ppc/sys/getpid.s

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 #include "SYS.h"
  26
  27         .data
  28         .globl  __current_pid
  29         .align  2
  30 __current_pid:
  31         .long 0
  32
  33 MI_ENTRY_POINT(_getpid)
  34 #if defined(__DYNAMIC__)
  35         mflr    r0              // note we cannot use MI_GET_ADDRESS...
  36         bcl    20,31,1f         // ...because we define __current_pid
  37 1:
  38         mflr    r5
  39         mtlr    r0
  40         addis   r5, r5, ha16(__current_pid - 1b)
  41         addi    r5, r5, lo16(__current_pid - 1b)
  42 #else
  43         lis     r5,hi16(__current_pid)
  44         ori     r5,r5,lo16(__current_pid)
  45 #endif
  46         lwz     r3,0(r5)                // get the cached pid
  47         cmpwi   r3,0                    // if positive,
  48         bgtlr++                 // return it
  49
  50         SYSCALL_NONAME(getpid, 0)
  51
  52         lwarx   r4,0,r5                 // see if we can cache it
  53         cmpwi   r4,0                    // we can't if there are any...
  54         blt--   1f              // ...vforks in progress
  55
  56         stwcx.  r3,0,r5                 // ignore cache conflicts
  57         blr
  58 1:
  59         li      r6,-4           // on 970, cancel the reservation using red zone...
  60         stwcx.  r3,r6,r1        // ...to avoid an errata
  61         blr