1 /* -----------------------------------------------------------------------
2 ffi.c - Copyright (c) 2014 Sebastian Macke <sebastian@macke.de>
3
4 OpenRISC Foreign Function Interface
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 ``Software''), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice shall be included
15 in all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
18 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
21 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
22 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 DEALINGS IN THE SOFTWARE.
25 ----------------------------------------------------------------------- */
26
27 #include <ffi.h>
28 #include "ffi_common.h"
29
30 /* ffi_prep_args is called by the assembly routine once stack space
31 has been allocated for the function's arguments */
32
33 void* ffi_prep_args(char *stack, extended_cif *ecif)
34 {
35 char *stacktemp = stack;
36 int i, s;
37 ffi_type **arg;
38 int count = 0;
39 int nfixedargs;
40
41 nfixedargs = ecif->cif->nfixedargs;
42 arg = ecif->cif->arg_types;
43 void **argv = ecif->avalue;
44
45 if (ecif->cif->rtype->type == FFI_TYPE_STRUCT)
46 {
47 *(void **) stack = ecif->rvalue;
48 stack += 4;
49 count = 4;
50 }
51 for(i=0; i<ecif->cif->nargs; i++)
52 {
53
54 /* variadic args are saved on stack */
55 if ((nfixedargs == 0) && (count < 24))
56 {
57 count = 24;
58 stack = stacktemp + 24;
59 }
60 nfixedargs--;
61
62 s = 4;
63 switch((*arg)->type)
64 {
65 case FFI_TYPE_STRUCT:
66 *(void **)stack = *argv;
67 break;
68
69 case FFI_TYPE_SINT8:
70 *(signed int *) stack = (signed int)*(SINT8 *)(* argv);
71 break;
72
73 case FFI_TYPE_UINT8:
74 *(unsigned int *) stack = (unsigned int)*(UINT8 *)(* argv);
75 break;
76
77 case FFI_TYPE_SINT16:
78 *(signed int *) stack = (signed int)*(SINT16 *)(* argv);
79 break;
80
81 case FFI_TYPE_UINT16:
82 *(unsigned int *) stack = (unsigned int)*(UINT16 *)(* argv);
83 break;
84
85 case FFI_TYPE_SINT32:
86 case FFI_TYPE_UINT32:
87 case FFI_TYPE_FLOAT:
88 case FFI_TYPE_POINTER:
89 *(int *)stack = *(int*)(*argv);
90 break;
91
92 default: /* 8 byte types */
93 if (count == 20) /* never split arguments */
94 {
95 stack += 4;
96 count += 4;
97 }
98 s = (*arg)->size;
99 memcpy(stack, *argv, s);
100 break;
101 }
102
103 stack += s;
104 count += s;
105 argv++;
106 arg++;
107 }
108 return stacktemp + ((count>24)?24:0);
109 }
110
111 extern void ffi_call_SYSV(unsigned,
112 extended_cif *,
113 void *(*)(int *, extended_cif *),
114 unsigned *,
115 void (*fn)(void),
116 unsigned);
117
118
119 void ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
120 {
121 int i;
122 int size;
123 ffi_type **arg;
124
125 /* Calculate size to allocate on stack */
126
127 for(i = 0, arg = cif->arg_types, size=0; i < cif->nargs; i++, arg++)
128 {
129 if ((*arg)->type == FFI_TYPE_STRUCT)
130 size += 4;
131 else
132 if ((*arg)->size <= 4)
133 size += 4;
134 else
135 size += 8;
136 }
137
138 /* for variadic functions more space is needed on the stack */
139 if (cif->nargs != cif->nfixedargs)
140 size += 24;
141
142 if (cif->rtype->type == FFI_TYPE_STRUCT)
143 size += 4;
144
145
146 extended_cif ecif;
147 ecif.cif = cif;
148 ecif.avalue = avalue;
149 ecif.rvalue = rvalue;
150
151 switch (cif->abi)
152 {
153 case FFI_SYSV:
154 ffi_call_SYSV(size, &ecif, ffi_prep_args, rvalue, fn, cif->flags);
155 break;
156 default:
157 FFI_ASSERT(0);
158 break;
159 }
160 }
161
162
163 void ffi_closure_SYSV(unsigned long r3, unsigned long r4, unsigned long r5,
164 unsigned long r6, unsigned long r7, unsigned long r8)
165 {
166 register int *sp __asm__ ("r17");
167 register int *r13 __asm__ ("r13");
168
169 ffi_closure* closure = (ffi_closure*) r13;
170 char *stack_args = sp;
171
172 /* Lay the register arguments down in a continuous chunk of memory. */
