xref: /openbmc/qemu/include/user/thunk.h (revision 7c08eefc)
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 USER_THUNK_H
21 #define USER_THUNK_H
22 
23 #ifndef CONFIG_USER_ONLY
24 #error Cannot include this header from system emulation
25 #endif
26 
27 #include "cpu.h"
28 #include "user/abitypes.h"
29 
30 /* types enums definitions */
31 
32 typedef enum argtype {
33     TYPE_NULL,
34     TYPE_CHAR,
35     TYPE_SHORT,
36     TYPE_INT,
37     TYPE_LONG,
38     TYPE_ULONG,
39     TYPE_PTRVOID, /* pointer on unknown data */
40     TYPE_LONGLONG,
41     TYPE_ULONGLONG,
42     TYPE_PTR,
43     TYPE_ARRAY,
44     TYPE_STRUCT,
45     TYPE_OLDDEVT,
46 } argtype;
47 
48 #define MK_PTR(type) TYPE_PTR, type
49 #define MK_ARRAY(type, size) TYPE_ARRAY, (int)(size), type
50 #define MK_STRUCT(id) TYPE_STRUCT, id
51 
52 #define THUNK_TARGET 0
53 #define THUNK_HOST   1
54 
55 typedef struct {
56     /* standard struct handling */
57     const argtype *field_types;
58     int nb_fields;
59     int *field_offsets[2];
60     /* special handling */
61     void (*convert[2])(void *dst, const void *src);
62     void (*print)(void *arg);
63     int size[2];
64     int align[2];
65     const char *name;
66 } StructEntry;
67 
68 /* Translation table for bitmasks... */
69 typedef struct bitmask_transtbl {
70     unsigned int target_mask;
71     unsigned int target_bits;
72     unsigned int host_mask;
73     unsigned int host_bits;
74 } bitmask_transtbl;
75 
76 void thunk_register_struct(int id, const char *name, const argtype *types);
77 void thunk_register_struct_direct(int id, const char *name,
78                                   const StructEntry *se1);
79 const argtype *thunk_convert(void *dst, const void *src,
80                              const argtype *type_ptr, int to_host);
81 const argtype *thunk_print(void *arg, const argtype *type_ptr);
82 
83 extern StructEntry *struct_entries;
84 
85 int thunk_type_size_array(const argtype *type_ptr, int is_host);
86 int thunk_type_align_array(const argtype *type_ptr, int is_host);
87 
88 static inline int thunk_type_size(const argtype *type_ptr, int is_host)
89 {
90     int type, size;
91     const StructEntry *se;
92 
93     type = *type_ptr;
94     switch(type) {
95     case TYPE_CHAR:
96         return 1;
97     case TYPE_SHORT:
98         return 2;
99     case TYPE_INT:
100         return 4;
101     case TYPE_LONGLONG:
102     case TYPE_ULONGLONG:
103         return 8;
104     case TYPE_LONG:
105     case TYPE_ULONG:
106     case TYPE_PTRVOID:
107     case TYPE_PTR:
108         if (is_host) {
109             return sizeof(void *);
110         } else {
111             return TARGET_ABI_BITS / 8;
112         }
113         break;
114     case TYPE_OLDDEVT:
115         if (is_host) {
116 #if defined(HOST_X86_64)
117             return 8;
118 #elif defined(HOST_MIPS) || defined(HOST_SPARC64)
119             return 4;
120 #elif defined(HOST_PPC)
121             return sizeof(void *);
122 #else
123             return 2;
124 #endif
125         } else {
126 #if defined(TARGET_X86_64)
127             return 8;
128 #elif defined(TARGET_ALPHA) || defined(TARGET_IA64) || defined(TARGET_MIPS) || \
129       defined(TARGET_PARISC) || defined(TARGET_SPARC64)
130             return 4;
131 #elif defined(TARGET_PPC)
132             return TARGET_ABI_BITS / 8;
133 #else
134             return 2;
135 #endif
136         }
137         break;
138     case TYPE_ARRAY:
139         size = type_ptr[1];
140         return size * thunk_type_size_array(type_ptr + 2, is_host);
141     case TYPE_STRUCT:
142         se = struct_entries + type_ptr[1];
143         return se->size[is_host];
144     default:
145         g_assert_not_reached();
146     }
147 }
148 
149 static inline int thunk_type_align(const argtype *type_ptr, int is_host)
150 {
151     int type;
152     const StructEntry *se;
153 
154     type = *type_ptr;
155     switch(type) {
156     case TYPE_CHAR:
157         return 1;
158     case TYPE_SHORT:
159         if (is_host) {
160             return __alignof__(short);
161         } else {
162             return ABI_SHORT_ALIGNMENT;
163         }
164     case TYPE_INT:
165         if (is_host) {
166             return __alignof__(int);
167         } else {
168             return ABI_INT_ALIGNMENT;
169         }
170     case TYPE_LONGLONG:
171     case TYPE_ULONGLONG:
172         if (is_host) {
173             return __alignof__(long long);
174         } else {
175             return ABI_LLONG_ALIGNMENT;
176         }
177     case TYPE_LONG:
178     case TYPE_ULONG:
179     case TYPE_PTRVOID:
180     case TYPE_PTR:
181         if (is_host) {
182             return __alignof__(long);
183         } else {
184             return ABI_LONG_ALIGNMENT;
185         }
186         break;
187     case TYPE_OLDDEVT:
188         return thunk_type_size(type_ptr, is_host);
189     case TYPE_ARRAY:
190         return thunk_type_align_array(type_ptr + 2, is_host);
191     case TYPE_STRUCT:
192         se = struct_entries + type_ptr[1];
193         return se->align[is_host];
194     default:
195         g_assert_not_reached();
196     }
197 }
198 
199 unsigned int target_to_host_bitmask_len(unsigned int target_mask,
200                                         const bitmask_transtbl *trans_tbl,
201                                         size_t trans_len);
202 unsigned int host_to_target_bitmask_len(unsigned int host_mask,
203                                         const bitmask_transtbl * trans_tbl,
204                                         size_t trans_len);
205 
206 #define target_to_host_bitmask(M, T) \
207     target_to_host_bitmask_len(M, T, ARRAY_SIZE(T))
208 #define host_to_target_bitmask(M, T) \
209     host_to_target_bitmask_len(M, T, ARRAY_SIZE(T))
210 
211 void thunk_init(unsigned int max_structs);
212 
213 #endif
214