arch/cris/arch-v10/kernel/entry.S

   1 /*
   2  *  linux/arch/cris/entry.S
   3  *
   4  *  Copyright (C) 2000, 2001, 2002 Axis Communications AB
   5  *
   6  *  Authors:    Bjorn Wesen (bjornw@axis.com)
   7  */
   8
   9 /*
  10  * entry.S contains the system-call and fault low-level handling routines.
  11  *
  12  * NOTE: This code handles signal-recognition, which happens every time
  13  * after a timer-interrupt and after each system call.
  14  *
  15  * Stack layout in 'ret_from_system_call':
  16  *      ptrace needs to have all regs on the stack.
  17  *      if the order here is changed, it needs to be
  18  *      updated in fork.c:copy_process, signal.c:do_signal,
  19  *      ptrace.c and ptrace.h
  20  *
  21  */
  22
  23 #include <linux/linkage.h>
  24 #include <linux/sys.h>
  25 #include <asm/unistd.h>
  26 #include <arch/sv_addr_ag.h>
  27 #include <asm/errno.h>
  28 #include <asm/thread_info.h>
  29 #include <asm/asm-offsets.h>
  30 #include <asm/page.h>
  31 #include <asm/pgtable.h>
  32
  33         ;; functions exported from this file
  34
  35         .globl system_call
  36         .globl ret_from_intr
  37         .globl ret_from_fork
  38         .globl resume
  39         .globl multiple_interrupt
  40         .globl hwbreakpoint
  41         .globl IRQ1_interrupt
  42         .globl spurious_interrupt
  43         .globl hw_bp_trigs
  44         .globl mmu_bus_fault
  45         .globl do_sigtrap
  46         .globl gdb_handle_breakpoint
  47         .globl sys_call_table
  48
  49         ;; below are various parts of system_call which are not in the fast-path
  50
  51 #ifdef CONFIG_PREEMPT
  52         ; Check if preemptive kernel scheduling should be done
  53 _resume_kernel:
  54         di
  55         ; Load current task struct
  56         movs.w  -8192, $r0      ;  THREAD_SIZE = 8192
  57         and.d   $sp, $r0
  58         move.d  [$r0+TI_preempt_count], $r10    ;  Preemption disabled?
  59         bne     _Rexit
  60         nop
  61 _need_resched:
  62         move.d  [$r0+TI_flags], $r10
  63         btstq   TIF_NEED_RESCHED, $r10  ; Check if need_resched is set
  64         bpl     _Rexit
  65         nop
  66         ; Ok, lets's do some preemptive kernel scheduling
  67         jsr     preempt_schedule_irq
  68         ; Load new task struct
  69         movs.w  -8192, $r0      ;  THREAD_SIZE = 8192
  70         and.d   $sp, $r0
  71         ; One more time (with new task)
  72         ba      _need_resched
  73         nop
  74 #else
  75 #define _resume_kernel _Rexit
  76 #endif
  77
  78         ; Called at exit from fork. schedule_tail must be called to drop
  79         ; spinlock if CONFIG_PREEMPT
  80 ret_from_fork:
  81         jsr schedule_tail
  82         ba  ret_from_sys_call
  83         nop
  84
  85 ret_from_intr:
  86         ;; check for resched if preemptive kernel or if we're going back to user-mode
  87         ;; this test matches the user_regs(regs) macro
  88         ;; we cannot simply test $dccr, because that does not necessarily
  89         ;; reflect what mode we'll return into.
  90
  91         move.d  [$sp + PT_dccr], $r0; regs->dccr
  92         btstq   8, $r0          ; U-flag
  93         bpl     _resume_kernel
  94         ; Note that di below is in delay slot
  95
  96 _resume_userspace:
  97         di                      ; so need_resched and sigpending don't change
  98
  99         movs.w  -8192, $r0      ; THREAD_SIZE == 8192
 100         and.d   $sp, $r0
 101
 102         move.d  [$r0+TI_flags], $r10    ; current->work
 103         and.d   _TIF_WORK_MASK, $r10    ; is there any work to be done on return
 104         bne     _work_pending
 105         nop
 106         ba      _Rexit
 107         nop
 108
 109         ;; The system_call is called by a BREAK instruction, which works like
 110         ;; an interrupt call but it stores the return PC in BRP instead of IRP.
 111         ;; Since we dont really want to have two epilogues (one for system calls
 112         ;; and one for interrupts) we push the contents of BRP instead of IRP in the
 113         ;; system call prologue, to make it look like an ordinary interrupt on the
 114         ;; stackframe.
 115         ;;
 116         ;; Since we can't have system calls inside interrupts, it should not matter
 117         ;; that we don't stack IRP.
 118         ;;
 119         ;; In r9 we have the wanted syscall number. Arguments come in r10,r11,r12,r13,mof,srp
 120         ;;
 121         ;; This function looks on the _surface_ like spaghetti programming, but it's
 122         ;; really designed so that the fast-path does not force cache-loading of non-used
 123         ;; instructions. Only the non-common cases cause the outlined code to run..
