[mirror_ubuntu-zesty-kernel.git] / arch / m68k / kernel / entry.S

/* -*- mode: asm -*-
 *
 *  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
 *
 */

/*
 * entry.S  contains the system-call and fault low-level handling routines.
 * This also contains the timer-interrupt handler, as well as all interrupts
 * and faults that can result in a task-switch.
 *
 * NOTE: This code handles signal-recognition, which happens every time
 * after a timer-interrupt and after each system call.
 *
 */

/*
 * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so
 *               all pointers that used to be 'current' are now entry
 *               number 0 in the 'current_set' list.
 *
 *  6/05/00 RZ:	 addedd writeback completion after return from sighandler
 *		 for 68040
 */

#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/traps.h>
#include <asm/unistd.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>

.globl system_call, buserr, trap, resume
.globl sys_call_table
.globl __sys_fork, __sys_clone, __sys_vfork
.globl bad_interrupt
.globl auto_irqhandler_fixup
.globl user_irqvec_fixup

.text
ENTRY(__sys_fork)
	SAVE_SWITCH_STACK
	jbsr	sys_fork
	lea     %sp@(24),%sp
	rts

ENTRY(__sys_clone)
	SAVE_SWITCH_STACK
	pea	%sp@(SWITCH_STACK_SIZE)
	jbsr	m68k_clone
	lea     %sp@(28),%sp
	rts

ENTRY(__sys_vfork)
	SAVE_SWITCH_STACK
	jbsr	sys_vfork
	lea     %sp@(24),%sp
	rts

ENTRY(sys_sigreturn)
	SAVE_SWITCH_STACK
	jbsr	do_sigreturn
	RESTORE_SWITCH_STACK
	rts

ENTRY(sys_rt_sigreturn)
	SAVE_SWITCH_STACK
	jbsr	do_rt_sigreturn
	RESTORE_SWITCH_STACK
	rts

ENTRY(buserr)
	SAVE_ALL_INT
	GET_CURRENT(%d0)
	movel	%sp,%sp@-		| stack frame pointer argument
	jbsr	buserr_c
	addql	#4,%sp
	jra	ret_from_exception

ENTRY(trap)
	SAVE_ALL_INT
	GET_CURRENT(%d0)
	movel	%sp,%sp@-		| stack frame pointer argument
	jbsr	trap_c
	addql	#4,%sp
	jra	ret_from_exception

	| After a fork we jump here directly from resume,
	| so that %d1 contains the previous task
	| schedule_tail now used regardless of CONFIG_SMP
ENTRY(ret_from_fork)
	movel	%d1,%sp@-
	jsr	schedule_tail
	addql	#4,%sp
	jra	ret_from_exception

ENTRY(ret_from_kernel_thread)
	| a3 contains the kernel thread payload, d7 - its argument
	movel	%d1,%sp@-
	jsr	schedule_tail
	movel	%d7,(%sp)
	jsr	%a3@
	addql	#4,%sp
	jra	ret_from_exception

#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)

#ifdef TRAP_DBG_INTERRUPT

.globl dbginterrupt
ENTRY(dbginterrupt)
	SAVE_ALL_INT
	GET_CURRENT(%d0)
	movel	%sp,%sp@- 		/* stack frame pointer argument */
	jsr	dbginterrupt_c
	addql	#4,%sp
	jra	ret_from_exception
#endif

ENTRY(reschedule)
	/* save top of frame */
	pea	%sp@
	jbsr	set_esp0
	addql	#4,%sp
	pea	ret_from_exception
	jmp	schedule

ENTRY(ret_from_user_signal)
	moveq #__NR_sigreturn,%d0
	trap #0

ENTRY(ret_from_user_rt_signal)
	movel #__NR_rt_sigreturn,%d0
	trap #0

#else

do_trace_entry:
	movel	#-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
	subql	#4,%sp
	SAVE_SWITCH_STACK
	jbsr	syscall_trace
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	movel	%sp@(PT_OFF_ORIG_D0),%d0
	cmpl	#NR_syscalls,%d0
	jcs	syscall
badsys:
	movel	#-ENOSYS,%sp@(PT_OFF_D0)
	jra	ret_from_syscall

do_trace_exit:
	subql	#4,%sp
	SAVE_SWITCH_STACK
	jbsr	syscall_trace
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	jra	.Lret_from_exception

