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v6.2
  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/traps.h>
 40#include <asm/unistd.h>
 41#include <asm/asm-offsets.h>
 42#include <asm/entry.h>
 43
 44.globl system_call, buserr, trap, resume
 45.globl sys_call_table
 46.globl __sys_fork, __sys_clone, __sys_vfork
 47.globl bad_interrupt
 48.globl auto_irqhandler_fixup
 49.globl user_irqvec_fixup
 50
 51.text
 52ENTRY(__sys_fork)
 53	SAVE_SWITCH_STACK
 54	jbsr	sys_fork
 55	lea     %sp@(24),%sp
 56	rts
 57
 58ENTRY(__sys_clone)
 59	SAVE_SWITCH_STACK
 60	pea	%sp@(SWITCH_STACK_SIZE)
 61	jbsr	m68k_clone
 62	lea     %sp@(28),%sp
 63	rts
 64
 65ENTRY(__sys_vfork)
 66	SAVE_SWITCH_STACK
 67	jbsr	sys_vfork
 68	lea     %sp@(24),%sp
 69	rts
 70
 71ENTRY(__sys_clone3)
 72	SAVE_SWITCH_STACK
 73	pea	%sp@(SWITCH_STACK_SIZE)
 74	jbsr	m68k_clone3
 75	lea	%sp@(28),%sp
 76	rts
 77
 78ENTRY(sys_sigreturn)
 79	SAVE_SWITCH_STACK
 80	movel	%sp,%a1			  	| switch_stack pointer
 81	lea	%sp@(SWITCH_STACK_SIZE),%a0	| pt_regs pointer
 82	lea     %sp@(-84),%sp			| leave a gap
 83	movel	%a1,%sp@-
 84	movel	%a0,%sp@-
 85	jbsr	do_sigreturn
 86	jra	1f				| shared with rt_sigreturn()
 
