include/exec/user/thunk.h

   1 /*
   2  *  Generic thunking code to convert data between host and target CPU
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #ifndef THUNK_H
  20 #define THUNK_H
  21
  22 #include "cpu.h"
  23
  24 /* types enums definitions */
  25
  26 typedef enum argtype {
  27     TYPE_NULL,
  28     TYPE_CHAR,
  29     TYPE_SHORT,
  30     TYPE_INT,
  31     TYPE_LONG,
  32     TYPE_ULONG,
  33     TYPE_PTRVOID, /* pointer on unknown data */
  34     TYPE_LONGLONG,
  35     TYPE_ULONGLONG,
  36     TYPE_PTR,
  37     TYPE_ARRAY,
  38     TYPE_STRUCT,
  39     TYPE_OLDDEVT,
  40 } argtype;
  41
  42 #define MK_PTR(type) TYPE_PTR, type
  43 #define MK_ARRAY(type, size) TYPE_ARRAY, size, type
  44 #define MK_STRUCT(id) TYPE_STRUCT, id
  45
  46 #define THUNK_TARGET 0
  47 #define THUNK_HOST   1
  48
  49 typedef struct {
  50     /* standard struct handling */
  51     const argtype *field_types;
  52     int nb_fields;
  53     int *field_offsets[2];
  54     /* special handling */
  55     void (*convert[2])(void *dst, const void *src);
  56     int size[2];
  57     int align[2];
  58     const char *name;
  59 } StructEntry;
  60
  61 /* Translation table for bitmasks... */
  62 typedef struct bitmask_transtbl {
  63     unsigned int target_mask;
  64     unsigned int target_bits;
  65     unsigned int host_mask;
  66     unsigned int host_bits;
  67 } bitmask_transtbl;
  68
  69 void thunk_register_struct(int id, const char *name, const argtype *types);
  70 void thunk_register_struct_direct(int id, const char *name,
  71                                   const StructEntry *se1);
  72 const argtype *thunk_convert(void *dst, const void *src,
  73                              const argtype *type_ptr, int to_host);
  74
  75 extern StructEntry *struct_entries;
  76
  77 int thunk_type_size_array(const argtype *type_ptr, int is_host);
  78 int thunk_type_align_array(const argtype *type_ptr, int is_host);
  79
  80 static inline int thunk_type_size(const argtype *type_ptr, int is_host)
  81 {
  82     int type, size;
  83     const StructEntry *se;
  84
  85     type = *type_ptr;
  86     switch(type) {
  87     case TYPE_CHAR:
  88         return 1;
  89     case TYPE_SHORT:
  90         return 2;
  91     case TYPE_INT:
  92         return 4;
  93     case TYPE_LONGLONG:
  94     case TYPE_ULONGLONG:
  95         return 8;
  96     case TYPE_LONG:
  97     case TYPE_ULONG:
  98     case TYPE_PTRVOID:
  99     case TYPE_PTR:
 100         if (is_host) {
 101             return sizeof(void *);
 102         } else {
 103             return TARGET_ABI_BITS / 8;
 104         }
 105         break;
 106     case TYPE_OLDDEVT:
 107         if (is_host) {
 108 #if defined(HOST_X86_64)
 109             return 8;
 110 #elif defined(HOST_ALPHA) || defined(HOST_IA64) || defined(HOST_MIPS) || \
 111       defined(HOST_PARISC) || defined(HOST_SPARC64)
 112             return 4;
 113 #elif defined(HOST_PPC)
 114             return sizeof(void *);
 115 #else
 116             return 2;
 117 #endif
 118         } else {
 119 #if defined(TARGET_X86_64)
 120             return 8;
 121 #elif defined(TARGET_ALPHA) || defined(TARGET_IA64) || defined(TARGET_MIPS) || \
 122       defined(TARGET_PARISC) || defined(TARGET_SPARC64)
 123             return 4;
 124 #elif defined(TARGET_PPC)
 125             return TARGET_ABI_BITS / 8;
 126 #else
 127             return 2;
 128 #endif
 129         }
 130         break;
 131     case TYPE_ARRAY:
 132         size = type_ptr[1];
 133         return size * thunk_type_size_array(type_ptr + 2, is_host);
 134     case TYPE_STRUCT:
 135         se = struct_entries + type_ptr[1];
 136         return se->size[is_host];
 137     default:
 138         return -1;
 139     }
 140 }
 141
 142 static inline int thunk_type_align(const argtype *type_ptr, int is_host)
 143 {
 144     int type;
 145     const StructEntry *se;
 146
 147     type = *type_ptr;
 148     switch(type) {
 149     case TYPE_CHAR:
 150         return 1;
 151     case TYPE_SHORT:
 152         if (is_host) {
 153             return __alignof__(short);
 154         } else {
 155             return ABI_SHORT_ALIGNMENT;
 156         }
 157     case TYPE_INT:
 158         if (is_host) {
 159             return __alignof__(int);
 160         } else {
 161             return ABI_INT_ALIGNMENT;
 162         }
 163     case TYPE_LONGLONG:
 164     case TYPE_ULONGLONG:
 165         if (is_host) {
 166             return __alignof__(long long);
 167         } else {
 168             return ABI_LLONG_ALIGNMENT;
 169         }
 170     case TYPE_LONG:
 171     case TYPE_ULONG:
 172     case TYPE_PTRVOID:
 173     case TYPE_PTR:
 174         if (is_host) {
 175             return __alignof__(long);
 176         } else {
 177             return ABI_LONG_ALIGNMENT;
 178         }
 179         break;
 180     case TYPE_OLDDEVT:
 181         return thunk_type_size(type_ptr, is_host);
 182     case TYPE_ARRAY:
 183         return thunk_type_align_array(type_ptr + 2, is_host);
 184     case TYPE_STRUCT:
 185         se = struct_entries + type_ptr[1];
 186         return se->align[is_host];
 187     default:
 188         return -1;
 189     }
 190 }
 191
 192 unsigned int target_to_host_bitmask(unsigned int target_mask,
 193                                     const bitmask_transtbl * trans_tbl);
 194 unsigned int host_to_target_bitmask(unsigned int host_mask,
 195                                     const bitmask_transtbl * trans_tbl);
 196
 197 void thunk_init(unsigned int max_structs);
 198
 199 #endif