forked from Minki/linux
9fde034864
Add a m68k-only set_fc helper to set the SFC and DFC registers for the few places that need to override it for special MM operations, but disconnect that from the deprecated kernel-wide set_fs() API. Note that the SFC/DFC registers are context switched, so there is no need to disable preemption. Partially based on an earlier patch from Linus Torvalds <torvalds@linux-foundation.org>. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Link: https://lore.kernel.org/r/20210916070405.52750-7-hch@lst.de Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
200 lines
5.2 KiB
ArmAsm
200 lines
5.2 KiB
ArmAsm
/*
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* entry.S -- interrupt and exception processing for ColdFire
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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/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/asm-offsets.h>
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#include <asm/entry.h>
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#ifdef CONFIG_COLDFIRE_SW_A7
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/*
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* Define software copies of the supervisor and user stack pointers.
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*/
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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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#endif /* CONFIG_COLDFIRE_SW_A7 */
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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 sys_call_table
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.globl inthandler
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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_SYS
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move #0x2000,%sr /* enable intrs again */
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GET_CURRENT(%d2)
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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@(TINFO_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_OFF_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_OFF_D0 */
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movel %d2,PT_OFF_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_enter
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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_OFF_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_leave
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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_OFF_SR) /* check if returning to kernel */
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jeq Luser_return /* if so, skip resched, signals */
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#ifdef CONFIG_PREEMPTION
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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@(TINFO_FLAGS),%d1 /* get thread_info->flags */
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andl #(1<<TIF_NEED_RESCHED),%d1
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jeq Lkernel_return
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movel %a0@(TINFO_PREEMPT),%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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moveb %a0@(TINFO_FLAGS+3),%d1 /* thread_info->flags (low 8 bits) */
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jne Lwork_to_do /* still work to do */
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Lreturn:
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RESTORE_USER
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Lwork_to_do:
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movel %a0@(TINFO_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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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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jsr do_notify_resume
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addql #4,%sp
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RESTORE_SWITCH_STACK
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addql #4,%sp
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jmp Luser_return
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/*
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* This is the generic interrupt handler (for all hardware interrupt
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* sources). Calls up to high level code to do all the work.
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*/
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ENTRY(inthandler)
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SAVE_ALL_INT
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GET_CURRENT(%d2)
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movew %sp@(PT_OFF_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_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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*/
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ENTRY(resume)
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movew %sr,%d1 /* save current status */
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movew %d1,%a0@(TASK_THREAD+THREAD_SR)
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movel %a0,%d1 /* get prev thread in d1 */
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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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RDUSP /* movel %usp,%a3 */
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movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */
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#ifdef CONFIG_MMU
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movel %a1,%a2 /* set new current */
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#endif
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movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */
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WRUSP /* movel %a3,%usp */
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movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */
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movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */
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movew %d7,%sr
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RESTORE_SWITCH_STACK
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rts
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