420 lines
9.0 KiB
ArmAsm
420 lines
9.0 KiB
ArmAsm
/* -*- 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/entry.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>
|
|
|
|
.globl system_call, buserr, trap, resume
|
|
.globl sys_call_table
|
|
.globl sys_fork, sys_clone, sys_vfork
|
|
.globl ret_from_interrupt, bad_interrupt
|
|
.globl auto_irqhandler_fixup
|
|
.globl user_irqvec_fixup
|
|
|
|
.text
|
|
ENTRY(buserr)
|
|
SAVE_ALL_INT
|
|
GET_CURRENT(%d0)
|
|
movel %sp,%sp@- | stack frame pointer argument
|
|
bsrl buserr_c
|
|
addql #4,%sp
|
|
jra .Lret_from_exception
|
|
|
|
ENTRY(trap)
|
|
SAVE_ALL_INT
|
|
GET_CURRENT(%d0)
|
|
movel %sp,%sp@- | stack frame pointer argument
|
|
bsrl trap_c
|
|
addql #4,%sp
|
|
jra .Lret_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 .Lret_from_exception
|
|
|
|
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
|
|
jmi 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
|
|
jmi 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_signal
|
|
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)
|
|
movel %d0,%a1
|
|
addqb #1,%a1@(TINFO_PREEMPT+1)
|
|
| 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
|
|
|
|
ret_from_interrupt:
|
|
movel %curptr@(TASK_STACK),%a1
|
|
subqb #1,%a1@(TINFO_PREEMPT+1)
|
|
jeq ret_from_last_interrupt
|
|
2: RESTORE_ALL
|
|
|
|
ALIGN
|
|
ret_from_last_interrupt:
|
|
moveq #(~ALLOWINT>>8)&0xff,%d0
|
|
andb %sp@(PT_OFF_SR),%d0
|
|
jne 2b
|
|
|
|
/* check if we need to do software interrupts */
|
|
tstl irq_stat+CPUSTAT_SOFTIRQ_PENDING
|
|
jeq .Lret_from_exception
|
|
pea ret_from_exception
|
|
jra do_softirq
|
|
|
|
/* Handler for user defined interrupt vectors */
|
|
|
|
ENTRY(user_inthandler)
|
|
SAVE_ALL_INT
|
|
GET_CURRENT(%d0)
|
|
movel %d0,%a1
|
|
addqb #1,%a1@(TINFO_PREEMPT+1)
|
|
| 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
|
|
|
|
movel %curptr@(TASK_STACK),%a1
|
|
subqb #1,%a1@(TINFO_PREEMPT+1)
|
|
jeq ret_from_last_interrupt
|
|
RESTORE_ALL
|
|
|
|
/* Handler for uninitialized and spurious interrupts */
|
|
|
|
ENTRY(bad_inthandler)
|
|
SAVE_ALL_INT
|
|
GET_CURRENT(%d0)
|
|
movel %d0,%a1
|
|
addqb #1,%a1@(TINFO_PREEMPT+1)
|
|
|
|
movel %sp,%sp@-
|
|
jsr handle_badint
|
|
addql #4,%sp
|
|
|
|
movel %curptr@(TASK_STACK),%a1
|
|
subqb #1,%a1@(TINFO_PREEMPT+1)
|
|
jeq ret_from_last_interrupt
|
|
RESTORE_ALL
|
|
|
|
|
|
ENTRY(sys_fork)
|
|
SAVE_SWITCH_STACK
|
|
pea %sp@(SWITCH_STACK_SIZE)
|
|
jbsr m68k_fork
|
|
addql #4,%sp
|
|
RESTORE_SWITCH_STACK
|
|
rts
|
|
|
|
ENTRY(sys_clone)
|
|
SAVE_SWITCH_STACK
|
|
pea %sp@(SWITCH_STACK_SIZE)
|
|
jbsr m68k_clone
|
|
addql #4,%sp
|
|
RESTORE_SWITCH_STACK
|
|
rts
|
|
|
|
ENTRY(sys_vfork)
|
|
SAVE_SWITCH_STACK
|
|
pea %sp@(SWITCH_STACK_SIZE)
|
|
jbsr m68k_vfork
|
|
addql #4,%sp
|
|
RESTORE_SWITCH_STACK
|
|
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
|
|
|
|
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
|
|
|