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_OFF_D0)
  43         jra     ret_from_exception
  44
  45 do_trace:
  46         movel   #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/
  47         subql   #4,%sp
  48         SAVE_SWITCH_STACK
  49         jbsr    syscall_trace_enter
  50         RESTORE_SWITCH_STACK
  51         addql   #4,%sp
  52         movel   %sp@(PT_OFF_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_OFF_D0)     /* save the return value */
  61         subql   #4,%sp                  /* dummy return address */
  62         SAVE_SWITCH_STACK
  63         jbsr    syscall_trace_leave
  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_OFF_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%8),%a2@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
  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_OFF_D0)     /* save the return value*/
  92
  93 ret_from_exception:
  94         btst    #5,%sp@(PT_OFF_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         bsrw    do_signal
 124         addql   #4,%sp
 125         RESTORE_SWITCH_STACK
 126         addql   #4,%sp
 127 Lreturn:
 128         RESTORE_ALL
 129
 130 /*
 131  * This is the main interrupt handler, responsible for calling process_int()
 132  */
 133 inthandler1:
 134         SAVE_ALL
 135         movew   %sp@(PT_OFF_FORMATVEC), %d0
 136         and     #0x3ff, %d0
 137
 138         movel   %sp,%sp@-
 139         movel   #65,%sp@-               /*  put vector # on stack*/
 140         jbsr    process_int             /*  process the IRQ*/
 141 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 142         bra     ret_from_interrupt
 143
 144 inthandler2:
 145         SAVE_ALL
 146         movew   %sp@(PT_OFF_FORMATVEC), %d0
 147         and     #0x3ff, %d0
 148
 149         movel   %sp,%sp@-
 150         movel   #66,%sp@-               /*  put vector # on stack*/
 151         jbsr    process_int             /*  process the IRQ*/
 152 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 153         bra     ret_from_interrupt
 154
 155 inthandler3:
 156         SAVE_ALL
 157         movew   %sp@(PT_OFF_FORMATVEC), %d0
 158         and     #0x3ff, %d0
 159
 160         movel   %sp,%sp@-
 161         movel   #67,%sp@-               /*  put vector # on stack*/
 162         jbsr    process_int             /*  process the IRQ*/
 163 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 164         bra     ret_from_interrupt
 165
 166 inthandler4:
 167         SAVE_ALL
 168         movew   %sp@(PT_OFF_FORMATVEC), %d0
 169         and     #0x3ff, %d0
 170
 171         movel   %sp,%sp@-
 172         movel   #68,%sp@-               /*  put vector # on stack*/
 173         jbsr    process_int             /*  process the IRQ*/
 174 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 175         bra     ret_from_interrupt
 176
 177 inthandler5:
 178         SAVE_ALL
 179         movew   %sp@(PT_OFF_FORMATVEC), %d0
 180         and     #0x3ff, %d0
 181
 182         movel   %sp,%sp@-
 183         movel   #69,%sp@-               /*  put vector # on stack*/
 184         jbsr    process_int             /*  process the IRQ*/
 185 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 186         bra     ret_from_interrupt
 187
 188 inthandler6:
 189         SAVE_ALL
 190         movew   %sp@(PT_OFF_FORMATVEC), %d0
 191         and     #0x3ff, %d0
 192
 193         movel   %sp,%sp@-
 194         movel   #70,%sp@-               /*  put vector # on stack*/
 195         jbsr    process_int             /*  process the IRQ*/
 196 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 197         bra     ret_from_interrupt
 198
 199 inthandler7:
 200         SAVE_ALL
 201         movew   %sp@(PT_OFF_FORMATVEC), %d0
 202         and     #0x3ff, %d0
 203
 204         movel   %sp,%sp@-
 205         movel   #71,%sp@-               /*  put vector # on stack*/
 206         jbsr    process_int             /*  process the IRQ*/
 207 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 208         bra     ret_from_interrupt
 209
 210 inthandler:
 211         SAVE_ALL
 212         movew   %sp@(PT_OFF_FORMATVEC), %d0
 213         and     #0x3ff, %d0
 214
 215         movel   %sp,%sp@-
 216         movel   %d0,%sp@-               /*  put vector # on stack*/
 217         jbsr    process_int             /*  process the IRQ*/
 218 3:      addql   #8,%sp                  /*  pop parameters off stack*/
 219         bra     ret_from_interrupt
 220
 221 ret_from_interrupt:
 222         jeq     1f
 223 2:
 224         RESTORE_ALL
 225 1:
 226         moveb   %sp@(PT_OFF_SR), %d0
 227         and     #7, %d0
 228         jhi     2b
 229
 230         /* check if we need to do software interrupts */
 231         jeq     ret_from_exception
 232
 233         pea     ret_from_exception
 234         jra     do_softirq
 235
 236
 237 /*
 238  * Handler for uninitialized and spurious interrupts.
 239  */
 240 ENTRY(bad_interrupt)
 241         addql   #1,num_spurious
 242         rte
 243
 244 /*
 245  * Beware - when entering resume, prev (the current task) is
 246  * in a0, next (the new task) is in a1,so don't change these
 247  * registers until their contents are no longer needed.
 248  */
 249 ENTRY(resume)
 250         movel   %a0,%d1                         /* save prev thread in d1 */
 251         movew   %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */
 252         movel   %usp,%a2                        /* save usp */
 253         movel   %a2,%a0@(TASK_THREAD+THREAD_USP)
 254
 255         SAVE_SWITCH_STACK
 256         movel   %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
 257         movel   %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
 258         RESTORE_SWITCH_STACK
 259
 260         movel   %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */
 261         movel   %a0,%usp
 262         movew   %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */
 263         rts
 264