ENTRY(ret_from_signal)
	movel	%curptr@(TASK_STACK),%a1
	tstb	%a1@(TINFO_FLAGS+2)
	jge	1f
	jbsr	syscall_trace
1:	RESTORE_SWITCH_STACK
	addql	#4,%sp
/* on 68040 complete pending writebacks if any */
#ifdef CONFIG_M68040
	bfextu	%sp@(PT_OFF_FORMATVEC){#0,#4},%d0
	subql	#7,%d0				| bus error frame ?
	jbne	1f
	movel	%sp,%sp@-
	jbsr	berr_040cleanup
	addql	#4,%sp
1:
#endif
	jra	.Lret_from_exception

ENTRY(system_call)
	SAVE_ALL_SYS

	GET_CURRENT(%d1)
	movel	%d1,%a1

	| save top of frame
	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)

	| syscall trace?
	tstb	%a1@(TINFO_FLAGS+2)
	jmi	do_trace_entry
	cmpl	#NR_syscalls,%d0
	jcc	badsys
syscall:
	jbsr	@(sys_call_table,%d0:l:4)@(0)
	movel	%d0,%sp@(PT_OFF_D0)	| save the return value
ret_from_syscall:
	|oriw	#0x0700,%sr
	movel	%curptr@(TASK_STACK),%a1
	movew	%a1@(TINFO_FLAGS+2),%d0
	jne	syscall_exit_work
1:	RESTORE_ALL

syscall_exit_work:
	btst	#5,%sp@(PT_OFF_SR)	| check if returning to kernel
	bnes	1b			| if so, skip resched, signals
	lslw	#1,%d0
	jcs	do_trace_exit
	jmi	do_delayed_trace
	lslw	#8,%d0
	jne	do_signal_return
	pea	resume_userspace
	jra	schedule


ENTRY(ret_from_exception)
.Lret_from_exception:
	btst	#5,%sp@(PT_OFF_SR)	| check if returning to kernel
	bnes	1f			| if so, skip resched, signals
	| only allow interrupts when we are really the last one on the
	| kernel stack, otherwise stack overflow can occur during
	| heavy interrupt load
	andw	#ALLOWINT,%sr

resume_userspace:
	movel	%curptr@(TASK_STACK),%a1
	moveb	%a1@(TINFO_FLAGS+3),%d0
	jne	exit_work
1:	RESTORE_ALL

exit_work:
	| save top of frame
	movel	%sp,%curptr@(TASK_THREAD+THREAD_ESP0)
	lslb	#1,%d0
	jne	do_signal_return
	pea	resume_userspace
	jra	schedule


do_signal_return:
	|andw	#ALLOWINT,%sr
	subql	#4,%sp			| dummy return address
	SAVE_SWITCH_STACK
	pea	%sp@(SWITCH_STACK_SIZE)
	bsrl	do_notify_resume
	addql	#4,%sp
	RESTORE_SWITCH_STACK
	addql	#4,%sp
	jbra	resume_userspace

do_delayed_trace:
	bclr	#7,%sp@(PT_OFF_SR)	| clear trace bit in SR
	pea	1			| send SIGTRAP
	movel	%curptr,%sp@-
	pea	LSIGTRAP
	jbsr	send_sig
	addql	#8,%sp
	addql	#4,%sp
	jbra	resume_userspace


/* This is the main interrupt handler for autovector interrupts */

ENTRY(auto_inthandler)
	SAVE_ALL_INT
	GET_CURRENT(%d0)
					|  put exception # in d0
	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0
	subw	#VEC_SPUR,%d0

	movel	%sp,%sp@-
	movel	%d0,%sp@-		|  put vector # on stack
auto_irqhandler_fixup = . + 2
	jsr	do_IRQ			|  process the IRQ
	addql	#8,%sp			|  pop parameters off stack
	jra	ret_from_exception

