c7bcd0df1f
Part of the code that did not make sense to me got removed by Greg. This is part two: The first compare is to check whether the interrupts are disabled or not. Depending on the result we exectute the RESTORE_ALL macro is not only restoring the stack but also returning to caller. The test for pending softirq has been removed because it is allready done in irq_exit(). Since system_call() is allso using the SAVE_ALL macro and returning via ret_from_exception label I see no reason why we could not do this here as well. This is also handy because if we return from the timer interrupt and we need to resched than we check for this :) Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Ungerer <gerg@uclinux.org>
241 lines
6.2 KiB
ArmAsm
241 lines
6.2 KiB
ArmAsm
/*
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* linux/arch/m68knommu/platform/5307/entry.S
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*
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* Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
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* Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
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* Kenneth Albanowski <kjahds@kjahds.com>,
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* Copyright (C) 2000 Lineo Inc. (www.lineo.com)
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* Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com)
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*
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* Based on:
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*
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* linux/arch/m68k/kernel/entry.S
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file README.legal in the main directory of this archive
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* for more details.
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*
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* Linux/m68k support by Hamish Macdonald
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*
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* 68060 fixes by Jesper Skov
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* ColdFire support by Greg Ungerer (gerg@snapgear.com)
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* 5307 fixes by David W. Miller
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* linux 2.4 support David McCullough <davidm@snapgear.com>
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* Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
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*/
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#include <linux/sys.h>
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#include <linux/linkage.h>
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#include <asm/unistd.h>
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#include <asm/thread_info.h>
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#include <asm/errno.h>
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#include <asm/setup.h>
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#include <asm/segment.h>
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#include <asm/asm-offsets.h>
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#include <asm/entry.h>
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.bss
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sw_ksp:
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.long 0
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sw_usp:
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.long 0
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.text
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.globl system_call
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.globl resume
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.globl ret_from_exception
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.globl ret_from_signal
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.globl sys_call_table
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.globl ret_from_interrupt
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.globl inthandler
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.globl fasthandler
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enosys:
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mov.l #sys_ni_syscall,%d3
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bra 1f
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ENTRY(system_call)
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SAVE_ALL
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move #0x2000,%sr /* enable intrs again */
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cmpl #NR_syscalls,%d0
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jcc enosys
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lea sys_call_table,%a0
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lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */
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movel %a0@(%d0),%d3
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jeq enosys
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1:
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movel %sp,%d2 /* get thread_info pointer */
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andl #-THREAD_SIZE,%d2 /* at start of kernel stack */
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movel %d2,%a0
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movel %a0@,%a1 /* save top of frame */
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movel %sp,%a1@(TASK_THREAD+THREAD_ESP0)
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btst #(TIF_SYSCALL_TRACE%8),%a0@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
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bnes 1f
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movel %d3,%a0
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jbsr %a0@
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movel %d0,%sp@(PT_D0) /* save the return value */
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jra ret_from_exception
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1:
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movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_D0 */
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movel %d2,PT_D0(%sp) /* on syscall entry */
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subql #4,%sp
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SAVE_SWITCH_STACK
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jbsr syscall_trace
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RESTORE_SWITCH_STACK
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addql #4,%sp
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movel %d3,%a0
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jbsr %a0@
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movel %d0,%sp@(PT_D0) /* save the return value */
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subql #4,%sp /* dummy return address */
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SAVE_SWITCH_STACK
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jbsr syscall_trace
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ret_from_signal:
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RESTORE_SWITCH_STACK
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addql #4,%sp
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ret_from_exception:
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move #0x2700,%sr /* disable intrs */
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btst #5,%sp@(PT_SR) /* check if returning to kernel */
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jeq Luser_return /* if so, skip resched, signals */
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#ifdef CONFIG_PREEMPT
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movel %sp,%d1 /* get thread_info pointer */
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andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
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movel %d1,%a0
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movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
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andl #_TIF_NEED_RESCHED,%d1
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jeq Lkernel_return
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movel %a0@(TI_PREEMPTCOUNT),%d1
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cmpl #0,%d1
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jne Lkernel_return
