1 /* -----------------------------------------------------------------------
2 ffi.c - Copyright (C) 2012, 2013, 2018 Anthony Green
3
4 Moxie 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 #include <stdlib.h>
31
32 /* ffi_prep_args is called by the assembly routine once stack space
33 has been allocated for the function's arguments */
34
35 void *ffi_prep_args(char *stack, extended_cif *ecif)
36 {
37 register unsigned int i;
38 register void **p_argv;
39 register char *argp;
40 register ffi_type **p_arg;
41 register int count = 0;
42
43 p_argv = ecif->avalue;
44 argp = stack;
45
46 if (ecif->cif->rtype->type == FFI_TYPE_STRUCT)
47 {
48 *(void **) argp = ecif->rvalue;
49 argp += 4;
50 }
51
52 for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
53 (i != 0);
54 i--, p_arg++)
55 {
56 size_t z;
57
58 z = (*p_arg)->size;
59
60 if ((*p_arg)->type == FFI_TYPE_STRUCT)
61 {
62 z = sizeof(void*);
63 *(void **) argp = *p_argv;
64 }
65 else if (z < sizeof(int))
66 {
67 z = sizeof(int);
68 switch ((*p_arg)->type)
69 {
70 case FFI_TYPE_SINT8:
71 *(signed int *) argp = (signed int)*(SINT8 *)(* p_argv);
72 break;
73
74 case FFI_TYPE_UINT8:
75 *(unsigned int *) argp = (unsigned int)*(UINT8 *)(* p_argv);
76 break;
77
78 case FFI_TYPE_SINT16:
79 *(signed int *) argp = (signed int)*(SINT16 *)(* p_argv);
80 break;
81
82 case FFI_TYPE_UINT16:
83 *(unsigned int *) argp = (unsigned int)*(UINT16 *)(* p_argv);
84 break;
85
86 default:
87 FFI_ASSERT(0);
88 }
89 }
90 else if (z == sizeof(int))
91 {
92 *(unsigned int *) argp = (unsigned int)*(UINT32 *)(* p_argv);
93 }
94 else
95 {
96 memcpy(argp, *p_argv, z);
97 }
98 p_argv++;
99 argp += z;
100 count += z;
101 }
102
103 return (stack + ((count > 24) ? 24 : FFI_ALIGN_DOWN(count, 8)));
104 }
105
106 /* Perform machine dependent cif processing */
107 ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
108 {
109 if (cif->rtype->type == FFI_TYPE_STRUCT)
110 cif->flags = -1;
111 else
112 cif->flags = cif->rtype->size;
113
114 cif->bytes = FFI_ALIGN (cif->bytes, 8);
115
116 return FFI_OK;
117 }
118
119 extern void ffi_call_EABI(void *(*)(char *, extended_cif *),
120 extended_cif *,
121 unsigned, unsigned,
122 unsigned *,
123 void (*fn)(void));
124
125 void ffi_call(ffi_cif *cif,
126 void (*fn)(void),
127 void *rvalue,
128 void **avalue)
129 {
130 extended_cif ecif;
131
132 ecif.cif = cif;
133 ecif.avalue = avalue;
134
135 /* If the return value is a struct and we don't have a return */
136 /* value address then we need to make one */
137
138 if ((rvalue == NULL) &&
139 (cif->rtype->type == FFI_TYPE_STRUCT))
140 {
141 ecif.rvalue = alloca(cif->rtype->size);
142 }
143 else
144 ecif.rvalue = rvalue;
145
146 switch (cif->abi)
147 {
148 case FFI_EABI:
149 ffi_call_EABI(ffi_prep_args, &ecif, cif->bytes,
150 cif->flags, ecif.rvalue, fn);
151 break;
152 default:
153 FFI_ASSERT(0);
154 break;
155 }
156 }
157
158 void ffi_closure_eabi (unsigned arg1, unsigned arg2, unsigned arg3,
159 unsigned arg4, unsigned arg5, unsigned arg6)
160 {
161 /* This function is called by a trampoline. The trampoline stows a
162 pointer to the ffi_closure object in $r12. We must save this
163 pointer in a place that will persist while we do our work. */
164 register ffi_closure *creg __asm__ ("$r12");
165 ffi_closure *closure = creg;
166
