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-rw-r--r--arch/m68k/kernel/entry.S452
1 files changed, 449 insertions, 3 deletions
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index b8daf64..165ee9f 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -1,5 +1,451 @@
-#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
-#include "entry_mm.S"
+/* -*- mode: asm -*-
+ *
+ * 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
+ *
+ */
+
+/*
+ * entry.S contains the system-call and fault low-level handling routines.
+ * This also contains the timer-interrupt handler, as well as all interrupts
+ * and faults that can result in a task-switch.
+ *
+ * NOTE: This code handles signal-recognition, which happens every time
+ * after a timer-interrupt and after each system call.
+ *
+ */
+
+/*
+ * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so
+ * all pointers that used to be 'current' are now entry
+ * number 0 in the 'current_set' list.
+ *
+ * 6/05/00 RZ: addedd writeback completion after return from sighandler
+ * for 68040
+ */
+
+#include <linux/linkage.h>
+#include <asm/errno.h>
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/traps.h>
+#include <asm/unistd.h>
+#include <asm/asm-offsets.h>
+#include <asm/entry.h>
+
+.globl system_call, buserr, trap, resume
+.globl sys_call_table
+.globl sys_fork, sys_clone, sys_vfork
+.globl ret_from_interrupt, bad_interrupt
+.globl auto_irqhandler_fixup
+.globl user_irqvec_fixup
+
+.text
+ENTRY(sys_fork)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_fork
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_clone)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_clone
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_vfork)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_vfork
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_sigreturn)
+ SAVE_SWITCH_STACK
+ jbsr do_sigreturn
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_rt_sigreturn)
+ SAVE_SWITCH_STACK
+ jbsr do_rt_sigreturn
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(buserr)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %sp,%sp@- | stack frame pointer argument
+ jbsr buserr_c
+ addql #4,%sp
+ jra ret_from_exception
+
+ENTRY(trap)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %sp,%sp@- | stack frame pointer argument
+ jbsr trap_c
+ addql #4,%sp
+ jra ret_from_exception
+
+ | After a fork we jump here directly from resume,
+ | so that %d1 contains the previous task
+ | schedule_tail now used regardless of CONFIG_SMP
+ENTRY(ret_from_fork)
+ movel %d1,%sp@-
+ jsr schedule_tail
+ addql #4,%sp
+ jra ret_from_exception
+
+#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
+
+#ifdef TRAP_DBG_INTERRUPT
+
+.globl dbginterrupt
+ENTRY(dbginterrupt)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %sp,%sp@- /* stack frame pointer argument */
+ jsr dbginterrupt_c
+ addql #4,%sp
+ jra ret_from_exception
+#endif
+
+ENTRY(reschedule)
+ /* save top of frame */
+ pea %sp@
+ jbsr set_esp0
+ addql #4,%sp
+ pea ret_from_exception
+ jmp schedule
+
+ENTRY(ret_from_user_signal)
+ moveq #__NR_sigreturn,%d0
+ trap #0
+
+ENTRY(ret_from_user_rt_signal)
+ movel #__NR_rt_sigreturn,%d0
+ trap #0
+
#else
-#include "entry_no.S"
+
+do_trace_entry:
+ movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
+ subql #4,%sp
+ SAVE_SWITCH_STACK
+ jbsr syscall_trace
+ RESTORE_SWITCH_STACK
+ addql #4,%sp
+ movel %sp@(PT_OFF_ORIG_D0),%d0
+ cmpl #NR_syscalls,%d0
+ jcs syscall
+badsys:
+ movel #-ENOSYS,%sp@(PT_OFF_D0)
+ jra ret_from_syscall
+
+do_trace_exit:
+ subql #4,%sp
+ SAVE_SWITCH_STACK
+ jbsr syscall_trace
+ RESTORE_SWITCH_STACK
+ addql #4,%sp
+ jra .Lret_from_exception
+
+ENTRY(ret_from_signal)
+ movel %curptr@(TASK_STACK),%a1
+ tstb %a1@(TINFO_FLAGS+2)
+ jge 1f
+ jbsr syscall_trace
+1: RESTORE_SWITCH_STACK
+ addql #4,%sp
+/* on 68040 complete pending writebacks if any */
+#ifdef CONFIG_M68040
+ bfextu %sp@(PT_OFF_FORMATVEC){#0,#4},%d0
+ subql #7,%d0 | bus error frame ?
