osfmk/ppc/misc.c

   1 /*
   2  * Copyright (c) 2000 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 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 #include <debug.h>
  29 #include <mach_debug.h>
  30
  31 #include <mach/ppc/thread_status.h>
  32 #include <mach/vm_types.h>
  33 #include <kern/thread.h>
  34 #include <kern/misc_protos.h>
  35 #include <ppc/proc_reg.h>
  36 #include <ppc/pmap.h>
  37 #include <ppc/misc_protos.h>
  38 #include <ppc/exception.h>
  39
  40 /*
  41  * copyin/out_multiple - the assembler copyin/out functions jump to C for
  42  * help when the copyin lies over a segment boundary. The C breaks
  43  * down the copy into two sub-copies and re-calls the assembler with
  44  * these sub-copies. Very rare occurrance. Warning: These functions are
  45  * called whilst active_thread->thread_recover is still set.
  46  */
  47
  48 extern boolean_t copyin_multiple(const char *src,
  49                                  char *dst,
  50                                  vm_size_t count);
  51
  52 boolean_t copyin_multiple(const char *src,
  53                           char *dst,
  54                           vm_size_t count)
  55 {
  56         const char *midpoint;
  57         vm_size_t first_count;
  58         boolean_t first_result;
  59
  60         /* Assert that we've been called because of a segment boundary,
  61          * this function is more expensive than the assembler, and should
  62          * only be called in this difficult case.
  63          */
  64         assert(((vm_offset_t)src & 0xF0000000) !=
  65                ((vm_offset_t)(src + count -1) & 0xF0000000));
  66
  67         /* TODO NMGS define sensible constants for segments, and apply
  68          * to C and assembler (assembler is much harder)
  69          */
  70         midpoint = (const char*) ((vm_offset_t)(src + count) & 0xF0000000);
  71         first_count = (midpoint - src);
  72
  73         first_result = copyin(src, dst, first_count);
  74
  75         /* If there was an error, stop now and return error */
  76         if (first_result != 0)
  77                 return first_result;
  78
  79         /* otherwise finish the job and return result */
  80         return copyin(midpoint, dst + first_count, count-first_count);
  81 }
  82
  83 extern int copyout_multiple(const char *src, char *dst, vm_size_t count);
  84
  85 int copyout_multiple(const char *src, char *dst, vm_size_t count)
  86 {
  87         char *midpoint;
  88         vm_size_t first_count;
  89         boolean_t first_result;
  90
  91         /* Assert that we've been called because of a segment boundary,
  92          * this function is more expensive than the assembler, and should
  93          * only be called in this difficult case. For copyout, the
  94          * segment boundary is on the dst
  95          */
  96         assert(((vm_offset_t)dst & 0xF0000000) !=
  97                ((vm_offset_t)(dst + count - 1) & 0xF0000000));
  98
  99         /* TODO NMGS define sensible constants for segments, and apply
 100          * to C and assembler (assembler is much harder)
 101          */
 102         midpoint = (char *) ((vm_offset_t)(dst + count) & 0xF0000000);
 103         first_count = (midpoint - dst);
 104
 105         first_result = copyout(src, dst, first_count);
 106
 107         /* If there was an error, stop now and return error */
 108         if (first_result != 0)
 109                 return first_result;
 110
 111         /* otherwise finish the job and return result */
 112
 113         return copyout(src + first_count, midpoint, count-first_count);
 114 }
 115