osfmk/ppc/misc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 #include <debug.h>
  26 #include <mach_debug.h>
  27
  28 #include <mach/ppc/thread_status.h>
  29 #include <mach/vm_types.h>
  30 #include <kern/thread.h>
  31 #include <kern/misc_protos.h>
  32 #include <ppc/proc_reg.h>
  33 #include <ppc/pmap.h>
  34 #include <ppc/misc_protos.h>
  35 #include <ppc/exception.h>
  36
  37 /*
  38  * copyin/out_multiple - the assembler copyin/out functions jump to C for
  39  * help when the copyin lies over a segment boundary. The C breaks
  40  * down the copy into two sub-copies and re-calls the assembler with
  41  * these sub-copies. Very rare occurrance. Warning: These functions are
  42  * called whilst active_thread->thread_recover is still set.
  43  */
  44
  45 extern boolean_t copyin_multiple(const char *src,
  46                                  char *dst,
  47                                  vm_size_t count);
  48
  49 boolean_t copyin_multiple(const char *src,
  50                           char *dst,
  51                           vm_size_t count)
  52 {
  53         const char *midpoint;
  54         vm_size_t first_count;
  55         boolean_t first_result;
  56
  57         /* Assert that we've been called because of a segment boundary,
  58          * this function is more expensive than the assembler, and should
  59          * only be called in this difficult case.
  60          */
  61         assert(((vm_offset_t)src & 0xF0000000) !=
  62                ((vm_offset_t)(src + count -1) & 0xF0000000));
  63
  64         /* TODO NMGS define sensible constants for segments, and apply
  65          * to C and assembler (assembler is much harder)
  66          */
  67         midpoint = (const char*) ((vm_offset_t)(src + count) & 0xF0000000);
  68         first_count = (midpoint - src);
  69
  70         first_result = copyin(src, dst, first_count);
  71
  72         /* If there was an error, stop now and return error */
  73         if (first_result != 0)
  74                 return first_result;
  75
  76         /* otherwise finish the job and return result */
  77         return copyin(midpoint, dst + first_count, count-first_count);
  78 }
  79
  80 extern int copyout_multiple(const char *src, char *dst, vm_size_t count);
  81
  82 int copyout_multiple(const char *src, char *dst, vm_size_t count)
  83 {
  84         char *midpoint;
  85         vm_size_t first_count;
  86         boolean_t first_result;
  87
  88         /* Assert that we've been called because of a segment boundary,
  89          * this function is more expensive than the assembler, and should
  90          * only be called in this difficult case. For copyout, the
  91          * segment boundary is on the dst
  92          */
  93         assert(((vm_offset_t)dst & 0xF0000000) !=
  94                ((vm_offset_t)(dst + count - 1) & 0xF0000000));
  95
  96         /* TODO NMGS define sensible constants for segments, and apply
  97          * to C and assembler (assembler is much harder)
  98          */
  99         midpoint = (char *) ((vm_offset_t)(dst + count) & 0xF0000000);
 100         first_count = (midpoint - dst);
 101
 102         first_result = copyout(src, dst, first_count);
 103
 104         /* If there was an error, stop now and return error */
 105         if (first_result != 0)
 106                 return first_result;
 107
 108         /* otherwise finish the job and return result */
 109
 110         return copyout(src + first_count, midpoint, count-first_count);
 111 }
 112