arch/m68knommu/platform/68328/entry.S

   1 /*
   2  *  linux/arch/m68knommu/platform/68328/entry.S
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file README.legal in the main directory of this archive
   8  * for more details.
   9  *
  10  * Linux/m68k support by Hamish Macdonald
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/sys.h>
  15 #include <linux/linkage.h>
  16 #include <asm/thread_info.h>
  17 #include <asm/unistd.h>
  18 #include <asm/errno.h>
  19 #include <asm/setup.h>
  20 #include <asm/segment.h>
  21 #include <asm/traps.h>
  22 #include <asm/asm-offsets.h>
  23 #include <asm/entry.h>
  24
  25 .text
  26
  27 .globl system_call
  28 .globl resume
  29 .globl ret_from_exception
  30 .globl ret_from_signal
  31 .globl sys_call_table
  32 .globl ret_from_interrupt
  33 .globl bad_interrupt
  34 .globl inthandler1
  35 .globl inthandler2
  36 .globl inthandler3
  37 .globl inthandler4
  38 .globl inthandler5
  39 .globl inthandler6
  40 .globl inthandler7
  41
  42 badsys:
  43         movel   #-ENOSYS,%sp@(PT_D0)
  44         jra     ret_from_exception
  45
  46 do_trace:
  47         movel   #-ENOSYS,%sp@(PT_D0)    /* needed for strace*/
  48         subql   #4,%sp
  49         SAVE_SWITCH_STACK
  50         jbsr    syscall_trace
  51         RESTORE_SWITCH_STACK
  52         addql   #4,%sp
  53         movel   %sp@(PT_ORIG_D0),%d1
  54         movel   #-ENOSYS,%d0
  55         cmpl    #NR_syscalls,%d1
  56         jcc     1f
  57         lsl     #2,%d1
  58         lea     sys_call_table, %a0
  59         jbsr    %a0@(%d1)
  60
  61 1:      movel   %d0,%sp@(PT_D0)         /* save the return value */
  62         subql   #4,%sp                  /* dummy return address */
  63         SAVE_SWITCH_STACK
  64         jbsr    syscall_trace
  65
  66 ret_from_signal:
  67         RESTORE_SWITCH_STACK
  68         addql   #4,%sp
  69         jra     ret_from_exception
  70
  71 ENTRY(system_call)
  72         SAVE_ALL
  73
  74         /* save top of frame*/
  75         pea     %sp@
  76         jbsr    set_esp0
  77         addql   #4,%sp
  78
  79         movel   %sp@(PT_ORIG_D0),%d0
  80
  81         movel   %sp,%d1                 /* get thread_info pointer */
  82         andl    #0xffffe000,%d1
  83         movel   %d1,%a2
  84         btst    #TIF_SYSCALL_TRACE,%a2@(TI_FLAGS)
  85         jne     do_trace
  86         cmpl    #NR_syscalls,%d0
  87         jcc     badsys
  88         lsl     #2,%d0
  89         lea     sys_call_table,%a0
  90         movel   %a0@(%d0), %a0
  91         jbsr    %a0@
  92         movel   %d0,%sp@(PT_D0)         /* save the return value*/
  93
  94 ret_from_exception:
  95         btst    #5,%sp@(PT_SR)          /* check if returning to kernel*/
  96         jeq     Luser_return            /* if so, skip resched, signals*/
  97
  98 Lkernel_return:
  99         RESTORE_ALL
 100
 101 Luser_return:
 102         /* only allow interrupts when we are really the last one on the*/
 103         /* kernel stack, otherwise stack overflow can occur during*/
 104         /* heavy interrupt load*/
 105         andw    #ALLOWINT,%sr
 106
 107         movel   %sp,%d1                 /* get thread_info pointer */
 108         andl    #0xffffe000,%d1
 109         movel   %d1,%a2
 110         move    %a2@(TI_FLAGS),%d1      /* thread_info->flags */
 111         andl    #_TIF_WORK_MASK,%d1
 112         jne     Lwork_to_do
 113         RESTORE_ALL
 114
 115 Lwork_to_do:
 116         movel   %a2@(TI_FLAGS),%d1      /* thread_info->flags */
 117         btst    #TIF_NEED_RESCHED,%d1
 118         jne     reschedule
 119
 120 Lsignal_return:
 121         subql   #4,%sp                  /* dummy return address*/
 122         SAVE_SWITCH_STACK
 123         pea     %sp@(SWITCH_STACK_SIZE)
 124         clrl    %sp@-
 125         bsrw    do_signal
 126         addql   #8,%sp
 127         RESTORE_SWITCH_STACK
 128         addql   #4,%sp
 129 Lreturn:
 130         RESTORE_ALL
 131
 132 /*
 133  * This is the main interrupt handler, responsible for calling process_int()
 134  */
 135 inthandler1:
 136         SAVE_ALL
 137         addql   #1,local_irq_count      /*  put exception # in d0*/
 138         movew   %sp@(PT_VECTOR), %d0
 139         and     #0x3ff, %d0
 140
 141         movel   %sp,%sp@-
 142         movel   #65,%sp@-               /*  put vector # on stack*/
 143         jbsr    process_int             /*  process the IRQ*/
 144 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 145         bra     ret_from_interrupt
 146
 147 inthandler2:
 148         SAVE_ALL
 149         addql   #1,local_irq_count      /*  put exception # in d0*/
 150         movew   %sp@(PT_VECTOR), %d0