173 unsigned register_args[6] =
174 { r3, r4, r5, r6, r7, r8 };
175
176 /* Pointer to a struct return value. */
177 void *struct_rvalue = (void *) r3;
178
179 ffi_cif *cif = closure->cif;
180 ffi_type **arg_types = cif->arg_types;
181 void **avalue = alloca (cif->nargs * sizeof(void *));
182 char *ptr = (char *) register_args;
183 int count = 0;
184 int nfixedargs = cif->nfixedargs;
185 int i;
186
187 /* preserve struct type return pointer passing */
188
189 if ((cif->rtype != NULL) && (cif->rtype->type == FFI_TYPE_STRUCT))
190 {
191 ptr += 4;
192 count = 4;
193 }
194
195 /* Find the address of each argument. */
196 for (i = 0; i < cif->nargs; i++)
197 {
198
199 /* variadic args are saved on stack */
200 if ((nfixedargs == 0) && (count < 24))
201 {
202 ptr = stack_args;
203 count = 24;
204 }
205 nfixedargs--;
206
207 switch (arg_types[i]->type)
208 {
209 case FFI_TYPE_SINT8:
210 case FFI_TYPE_UINT8:
211 avalue[i] = ptr + 3;
212 break;
213
214 case FFI_TYPE_SINT16:
215 case FFI_TYPE_UINT16:
216 avalue[i] = ptr + 2;
217 break;
218
219 case FFI_TYPE_SINT32:
220 case FFI_TYPE_UINT32:
221 case FFI_TYPE_FLOAT:
222 case FFI_TYPE_POINTER:
223 avalue[i] = ptr;
224 break;
225
226 case FFI_TYPE_STRUCT:
227 avalue[i] = *(void**)ptr;
228 break;
229
230 default:
231 /* 8-byte values */
232
233 /* arguments are never splitted */
234 if (ptr == ®ister_args[5])
235 ptr = stack_args;
236 avalue[i] = ptr;
237 ptr += 4;
238 count += 4;
239 break;
240 }
241 ptr += 4;
242 count += 4;
243
244 /* If we've handled more arguments than fit in registers,
245 start looking at the those passed on the stack. */
246
247 if (count == 24)
248 ptr = stack_args;
249 }
250
251 if (cif->rtype && (cif->rtype->type == FFI_TYPE_STRUCT))
252 {
253 (closure->fun) (cif, struct_rvalue, avalue, closure->user_data);
254 } else
255 {
256 long long rvalue;
257 (closure->fun) (cif, &rvalue, avalue, closure->user_data);
258 if (cif->rtype)
259 asm ("l.ori r12, %0, 0x0\n l.lwz r11, 0(r12)\n l.lwz r12, 4(r12)" : : "r" (&rvalue));
260 }
261 }
262
263
264 ffi_status
265 ffi_prep_closure_loc (ffi_closure* closure,
266 ffi_cif* cif,
267 void (*fun)(ffi_cif*,void*,void**,void*),
268 void *user_data,
269 void *codeloc)
270 {
271 unsigned short *tramp = (unsigned short *) closure->tramp;
272 unsigned long fn = (unsigned long) ffi_closure_SYSV;
273 unsigned long cls = (unsigned long) codeloc;
274
275 if (cif->abi != FFI_SYSV)
276 return FFI_BAD_ABI;
277
278 closure->cif = cif;
279 closure->user_data = user_data;
280 closure->fun = fun;
281
282 /* write pointers to temporary registers */
283 tramp[0] = (0x6 << 10) | (13 << 5); /* l.movhi r13, ... */
284 tramp[1] = cls >> 16;
285 tramp[2] = (0x2a << 10) | (13 << 5) | 13; /* l.ori r13, r13, ... */
286 tramp[3] = cls & 0xFFFF;
287
288 tramp[4] = (0x6 << 10) | (15 << 5); /* l.movhi r15, ... */
289 tramp[5] = fn >> 16;
290 tramp[6] = (0x2a << 10) | (15 << 5) | 15; /* l.ori r15, r15 ... */
291 tramp[7] = fn & 0xFFFF;
292
293 tramp[8] = (0x11 << 10); /* l.jr r15 */
294 tramp[9] = 15 << 11;
295
296 tramp[10] = (0x2a << 10) | (17 << 5) | 1; /* l.ori r17, r1, ... */
297 tramp[11] = 0x0;
298
299 return FFI_OK;
300 }
301
302
303 ffi_status ffi_prep_cif_machdep (ffi_cif *cif)
304 {
305 cif->flags = 0;
306
307 /* structures are returned as pointers */
308 if (cif->rtype->type == FFI_TYPE_STRUCT)
309 cif->flags = FFI_TYPE_STRUCT;
310 else
311 if (cif->rtype->size > 4)
312 cif->flags = FFI_TYPE_UINT64;
313
314 cif->nfixedargs = cif->nargs;
315
316 return FFI_OK;
317 }
318
319
320 ffi_status ffi_prep_cif_machdep_var(ffi_cif *cif,
321 unsigned int nfixedargs, unsigned int ntotalargs)
322 {
323 ffi_status status;
324
325 status = ffi_prep_cif_machdep (cif);
326 cif->nfixedargs = nfixedargs;
327 return status;
328 }