xref: /qemu/include/exec/user/thunk.h (revision b49f4755)
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 2.1 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 
20 #ifndef THUNK_H
21 #define THUNK_H
22 
23 #include "cpu.h"
24 #include "exec/user/abitypes.h"
25 
26 /* types enums definitions */
27 
28 typedef enum argtype {
29     TYPE_NULL,
30     TYPE_CHAR,
31     TYPE_SHORT,
32     TYPE_INT,
33     TYPE_LONG,
34     TYPE_ULONG,
35     TYPE_PTRVOID, /* pointer on unknown data */
36     TYPE_LONGLONG,
37     TYPE_ULONGLONG,
38     TYPE_PTR,
39     TYPE_ARRAY,
40     TYPE_STRUCT,
41     TYPE_OLDDEVT,
42 } argtype;
43 
44 #define MK_PTR(type) TYPE_PTR, type
45 #define MK_ARRAY(type, size) TYPE_ARRAY, (int)(size), type
46 #define MK_STRUCT(id) TYPE_STRUCT, id
47 
48 #define THUNK_TARGET 0
49 #define THUNK_HOST   1
50 
51 typedef struct {
52     /* standard struct handling */
53     const argtype *field_types;
54     int nb_fields;
55     int *field_offsets[2];
56     /* special handling */
57     void (*convert[2])(void *dst, const void *src);
58     void (*print)(void *arg);
59     int size[2];
60     int align[2];
61     const char *name;
62 } StructEntry;
63 
64 /* Translation table for bitmasks... */
65 typedef struct bitmask_transtbl {
66     unsigned int target_mask;
67     unsigned int target_bits;
68     unsigned int host_mask;
69     unsigned int host_bits;
70 } bitmask_transtbl;
71 
72 void thunk_register_struct(int id, const char *name, const argtype *types);
73 void thunk_register_struct_direct(int id, const char *name,
74                                   const StructEntry *se1);
75 const argtype *thunk_convert(void *dst, const void *src,
76                              const argtype *type_ptr, int to_host);
77 const argtype *thunk_print(void *arg, const argtype *type_ptr);
78 
79 extern StructEntry *struct_entries;
80 
81 int thunk_type_size_array(const argtype *type_ptr, int is_host);
82 int thunk_type_align_array(const argtype *type_ptr, int is_host);
83 
84 static inline int thunk_type_size(const argtype *type_ptr, int is_host)
85 {
86     int type, size;
87     const StructEntry *se;
88 
89     type = *type_ptr;
90     switch(type) {
91     case TYPE_CHAR:
92         return 1;
93     case TYPE_SHORT:
94         return 2;
95     case TYPE_INT:
96         return 4;
97     case TYPE_LONGLONG:
98     case TYPE_ULONGLONG:
99         return 8;
100     case TYPE_LONG:
101     case TYPE_ULONG:
102     case TYPE_PTRVOID:
103     case TYPE_PTR:
104         if (is_host) {
105             return sizeof(void *);
106         } else {
107             return TARGET_ABI_BITS / 8;
108         }
109         break;
110     case TYPE_OLDDEVT:
111         if (is_host) {
112 #if defined(HOST_X86_64)
113             return 8;
114 #elif defined(HOST_MIPS) || defined(HOST_SPARC64)
115             return 4;
116 #elif defined(HOST_PPC)
117             return sizeof(void *);
118 #else
119             return 2;
120 #endif
121         } else {
122 #if defined(TARGET_X86_64)
123             return 8;
124 #elif defined(TARGET_ALPHA) || defined(TARGET_IA64) || defined(TARGET_MIPS) || \
125       defined(TARGET_PARISC) || defined(TARGET_SPARC64)
126             return 4;
127 #elif defined(TARGET_PPC)
128             return TARGET_ABI_BITS / 8;
129 #else
130             return 2;
131 #endif
132         }
133         break;
134     case TYPE_ARRAY:
135         size = type_ptr[1];
136         return size * thunk_type_size_array(type_ptr + 2, is_host);
137     case TYPE_STRUCT:
138         se = struct_entries + type_ptr[1];
139         return se->size[is_host];
140     default:
141         g_assert_not_reached();
142     }
143 }
144 
145 static inline int thunk_type_align(const argtype *type_ptr, int is_host)
146 {
147     int type;
148     const StructEntry *se;
149 
150     type = *type_ptr;
151     switch(type) {
152     case TYPE_CHAR:
153         return 1;
154     case TYPE_SHORT:
155         if (is_host) {
156             return __alignof__(short);
157         } else {
158             return ABI_SHORT_ALIGNMENT;
159         }
160     case TYPE_INT:
161         if (is_host) {
162             return __alignof__(int);
163         } else {
164             return ABI_INT_ALIGNMENT;
165         }
166     case TYPE_LONGLONG:
167     case TYPE_ULONGLONG:
168         if (is_host) {
169             return __alignof__(long long);
170         } else {
171             return ABI_LLONG_ALIGNMENT;
172         }
173     case TYPE_LONG:
174     case TYPE_ULONG:
175     case TYPE_PTRVOID:
176     case TYPE_PTR:
177         if (is_host) {
178             return __alignof__(long);
179         } else {
180             return ABI_LONG_ALIGNMENT;
181         }
182         break;
183     case TYPE_OLDDEVT:
184         return thunk_type_size(type_ptr, is_host);
185     case TYPE_ARRAY:
186         return thunk_type_align_array(type_ptr + 2, is_host);
187     case TYPE_STRUCT:
188         se = struct_entries + type_ptr[1];
189         return se->align[is_host];
190     default:
191         g_assert_not_reached();
192     }
193 }
194 
195 unsigned int target_to_host_bitmask_len(unsigned int target_mask,
196                                         const bitmask_transtbl *trans_tbl,
197                                         size_t trans_len);
198 unsigned int host_to_target_bitmask_len(unsigned int host_mask,
199                                         const bitmask_transtbl * trans_tbl,
200                                         size_t trans_len);
201 
202 #define target_to_host_bitmask(M, T) \
203     target_to_host_bitmask_len(M, T, ARRAY_SIZE(T))
204 #define host_to_target_bitmask(M, T) \
205     host_to_target_bitmask_len(M, T, ARRAY_SIZE(T))
206 
207 void thunk_init(unsigned int max_structs);
208 
209 #endif
210