 
 87
 88ENTRY(sys_rt_sigreturn)
 89	SAVE_SWITCH_STACK
 90	movel	%sp,%a1			  	| switch_stack pointer
 91	lea	%sp@(SWITCH_STACK_SIZE),%a0	| pt_regs pointer
 92	lea     %sp@(-84),%sp			| leave a gap
 93	movel	%a1,%sp@-
 94	movel	%a0,%sp@-
 95	| stack contents:
 96	|   [original pt_regs address] [original switch_stack address]
 97	|   [gap] [switch_stack] [pt_regs] [exception frame]
 98	jbsr	do_rt_sigreturn
 99
1001:
101	| stack contents now:
102	|   [original pt_regs address] [original switch_stack address]
103	|   [unused part of the gap] [moved switch_stack] [moved pt_regs]
104	|   [replacement exception frame]
105	| return value of do_{rt_,}sigreturn() points to moved switch_stack.
106
107	movel	%d0,%sp				| discard the leftover junk
108	RESTORE_SWITCH_STACK
109	| stack contents now is just [syscall return address] [pt_regs] [frame]
110	| return pt_regs.d0
111	movel	%sp@(PT_OFF_D0+4),%d0
112	rts
113
114ENTRY(buserr)
115	SAVE_ALL_INT
116	GET_CURRENT(%d0)
117	movel	%sp,%sp@-		| stack frame pointer argument
118	jbsr	buserr_c
119	addql	#4,%sp
120	jra	ret_from_exception
121
122ENTRY(trap)
123	SAVE_ALL_INT
124	GET_CURRENT(%d0)
125	movel	%sp,%sp@-		| stack frame pointer argument
126	jbsr	trap_c
127	addql	#4,%sp
128	jra	ret_from_exception
129
130	| After a fork we jump here directly from resume,
131	| so that %d1 contains the previous task
132	| schedule_tail now used regardless of CONFIG_SMP
133ENTRY(ret_from_fork)
134	movel	%d1,%sp@-
135	jsr	schedule_tail
136	addql	#4,%sp
137	jra	ret_from_exception
138
139ENTRY(ret_from_kernel_thread)
140	| a3 contains the kernel thread payload, d7 - its argument
141	movel	%d1,%sp@-
142	jsr	schedule_tail
143	movel	%d7,(%sp)
144	jsr	%a3@
145	addql	#4,%sp
146	jra	ret_from_exception
147
148#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
149
150#ifdef TRAP_DBG_INTERRUPT
151
152.globl dbginterrupt
153ENTRY(dbginterrupt)
154	SAVE_ALL_INT
155	GET_CURRENT(%d0)
156	movel	%sp,%sp@- 		/* stack frame pointer argument */
157	jsr	dbginterrupt_c
158	addql	#4,%sp
159	jra	ret_from_exception
160#endif
161
162ENTRY(reschedule)
163	/* save top of frame */
164	pea	%sp@
165	jbsr	set_esp0
166	addql	#4,%sp
167	pea	ret_from_exception
168	jmp	schedule
169
170ENTRY(ret_from_user_signal)
171	moveq #__NR_sigreturn,%d0
172	trap #0
173
174ENTRY(ret_from_user_rt_signal)
175	movel #__NR_rt_sigreturn,%d0
176	trap #0
177
178#else
179
180do_trace_entry:
181	movel	#-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
182	subql	#4,%sp
183	SAVE_SWITCH_STACK
184	jbsr	syscall_trace_enter
185	RESTORE_SWITCH_STACK
186	addql	#4,%sp
187	movel	%sp@(PT_OFF_ORIG_D0),%d0
188	cmpl	#NR_syscalls,%d0
189	jcs	syscall
190badsys:
191	movel	#-ENOSYS,%sp@(PT_OFF_D0)
192	jra	ret_from_syscall
193
194do_trace_exit:
195	subql	#4,%sp
196	SAVE_SWITCH_STACK
197	jbsr	syscall_trace_leave
198	RESTORE_SWITCH_STACK
199	addql	#4,%sp
200	jra	.Lret_from_exception
201
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
202ENTRY(system_call)
203	SAVE_ALL_SYS
204
205	GET_CURRENT(%d1)
206	movel	%d1,%a1
207
208	| save top of frame
209	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)
210
211	| syscall trace?
212	tstb	%a1@(TINFO_FLAGS+2)
213	jmi	do_trace_entry
214	cmpl	#NR_syscalls,%d0