 124
 125 system_call:
 126         ;; stack-frame similar to the irq heads, which is reversed in ret_from_sys_call
 127         move    $brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
 128         push    $srp
 129         push    $dccr
 130         push    $mof
 131         subq    14*4, $sp               ; make room for r0-r13
 132         movem   $r13, [$sp]     ; push r0-r13
 133         push    $r10            ; push orig_r10
 134         clear.d [$sp=$sp-4]     ; frametype == 0, normal stackframe
 135
 136         movs.w  -ENOSYS, $r0
 137         move.d  $r0, [$sp+PT_r10]       ; put the default return value in r10 in the frame
 138
 139         ;; check if this process is syscall-traced
 140
 141         movs.w  -8192, $r0      ; THREAD_SIZE == 8192
 142         and.d   $sp, $r0
 143
 144         move.d  [$r0+TI_flags], $r0
 145         btstq   TIF_SYSCALL_TRACE, $r0
 146         bmi     _syscall_trace_entry
 147         nop
 148
 149 _syscall_traced:
 150
 151         ;; check for sanity in the requested syscall number
 152
 153         cmpu.w  NR_syscalls, $r9
 154         bcc     ret_from_sys_call
 155         lslq    2, $r9          ;  multiply by 4, in the delay slot
 156
 157         ;; as a bonus 7th parameter, we give the location on the stack
 158         ;; of the register structure itself. some syscalls need this.
 159
 160         push    $sp
 161
 162         ;; the parameter carrying registers r10, r11, r12 and 13 are intact.
 163         ;; the fifth and sixth parameters (if any) was in mof and srp
 164         ;; respectively, and we need to put them on the stack.
 165
 166         push    $srp
 167         push    $mof
 168
 169         jsr     [$r9+sys_call_table]    ; actually do the system call
 170         addq    3*4, $sp                ; pop the mof, srp and regs parameters
 171         move.d  $r10, [$sp+PT_r10]      ; save the return value
 172
 173         moveq   1, $r9          ; "parameter" to ret_from_sys_call to show it was a sys call
 174
 175         ;; fall through into ret_from_sys_call to return
 176
 177 ret_from_sys_call:
 178         ;; r9 is a parameter - if >=1 we came from a syscall, if 0, from an irq
 179
 180         ;; get the current task-struct pointer (see top for defs)
 181
 182         movs.w  -8192, $r0      ; THREAD_SIZE == 8192
 183         and.d   $sp, $r0
 184
 185         di                      ; make sure need_resched and sigpending don't change
 186         move.d  [$r0+TI_flags],$r1
 187         and.d   _TIF_ALLWORK_MASK, $r1
 188         bne     _syscall_exit_work
 189         nop
 190
 191 _Rexit:
 192         ;; this epilogue MUST match the prologues in multiple_interrupt, irq.h and ptregs.h
 193         pop     $r10            ; frametype
 194         bne     _RBFexit        ; was not CRIS_FRAME_NORMAL, handle otherwise
 195         addq    4, $sp          ; skip orig_r10, in delayslot
 196         movem   [$sp+], $r13    ; registers r0-r13
 197         pop     $mof            ; multiply overflow register
 198         pop     $dccr           ; condition codes
 199         pop     $srp            ; subroutine return pointer
 200         ;; now we have a 4-word SBFS frame which we do not want to restore
 201         ;; using RBF since it was not stacked with SBFS. instead we would like to
 202         ;; just get the PC value to restart it with, and skip the rest of
 203         ;; the frame.
 204         ;; Also notice that it's important to use instructions here that
 205         ;; keep the interrupts disabled (since we've already popped DCCR)
 206         move    [$sp=$sp+16], $p8; pop the SBFS frame from the sp
 207         jmpu    [$sp-16]        ; return through the irp field in the sbfs frame
 208
 209 _RBFexit:
 210         movem   [$sp+], $r13    ; registers r0-r13, in delay slot
 211         pop     $mof            ; multiply overflow register
 212         pop     $dccr           ; condition codes
 213         pop     $srp            ; subroutine return pointer
 214         rbf     [$sp+]          ; return by popping the CPU status
 215
 216         ;; We get here after doing a syscall if extra work might need to be done
 217         ;; perform syscall exit tracing if needed
 218
 219 _syscall_exit_work:
 220         ;; $r0 contains current at this point and irq's are disabled
 221
 222         move.d  [$r0+TI_flags], $r1
 223         btstq   TIF_SYSCALL_TRACE, $r1
 224         bpl     _work_pending
 225         nop
 226
 227         ei
 228
 229         move.d  $r9, $r1        ; preserve r9
 230         jsr     do_syscall_trace
 231         move.d  $r1, $r9
 232
 233         ba      _resume_userspace
 234         nop
 235
 236 _work_pending:
 237         move.d  [$r0+TI_flags], $r1
 238         btstq   TIF_NEED_RESCHED, $r1
 239         bpl     _work_notifysig ; was neither trace nor sched, must be signal/notify
 240         nop
 241
 242 _work_resched:
 243         move.d  $r9, $r1        ; preserve r9
 244         jsr     schedule
 245         move.d  $r1, $r9
 246         di
 247
 248         move.d  [$r0+TI_flags], $r1
 249         and.d   _TIF_WORK_MASK, $r1; ignore the syscall trace counter
 250         beq     _Rexit
 251         nop
 252         btstq   TIF_NEED_RESCHED, $r1
 253         bmi     _work_resched   ; current->work.need_resched
 254         nop
 255
 256 _work_notifysig:
 257         ;; deal with pending signals and notify-resume requests
 258
 259         move.d  $r9, $r10       ; do_notify_resume syscall/irq param
 260         move.d  $sp, $r11       ; the regs param
 261         move.d  $r1, $r12       ; the thread_info_flags parameter
 262         jsr     do_notify_resume
 263
 264         ba _Rexit
 265         nop
 266
 267         ;; We get here as a sidetrack when we've entered a syscall with the
 268         ;; trace-bit set. We need to call do_syscall_trace and then continue
 269         ;; with the call.
