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/*
 *
 *  linux/arch/m68knommu/kernel/entry.S
 *
 *  Copyright (C) 1999  Keith Adams <kma@cse.ogi.edu>,
 *                      Oregon Graduate Institute
 *
 */

/*
 * syscall, interrupt, and fault entry points
 */

#include <asm/i960.h>
#include <asm/unistd.h>
#define ALL_ONES 0xffffffff

#include <linux/sys.h>
#include <linux/config.h>
#include <linux/linkage.h>
#include <asm/setup.h>
#include <asm/segment.h>
#ifdef CONFIG_I960VH
#include <asm/i960jx.h>
#endif


        .globl  SYMBOL_NAME(atmod)
SYMBOL_NAME_LABEL(atmod)
        atmod   g0, g1, g2
        mov     g2, g0
        ret

/*
 * The birthplace of kernel threads. Once here, we find the function to call
 * in register r3, and its argument in r4. See kernel_thread in asm/unistd.h
 * for why this exists.
 */
        .globl  SYMBOL_NAME(kthread_trampoline)
SYMBOL_NAME_LABEL(kthread_trampoline)
        mov     r3, g0
        mov     r4, g1
        call    SYMBOL_NAME(kthread_start)
        ldconst 0, g0
        b       SYMBOL_NAME(do_exit)
/* no ret */

/*
 * signal handlers start here in signal_head.
 */
        .globl  SYMBOL_NAME(signal_head)
SYMBOL_NAME_LABEL(signal_head)
        mov     g0, r5
        mov     r4, g0
        callx   (r3)
        mov     r5, g0
        ret

#define USER_AC 0x3b001000
#define USER_PC 0x00002000      /* bit 13 set: interrupted mode */
#define KSP_OFFSET      0x58

#if 0
#define CKPT(x,y)       \
        ldconst x, g0;  \
        mov     y, g1;  \
        call    SYMBOL_NAME(ckpt);
#endif

        /* XXX: todo: emulate an interrupt: put PC and AC on stack */
/*
 * This is branched to by intr and syscall; it switches to the kernel stack,
 * and returns to the ip in r6. The choice of registers lets us economize
 * on store operations.
 *
 * Be sure to branch here, rather than call; we can't use a single frame of
 * the shared intr/syscall stacks.
 *
 * Observe weird register conventions (because we can't alter g* regs):
 *      ip after switch:                r6
 *      r3 in new stack:                r7 (for intr/fault)
 *      PC to be seen in new stack:     r8
 */
        .align  4
switch_to_kstack:
        ld      SYMBOL_NAME(current_set), r3
        ld      KSP_OFFSET(r3), r3
        ldconst 64, r5
        addo    r3, r5, r3              # get some space on stack (for PC/AC)
/*
 * r3 now points to the address of the new stack frame. We build an image of
 * the new stack frame in regs r4-r7. The intr needs to
 * remember its intr vector, so we also put r7 on the stack, in the r3
 * position.
 */

        mov     pfp, r4                 # newframe->pfp = current pfp
        addo    r5, r3, r5              # newframe->sp = newframe + 64
                                        # newframe->rip = rip (passed in r6)
                                        # newframe->r3 = r7
        stq     r4, (r3)

/* Store AC, PC as if in interrupt context */
        modac   0, 0, r9
        stl     r8, -16(r3)             # current ac, pc passed in r8
        flushreg
        mov     r3, pfp
        flushreg
        ret                             # returns to ip from r6

/*
 * System calls all end up here.
 */
        .globl  SYMBOL_NAME(syscall)
        .align  4
SYMBOL_NAME_LABEL(syscall)
        /*
         * first, examine pfp; if its 1st and 2nd bits are 1 and 0 respectively,
         * we're coming from user mode, so we need to switch stacks.
         */

        bbs     2, pfp, 1f      # if bit 2 is set, we're cool
        bbc     1, pfp, 1f      # same if bit 1 is clear
        /* uh-oh, we're coming from user mode: switch stacks */
        lda     1f, r6
        ldconst USER_PC, r8
        b       switch_to_kstack