215	jcc	badsys
216syscall:
217	jbsr	@(sys_call_table,%d0:l:4)@(0)
218	movel	%d0,%sp@(PT_OFF_D0)	| save the return value
219ret_from_syscall:
220	|oriw	#0x0700,%sr
221	movel	%curptr@(TASK_STACK),%a1
222	movew	%a1@(TINFO_FLAGS+2),%d0
223	jne	syscall_exit_work
2241:	RESTORE_ALL
225
226syscall_exit_work:
227	btst	#5,%sp@(PT_OFF_SR)	| check if returning to kernel
228	bnes	1b			| if so, skip resched, signals
229	lslw	#1,%d0
230	jcs	do_trace_exit
231	jmi	do_delayed_trace
232	lslw	#8,%d0
233	jne	do_signal_return
234	pea	resume_userspace
235	jra	schedule
236
237
238ENTRY(ret_from_exception)
239.Lret_from_exception:
240	btst	#5,%sp@(PT_OFF_SR)	| check if returning to kernel
241	bnes	1f			| if so, skip resched, signals
242	| only allow interrupts when we are really the last one on the
243	| kernel stack, otherwise stack overflow can occur during
244	| heavy interrupt load
245	andw	#ALLOWINT,%sr
246
247resume_userspace:
248	movel	%curptr@(TASK_STACK),%a1
249	moveb	%a1@(TINFO_FLAGS+3),%d0
250	jne	exit_work
2511:	RESTORE_ALL
252
253exit_work:
254	| save top of frame
255	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)
256	lslb	#1,%d0
257	jne	do_signal_return
258	pea	resume_userspace
259	jra	schedule
260
261
262do_signal_return:
263	|andw	#ALLOWINT,%sr
264	subql	#4,%sp			| dummy return address
265	SAVE_SWITCH_STACK
266	pea	%sp@(SWITCH_STACK_SIZE)
267	bsrl	do_notify_resume
268	addql	#4,%sp
269	RESTORE_SWITCH_STACK
270	addql	#4,%sp
271	jbra	resume_userspace
272
273do_delayed_trace:
274	bclr	#7,%sp@(PT_OFF_SR)	| clear trace bit in SR
275	pea	1			| send SIGTRAP
276	movel	%curptr,%sp@-
277	pea	LSIGTRAP
278	jbsr	send_sig
279	addql	#8,%sp
280	addql	#4,%sp
281	jbra	resume_userspace
282
283
284/* This is the main interrupt handler for autovector interrupts */
285
286ENTRY(auto_inthandler)
287	SAVE_ALL_INT
288	GET_CURRENT(%d0)
289					|  put exception # in d0
290	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0
291	subw	#VEC_SPUR,%d0
292
293	movel	%sp,%sp@-
294	movel	%d0,%sp@-		|  put vector # on stack
295auto_irqhandler_fixup = . + 2
296	jsr	do_IRQ			|  process the IRQ
297	addql	#8,%sp			|  pop parameters off stack
298	jra	ret_from_exception
299
300/* Handler for user defined interrupt vectors */
301
302ENTRY(user_inthandler)
303	SAVE_ALL_INT
304	GET_CURRENT(%d0)
305					|  put exception # in d0
306	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0
307user_irqvec_fixup = . + 2
308	subw	#VEC_USER,%d0
309
310	movel	%sp,%sp@-
311	movel	%d0,%sp@-		|  put vector # on stack
312	jsr	do_IRQ			|  process the IRQ
313	addql	#8,%sp			|  pop parameters off stack
314	jra	ret_from_exception
315
316/* Handler for uninitialized and spurious interrupts */
317
318ENTRY(bad_inthandler)
319	SAVE_ALL_INT
320	GET_CURRENT(%d0)
321
322	movel	%sp,%sp@-
323	jsr	handle_badint
324	addql	#4,%sp
325	jra	ret_from_exception
326
327resume:
328	/*
329	 * Beware - when entering resume, prev (the current task) is
330	 * in a0, next (the new task) is in a1,so don't change these
331	 * registers until their contents are no longer needed.
332	 */
333
334	/* save sr */
335	movew	%sr,%a0@(TASK_THREAD+THREAD_SR)
336
337	/* save fs (sfc,%dfc) (may be pointing to kernel memory) */