 270
 271 _syscall_trace_entry:
 272         ;; PT_r10 in the frame contains -ENOSYS as required, at this point
 273
 274         jsr     do_syscall_trace
 275
 276         ;; now re-enter the syscall code to do the syscall itself
 277         ;; we need to restore $r9 here to contain the wanted syscall, and
 278         ;; the other parameter-bearing registers
 279
 280         move.d  [$sp+PT_r9], $r9
 281         move.d  [$sp+PT_orig_r10], $r10  ; PT_r10 is already filled with -ENOSYS.
 282         move.d  [$sp+PT_r11],      $r11
 283         move.d  [$sp+PT_r12],      $r12
 284         move.d  [$sp+PT_r13],      $r13
 285         move    [$sp+PT_mof],      $mof
 286         move    [$sp+PT_srp],      $srp
 287
 288         ba      _syscall_traced
 289         nop
 290
 291         ;; resume performs the actual task-switching, by switching stack pointers
 292         ;; input arguments: r10 = prev, r11 = next, r12 = thread offset in task struct
 293         ;; returns old current in r10
 294         ;;
 295         ;; TODO:  see the i386 version. The switch_to which calls resume in our version
 296         ;;        could really be an inline asm of this.
 297
 298 resume:
 299         push    $srp                     ; we keep the old/new PC on the stack
 300         add.d   $r12, $r10               ; r10 = current tasks tss
 301         move    $dccr, [$r10+THREAD_dccr]; save irq enable state
 302         di
 303
 304         move    $usp, [$r10+ THREAD_usp] ; save user-mode stackpointer
 305
 306         ;; See copy_thread for the reason why register R9 is saved.
 307         subq    10*4, $sp
 308         movem   $r9, [$sp]               ; save non-scratch registers and R9.
 309
 310         move.d  $sp, [$r10+THREAD_ksp]   ; save the kernel stack pointer for the old task
 311         move.d  $sp, $r10                ; return last running task in r10
 312         and.d   -8192, $r10              ; get thread_info from stackpointer
 313         move.d  [$r10+TI_task], $r10     ; get task
 314         add.d   $r12, $r11               ; find the new tasks tss
 315         move.d  [$r11+THREAD_ksp], $sp   ; switch into the new stackframe by restoring kernel sp
 316
 317         movem   [$sp+], $r9              ; restore non-scratch registers and R9.
 318
 319         move    [$r11+THREAD_usp], $usp ; restore user-mode stackpointer
 320
 321         move    [$r11+THREAD_dccr], $dccr ; restore irq enable status
 322         jump    [$sp+]                   ; restore PC
 323
 324         ;; This is the MMU bus fault handler.
 325         ;; It needs to stack the CPU status and overall is different
 326         ;; from the other interrupt handlers.
 327
 328 mmu_bus_fault:
 329         ;; For refills we try to do a quick page table lookup. If it is
 330         ;; a real fault we let the mm subsystem handle it.
 331
 332         ;; the first longword in the sbfs frame was the interrupted PC
 333         ;; which fits nicely with the "IRP" slot in pt_regs normally used to
 334         ;; contain the return address. used by Oops to print kernel errors.
 335         sbfs    [$sp=$sp-16]    ; push the internal CPU status
 336         push    $dccr
 337         di
 338         subq    2*4, $sp
 339         movem   $r1, [$sp]
 340         move.d  [R_MMU_CAUSE], $r1
 341         ;; ETRAX 100LX TR89 bugfix: if the second half of an unaligned
 342         ;; write causes a MMU-fault, it will not be restarted correctly.
 343         ;; This could happen if a write crosses a page-boundary and the
 344         ;; second page is not yet COW'ed or even loaded. The workaround
 345         ;; is to clear the unaligned bit in the CPU status record, so
 346         ;; that the CPU will rerun both the first and second halves of
 347         ;; the instruction. This will not have any sideeffects unless
 348         ;; the first half goes to any device or memory that can't be
 349         ;; written twice, and which is mapped through the MMU.