+ jbne 1f
+ movel %sp,%sp@-
+ jbsr berr_040cleanup
+ addql #4,%sp
+1:
+#endif
+ jra .Lret_from_exception
+
+ENTRY(system_call)
+ SAVE_ALL_SYS
+
+ GET_CURRENT(%d1)
+ movel %d1,%a1
+
+ | save top of frame
+ movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
+
+ | syscall trace?
+ tstb %a1@(TINFO_FLAGS+2)
+ jmi do_trace_entry
+ cmpl #NR_syscalls,%d0
+ jcc badsys
+syscall:
+ jbsr @(sys_call_table,%d0:l:4)@(0)
+ movel %d0,%sp@(PT_OFF_D0) | save the return value
+ret_from_syscall:
+ |oriw #0x0700,%sr
+ movel %curptr@(TASK_STACK),%a1
+ movew %a1@(TINFO_FLAGS+2),%d0
+ jne syscall_exit_work
+1: RESTORE_ALL
+
+syscall_exit_work:
+ btst #5,%sp@(PT_OFF_SR) | check if returning to kernel
+ bnes 1b | if so, skip resched, signals
+ lslw #1,%d0
+ jcs do_trace_exit
+ jmi do_delayed_trace
+ lslw #8,%d0
+ jne do_signal_return
+ pea resume_userspace
+ jra schedule
+
+
+ENTRY(ret_from_exception)
+.Lret_from_exception:
+ btst #5,%sp@(PT_OFF_SR) | check if returning to kernel
+ bnes 1f | if so, skip resched, signals
+ | 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
+
+resume_userspace:
+ movel %curptr@(TASK_STACK),%a1
+ moveb %a1@(TINFO_FLAGS+3),%d0
+ jne exit_work
+1: RESTORE_ALL
+
+exit_work:
+ | save top of frame
+ movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
+ lslb #1,%d0
+ jne do_signal_return
+ pea resume_userspace
+ jra schedule
+
+
+do_signal_return:
+ |andw #ALLOWINT,%sr
+ subql #4,%sp | dummy return address
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ bsrl do_notify_resume
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ addql #4,%sp
+ jbra resume_userspace
+
+do_delayed_trace:
+ bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR
+ pea 1 | send SIGTRAP
+ movel %curptr,%sp@-
+ pea LSIGTRAP
+ jbsr send_sig
+ addql #8,%sp
+ addql #4,%sp
+ jbra resume_userspace
+
+
+/* This is the main interrupt handler for autovector interrupts */
+
+ENTRY(auto_inthandler)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %d0,%a1
+ addqb #1,%a1@(TINFO_PREEMPT+1)
+ | put exception # in d0
+ bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0
+ subw #VEC_SPUR,%d0
+
+ movel %sp,%sp@-
+ movel %d0,%sp@- | put vector # on stack
+auto_irqhandler_fixup = . + 2
+ jsr do_IRQ | process the IRQ
+ addql #8,%sp | pop parameters off stack
+
+ret_from_interrupt:
+ movel %curptr@(TASK_STACK),%a1
+ subqb #1,%a1@(TINFO_PREEMPT+1)
+ jeq ret_from_last_interrupt
+2: RESTORE_ALL
+
+ ALIGN
+ret_from_last_interrupt:
+ moveq #(~ALLOWINT>>8)&0xff,%d0
+ andb %sp@(PT_OFF_SR),%d0
+ jne 2b
+
+ /* check if we need to do software interrupts */
+ tstl irq_stat+CPUSTAT_SOFTIRQ_PENDING
+ jeq .Lret_from_exception
+ pea ret_from_exception
+ jra do_softirq
+
+/* Handler for user defined interrupt vectors */
+
+ENTRY(user_inthandler)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %d0,%a1
+ addqb #1,%a1@(TINFO_PREEMPT+1)
+ | put exception # in d0
+ bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0
+user_irqvec_fixup = . + 2
+ subw #VEC_USER,%d0
+
+ movel %sp,%sp@-
+ movel %d0,%sp@- | put vector # on stack
+ jsr do_IRQ | process the IRQ
+ addql #8,%sp | pop parameters off stack
+
+ movel %curptr@(TASK_STACK),%a1
+ subqb #1,%a1@(TINFO_PREEMPT+1)
+ jeq ret_from_last_interrupt
+ RESTORE_ALL
+
+/* Handler for uninitialized and spurious interrupts */
+
+ENTRY(bad_inthandler)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %d0,%a1
+ addqb #1,%a1@(TINFO_PREEMPT+1)
+
+ movel %sp,%sp@-
+ jsr handle_badint
+ addql #4,%sp
+
+ movel %curptr@(TASK_STACK),%a1
+ subqb #1,%a1@(TINFO_PREEMPT+1)
+ jeq ret_from_last_interrupt
+ RESTORE_ALL
+
+
+resume:
+ /*
+ * 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.