338	movec	%sfc,%d0
339	movew	%d0,%a0@(TASK_THREAD+THREAD_FC)
340
341	/* save usp */
342	/* it is better to use a movel here instead of a movew 8*) */
343	movec	%usp,%d0
344	movel	%d0,%a0@(TASK_THREAD+THREAD_USP)
345
346	/* save non-scratch registers on stack */
347	SAVE_SWITCH_STACK
348
349	/* save current kernel stack pointer */
350	movel	%sp,%a0@(TASK_THREAD+THREAD_KSP)
351
352	/* save floating point context */
353#ifndef CONFIG_M68KFPU_EMU_ONLY
354#ifdef CONFIG_M68KFPU_EMU
355	tstl	m68k_fputype
356	jeq	3f
357#endif
358	fsave	%a0@(TASK_THREAD+THREAD_FPSTATE)
359
360#if defined(CONFIG_M68060)
361#if !defined(CPU_M68060_ONLY)
362	btst	#3,m68k_cputype+3
363	beqs	1f
364#endif
365	/* The 060 FPU keeps status in bits 15-8 of the first longword */
366	tstb	%a0@(TASK_THREAD+THREAD_FPSTATE+2)
367	jeq	3f
368#if !defined(CPU_M68060_ONLY)
369	jra	2f
370#endif
371#endif /* CONFIG_M68060 */
372#if !defined(CPU_M68060_ONLY)
3731:	tstb	%a0@(TASK_THREAD+THREAD_FPSTATE)
374	jeq	3f
375#endif
3762:	fmovemx	%fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG)
377	fmoveml	%fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL)
3783:
379#endif	/* CONFIG_M68KFPU_EMU_ONLY */
380	/* Return previous task in %d1 */
381	movel	%curptr,%d1
382
383	/* switch to new task (a1 contains new task) */
384	movel	%a1,%curptr
385
386	/* restore floating point context */
387#ifndef CONFIG_M68KFPU_EMU_ONLY
388#ifdef CONFIG_M68KFPU_EMU
389	tstl	m68k_fputype
390	jeq	4f
391#endif
392#if defined(CONFIG_M68060)
393#if !defined(CPU_M68060_ONLY)
394	btst	#3,m68k_cputype+3
395	beqs	1f
396#endif
397	/* The 060 FPU keeps status in bits 15-8 of the first longword */
398	tstb	%a1@(TASK_THREAD+THREAD_FPSTATE+2)
399	jeq	3f
400#if !defined(CPU_M68060_ONLY)
401	jra	2f
402#endif
403#endif /* CONFIG_M68060 */
404#if !defined(CPU_M68060_ONLY)
4051:	tstb	%a1@(TASK_THREAD+THREAD_FPSTATE)
406	jeq	3f
407#endif
4082:	fmovemx	%a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7
409	fmoveml	%a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar
4103:	frestore %a1@(TASK_THREAD+THREAD_FPSTATE)
4114:
412#endif	/* CONFIG_M68KFPU_EMU_ONLY */
413
414	/* restore the kernel stack pointer */
415	movel	%a1@(TASK_THREAD+THREAD_KSP),%sp
416
417	/* restore non-scratch registers */
418	RESTORE_SWITCH_STACK
419
420	/* restore user stack pointer */
421	movel	%a1@(TASK_THREAD+THREAD_USP),%a0
422	movel	%a0,%usp
423
424	/* restore fs (sfc,%dfc) */
425	movew	%a1@(TASK_THREAD+THREAD_FC),%a0
426	movec	%a0,%sfc
427	movec	%a0,%dfc
428
429	/* restore status register */
430	movew	%a1@(TASK_THREAD+THREAD_SR),%sr
431
432	rts
433
434#endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
v4.17
  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
 47.globl __sys_fork, __sys_clone, __sys_vfork
 48.globl bad_interrupt
 49.globl auto_irqhandler_fixup
 50.globl user_irqvec_fixup
 51
 52.text
 53ENTRY(__sys_fork)
 54	SAVE_SWITCH_STACK
 55	jbsr	sys_fork
 56	lea     %sp@(24),%sp
 57	rts
 58
 59ENTRY(__sys_clone)
 60	SAVE_SWITCH_STACK
 61	pea	%sp@(SWITCH_STACK_SIZE)
 62	jbsr	m68k_clone
 63	lea     %sp@(28),%sp
 64	rts
 65
 66ENTRY(__sys_vfork)
 67	SAVE_SWITCH_STACK
 68	jbsr	sys_vfork
 69	lea     %sp@(24),%sp
 70	rts
 71
 