 350         ;;
 351         ;; We only need to do this for writes.
 352         btstq   8, $r1             ; Write access?
 353         bpl     1f
 354         nop
 355         move.d  [$sp+16], $r0      ; Clear unaligned bit in csrinstr
 356         and.d   ~(1<<5), $r0
 357         move.d  $r0, [$sp+16]
 358 1:      btstq   12, $r1            ; Refill?
 359         bpl     2f
 360         lsrq    24, $r1     ; Get PGD index (bit 24-31)
 361         move.d  [current_pgd], $r0 ; PGD for the current process
 362         move.d  [$r0+$r1.d], $r0   ; Get PMD
 363         beq     2f
 364         nop
 365         and.w   PAGE_MASK, $r0     ; Remove PMD flags
 366         move.d  [R_MMU_CAUSE], $r1
 367         lsrq    PAGE_SHIFT, $r1
 368         and.d   0x7ff, $r1         ; Get PTE index into PGD (bit 13-23)
 369         move.d  [$r0+$r1.d], $r1   ; Get PTE
 370         beq     2f
 371         nop
 372         ;; Store in TLB
 373         move.d  $r1, [R_TLB_LO]
 374         ;; Return
 375         movem   [$sp+], $r1
 376         pop     $dccr
 377         rbf     [$sp+]          ; return by popping the CPU status
 378
 379 2:      ; PMD or PTE missing, let the mm subsystem fix it up.
 380         movem   [$sp+], $r1
 381         pop     $dccr
 382
 383         ; Ok, not that easy, pass it on to the mm subsystem
 384         ; The MMU status record is now on the stack
 385         push    $srp            ; make a stackframe similar to pt_regs
 386         push    $dccr
 387         push    $mof
 388         di
 389         subq    14*4, $sp
 390         movem   $r13, [$sp]
 391         push    $r10            ; dummy orig_r10
 392         moveq   1, $r10
 393         push    $r10            ; frametype == 1, BUSFAULT frame type
 394
 395         move.d  $sp, $r10       ; pt_regs argument to handle_mmu_bus_fault
 396
 397         jsr     handle_mmu_bus_fault  ; in arch/cris/arch-v10/mm/fault.c
 398
 399         ;; now we need to return through the normal path, we cannot just
 400         ;; do the RBFexit since we might have killed off the running
 401         ;; process due to a SEGV, scheduled due to a page blocking or
 402         ;; whatever.
 403
 404         moveq   0, $r9          ; busfault is equivalent to an irq
 405
 406         ba      ret_from_intr
 407         nop
 408
 409         ;; special handlers for breakpoint and NMI
 410 hwbreakpoint:
 411         push    $dccr
 412         di
 413         push    $r10
 414         push    $r11
 415         move.d  [hw_bp_trig_ptr],$r10
 416         move    $brp,$r11
 417         move.d  $r11,[$r10+]
 418         move.d  $r10,[hw_bp_trig_ptr]
 419 1:      pop     $r11
 420         pop     $r10
 421         pop     $dccr
 422         retb
 423         nop
 424
 425 IRQ1_interrupt:
 426         ;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
 427         move    $brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
 428         push    $srp
 429         push    $dccr
 430         push    $mof
 431         di
 432         subq    14*4, $sp
 433         movem   $r13, [$sp]
 434         push    $r10            ; push orig_r10
 435         clear.d [$sp=$sp-4]     ; frametype == 0, normal frame
 436
 437         ;; If there is a glitch on the NMI pin shorter than ~100ns
 438         ;; (i.e. non-active by the time we get here) then the nmi_pin bit
 439         ;; in R_IRQ_MASK0_RD will already be cleared.  The watchdog_nmi bit
 440         ;; is cleared by us however (when feeding the watchdog), which is why
 441         ;; we use that bit to determine what brought us here.
 442
 443         move.d  [R_IRQ_MASK0_RD], $r1 ; External NMI or watchdog?
 444         and.d   (1<<30), $r1
 445         bne     wdog
 446         move.d  $sp, $r10
 447         jsr     handle_nmi
 448         setf m                  ; Enable NMI again
 449         ba      _Rexit          ; Return the standard way
 450         nop
 451 wdog:
 452 #if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
 453 ;; Check if we're waiting for reset to happen, as signalled by
 454 ;; hard_reset_now setting cause_of_death to a magic value.  If so, just
 455 ;; get stuck until reset happens.
 456         .comm   cause_of_death, 4       ;; Don't declare this anywhere.
 457         move.d  [cause_of_death], $r10
 458         cmp.d   0xbedead, $r10
 459 _killed_by_death:
 460         beq     _killed_by_death
 461         nop
 462
 463 ;; We'll see this in ksymoops dumps.