1:
        SAVE_ALL(r3)
        subo    16, fp, g0
        call    SYMBOL_NAME(csyscall)
        RESTORE_ALL(r3)
        ret

/*
 * This is the main interrupt handler; it is also the entry point for 
 * system calls.
 */
        .globl  SYMBOL_NAME(intr)
        .align  4
SYMBOL_NAME_LABEL(intr)
        ld      -16(fp), r3
        ldob    -8(fp), r7
        bbs     1, r3, 1f               # if we're supervisor, forget it
        /* uh-oh, switch stacks */
        lda     2f, r6
        mov     r3, r8
        b       switch_to_kstack

1:
        mov     r7, r3
2:
/*
 * by now we're on a valid stack, and the interrupt vector number is in
 * r3.
 */
        SAVE_ALL(r4)
        mov     r3, g0          # 1st arg is intr vector
        flushreg                # get regs on stack
        subo    16, fp, g1      # 2nd arg is pointer to pt_regs
        call    SYMBOL_NAME(cintr)
        RESTORE_ALL(r3)
        ret                     # back to user-level

/*
 * Again, if we're coming from user mode, switch to kstack. We get this info
 * from the fault record, 16 bytes below the current fp. We play games similar
 * to intr to hold onto the fault record...
 */
        .globl  SYMBOL_NAME(fault)
SYMBOL_NAME_LABEL(fault)
        subo    16, fp, r7
        ld      (r7), r3        # r3 gets pc of faulting instr
        bbs     1, r3, 1f       # if it was a supervisor fault, don't switch

        lda     2f, r6
        ldconst USER_PC, r8
        b       switch_to_kstack
1:
        mov     r7, r3
2:
        SAVE_ALL(r4)
        mov     r3, g0
        subo    16, fp, g1
        call    SYMBOL_NAME(cfault)
        RESTORE_ALL(r4)
        ret

