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/*
* linux/arch/m68knommu/platform/5307/entry.S
*
* Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
* Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
* Kenneth Albanowski <kjahds@kjahds.com>,
* Copyright (C) 2000 Lineo Inc. (www.lineo.com)
* Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com)
*
* Based on:
*
* 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
* ColdFire support by Greg Ungerer (gerg@snapgear.com)
* 5307 fixes by David W. Miller
* linux 2.4 support David McCullough <davidm@snapgear.com>
* Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
*/
#include <linux/sys.h>
#include <linux/linkage.h>
#include <asm/unistd.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
.bss
sw_ksp:
.long 0
sw_usp:
.long 0
.text
.globl system_call
.globl resume
.globl ret_from_exception
.globl ret_from_signal
.globl sys_call_table
.globl ret_from_interrupt
.globl inthandler
.globl fasthandler
enosys:
mov.l #sys_ni_syscall,%d3
bra 1f
ENTRY(system_call)
SAVE_ALL
move #0x2000,%sr /* enable intrs again */
cmpl #NR_syscalls,%d0
jcc enosys
lea sys_call_table,%a0
lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */
movel %a0@(%d0),%d3
jeq enosys
1:
movel %sp,%d2 /* get thread_info pointer */
andl #-THREAD_SIZE,%d2 /* at start of kernel stack */
movel %d2,%a0
movel %a0@,%a1 /* save top of frame */
movel %sp,%a1@(TASK_THREAD+THREAD_ESP0)
btst #(TIF_SYSCALL_TRACE%8),%a0@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
bnes 1f
movel %d3,%a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value */
jra ret_from_exception
1:
movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */
movel %d2,PT_OFF_D0(%sp) /* on syscall entry */
subql #4,%sp
SAVE_SWITCH_STACK
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
movel %d3,%a0
jbsr %a0@
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
ret_from_exception:
move #0x2700,%sr /* disable intrs */
btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */
jeq Luser_return /* if so, skip resched, signals */
#ifdef CONFIG_PREEMPT
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
movel %d1,%a0
movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
andl #(1<<TIF_NEED_RESCHED),%d1
jeq Lkernel_return
movel %a0@(TI_PREEMPTCOUNT),%d1
cmpl #0,%d1
jne Lkernel_return
pea Lkernel_return
jmp preempt_schedule_irq /* preempt the kernel */
#endif
Lkernel_return:
moveml %sp@,%d1-%d5/%a0-%a2
lea %sp@(32),%sp /* space for 8 regs */
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stk adj */
rte
Luser_return:
movel %sp,%d1 /* get thread_info pointer */
andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
movel %d1,%a0
movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
andl #0xefff,%d1
jne Lwork_to_do /* still work to do */
Lreturn:
move #0x2700,%sr /* disable intrs */
movel sw_usp,%a0 /* get usp */
movel %sp@(PT_OFF_PC),%a0@- /* copy exception program counter */
movel %sp@(PT_OFF_FORMATVEC),%a0@- /* copy exception format/vector/sr */
moveml %sp@,%d1-%d5/%a0-%a2
lea %sp@(32),%sp /* space for 8 regs */
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stk adj */
addql #8,%sp /* remove exception */
movel %sp,sw_ksp /* save ksp */
subql #8,sw_usp /* set exception */
movel sw_usp,%sp /* restore usp */
rte
Lwork_to_do:
movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
move #0x2000,%sr /* enable intrs again */
btst #TIF_NEED_RESCHED,%d1
jne reschedule
/* GERG: do we need something here for TRACEing?? */
Lsignal_return:
subql #4,%sp /* dummy return address */
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jsr do_signal
addql #4,%sp
RESTORE_SWITCH_STACK
addql #4,%sp
jmp Lreturn
/*
* This is the generic interrupt handler (for all hardware interrupt
* sources). Calls upto high level code to do all the work.
*/
ENTRY(inthandler)
SAVE_ALL
moveq #-1,%d0
movel %d0,%sp@(PT_OFF_ORIG_D0)
movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
andl #0x03fc,%d0 /* mask out vector only */
movel %sp,%sp@- /* push regs arg */
lsrl #2,%d0 /* calculate real vector # */
movel %d0,%sp@- /* push vector number */
jbsr do_IRQ /* call high level irq handler */
lea %sp@(8),%sp /* pop args off stack */
bra ret_from_interrupt /* this was fallthrough */
/*
* This is the fast interrupt handler (for certain hardware interrupt
* sources). Unlike the normal interrupt handler it just uses the
* current stack (doesn't care if it is user or kernel). It also
* doesn't bother doing the bottom half handlers.
*/
ENTRY(fasthandler)
SAVE_LOCAL
movew %sp@(PT_OFF_FORMATVEC),%d0
andl #0x03fc,%d0 /* mask out vector only */
movel %sp,%sp@- /* push regs arg */
lsrl #2,%d0 /* calculate real vector # */
movel %d0,%sp@- /* push vector number */
jbsr do_IRQ /* call high level irq handler */
lea %sp@(8),%sp /* pop args off stack */
RESTORE_LOCAL
ENTRY(ret_from_interrupt)
/* the fasthandler is confusing me, haven't seen any user */
jmp ret_from_exception
/*
* 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.
* This is always called in supervisor mode, so don't bother to save
* and restore sr; user's process sr is actually in the stack.
*/
ENTRY(resume)
movel %a0, %d1 /* get prev thread in d1 */
movel sw_usp,%d0 /* save usp */
movel %d0,%a0@(TASK_THREAD+THREAD_USP)
SAVE_SWITCH_STACK
movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
RESTORE_SWITCH_STACK
movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
movel %a0, sw_usp
rts
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