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/*
* linux/arch/m68knommu/platform/68360/entry.S
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2001 SED Systems, a Division of Calian Ltd.
*
* 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
* M68360 Port by SED Systems, and Lineo.
*/
#include <linux/sys.h>
#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 ret_from_interrupt
.globl bad_interrupt
.globl inthandler
badsys:
movel #-ENOSYS,%sp@(PT_D0)
jra ret_from_exception
do_trace:
movel #-ENOSYS,%sp@(PT_D0) /* needed for strace*/
subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace
RESTORE_SWITCH_STACK
addql #4,%sp
movel %sp@(PT_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_D0) /* save the return value */
subql #4,%sp /* dummy return address */
SAVE_SWITCH_STACK
jbsr syscall_trace
ret_from_signal:
RESTORE_SWITCH_STACK
addql #4,%sp
jra ret_from_exception
ENTRY(system_call)
SAVE_ALL
/* save top of frame*/
pea %sp@
jbsr set_esp0
addql #4,%sp
btst #PF_TRACESYS_BIT,%a2@(TASK_FLAGS+PF_TRACESYS_OFF)
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_D0) /* save the return value*/
ret_from_exception:
btst #5,%sp@(PT_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
move %a2@(TI_FLAGS),%d1 /* thread_info->flags */
andl #_TIF_WORK_MASK,%d1
jne Lwork_to_do
RESTORE_ALL
Lwork_to_do:
movel %a2@(TI_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)
clrl %sp@-
bsrw do_signal
addql #8,%sp
RESTORE_SWITCH_STACK
addql #4,%sp
Lreturn:
RESTORE_ALL
/*
* This is the main interrupt handler, responsible for calling process_int()
*/
inthandler:
SAVE_ALL
addql #1,local_irq_count /* put exception # in d0*/
movew %sp@(PT_VECTOR), %d0
and.l #0x3ff, %d0
lsr.l #0x02, %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_interrupt
ret_from_interrupt:
subql #1,local_irq_count
jeq 1f
2:
RESTORE_ALL
1:
moveb %sp@(PT_SR), %d0
and #7, %d0
jhi 2b
/* check if we need to do software interrupts */
movel irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0
jeq ret_from_exception
pea ret_from_exception
jra do_softirq
/*
* Handler for uninitialized and spurious interrupts.
*/
bad_interrupt:
addql #1,num_spurious
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 */
movel %usp,%a2 /* save usp */
movel %a2,%a0@(TASK_THREAD+THREAD_USP)
SAVE_SWITCH_STACK
movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
RESTORE_SWITCH_STACK
movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */
movel %a0,%usp
movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */
rts
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