/*
 * The table of system calls.
 */
        .globl  SYMBOL_NAME(syscall_tab)
SYMBOL_NAME_LABEL(syscall_tab)
        .long SYMBOL_NAME(sys_setup)            /* 0 */
        .long SYMBOL_NAME(sys_exit)
        .long SYMBOL_NAME(sys_fork)
        .long SYMBOL_NAME(sys_read)
        .long SYMBOL_NAME(sys_write)
        .long SYMBOL_NAME(sys_open)             /* 5 */
        .long SYMBOL_NAME(sys_close)
        .long SYMBOL_NAME(sys_waitpid)
        .long SYMBOL_NAME(sys_creat)
        .long SYMBOL_NAME(sys_link)
        .long SYMBOL_NAME(sys_unlink)           /* 10 */
        .long SYMBOL_NAME(sys_execve)
        .long SYMBOL_NAME(sys_chdir)
        .long SYMBOL_NAME(sys_time)
        .long SYMBOL_NAME(sys_mknod)
        .long SYMBOL_NAME(sys_chmod)            /* 15 */
        .long SYMBOL_NAME(sys_chown)
        .long SYMBOL_NAME(sys_break)
        .long SYMBOL_NAME(sys_stat)
        .long SYMBOL_NAME(sys_lseek)
        .long SYMBOL_NAME(sys_getpid)           /* 20 */
        .long SYMBOL_NAME(sys_mount)
        .long SYMBOL_NAME(sys_umount)
        .long SYMBOL_NAME(sys_setuid)
        .long SYMBOL_NAME(sys_getuid)
        .long SYMBOL_NAME(sys_stime)            /* 25 */
        .long SYMBOL_NAME(sys_ptrace)
        .long SYMBOL_NAME(sys_alarm)
        .long SYMBOL_NAME(sys_fstat)
        .long SYMBOL_NAME(sys_pause)
        .long SYMBOL_NAME(sys_utime)            /* 30 */
        .long SYMBOL_NAME(sys_stty)
        .long SYMBOL_NAME(sys_gtty)
        .long SYMBOL_NAME(sys_access)
        .long SYMBOL_NAME(sys_nice)
        .long SYMBOL_NAME(sys_ftime)            /* 35 */
        .long SYMBOL_NAME(sys_sync)
        .long SYMBOL_NAME(sys_kill)
        .long SYMBOL_NAME(sys_rename)
        .long SYMBOL_NAME(sys_mkdir)
        .long SYMBOL_NAME(sys_rmdir)            /* 40 */
        .long SYMBOL_NAME(sys_dup)
        .long SYMBOL_NAME(do_pipe)
        .long SYMBOL_NAME(sys_times)
        .long SYMBOL_NAME(sys_prof)
        .long SYMBOL_NAME(sys_brk)              /* 45 */
        .long SYMBOL_NAME(sys_setgid)
        .long SYMBOL_NAME(sys_getgid)
        .long SYMBOL_NAME(sys_signal)
        .long SYMBOL_NAME(sys_geteuid)
        .long SYMBOL_NAME(sys_getegid)          /* 50 */
        .long SYMBOL_NAME(sys_acct)
        .long SYMBOL_NAME(sys_phys)
        .long SYMBOL_NAME(sys_lock)
        .long SYMBOL_NAME(sys_ioctl)
        .long SYMBOL_NAME(sys_fcntl)            /* 55 */
        .long SYMBOL_NAME(sys_mpx)
        .long SYMBOL_NAME(sys_setpgid)
        .long SYMBOL_NAME(sys_ulimit)
        .long SYMBOL_NAME(sys_olduname)
        .long SYMBOL_NAME(sys_umask)            /* 60 */
        .long SYMBOL_NAME(sys_chroot)
        .long SYMBOL_NAME(sys_ustat)
        .long SYMBOL_NAME(sys_dup2)
        .long SYMBOL_NAME(sys_getppid)
        .long SYMBOL_NAME(sys_getpgrp)          /* 65 */
        .long SYMBOL_NAME(sys_setsid)
        .long SYMBOL_NAME(sys_sigaction)
        .long SYMBOL_NAME(sys_sgetmask)
        .long SYMBOL_NAME(sys_ssetmask)
        .long SYMBOL_NAME(sys_setreuid)         /* 70 */
        .long SYMBOL_NAME(sys_setregid)
        .long SYMBOL_NAME(do_sigsuspend)
        .long SYMBOL_NAME(sys_sigpending)
        .long SYMBOL_NAME(sys_sethostname)
        .long SYMBOL_NAME(sys_setrlimit)        /* 75 */
        .long SYMBOL_NAME(sys_getrlimit)
        .long SYMBOL_NAME(sys_getrusage)
        .long SYMBOL_NAME(sys_gettimeofday)
        .long SYMBOL_NAME(sys_settimeofday)
        .long SYMBOL_NAME(sys_getgroups)        /* 80 */
        .long SYMBOL_NAME(sys_setgroups)
        .long SYMBOL_NAME(sys_select)
        .long SYMBOL_NAME(sys_symlink)