 464 Watchdog_bite:
 465
 466 #ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
 467        ;; We just restart the watchdog here to be sure we dont get
 468        ;; hit while printing the watchdogmsg below
 469        ;; This restart is compatible with the rest of the C-code, so
 470        ;; the C-code can keep restarting the watchdog after this point.
 471        ;; The non-NICE_DOGGY code below though, disables the possibility
 472        ;; to restart since it changes the watchdog key, to avoid any
 473        ;; buggy loops etc. keeping the watchdog alive after this.
 474        jsr     reset_watchdog
 475 #else
 476
 477 ;; We need to extend the 3.3ms after the NMI at watchdog bite, so we have
 478 ;; time for an oops-dump over a 115k2 serial wire.  Another 100ms should do.
 479
 480 ;; Change the watchdog key to an arbitrary 3-bit value and restart the
 481 ;; watchdog.
 482 #define WD_INIT 2
 483         moveq     IO_FIELD (R_WATCHDOG, key, WD_INIT), $r10
 484         move.d  R_WATCHDOG, $r11
 485
 486         move.d  $r10, [$r11]
 487         moveq     IO_FIELD (R_WATCHDOG, key,                            \
 488                             IO_EXTRACT (R_WATCHDOG, key,                \
 489                                         IO_MASK (R_WATCHDOG, key))      \
 490                             ^ WD_INIT)                                  \
 491                 | IO_STATE (R_WATCHDOG, enable, start), $r10
 492         move.d  $r10, [$r11]
 493
 494 #endif
 495
 496 ;; Note that we don't do "setf m" here (or after two necessary NOPs),
 497 ;; since *not* doing that saves us from re-entrancy checks.  We don't want
 498 ;; to get here again due to possible subsequent NMIs; we want the watchdog
 499 ;; to reset us.
 500
 501         move.d  _watchdogmsg,$r10
 502         jsr     printk
 503
 504         move.d  $sp, $r10
 505         jsr     watchdog_bite_hook
 506
 507 ;; This nop is here so we see the "Watchdog_bite" label in ksymoops dumps
 508 ;; rather than "spurious_interrupt".
 509         nop
 510 ;; At this point we drop down into spurious_interrupt, which will do a
 511 ;; hard reset.
 512
 513         .section .rodata,"a"
 514 _watchdogmsg:
 515         .ascii  "Oops: bitten by watchdog\n\0"
 516         .previous
 517
 518 #endif /* CONFIG_ETRAX_WATCHDOG and not CONFIG_SVINTO_SIM */
 519
 520 spurious_interrupt:
 521         di
 522         jump hard_reset_now
 523
 524         ;; this handles the case when multiple interrupts arrive at the same time
 525         ;; we jump to the first set interrupt bit in a priority fashion
 526         ;; the hardware will call the unserved interrupts after the handler finishes
 527
 528 multiple_interrupt:
 529         ;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
 530         move    $irp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
 531         push    $srp
 532         push    $dccr
 533         push    $mof
 534         di
 535         subq    14*4, $sp
 536         movem   $r13, [$sp]
 537         push    $r10            ; push orig_r10
 538         clear.d [$sp=$sp-4]     ; frametype == 0, normal frame
 539
 540         move.d  $sp, $r10
 541         jsr     do_multiple_IRQ
 542
 543         jump    ret_from_intr
 544
 545 do_sigtrap:
 546         ;;
 547         ;; SIGTRAP the process that executed the break instruction.
 548         ;; Make a frame that Rexit in entry.S expects.
 549         ;;
 550         move    $brp, [$sp=$sp-16]      ; Push BRP while faking a cpu status record.
 551         push    $srp                    ; Push subroutine return pointer.
 552         push    $dccr                   ; Push condition codes.
 553         push    $mof                    ; Push multiply overflow reg.
 554         di                              ; Need to disable irq's at this point.
 555         subq    14*4, $sp               ; Make room for r0-r13.
 556         movem   $r13, [$sp]             ; Push the r0-r13 registers.
 557         push    $r10                    ; Push orig_r10.
 558         clear.d [$sp=$sp-4]             ; Frametype - this is a normal stackframe.
 559
 560         movs.w  -8192,$r9               ; THREAD_SIZE == 8192
 561         and.d   $sp, $r9
 562         move.d  [$r9+TI_task], $r10
 563         move.d  [$r10+TASK_pid], $r10   ; current->pid as arg1.
 564         moveq   5, $r11                 ; SIGTRAP as arg2.
 565         jsr     sys_kill
 566         jump    ret_from_intr           ; Use the return routine for interrupts.
 567
 568 gdb_handle_breakpoint:
 569         push    $dccr
 570         push    $r0
 571 #ifdef CONFIG_ETRAX_KGDB
 572         move    $dccr, $r0              ; U-flag not affected by previous insns.
 573         btstq   8, $r0                  ; Test the U-flag.
 574         bmi     _ugdb_handle_breakpoint ; Go to user mode debugging.
 575         nop                             ; Empty delay slot (cannot pop r0 here).
 576         pop     $r0                     ; Restore r0.
