/*
* entry.S -- non-mmu 68000 interrupt and exception entry points
*
* 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
*/
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/traps.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
.text
.globl system_call
.globl resume
.globl ret_from_exception
.globl ret_from_signal
.globl sys_call_table
.globl bad_interrupt
.globl inthandler1
.globl inthandler2
.globl inthandler3
.globl inthandler4
.globl inthandler5
.globl inthandler6
.globl inthandler7
badsys:
movel #-ENOSYS,%sp@(PT_OFF_D0)
jra ret_from_exception
do_trace:
movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/
subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
movel %sp@(PT_OFF_ORIG_D0),%d1
movel #-ENOSYS,%d0
cmpl #NR_syscalls,%d1
jcc 1f
lsl #2,%d1
lea sys_call_table, %a0
jbsr %a0@(%d1)
1: movel %d0,%sp@(PT_OFF_D0) /* save the return value */
subql #4,%sp /* dummy return address */
SAVE_SWITCH_STACK
jbsr syscall_trace_leave
ret_from_signal:
RESTORE_SWITCH_STACK
addql #4,%sp
jra ret_from_exception
ENTRY(system_call)
SAVE_ALL_SYS
/* save top of frame*/
pea %sp@
jbsr set_esp0
addql #4,%sp
movel %sp@(PT_OFF_ORIG_D0),%d0
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1
movel %d1,%a2
btst #(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
jne do_trace
cmpl #NR_syscalls,%d0
jcc badsys
lsl #2,%d0
lea sys_call_table,%a0
movel %a0@(%d0), %a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value*/
ret_from_exception:
btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/
jeq Luser_return /* if so, skip resched, signals*/
Lkernel_return:
RESTORE_ALL
Luser_return:
/* 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
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1
movel %d1,%a2
1:
move %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */
jne Lwork_to_do
RESTORE_ALL
Lwork_to_do:
movel %a2@(TINFO_FLAGS),%d1 /* thread_info->flags */
btst #TIF_NEED_RESCHED,%d1
jne reschedule
Lsignal_return:
subql #4,%sp /* dummy return address*/
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
bsrw do_notify_resume
addql #4,%sp
RESTORE_SWITCH_STACK
addql #4,%sp
jra 1b
/*
* This is the main interrupt handler, responsible for calling process_int()
*/
inthandler1:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #65,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler2:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #66,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler3:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #67,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler4:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #68,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler5:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #69,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler6:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #70,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler7:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel #71,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
inthandler:
SAVE_ALL_INT
movew %sp@(PT_OFF_FORMATVEC), %d0
and #0x3ff, %d0
movel %sp,%sp@-
movel %d0,%sp@- /* put vector # on stack*/
jbsr process_int /* process the IRQ*/
3: addql #8,%sp /* pop parameters off stack*/
bra ret_from_exception
/*
* Handler for uninitialized and spurious interrupts.
*/
ENTRY(bad_interrupt)
addql #1,irq_err_count
rte
/*
* 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.
*/
ENTRY(resume)
movel %a0,%d1 /* save prev thread in d1 */
movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */
SAVE_SWITCH_STACK
movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
movel %usp,%a3 /* save usp */
movel %a3,%a0@(TASK_THREAD+THREAD_USP)
movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */
movel %a3,%usp
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
RESTORE_SWITCH_STACK
movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */
rts