Linux-2.6.33.2/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/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, user_irqhandler_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)
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)
| save top of frame
movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
| syscall trace?
tstb %curptr@(TASK_INFO+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
movew %curptr@(TASK_INFO+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:
moveb %curptr@(TASK_INFO+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)
clrl %sp@-
bsrl do_signal
addql #8,%sp
RESTORE_SWITCH_STACK
addql #4,%sp
tstl %d0
jeq resume_userspace
| when single stepping into handler stop at the first insn
btst #6,%curptr@(TASK_INFO+TINFO_FLAGS+2)
jeq 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)
addqb #1,%curptr@(TASK_INFO+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 __m68k_handle_int | process the IRQ
addql #8,%sp | pop parameters off stack
ret_from_interrupt:
subqb #1,%curptr@(TASK_INFO+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)
addqb #1,%curptr@(TASK_INFO+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
user_irqhandler_fixup = . + 2
jsr __m68k_handle_int | process the IRQ
addql #8,%sp | pop parameters off stack
subqb #1,%curptr@(TASK_INFO+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)
addqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1)
movel %sp,%sp@-
jsr handle_badint
addql #4,%sp
subqb #1,%curptr@(TASK_INFO+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_sigsuspend)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr do_sigsuspend
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_rt_sigsuspend)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr do_rt_sigsuspend
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
.data
ALIGN
sys_call_table:
.long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */
.long sys_exit
.long sys_fork
.long sys_read
.long sys_write
.long sys_open /* 5 */
.long sys_close
.long sys_waitpid
.long sys_creat
.long sys_link
.long sys_unlink /* 10 */
.long sys_execve
.long sys_chdir
.long sys_time
.long sys_mknod
.long sys_chmod /* 15 */
.long sys_chown16
.long sys_ni_syscall /* old break syscall holder */
.long sys_stat
.long sys_lseek
.long sys_getpid /* 20 */
.long sys_mount
.long sys_oldumount
.long sys_setuid16
.long sys_getuid16
.long sys_stime /* 25 */
.long sys_ptrace
.long sys_alarm
.long sys_fstat
.long sys_pause
.long sys_utime /* 30 */
.long sys_ni_syscall /* old stty syscall holder */
.long sys_ni_syscall /* old gtty syscall holder */
.long sys_access
.long sys_nice
.long sys_ni_syscall /* 35 */ /* old ftime syscall holder */
.long sys_sync
.long sys_kill
.long sys_rename
.long sys_mkdir
.long sys_rmdir /* 40 */
.long sys_dup
.long sys_pipe
.long sys_times
.long sys_ni_syscall /* old prof syscall holder */
.long sys_brk /* 45 */
.long sys_setgid16
.long sys_getgid16
.long sys_signal
.long sys_geteuid16
.long sys_getegid16 /* 50 */
.long sys_acct
.long sys_umount /* recycled never used phys() */
.long sys_ni_syscall /* old lock syscall holder */
.long sys_ioctl
.long sys_fcntl /* 55 */
.long sys_ni_syscall /* old mpx syscall holder */
.long sys_setpgid