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pea Lkernel_return
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jmp preempt_schedule_irq /* preempt the kernel */
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#endif
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Lkernel_return:
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moveml %sp@,%d1-%d5/%a0-%a2
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lea %sp@(32),%sp /* space for 8 regs */
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movel %sp@+,%d0
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addql #4,%sp /* orig d0 */
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addl %sp@+,%sp /* stk adj */
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rte
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Luser_return:
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movel %sp,%d1 /* get thread_info pointer */
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andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
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movel %d1,%a0
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movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
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andl #_TIF_WORK_MASK,%d1
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jne Lwork_to_do /* still work to do */
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Lreturn:
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move #0x2700,%sr /* disable intrs */
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movel sw_usp,%a0 /* get usp */
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movel %sp@(PT_PC),%a0@- /* copy exception program counter */
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movel %sp@(PT_FORMATVEC),%a0@-/* copy exception format/vector/sr */
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moveml %sp@,%d1-%d5/%a0-%a2
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lea %sp@(32),%sp /* space for 8 regs */
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movel %sp@+,%d0
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addql #4,%sp /* orig d0 */
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addl %sp@+,%sp /* stk adj */
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addql #8,%sp /* remove exception */
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movel %sp,sw_ksp /* save ksp */
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subql #8,sw_usp /* set exception */
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movel sw_usp,%sp /* restore usp */
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rte
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Lwork_to_do:
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movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
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move #0x2000,%sr /* enable intrs again */
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btst #TIF_NEED_RESCHED,%d1
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jne reschedule
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/* GERG: do we need something here for TRACEing?? */
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Lsignal_return:
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subql #4,%sp /* dummy return address */
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SAVE_SWITCH_STACK
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pea %sp@(SWITCH_STACK_SIZE)
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clrl %sp@-
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jsr do_signal
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addql #8,%sp
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RESTORE_SWITCH_STACK
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addql #4,%sp
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jmp Lreturn
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/*
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* This is the generic interrupt handler (for all hardware interrupt
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* sources). Calls upto high level code to do all the work.
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*/
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ENTRY(inthandler)
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SAVE_ALL
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moveq #-1,%d0
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movel %d0,%sp@(PT_ORIG_D0)
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movew %sp@(PT_FORMATVEC),%d0 /* put exception # in d0 */
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andl #0x03fc,%d0 /* mask out vector only */
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movel %sp,%sp@- /* push regs arg */
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lsrl #2,%d0 /* calculate real vector # */
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movel %d0,%sp@- /* push vector number */
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jbsr do_IRQ /* call high level irq handler */
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lea %sp@(8),%sp /* pop args off stack */
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bra ret_from_interrupt /* this was fallthrough */
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/*
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* This is the fast interrupt handler (for certain hardware interrupt
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* sources). Unlike the normal interrupt handler it just uses the
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* current stack (doesn't care if it is user or kernel). It also
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* doesn't bother doing the bottom half handlers.
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*/
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ENTRY(fasthandler)
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SAVE_LOCAL
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movew %sp@(PT_FORMATVEC),%d0
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andl #0x03fc,%d0 /* mask out vector only */
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movel %sp,%sp@- /* push regs arg */
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lsrl #2,%d0 /* calculate real vector # */
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movel %d0,%sp@- /* push vector number */
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jbsr do_IRQ /* call high level irq handler */
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lea %sp@(8),%sp /* pop args off stack */
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RESTORE_LOCAL
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ENTRY(ret_from_interrupt)
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/* the fasthandler is confusing me, haven't seen any user */
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jmp ret_from_exception
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/*
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* Beware - when entering resume, prev (the current task) is
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* in a0, next (the new task) is in a1,so don't change these
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* registers until their contents are no longer needed.
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* This is always called in supervisor mode, so don't bother to save
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* and restore sr; user's process sr is actually in the stack.
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*/
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ENTRY(resume)
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movel %a0, %d1 /* get prev thread in d1 */
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movel sw_usp,%d0 /* save usp */
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movel %d0,%a0@(TASK_THREAD+THREAD_USP)
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SAVE_SWITCH_STACK
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movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
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movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
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RESTORE_SWITCH_STACK
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movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
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movel %a0, sw_usp
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rts
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