        .long SYMBOL_NAME(sys_lstat)
        .long SYMBOL_NAME(sys_readlink)         /* 85 */
        .long SYMBOL_NAME(sys_uselib)
        .long SYMBOL_NAME(sys_swapon)
        .long SYMBOL_NAME(sys_reboot)
        .long SYMBOL_NAME(sys_ni_syscall)
        .long SYMBOL_NAME(sys_ni_syscall)               /* 90 */
        .long SYMBOL_NAME(sys_munmap)
        .long SYMBOL_NAME(sys_truncate)
        .long SYMBOL_NAME(sys_ftruncate)
        .long SYMBOL_NAME(sys_fchmod)
        .long SYMBOL_NAME(sys_fchown)           /* 95 */
        .long SYMBOL_NAME(sys_getpriority)
        .long SYMBOL_NAME(sys_setpriority)
        .long SYMBOL_NAME(sys_profil)
        .long SYMBOL_NAME(sys_statfs)
        .long SYMBOL_NAME(sys_fstatfs)          /* 100 */
        .long SYMBOL_NAME(sys_ioperm)
        .long SYMBOL_NAME(sys_socketcall)
        .long SYMBOL_NAME(sys_syslog)
        .long SYMBOL_NAME(sys_setitimer)
        .long SYMBOL_NAME(sys_getitimer)        /* 105 */
        .long SYMBOL_NAME(sys_newstat)
        .long SYMBOL_NAME(sys_newlstat)
        .long SYMBOL_NAME(sys_newfstat)
        .long SYMBOL_NAME(sys_uname)
        .long SYMBOL_NAME(sys_ni_syscall)       /* iopl for i386 */ /* 110 */
        .long SYMBOL_NAME(sys_vhangup)
        .long SYMBOL_NAME(sys_idle)
        .long SYMBOL_NAME(sys_ni_syscall)       /* vm86 for i386 */
        .long SYMBOL_NAME(sys_wait4)
        .long SYMBOL_NAME(sys_swapoff)          /* 115 */
        .long SYMBOL_NAME(sys_sysinfo)
        .long SYMBOL_NAME(sys_ipc)
        .long SYMBOL_NAME(sys_fsync)
        .long SYMBOL_NAME(do_sigreturn)
        .long SYMBOL_NAME(sys_clone)            /* 120 */
        .long SYMBOL_NAME(sys_setdomainname)
        .long SYMBOL_NAME(sys_newuname)
        .long SYMBOL_NAME(sys_cacheflush)       /* modify_ldt for i386 */
        .long SYMBOL_NAME(sys_adjtimex)
        .long SYMBOL_NAME(sys_mprotect)         /* 125 */
        .long SYMBOL_NAME(sys_sigprocmask)
        .long SYMBOL_NAME(sys_create_module)
        .long SYMBOL_NAME(sys_init_module)
        .long SYMBOL_NAME(sys_delete_module)
        .long SYMBOL_NAME(sys_get_kernel_syms)  /* 130 */
        .long SYMBOL_NAME(sys_quotactl)
        .long SYMBOL_NAME(sys_getpgid)
        .long SYMBOL_NAME(sys_fchdir)
        .long SYMBOL_NAME(sys_bdflush)
        .long SYMBOL_NAME(sys_sysfs)            /* 135 */
        .long SYMBOL_NAME(sys_personality)
        .long SYMBOL_NAME(sys_ni_syscall)       /* for afs_syscall */
        .long SYMBOL_NAME(sys_setfsuid)
        .long SYMBOL_NAME(sys_setfsgid)
        .long SYMBOL_NAME(sys_llseek)           /* 140 */
        .long SYMBOL_NAME(sys_getdents)
        .long SYMBOL_NAME(sys_select)
        .long SYMBOL_NAME(sys_flock)
        .long SYMBOL_NAME(sys_msync)
        .long SYMBOL_NAME(sys_readv)            /* 145 */
        .long SYMBOL_NAME(sys_writev)
        .long SYMBOL_NAME(sys_getsid)
        .long SYMBOL_NAME(sys_fdatasync)
        .long SYMBOL_NAME(sys_sysctl)
        .long SYMBOL_NAME(sys_mlock)            /* 150 */
        .long SYMBOL_NAME(sys_munlock)
        .long SYMBOL_NAME(sys_mlockall)
        .long SYMBOL_NAME(sys_munlockall)
        .long SYMBOL_NAME(sys_sched_setparam)
        .long SYMBOL_NAME(sys_sched_getparam)   /* 155 */
        .long SYMBOL_NAME(sys_sched_setscheduler)
        .long SYMBOL_NAME(sys_sched_getscheduler)
        .long SYMBOL_NAME(sys_sched_yield)
        .long SYMBOL_NAME(sys_sched_get_priority_max)
        .long SYMBOL_NAME(sys_sched_get_priority_min)  /* 160 */
        .long SYMBOL_NAME(sys_sched_rr_get_interval)
        .long SYMBOL_NAME(sys_nanosleep)
        .long SYMBOL_NAME(sys_mremap)