xref: /qemu/include/exec/user/thunk.h (revision ab9056ff)
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 
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, 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     int size[2];
59     int align[2];
60     const char *name;
61 } StructEntry;
62 
63 /* Translation table for bitmasks... */
64 typedef struct bitmask_transtbl {
65     unsigned int target_mask;
66     unsigned int target_bits;
67     unsigned int host_mask;
68     unsigned int host_bits;
69 } bitmask_transtbl;
70 
71 void thunk_register_struct(int id, const char *name, const argtype *types);
72 void thunk_register_struct_direct(int id, const char *name,
73                                   const StructEntry *se1);
74 const argtype *thunk_convert(void *dst, const void *src,
75                              const argtype *type_ptr, int to_host);
76 
77 extern StructEntry *struct_entries;
78 
79 int thunk_type_size_array(const argtype *type_ptr, int is_host);
80 int thunk_type_align_array(const argtype *type_ptr, int is_host);
81 
82 static inline int thunk_type_size(const argtype *type_ptr, int is_host)
83 {
84     int type, size;
85     const StructEntry *se;
86 
87     type = *type_ptr;
88     switch(type) {
89     case TYPE_CHAR:
90         return 1;
91     case TYPE_SHORT:
92         return 2;
93     case TYPE_INT:
94         return 4;
95     case TYPE_LONGLONG:
96     case TYPE_ULONGLONG:
97         return 8;
98     case TYPE_LONG:
99     case TYPE_ULONG:
100     case TYPE_PTRVOID:
101     case TYPE_PTR:
102         if (is_host) {
103             return sizeof(void *);
104         } else {
105             return TARGET_ABI_BITS / 8;
106         }
107         break;
108     case TYPE_OLDDEVT:
109         if (is_host) {
110 #if defined(HOST_X86_64)
111             return 8;
112 #elif defined(HOST_ALPHA) || defined(HOST_IA64) || defined(HOST_MIPS) || \
113       defined(HOST_PARISC) || defined(HOST_SPARC64)
114             return 4;
115 #elif defined(HOST_PPC)
116             return sizeof(void *);
117 #else
118             return 2;
119 #endif
120         } else {
121 #if defined(TARGET_X86_64)
122             return 8;
123 #elif defined(TARGET_ALPHA) || defined(TARGET_IA64) || defined(TARGET_MIPS) || \
124       defined(TARGET_PARISC) || defined(TARGET_SPARC64)
125             return 4;
126 #elif defined(TARGET_PPC)
127             return TARGET_ABI_BITS / 8;
128 #else
129             return 2;
130 #endif
131         }
132         break;
133     case TYPE_ARRAY:
134         size = type_ptr[1];
135         return size * thunk_type_size_array(type_ptr + 2, is_host);
136     case TYPE_STRUCT:
137         se = struct_entries + type_ptr[1];
138         return se->size[is_host];
139     default:
140         g_assert_not_reached();
141     }
142 }
143 
144 static inline int thunk_type_align(const argtype *type_ptr, int is_host)
145 {
146     int type;
147     const StructEntry *se;
148 
149     type = *type_ptr;
150     switch(type) {
151     case TYPE_CHAR:
152         return 1;
153     case TYPE_SHORT:
154         if (is_host) {
155             return __alignof__(short);
156         } else {
157             return ABI_SHORT_ALIGNMENT;
158         }
159     case TYPE_INT:
160         if (is_host) {
161             return __alignof__(int);
162         } else {
163             return ABI_INT_ALIGNMENT;
164         }
165     case TYPE_LONGLONG:
166     case TYPE_ULONGLONG:
167         if (is_host) {
168             return __alignof__(long long);
169         } else {
170             return ABI_LLONG_ALIGNMENT;
171         }
172     case TYPE_LONG:
173     case TYPE_ULONG:
174     case TYPE_PTRVOID:
175     case TYPE_PTR:
176         if (is_host) {
177             return __alignof__(long);
178         } else {
179             return ABI_LONG_ALIGNMENT;
180         }
181         break;
182     case TYPE_OLDDEVT:
183         return thunk_type_size(type_ptr, is_host);
184     case TYPE_ARRAY:
185         return thunk_type_align_array(type_ptr + 2, is_host);
186     case TYPE_STRUCT:
187         se = struct_entries + type_ptr[1];
188         return se->align[is_host];
189     default:
190         g_assert_not_reached();
191     }
192 }
193 
194 unsigned int target_to_host_bitmask(unsigned int target_mask,
195                                     const bitmask_transtbl * trans_tbl);
196 unsigned int host_to_target_bitmask(unsigned int host_mask,
197                                     const bitmask_transtbl * trans_tbl);
198 
199 void thunk_init(unsigned int max_structs);
200 
201 #endif
202