 577         ba      kgdb_handle_breakpoint  ; Go to kernel debugging.
 578         pop     $dccr                   ; Restore dccr in delay slot.
 579 #endif
 580
 581 _ugdb_handle_breakpoint:
 582         move    $brp, $r0               ; Use r0 temporarily for calculation.
 583         subq    2, $r0                  ; Set to address of previous instruction.
 584         move    $r0, $brp
 585         pop     $r0                     ; Restore r0.
 586         ba      do_sigtrap              ; SIGTRAP the offending process.
 587         pop     $dccr                   ; Restore dccr in delay slot.
 588
 589         .global kernel_execve
 590 kernel_execve:
 591         move.d __NR_execve, $r9
 592         break 13
 593         ret
 594         nop
 595
 596         .data
 597
 598 hw_bp_trigs:
 599         .space 64*4
 600 hw_bp_trig_ptr:
 601         .dword hw_bp_trigs
 602
 603         .section .rodata,"a"
 604 sys_call_table:
 605         .long sys_restart_syscall       /* 0 - old "setup()" system call, used for restarting */
 606         .long sys_exit
 607         .long sys_fork
 608         .long sys_read
 609         .long sys_write
 610         .long sys_open          /* 5 */
 611         .long sys_close
 612         .long sys_waitpid
 613         .long sys_creat
 614         .long sys_link
 615         .long sys_unlink        /* 10 */
 616         .long sys_execve
 617         .long sys_chdir
 618         .long sys_time
 619         .long sys_mknod
 620         .long sys_chmod         /* 15 */
 621         .long sys_lchown16
 622         .long sys_ni_syscall    /* old break syscall holder */
 623         .long sys_stat
 624         .long sys_lseek
 625         .long sys_getpid        /* 20 */
 626         .long sys_mount
 627         .long sys_oldumount
 628         .long sys_setuid16
 629         .long sys_getuid16
 630         .long sys_stime         /* 25 */
 631         .long sys_ptrace
 632         .long sys_alarm
 633         .long sys_fstat
 634         .long sys_pause
 635         .long sys_utime         /* 30 */
 636         .long sys_ni_syscall    /* old stty syscall holder */
 637         .long sys_ni_syscall    /* old gtty syscall holder */
 638         .long sys_access
 639         .long sys_nice
 640         .long sys_ni_syscall    /* 35  old ftime syscall holder */
 641         .long sys_sync
 642         .long sys_kill
 643         .long sys_rename
 644         .long sys_mkdir
 645         .long sys_rmdir         /* 40 */
 646         .long sys_dup
 647         .long sys_pipe
 648         .long sys_times
 649         .long sys_ni_syscall    /* old prof syscall holder */
 650         .long sys_brk           /* 45 */
 651         .long sys_setgid16
 652         .long sys_getgid16
 653         .long sys_signal
 654         .long sys_geteuid16
 655         .long sys_getegid16     /* 50 */
 656         .long sys_acct
 657         .long sys_umount        /* recycled never used phys( */
 658         .long sys_ni_syscall    /* old lock syscall holder */
 659         .long sys_ioctl
 660         .long sys_fcntl         /* 55 */
 661         .long sys_ni_syscall    /* old mpx syscall holder */
 662         .long sys_setpgid
 663         .long sys_ni_syscall    /* old ulimit syscall holder */
 664         .long sys_ni_syscall    /* old sys_olduname holder */
 665         .long sys_umask         /* 60 */
 666         .long sys_chroot
 667         .long sys_ustat
 668         .long sys_dup2
 669         .long sys_getppid
 670         .long sys_getpgrp       /* 65 */
 671         .long sys_setsid
 672         .long sys_sigaction
 673         .long sys_sgetmask
 674         .long sys_ssetmask
 675         .long sys_setreuid16    /* 70 */
 676         .long sys_setregid16
 677         .long sys_sigsuspend
 678         .long sys_sigpending
 679         .long sys_sethostname
 680         .long sys_setrlimit     /* 75 */
 681         .long sys_old_getrlimit
 682         .long sys_getrusage
 683         .long sys_gettimeofday
 684         .long sys_settimeofday
 685         .long sys_getgroups16   /* 80 */
 686         .long sys_setgroups16
 687         .long sys_select        /* was old_select in Linux/E100 */
 688         .long sys_symlink
 689         .long sys_lstat
 690         .long sys_readlink      /* 85 */
 691         .long sys_uselib
 692         .long sys_swapon
 693         .long sys_reboot
 694         .long sys_old_readdir
 695         .long sys_old_mmap      /* 90 */
 696         .long sys_munmap
 697         .long sys_truncate
 698         .long sys_ftruncate
 699         .long sys_fchmod
 700         .long sys_fchown16      /* 95 */
 701         .long sys_getpriority
 702         .long sys_setpriority
 703         .long sys_ni_syscall    /* old profil syscall holder */
 704         .long sys_statfs