.long sys_ni_syscall /* old ulimit syscall holder */
.long sys_ni_syscall
.long sys_umask /* 60 */
.long sys_chroot
.long sys_ustat
.long sys_dup2
.long sys_getppid
.long sys_getpgrp /* 65 */
.long sys_setsid
.long sys_sigaction
.long sys_sgetmask
.long sys_ssetmask
.long sys_setreuid16 /* 70 */
.long sys_setregid16
.long sys_sigsuspend
.long sys_sigpending
.long sys_sethostname
.long sys_setrlimit /* 75 */
.long sys_old_getrlimit
.long sys_getrusage
.long sys_gettimeofday
.long sys_settimeofday
.long sys_getgroups16 /* 80 */
.long sys_setgroups16
.long old_select
.long sys_symlink
.long sys_lstat
.long sys_readlink /* 85 */
.long sys_uselib
.long sys_swapon
.long sys_reboot
.long sys_old_readdir
.long old_mmap /* 90 */
.long sys_munmap
.long sys_truncate
.long sys_ftruncate
.long sys_fchmod
.long sys_fchown16 /* 95 */
.long sys_getpriority
.long sys_setpriority
.long sys_ni_syscall /* old profil syscall holder */
.long sys_statfs
.long sys_fstatfs /* 100 */
.long sys_ni_syscall /* ioperm for i386 */
.long sys_socketcall
.long sys_syslog
.long sys_setitimer
.long sys_getitimer /* 105 */
.long sys_newstat
.long sys_newlstat
.long sys_newfstat
.long sys_ni_syscall
.long sys_ni_syscall /* 110 */ /* iopl for i386 */
.long sys_vhangup
.long sys_ni_syscall /* obsolete idle() syscall */
.long sys_ni_syscall /* vm86old for i386 */
.long sys_wait4
.long sys_swapoff /* 115 */
.long sys_sysinfo
.long sys_ipc
.long sys_fsync
.long sys_sigreturn
.long sys_clone /* 120 */
.long sys_setdomainname
.long sys_newuname
.long sys_cacheflush /* modify_ldt for i386 */
.long sys_adjtimex
.long sys_mprotect /* 125 */
.long sys_sigprocmask
.long sys_ni_syscall /* old "create_module" */
.long sys_init_module
.long sys_delete_module
.long sys_ni_syscall /* 130 - old "get_kernel_syms" */
.long sys_quotactl
.long sys_getpgid
.long sys_fchdir
.long sys_bdflush
.long sys_sysfs /* 135 */
.long sys_personality
.long sys_ni_syscall /* for afs_syscall */
.long sys_setfsuid16
.long sys_setfsgid16
.long sys_llseek /* 140 */
.long sys_getdents
.long sys_select
.long sys_flock
.long sys_msync
.long sys_readv /* 145 */
.long sys_writev
.long sys_getsid
.long sys_fdatasync
.long sys_sysctl
.long sys_mlock /* 150 */
.long sys_munlock
.long sys_mlockall
.long sys_munlockall
.long sys_sched_setparam
.long sys_sched_getparam /* 155 */
.long sys_sched_setscheduler
.long sys_sched_getscheduler
.long sys_sched_yield
.long sys_sched_get_priority_max
.long sys_sched_get_priority_min /* 160 */
.long sys_sched_rr_get_interval
.long sys_nanosleep
.long sys_mremap
.long sys_setresuid16
.long sys_getresuid16 /* 165 */
.long sys_getpagesize
.long sys_ni_syscall /* old sys_query_module */
.long sys_poll
.long sys_nfsservctl
.long sys_setresgid16 /* 170 */
.long sys_getresgid16
.long sys_prctl
.long sys_rt_sigreturn
.long sys_rt_sigaction
.long sys_rt_sigprocmask /* 175 */
.long sys_rt_sigpending
.long sys_rt_sigtimedwait
.long sys_rt_sigqueueinfo
.long sys_rt_sigsuspend
.long sys_pread64 /* 180 */
.long sys_pwrite64
.long sys_lchown16;
.long sys_getcwd
.long sys_capget
.long sys_capset /* 185 */
.long sys_sigaltstack
.long sys_sendfile
.long sys_ni_syscall /* streams1 */
.long sys_ni_syscall /* streams2 */
.long sys_vfork /* 190 */
.long sys_getrlimit