 
 
 
 
 
 
 72ENTRY(sys_sigreturn)
 73	SAVE_SWITCH_STACK
 74	movel	%sp,%sp@-		  | switch_stack pointer
 75	pea	%sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer
 
 
 
 76	jbsr	do_sigreturn
 77	addql	#8,%sp
 78	RESTORE_SWITCH_STACK
 79	rts
 80
 81ENTRY(sys_rt_sigreturn)
 82	SAVE_SWITCH_STACK
 83	movel	%sp,%sp@-		  | switch_stack pointer
 84	pea	%sp@(SWITCH_STACK_SIZE+4) | pt_regs pointer
 
 
 
 
 
 
 85	jbsr	do_rt_sigreturn
 86	addql	#8,%sp
 
 
 
 
 
 
 
 
 87	RESTORE_SWITCH_STACK
 
 
 
 88	rts
 89
 90ENTRY(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
 98ENTRY(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
109ENTRY(ret_from_fork)
110	movel	%d1,%sp@-
111	jsr	schedule_tail
112	addql	#4,%sp
113	jra	ret_from_exception
114
115ENTRY(ret_from_kernel_thread)
116	| a3 contains the kernel thread payload, d7 - its argument
117	movel	%d1,%sp@-
118	jsr	schedule_tail
119	movel	%d7,(%sp)
120	jsr	%a3@
121	addql	#4,%sp
122	jra	ret_from_exception
123
124#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
125
126#ifdef TRAP_DBG_INTERRUPT
127
128.globl dbginterrupt
129ENTRY(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
138ENTRY(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
146ENTRY(ret_from_user_signal)
147	moveq #__NR_sigreturn,%d0
148	trap #0
149
150ENTRY(ret_from_user_rt_signal)
151	movel #__NR_rt_sigreturn,%d0
152	trap #0
153
154#else
155
156do_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
166badsys:
167	movel	#-ENOSYS,%sp@(PT_OFF_D0)
168	jra	ret_from_syscall
169
170do_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
178ENTRY(ret_from_signal)
179	movel	%curptr@(TASK_STACK),%a1
180	tstb	%a1@(TINFO_FLAGS+2)
181	jge	1f
182	jbsr	syscall_trace
1831:	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
1931:
194#endif
195	jra	.Lret_from_exception
196
197ENTRY(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
211syscall:
212	jbsr	@(sys_call_table,%d0:l:4)@(0)
213	movel	%d0,%sp@(PT_OFF_D0)	| save the return value
214ret_from_syscall:
215	|oriw	#0x0700,%sr
216	movel	%curptr@(TASK_STACK),%a1
217	movew	%a1@(TINFO_FLAGS+2),%d0
218	jne	syscall_exit_work
2191:	RESTORE_ALL
220
221syscall_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
233ENTRY(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
242resume_userspace:
243	movel	%curptr@(TASK_STACK),%a1
244	moveb	%a1@(TINFO_FLAGS+3),%d0
245	jne	exit_work
2461:	RESTORE_ALL
247
248exit_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
257do_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
268do_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
281ENTRY(auto_inthandler)
282	SAVE_ALL_INT
283	GET_CURRENT(%d0)
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
290auto_irqhandler_fixup = . + 2
291	jsr	do_IRQ			|  process the IRQ
292	addql	#8,%sp			|  pop parameters off stack
293	jra	ret_from_exception
294
295/* Handler for user defined interrupt vectors */
296
297ENTRY(user_inthandler)
298	SAVE_ALL_INT
299	GET_CURRENT(%d0)
300					|  put exception # in d0
301	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0
302user_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
309	jra	ret_from_exception
310
311/* Handler for uninitialized and spurious interrupts */
312
313ENTRY(bad_inthandler)
314	SAVE_ALL_INT
315	GET_CURRENT(%d0)
316
317	movel	%sp,%sp@-
318	jsr	handle_badint
319	addql	#4,%sp
320	jra	ret_from_exception
321
322resume:
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)
3681:	tstb	%a0@(TASK_THREAD+THREAD_FPSTATE)
369	jeq	3f
370#endif
3712:	fmovemx	%fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG)
372	fmoveml	%fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL)
3733:
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)
4001:	tstb	%a1@(TASK_THREAD+THREAD_FPSTATE)
401	jeq	3f
402#endif
4032:	fmovemx	%a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7
404	fmoveml	%a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar
4053:	frestore %a1@(TASK_THREAD+THREAD_FPSTATE)
4064:
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 */