 705         .long sys_fstatfs       /* 100 */
 706         .long sys_ni_syscall    /* sys_ioperm in i386 */
 707         .long sys_socketcall
 708         .long sys_syslog
 709         .long sys_setitimer
 710         .long sys_getitimer     /* 105 */
 711         .long sys_newstat
 712         .long sys_newlstat
 713         .long sys_newfstat
 714         .long sys_ni_syscall    /* old sys_uname holder */
 715         .long sys_ni_syscall    /* sys_iopl in i386 */
 716         .long sys_vhangup
 717         .long sys_ni_syscall    /* old "idle" system call */
 718         .long sys_ni_syscall    /* vm86old in i386 */
 719         .long sys_wait4
 720         .long sys_swapoff       /* 115 */
 721         .long sys_sysinfo
 722         .long sys_ipc
 723         .long sys_fsync
 724         .long sys_sigreturn
 725         .long sys_clone         /* 120 */
 726         .long sys_setdomainname
 727         .long sys_newuname
 728         .long sys_ni_syscall    /* sys_modify_ldt */
 729         .long sys_adjtimex
 730         .long sys_mprotect      /* 125 */
 731         .long sys_sigprocmask
 732         .long sys_ni_syscall    /* old "create_module" */
 733         .long sys_init_module
 734         .long sys_delete_module
 735         .long sys_ni_syscall    /* 130: old "get_kernel_syms" */
 736         .long sys_quotactl
 737         .long sys_getpgid
 738         .long sys_fchdir
 739         .long sys_bdflush
 740         .long sys_sysfs         /* 135 */
 741         .long sys_personality
 742         .long sys_ni_syscall    /* for afs_syscall */
 743         .long sys_setfsuid16
 744         .long sys_setfsgid16
 745         .long sys_llseek        /* 140 */
 746         .long sys_getdents
 747         .long sys_select
 748         .long sys_flock
 749         .long sys_msync
 750         .long sys_readv         /* 145 */
 751         .long sys_writev
 752         .long sys_getsid
 753         .long sys_fdatasync
 754         .long sys_sysctl
 755         .long sys_mlock         /* 150 */
 756         .long sys_munlock
 757         .long sys_mlockall
 758         .long sys_munlockall
 759         .long sys_sched_setparam
 760         .long sys_sched_getparam        /* 155 */
 761         .long sys_sched_setscheduler
 762         .long sys_sched_getscheduler
 763         .long sys_sched_yield
 764         .long sys_sched_get_priority_max
 765         .long sys_sched_get_priority_min        /* 160 */
 766         .long sys_sched_rr_get_interval
 767         .long sys_nanosleep
 768         .long sys_mremap
 769         .long sys_setresuid16
 770         .long sys_getresuid16   /* 165 */
 771         .long sys_ni_syscall    /* sys_vm86 */
 772         .long sys_ni_syscall    /* Old sys_query_module */
 773         .long sys_poll
 774         .long sys_nfsservctl
 775         .long sys_setresgid16   /* 170 */
 776         .long sys_getresgid16
 777         .long sys_prctl
 778         .long sys_rt_sigreturn
 779         .long sys_rt_sigaction
 780         .long sys_rt_sigprocmask        /* 175 */
 781         .long sys_rt_sigpending
 782         .long sys_rt_sigtimedwait
 783         .long sys_rt_sigqueueinfo
 784         .long sys_rt_sigsuspend
 785         .long sys_pread64       /* 180 */
 786         .long sys_pwrite64
 787         .long sys_chown16
 788         .long sys_getcwd
 789         .long sys_capget
 790         .long sys_capset        /* 185 */
 791         .long sys_sigaltstack
 792         .long sys_sendfile
 793         .long sys_ni_syscall    /* streams1 */
 794         .long sys_ni_syscall    /* streams2 */
 795         .long sys_vfork         /* 190 */
 796         .long sys_getrlimit
 797         .long sys_mmap2
 798         .long sys_truncate64
 799         .long sys_ftruncate64
 800         .long sys_stat64        /* 195 */
 801         .long sys_lstat64
 802         .long sys_fstat64
 803         .long sys_lchown
 804         .long sys_getuid
 805         .long sys_getgid        /* 200 */
 806         .long sys_geteuid
 807         .long sys_getegid
 808         .long sys_setreuid
 809         .long sys_setregid
 810         .long sys_getgroups     /* 205 */
 811         .long sys_setgroups
 812         .long sys_fchown
 813         .long sys_setresuid
 814         .long sys_getresuid
 815         .long sys_setresgid     /* 210 */
 816         .long sys_getresgid
 817         .long sys_chown
 818         .long sys_setuid
 819         .long sys_setgid
 820         .long sys_setfsuid      /* 215 */
 821         .long sys_setfsgid
 822         .long sys_pivot_root
 823         .long sys_mincore
 824         .long sys_madvise
 825         .long sys_getdents64    /* 220 */
 826         .long sys_fcntl64
 827         .long sys_ni_syscall    /* reserved for TUX */
 828         .long sys_ni_syscall