.long sys_mmap2
.long sys_truncate64
.long sys_ftruncate64
.long sys_stat64 /* 195 */
.long sys_lstat64
.long sys_fstat64
.long sys_chown
.long sys_getuid
.long sys_getgid /* 200 */
.long sys_geteuid
.long sys_getegid
.long sys_setreuid
.long sys_setregid
.long sys_getgroups /* 205 */
.long sys_setgroups
.long sys_fchown
.long sys_setresuid
.long sys_getresuid
.long sys_setresgid /* 210 */
.long sys_getresgid
.long sys_lchown
.long sys_setuid
.long sys_setgid
.long sys_setfsuid /* 215 */
.long sys_setfsgid
.long sys_pivot_root
.long sys_ni_syscall
.long sys_ni_syscall
.long sys_getdents64 /* 220 */
.long sys_gettid
.long sys_tkill
.long sys_setxattr
.long sys_lsetxattr
.long sys_fsetxattr /* 225 */
.long sys_getxattr
.long sys_lgetxattr
.long sys_fgetxattr
.long sys_listxattr
.long sys_llistxattr /* 230 */
.long sys_flistxattr
.long sys_removexattr
.long sys_lremovexattr
.long sys_fremovexattr
.long sys_futex /* 235 */
.long sys_sendfile64
.long sys_mincore
.long sys_madvise
.long sys_fcntl64
.long sys_readahead /* 240 */
.long sys_io_setup
.long sys_io_destroy
.long sys_io_getevents
.long sys_io_submit
.long sys_io_cancel /* 245 */
.long sys_fadvise64
.long sys_exit_group
.long sys_lookup_dcookie
.long sys_epoll_create
.long sys_epoll_ctl /* 250 */
.long sys_epoll_wait
.long sys_remap_file_pages
.long sys_set_tid_address
.long sys_timer_create
.long sys_timer_settime /* 255 */
.long sys_timer_gettime
.long sys_timer_getoverrun
.long sys_timer_delete
.long sys_clock_settime
.long sys_clock_gettime /* 260 */
.long sys_clock_getres
.long sys_clock_nanosleep
.long sys_statfs64
.long sys_fstatfs64
.long sys_tgkill /* 265 */
.long sys_utimes
.long sys_fadvise64_64
.long sys_mbind
.long sys_get_mempolicy
.long sys_set_mempolicy /* 270 */
.long sys_mq_open
.long sys_mq_unlink
.long sys_mq_timedsend
.long sys_mq_timedreceive
.long sys_mq_notify /* 275 */
.long sys_mq_getsetattr
.long sys_waitid
.long sys_ni_syscall /* for sys_vserver */
.long sys_add_key
.long sys_request_key /* 280 */
.long sys_keyctl
.long sys_ioprio_set
.long sys_ioprio_get
.long sys_inotify_init
.long sys_inotify_add_watch /* 285 */
.long sys_inotify_rm_watch
.long sys_migrate_pages
.long sys_openat
.long sys_mkdirat
.long sys_mknodat /* 290 */
.long sys_fchownat
.long sys_futimesat
.long sys_fstatat64
.long sys_unlinkat
.long sys_renameat /* 295 */
.long sys_linkat
.long sys_symlinkat
.long sys_readlinkat
.long sys_fchmodat
.long sys_faccessat /* 300 */
.long sys_ni_syscall /* Reserved for pselect6 */
.long sys_ni_syscall /* Reserved for ppoll */
.long sys_unshare
.long sys_set_robust_list
.long sys_get_robust_list /* 305 */
.long sys_splice
.long sys_sync_file_range
.long sys_tee
.long sys_vmsplice
.long sys_move_pages /* 310 */
.long sys_sched_setaffinity
.long sys_sched_getaffinity
.long sys_kexec_load
.long sys_getcpu
.long sys_epoll_pwait /* 315 */
.long sys_utimensat
.long sys_signalfd
.long sys_timerfd_create
.long sys_eventfd
.long sys_fallocate /* 320 */
.long sys_timerfd_settime
.long sys_timerfd_gettime
.long sys_signalfd4
.long sys_eventfd2
.long sys_epoll_create1 /* 325 */
.long sys_dup3
.long sys_pipe2
.long sys_inotify_init1
.long sys_preadv
.long sys_pwritev /* 330 */
.long sys_rt_tgsigqueueinfo
.long sys_perf_event_open