+ */
+
+ /* save sr */
+ movew %sr,%a0@(TASK_THREAD+THREAD_SR)
+
+ /* save fs (sfc,%dfc) (may be pointing to kernel memory) */
+ movec %sfc,%d0
+ movew %d0,%a0@(TASK_THREAD+THREAD_FS)
+
+ /* save usp */
+ /* it is better to use a movel here instead of a movew 8*) */
+ movec %usp,%d0
+ movel %d0,%a0@(TASK_THREAD+THREAD_USP)
+
+ /* save non-scratch registers on stack */
+ SAVE_SWITCH_STACK
+
+ /* save current kernel stack pointer */
+ movel %sp,%a0@(TASK_THREAD+THREAD_KSP)
+
+ /* save floating point context */
+#ifndef CONFIG_M68KFPU_EMU_ONLY
+#ifdef CONFIG_M68KFPU_EMU
+ tstl m68k_fputype
+ jeq 3f
+#endif
+ fsave %a0@(TASK_THREAD+THREAD_FPSTATE)
+
+#if defined(CONFIG_M68060)
+#if !defined(CPU_M68060_ONLY)
+ btst #3,m68k_cputype+3
+ beqs 1f
+#endif
+ /* The 060 FPU keeps status in bits 15-8 of the first longword */
+ tstb %a0@(TASK_THREAD+THREAD_FPSTATE+2)
+ jeq 3f
+#if !defined(CPU_M68060_ONLY)
+ jra 2f
+#endif
+#endif /* CONFIG_M68060 */
+#if !defined(CPU_M68060_ONLY)
+1: tstb %a0@(TASK_THREAD+THREAD_FPSTATE)
+ jeq 3f
+#endif
+2: fmovemx %fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG)
+ fmoveml %fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL)
+3:
+#endif /* CONFIG_M68KFPU_EMU_ONLY */
+ /* Return previous task in %d1 */
+ movel %curptr,%d1
+
+ /* switch to new task (a1 contains new task) */
+ movel %a1,%curptr
+
+ /* restore floating point context */
+#ifndef CONFIG_M68KFPU_EMU_ONLY
+#ifdef CONFIG_M68KFPU_EMU
+ tstl m68k_fputype
+ jeq 4f
+#endif
+#if defined(CONFIG_M68060)
+#if !defined(CPU_M68060_ONLY)
+ btst #3,m68k_cputype+3
+ beqs 1f
+#endif
+ /* The 060 FPU keeps status in bits 15-8 of the first longword */
+ tstb %a1@(TASK_THREAD+THREAD_FPSTATE+2)
+ jeq 3f
+#if !defined(CPU_M68060_ONLY)
+ jra 2f
+#endif
+#endif /* CONFIG_M68060 */
+#if !defined(CPU_M68060_ONLY)
+1: tstb %a1@(TASK_THREAD+THREAD_FPSTATE)
+ jeq 3f
#endif
+2: fmovemx %a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7
+ fmoveml %a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar
+3: frestore %a1@(TASK_THREAD+THREAD_FPSTATE)
+4:
+#endif /* CONFIG_M68KFPU_EMU_ONLY */
+
+ /* restore the kernel stack pointer */
+ movel %a1@(TASK_THREAD+THREAD_KSP),%sp
+
+ /* restore non-scratch registers */
+ RESTORE_SWITCH_STACK
+
+ /* restore user stack pointer */
+ movel %a1@(TASK_THREAD+THREAD_USP),%a0
+ movel %a0,%usp
+
+ /* restore fs (sfc,%dfc) */
+ movew %a1@(TASK_THREAD+THREAD_FS),%a0
+ movec %a0,%sfc
+ movec %a0,%dfc
+
+ /* restore status register */
+ movew %a1@(TASK_THREAD+THREAD_SR),%sr
+
+ rts
+
+#endif /* CONFIG_MMU && !CONFIG_COLDFIRE */