linux/arch/cris/arch-v10/kernel/entry.S
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   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
  80ret_from_fork:
  81        jsr schedule_tail
  82        ba  ret_from_sys_call
  83        nop
  84                
  85ret_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
 125system_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        
 177ret_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
 298resume: 
 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
 328mmu_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]
 3581:      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
 3792:      ; 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
 410hwbreakpoint:
 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]
 4191:      pop     $r11
 420        pop     $r10
 421        pop     $dccr
 422        retb
 423        nop
 424        
 425IRQ1_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
 451wdog:
 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.
 464Watchdog_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
 520spurious_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        
 528multiple_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
 545do_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
 568gdb_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
 590kernel_execve:
 591        move.d __NR_execve, $r9
 592        break 13
 593        ret
 594        nop
 595
 596        .data
 597
 598hw_bp_trigs:
 599        .space 64*4
 600hw_bp_trig_ptr:
 601        .dword hw_bp_trigs
 602
 603        .section .rodata,"a"
 604sys_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_ni_syscall    /* old 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        .long sys_setns                 /* 335 */
 941
 942        /*
 943         * NOTE!! This doesn't have to be exact - we just have
 944         * to make sure we have _enough_ of the "sys_ni_syscall"
 945         * entries. Don't panic if you notice that this hasn't
 946         * been shrunk every time we add a new system call.
 947         */
 948
 949        .rept NR_syscalls-(.-sys_call_table)/4
 950                .long sys_ni_syscall
 951        .endr
 952        
 953