 151         and     #0x3ff, %d0
 152
 153         movel   %sp,%sp@-
 154         movel   #66,%sp@-               /*  put vector # on stack*/
 155         jbsr    process_int             /*  process the IRQ*/
 156 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 157         bra     ret_from_interrupt
 158
 159 inthandler3:
 160         SAVE_ALL
 161         addql   #1,local_irq_count      /*  put exception # in d0*/
 162         movew   %sp@(PT_VECTOR), %d0
 163         and     #0x3ff, %d0
 164
 165         movel   %sp,%sp@-
 166         movel   #67,%sp@-               /*  put vector # on stack*/
 167         jbsr    process_int             /*  process the IRQ*/
 168 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 169         bra     ret_from_interrupt
 170
 171 inthandler4:
 172         SAVE_ALL
 173         addql   #1,local_irq_count      /*  put exception # in d0*/
 174         movew   %sp@(PT_VECTOR), %d0
 175         and     #0x3ff, %d0
 176
 177         movel   %sp,%sp@-
 178         movel   #68,%sp@-               /*  put vector # on stack*/
 179         jbsr    process_int             /*  process the IRQ*/
 180 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 181         bra     ret_from_interrupt
 182
 183 inthandler5:
 184         SAVE_ALL
 185         addql   #1,local_irq_count      /*  put exception # in d0*/
 186         movew   %sp@(PT_VECTOR), %d0
 187         and     #0x3ff, %d0
 188
 189         movel   %sp,%sp@-
 190         movel   #69,%sp@-               /*  put vector # on stack*/
 191         jbsr    process_int             /*  process the IRQ*/
 192 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 193         bra     ret_from_interrupt
 194
 195 inthandler6:
 196         SAVE_ALL
 197         addql   #1,local_irq_count      /*  put exception # in d0*/
 198         movew   %sp@(PT_VECTOR), %d0
 199         and     #0x3ff, %d0
 200
 201         movel   %sp,%sp@-
 202         movel   #70,%sp@-               /*  put vector # on stack*/
 203         jbsr    process_int             /*  process the IRQ*/
 204 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 205         bra     ret_from_interrupt
 206
 207 inthandler7:
 208         SAVE_ALL
 209         addql   #1,local_irq_count      /*  put exception # in d0*/
 210         movew   %sp@(PT_VECTOR), %d0
 211         and     #0x3ff, %d0
 212
 213         movel   %sp,%sp@-
 214         movel   #71,%sp@-               /*  put vector # on stack*/
 215         jbsr    process_int             /*  process the IRQ*/
 216 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 217         bra     ret_from_interrupt
 218
 219 inthandler:
 220         SAVE_ALL
 221         addql   #1,local_irq_count      /*  put exception # in d0*/
 222         movew   %sp@(PT_VECTOR), %d0
 223         and     #0x3ff, %d0
 224
 225         movel   %sp,%sp@-
 226         movel   %d0,%sp@-               /*  put vector # on stack*/
 227         jbsr    process_int             /*  process the IRQ*/
 228 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 229         bra     ret_from_interrupt
 230
 231 ret_from_interrupt:
 232         subql   #1,local_irq_count
 233         jeq     1f
 234 2:
 235         RESTORE_ALL
 236 1:
 237         moveb   %sp@(PT_SR), %d0
 238         and     #7, %d0
 239         jhi     2b
 240
 241         /* check if we need to do software interrupts */
 242         movel   local_irq_count,%d0
 243         jeq     ret_from_exception
 244
 245         pea     ret_from_exception
 246         jra     do_softirq
 247
 248
 249 /*
 250  * Handler for uninitialized and spurious interrupts.
 251  */
 252 ENTRY(bad_interrupt)
 253         addql   #1,num_spurious
 254         rte
 255
 256 /*
 257  * Beware - when entering resume, prev (the current task) is
 258  * in a0, next (the new task) is in a1,so don't change these
 259  * registers until their contents are no longer needed.
 260  */
 261 ENTRY(resume)
 262         movel   %a0,%d1                         /* save prev thread in d1 */
 263         movew   %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */
 264         movel   %usp,%a2                        /* save usp */
 265         movel   %a2,%a0@(TASK_THREAD+THREAD_USP)
 266
 267         SAVE_SWITCH_STACK
 268         movel   %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
 269         movel   %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
 270         RESTORE_SWITCH_STACK
 271
 272         movel   %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */
 273         movel   %a0,%usp
 274         movew   %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */
 275         rts
 276