registers on stack */ | |
342 | SAVE_SWITCH_STACK | |
343 | ||
344 | /* save current kernel stack pointer */ | |
345 | movel %sp,%a0@(TASK_THREAD+THREAD_KSP) | |
346 | ||
347 | /* save floating point context */ | |
348 | #ifndef CONFIG_M68KFPU_EMU_ONLY | |
349 | #ifdef CONFIG_M68KFPU_EMU | |
350 | tstl m68k_fputype | |
351 | jeq 3f | |
352 | #endif | |
353 | fsave %a0@(TASK_THREAD+THREAD_FPSTATE) | |
354 | ||
355 | #if defined(CONFIG_M68060) | |
356 | #if !defined(CPU_M68060_ONLY) | |
357 | btst #3,m68k_cputype+3 | |
358 | beqs 1f | |
359 | #endif | |
360 | /* The 060 FPU keeps status in bits 15-8 of the first longword */ | |
361 | tstb %a0@(TASK_THREAD+THREAD_FPSTATE+2) | |
362 | jeq 3f | |
363 | #if !defined(CPU_M68060_ONLY) | |
364 | jra 2f | |
365 | #endif | |
366 | #endif /* CONFIG_M68060 */ | |
367 | #if !defined(CPU_M68060_ONLY) | |
368 | 1: tstb %a0@(TASK_THREAD+THREAD_FPSTATE) | |
369 | jeq 3f | |
370 | #endif | |
371 | 2: fmovemx %fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG) | |
372 | fmoveml %fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL) | |
373 | 3: | |
374 | #endif /* CONFIG_M68KFPU_EMU_ONLY */ | |
375 | /* Return previous task in %d1 */ | |
376 | movel %curptr,%d1 | |
377 | ||
378 | /* switch to new task (a1 contains new task) */ | |
379 | movel %a1,%curptr | |
380 | ||
381 | /* restore floating point context */ | |
382 | #ifndef CONFIG_M68KFPU_EMU_ONLY | |
383 | #ifdef CONFIG_M68KFPU_EMU | |
384 | tstl m68k_fputype | |
385 | jeq 4f | |
386 | #endif | |
387 | #if defined(CONFIG_M68060) | |
388 | #if !defined(CPU_M68060_ONLY) | |
389 | btst #3,m68k_cputype+3 | |
390 | beqs 1f | |
391 | #endif | |
392 | /* The 060 FPU keeps status in bits 15-8 of the first longword */ | |
393 | tstb %a1@(TASK_THREAD+THREAD_FPSTATE+2) | |
394 | jeq 3f | |
395 | #if !defined(CPU_M68060_ONLY) | |
396 | jra 2f | |
397 | #endif | |
398 | #endif /* CONFIG_M68060 */ | |
399 | #if !defined(CPU_M68060_ONLY) | |
400 | 1: tstb %a1@(TASK_THREAD+THREAD_FPSTATE) | |
401 | jeq 3f | |
1da177e4 | 402 | #endif |
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403 | 2: fmovemx %a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7 |
404 | fmoveml %a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar | |
405 | 3: frestore %a1@(TASK_THREAD+THREAD_FPSTATE) | |
406 | 4: | |
407 | #endif /* CONFIG_M68KFPU_EMU_ONLY */ | |
408 | ||
409 | /* restore the kernel stack pointer */ | |
410 | movel %a1@(TASK_THREAD+THREAD_KSP),%sp | |
411 | ||
412 | /* restore non-scratch registers */ | |
413 | RESTORE_SWITCH_STACK | |
414 | ||
415 | /* restore user stack pointer */ | |
416 | movel %a1@(TASK_THREAD+THREAD_USP),%a0 | |
417 | movel %a0,%usp | |
418 | ||
419 | /* restore fs (sfc,%dfc) */ | |
420 | movew %a1@(TASK_THREAD+THREAD_FS),%a0 | |
421 | movec %a0,%sfc | |
422 | movec %a0,%dfc | |
423 | ||
424 | /* restore status register */ | |
425 | movew %a1@(TASK_THREAD+THREAD_SR),%sr | |
426 | ||
427 | rts | |
428 | ||
429 | #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */ |