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