167 /* Arguments that don't fit in registers are found on the stack
168 at a fixed offset above the current frame pointer. */
169 register char *frame_pointer __asm__ ("$fp");
170
171 /* Pointer to a struct return value. */
172 void *struct_rvalue = (void *) arg1;
173
174 /* 6 words reserved for register args + 3 words from jsr */
175 char *stack_args = frame_pointer + 9*4;
176
177 /* Lay the register arguments down in a continuous chunk of memory. */
178 unsigned register_args[6] =
179 { arg1, arg2, arg3, arg4, arg5, arg6 };
180 char *register_args_ptr = (char *) register_args;
181
182 ffi_cif *cif = closure->cif;
183 ffi_type **arg_types = cif->arg_types;
184 void **avalue = alloca (cif->nargs * sizeof(void *));
185 char *ptr = (char *) register_args;
186 int i;
187
188 /* preserve struct type return pointer passing */
189 if ((cif->rtype != NULL) && (cif->rtype->type == FFI_TYPE_STRUCT)) {
190 ptr += 4;
191 register_args_ptr = (char *)®ister_args[1];
192 }
193
194 /* Find the address of each argument. */
195 for (i = 0; i < cif->nargs; i++)
196 {
197 switch (arg_types[i]->type)
198 {
199 case FFI_TYPE_SINT8:
200 case FFI_TYPE_UINT8:
201 avalue[i] = ptr + 3;
202 break;
203 case FFI_TYPE_SINT16:
204 case FFI_TYPE_UINT16:
205 avalue[i] = ptr + 2;
206 break;
207 case FFI_TYPE_SINT32:
208 case FFI_TYPE_UINT32:
209 case FFI_TYPE_FLOAT:
210 case FFI_TYPE_POINTER:
211 avalue[i] = ptr;
212 break;
213 case FFI_TYPE_STRUCT:
214 avalue[i] = *(void**)ptr;
215 break;
216 default:
217 /* This is an 8-byte value. */
218 if (ptr == (char *) ®ister_args[5])
219 {
220 /* The value is split across two locations */
221 unsigned *ip = alloca(8);
222 avalue[i] = ip;
223 ip[0] = *(unsigned *) ptr;
224 ip[1] = *(unsigned *) stack_args;
225 }
226 else
227 {
228 avalue[i] = ptr;
229 }
230 ptr += 4;
231 break;
232 }
233 ptr += 4;
234
235 /* If we've handled more arguments than fit in registers,
236 start looking at the those passed on the stack. */
237 if (ptr == (char *) ®ister_args[6])
238 ptr = stack_args;
239 else if (ptr == (char *) ®ister_args[7])
240 ptr = stack_args + 4;
241 }
242
243 /* Invoke the closure. */
244 if (cif->rtype && (cif->rtype->type == FFI_TYPE_STRUCT))
245 {
246 (closure->fun) (cif, struct_rvalue, avalue, closure->user_data);
247 }
248 else
249 {
250 /* Allocate space for the return value and call the function. */
251 long long rvalue;
252 (closure->fun) (cif, &rvalue, avalue, closure->user_data);
253 asm ("mov $r12, %0\n ld.l $r0, ($r12)\n ldo.l $r1, 4($r12)" : : "r" (&rvalue));
254 }
255 }
256
257 ffi_status
258 ffi_prep_closure_loc (ffi_closure* closure,
259 ffi_cif* cif,
260 void (*fun)(ffi_cif*, void*, void**, void*),
261 void *user_data,
262 void *codeloc)
263 {
264 unsigned short *tramp = (unsigned short *) &closure->tramp[0];
265 unsigned long fn = (long) ffi_closure_eabi;
266 unsigned long cls = (long) codeloc;
267
268 if (cif->abi != FFI_EABI)
269 return FFI_BAD_ABI;
270
271 fn = (unsigned long) ffi_closure_eabi;
272
273 tramp[0] = 0x01e0; /* ldi.l $r12, .... */
274 tramp[1] = cls >> 16;
275 tramp[2] = cls & 0xffff;
276 tramp[3] = 0x1a00; /* jmpa .... */
277 tramp[4] = fn >> 16;
278 tramp[5] = fn & 0xffff;
279
280 closure->cif = cif;
281 closure->fun = fun;
282 closure->user_data = user_data;
283
284 return FFI_OK;
285 }