osfmk/ppc/misc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 #if 0  // dead code
  32 #include <debug.h>
  33 #include <mach_debug.h>
  34
  35 #include <mach/ppc/thread_status.h>
  36 #include <mach/vm_types.h>
  37 #include <kern/thread.h>
  38 #include <kern/misc_protos.h>
  39 #include <ppc/proc_reg.h>
  40 #include <ppc/pmap.h>
  41 #include <ppc/misc_protos.h>
  42 #include <ppc/exception.h>
  43
  44 /*
  45  * copyin/out_multiple - the assembler copyin/out functions jump to C for
  46  * help when the copyin lies over a segment boundary. The C breaks
  47  * down the copy into two sub-copies and re-calls the assembler with
  48  * these sub-copies. Very rare occurrance. Warning: These functions are
  49  * called whilst active_thread->thread_recover is still set.
  50  */
  51
  52 extern boolean_t copyin_multiple(const char *src,
  53                                  char *dst,
  54                                  vm_size_t count);
  55
  56 boolean_t copyin_multiple(const char *src,
  57                           char *dst,
  58                           vm_size_t count)
  59 {
  60         const char *midpoint;
  61         vm_size_t first_count;
  62         boolean_t first_result;
  63
  64         /* Assert that we've been called because of a segment boundary,
  65          * this function is more expensive than the assembler, and should
  66          * only be called in this difficult case.
  67          */
  68         assert(((vm_offset_t)src & 0xF0000000) !=
  69                ((vm_offset_t)(src + count -1) & 0xF0000000));
  70
  71         /* TODO NMGS define sensible constants for segments, and apply
  72          * to C and assembler (assembler is much harder)
  73          */
  74         midpoint = (const char*) ((vm_offset_t)(src + count) & 0xF0000000);
  75         first_count = (midpoint - src);
  76
  77         first_result = copyin(CAST_USER_ADDR_T(src), dst, first_count);
  78
  79         /* If there was an error, stop now and return error */
  80         if (first_result != 0)
  81                 return first_result;
  82
  83         /* otherwise finish the job and return result */
  84         return copyin(CAST_USER_ADDR_T(midpoint), dst + first_count, count-first_count);
  85 }
  86
  87 extern int copyout_multiple(const char *src, char *dst, vm_size_t count);
  88
  89 int copyout_multiple(const char *src, char *dst, vm_size_t count)
  90 {
  91         char *midpoint;
  92         vm_size_t first_count;
  93         boolean_t first_result;
  94
  95         /* Assert that we've been called because of a segment boundary,
  96          * this function is more expensive than the assembler, and should
  97          * only be called in this difficult case. For copyout, the
  98          * segment boundary is on the dst
  99          */
 100         assert(((vm_offset_t)dst & 0xF0000000) !=
 101                ((vm_offset_t)(dst + count - 1) & 0xF0000000));
 102
 103         /* TODO NMGS define sensible constants for segments, and apply
 104          * to C and assembler (assembler is much harder)
 105          */
 106         midpoint = (char *) ((vm_offset_t)(dst + count) & 0xF0000000);
 107         first_count = (midpoint - dst);
 108
 109         first_result = copyout(src, CAST_USER_ADDR_T(dst), first_count);
 110
 111         /* If there was an error, stop now and return error */
 112         if (first_result != 0)
 113                 return first_result;
 114
 115         /* otherwise finish the job and return result */
 116
 117         return copyout(src + first_count, CAST_USER_ADDR_T(midpoint), count-first_count);
 118 }
 119 #endif // dead code
 120