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 <inttypes.h>
  23 #include "cpu.h"
  24
  25 /* types enums definitions */
  26
  27 typedef enum argtype {
  28     TYPE_NULL,
  29     TYPE_CHAR,
  30     TYPE_SHORT,
  31     TYPE_INT,
  32     TYPE_LONG,
  33     TYPE_ULONG,
  34     TYPE_PTRVOID, /* pointer on unknown data */
  35     TYPE_LONGLONG,
  36     TYPE_ULONGLONG,
  37     TYPE_PTR,
  38     TYPE_ARRAY,
  39     TYPE_STRUCT,
  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    x86_mask;
  64         unsigned int    x86_bits;
  65         unsigned int    alpha_mask;
  66         unsigned int    alpha_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 #ifndef NO_THUNK_TYPE_SIZE
  75
  76 extern StructEntry struct_entries[];
  77
  78 int thunk_type_size_array(const argtype *type_ptr, int is_host);
  79 int thunk_type_align_array(const argtype *type_ptr, int is_host);
  80
  81 static inline int thunk_type_size(const argtype *type_ptr, int is_host)
  82 {
  83     int type, size;
  84     const StructEntry *se;
  85
  86     type = *type_ptr;
  87     switch(type) {
  88     case TYPE_CHAR:
  89         return 1;
  90     case TYPE_SHORT:
  91         return 2;
  92     case TYPE_INT:
  93         return 4;
  94     case TYPE_LONGLONG:
  95     case TYPE_ULONGLONG:
  96         return 8;
  97     case TYPE_LONG:
  98     case TYPE_ULONG:
  99     case TYPE_PTRVOID:
 100     case TYPE_PTR:
 101         if (is_host) {
 102             return sizeof(void *);
 103         } else {
 104             return TARGET_ABI_BITS / 8;
 105         }
 106         break;
 107     case TYPE_ARRAY:
 108         size = type_ptr[1];
 109         return size * thunk_type_size_array(type_ptr + 2, is_host);
 110     case TYPE_STRUCT:
 111         se = struct_entries + type_ptr[1];
 112         return se->size[is_host];
 113     default:
 114         return -1;
 115     }
 116 }
 117
 118 static inline int thunk_type_align(const argtype *type_ptr, int is_host)
 119 {
 120     int type;
 121     const StructEntry *se;
 122
 123     type = *type_ptr;
 124     switch(type) {
 125     case TYPE_CHAR:
 126         return 1;
 127     case TYPE_SHORT:
 128         return 2;
 129     case TYPE_INT:
 130         return 4;
 131     case TYPE_LONGLONG:
 132     case TYPE_ULONGLONG:
 133         return 8;
 134     case TYPE_LONG:
 135     case TYPE_ULONG:
 136     case TYPE_PTRVOID:
 137     case TYPE_PTR:
 138         if (is_host) {
 139             return sizeof(void *);
 140         } else {
 141             return TARGET_ABI_BITS / 8;
 142         }
 143         break;
 144     case TYPE_ARRAY:
 145         return thunk_type_align_array(type_ptr + 2, is_host);
 146     case TYPE_STRUCT:
 147         se = struct_entries + type_ptr[1];
 148         return se->align[is_host];
 149     default:
 150         return -1;
 151     }
 152 }
 153
 154 #endif /* NO_THUNK_TYPE_SIZE */
 155
 156 unsigned int target_to_host_bitmask(unsigned int x86_mask,
 157                                     const bitmask_transtbl * trans_tbl);
 158 unsigned int host_to_target_bitmask(unsigned int alpha_mask,
 159                                     const bitmask_transtbl * trans_tbl);
 160
 161 #endif