 829         .long sys_gettid
 830         .long sys_readahead     /* 225 */
 831         .long sys_setxattr
 832         .long sys_lsetxattr
 833         .long sys_fsetxattr
 834         .long sys_getxattr
 835         .long sys_lgetxattr     /* 230 */
 836         .long sys_fgetxattr
 837         .long sys_listxattr
 838         .long sys_llistxattr
 839         .long sys_flistxattr
 840         .long sys_removexattr   /* 235 */
 841         .long sys_lremovexattr
 842         .long sys_fremovexattr
 843         .long sys_tkill
 844         .long sys_sendfile64
 845         .long sys_futex         /* 240 */
 846         .long sys_sched_setaffinity
 847         .long sys_sched_getaffinity
 848         .long sys_ni_syscall    /* sys_set_thread_area */
 849         .long sys_ni_syscall    /* sys_get_thread_area */
 850         .long sys_io_setup      /* 245 */
 851         .long sys_io_destroy
 852         .long sys_io_getevents
 853         .long sys_io_submit
 854         .long sys_io_cancel
 855         .long sys_fadvise64     /* 250 */
 856         .long sys_ni_syscall
 857         .long sys_exit_group
 858         .long sys_lookup_dcookie
 859         .long sys_epoll_create
 860         .long sys_epoll_ctl     /* 255 */
 861         .long sys_epoll_wait
 862         .long sys_remap_file_pages
 863         .long sys_set_tid_address
 864         .long sys_timer_create
 865         .long sys_timer_settime         /* 260 */
 866         .long sys_timer_gettime
 867         .long sys_timer_getoverrun
 868         .long sys_timer_delete
 869         .long sys_clock_settime
 870         .long sys_clock_gettime         /* 265 */
 871         .long sys_clock_getres
 872         .long sys_clock_nanosleep
 873         .long sys_statfs64
 874         .long sys_fstatfs64
 875         .long sys_tgkill        /* 270 */
 876         .long sys_utimes
 877         .long sys_fadvise64_64
 878         .long sys_ni_syscall    /* sys_vserver */
 879         .long sys_ni_syscall    /* sys_mbind */
 880         .long sys_ni_syscall    /* 275 sys_get_mempolicy */
 881         .long sys_ni_syscall    /* sys_set_mempolicy */
 882         .long sys_mq_open
 883         .long sys_mq_unlink
 884         .long sys_mq_timedsend
 885         .long sys_mq_timedreceive       /* 280 */
 886         .long sys_mq_notify
 887         .long sys_mq_getsetattr
 888         .long sys_ni_syscall            /* reserved for kexec */
 889         .long sys_waitid
 890         .long sys_ni_syscall            /* 285 */ /* available */
 891         .long sys_add_key
 892         .long sys_request_key
 893         .long sys_keyctl
 894         .long sys_ioprio_set
 895         .long sys_ioprio_get            /* 290 */
 896         .long sys_inotify_init
 897         .long sys_inotify_add_watch
 898         .long sys_inotify_rm_watch
 899         .long sys_migrate_pages
 900         .long sys_openat                /* 295 */
 901         .long sys_mkdirat
 902         .long sys_mknodat
 903         .long sys_fchownat
 904         .long sys_futimesat
 905         .long sys_fstatat64             /* 300 */
 906         .long sys_unlinkat
 907         .long sys_renameat
 908         .long sys_linkat
 909         .long sys_symlinkat
 910         .long sys_readlinkat            /* 305 */
 911         .long sys_fchmodat
 912         .long sys_faccessat
 913         .long sys_pselect6
 914         .long sys_ppoll
 915         .long sys_unshare               /* 310 */
 916         .long sys_set_robust_list
 917         .long sys_get_robust_list
 918         .long sys_splice
 919         .long sys_sync_file_range
 920         .long sys_tee                   /* 315 */
 921         .long sys_vmsplice
 922         .long sys_move_pages
 923         .long sys_getcpu
 924         .long sys_epoll_pwait
 925         .long sys_utimensat             /* 320 */
 926         .long sys_signalfd
 927         .long sys_timerfd_create
 928         .long sys_eventfd
 929         .long sys_fallocate
 930         .long sys_timerfd_settime       /* 325 */
 931         .long sys_timerfd_gettime
 932         .long sys_signalfd4
 933         .long sys_eventfd2
 934         .long sys_epoll_create1
 935         .long sys_dup3                  /* 330 */
 936         .long sys_pipe2
 937         .long sys_inotify_init1
 938         .long sys_preadv
 939         .long sys_pwritev
 940
 941         /*
 942          * NOTE!! This doesn't have to be exact - we just have
 943          * to make sure we have _enough_ of the "sys_ni_syscall"
 944          * entries. Don't panic if you notice that this hasn't
 945          * been shrunk every time we add a new system call.
 946          */
 947
 948         .rept NR_syscalls-(.-sys_call_table)/4
 949                 .long sys_ni_syscall
 950         .endr
 951