/* Handler for user defined interrupt vectors */

ENTRY(user_inthandler)
	SAVE_ALL_INT
	GET_CURRENT(%d0)
					|  put exception # in d0
	bfextu	%sp@(PT_OFF_FORMATVEC){#4,#10},%d0
user_irqvec_fixup = . + 2
	subw	#VEC_USER,%d0

	movel	%sp,%sp@-
	movel	%d0,%sp@-		|  put vector # on stack
	jsr	do_IRQ			|  process the IRQ
	addql	#8,%sp			|  pop parameters off stack
	jra	ret_from_exception

/* Handler for uninitialized and spurious interrupts */

ENTRY(bad_inthandler)
	SAVE_ALL_INT
	GET_CURRENT(%d0)

	movel	%sp,%sp@-
	jsr	handle_badint
	addql	#4,%sp
	jra	ret_from_exception

resume:
	/*
	 * 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.
	 */

	/* save sr */
	movew	%sr,%a0@(TASK_THREAD+THREAD_SR)

	/* save fs (sfc,%dfc) (may be pointing to kernel memory) */
	movec	%sfc,%d0
	movew	%d0,%a0@(TASK_THREAD+THREAD_FS)

	/* save usp */
	/* it is better to use a movel here instead of a movew 8*) */
	movec	%usp,%d0
	movel	%d0,%a0@(TASK_THREAD+THREAD_USP)

	/* save non-scratch registers on stack */
	SAVE_SWITCH_STACK

	/* save current kernel stack pointer */
	movel	%sp,%a0@(TASK_THREAD+THREAD_KSP)

	/* save floating point context */
#ifndef CONFIG_M68KFPU_EMU_ONLY
#ifdef CONFIG_M68KFPU_EMU
	tstl	m68k_fputype
	jeq	3f
#endif
	fsave	%a0@(TASK_THREAD+THREAD_FPSTATE)

#if defined(CONFIG_M68060)
#if !defined(CPU_M68060_ONLY)
	btst	#3,m68k_cputype+3
	beqs	1f
#endif
	/* The 060 FPU keeps status in bits 15-8 of the first longword */
	tstb	%a0@(TASK_THREAD+THREAD_FPSTATE+2)
	jeq	3f
#if !defined(CPU_M68060_ONLY)
	jra	2f
#endif
#endif /* CONFIG_M68060 */
#if !defined(CPU_M68060_ONLY)
1:	tstb	%a0@(TASK_THREAD+THREAD_FPSTATE)
	jeq	3f
#endif
2:	fmovemx	%fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG)
	fmoveml	%fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL)
3:
#endif	/* CONFIG_M68KFPU_EMU_ONLY */
	/* Return previous task in %d1 */
	movel	%curptr,%d1

	/* switch to new task (a1 contains new task) */
	movel	%a1,%curptr

	/* restore floating point context */
#ifndef CONFIG_M68KFPU_EMU_ONLY
#ifdef CONFIG_M68KFPU_EMU
	tstl	m68k_fputype
	jeq	4f
#endif
#if defined(CONFIG_M68060)
#if !defined(CPU_M68060_ONLY)
	btst	#3,m68k_cputype+3
	beqs	1f
#endif
	/* The 060 FPU keeps status in bits 15-8 of the first longword */
	tstb	%a1@(TASK_THREAD+THREAD_FPSTATE+2)
	jeq	3f
#if !defined(CPU_M68060_ONLY)
	jra	2f
#endif
#endif /* CONFIG_M68060 */
#if !defined(CPU_M68060_ONLY)
1:	tstb	%a1@(TASK_THREAD+THREAD_FPSTATE)
	jeq	3f
#endif
2:	fmovemx	%a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7
	fmoveml	%a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar
3:	frestore %a1@(TASK_THREAD+THREAD_FPSTATE)
4:
#endif	/* CONFIG_M68KFPU_EMU_ONLY */

	/* restore the kernel stack pointer */
	movel	%a1@(TASK_THREAD+THREAD_KSP),%sp

	/* restore non-scratch registers */
	RESTORE_SWITCH_STACK

	/* restore user stack pointer */
	movel	%a1@(TASK_THREAD+THREAD_USP),%a0
	movel	%a0,%usp

	/* restore fs (sfc,%dfc) */
	movew	%a1@(TASK_THREAD+THREAD_FS),%a0
	movec	%a0,%sfc
	movec	%a0,%dfc

	/* restore status register */
	movew	%a1@(TASK_THREAD+THREAD_SR),%sr

	rts

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