1 /* ----------------------------------------------------------------------- 2 ffi.c - Copyright (c) 1998, 2008 Red Hat, Inc. 3 4 ARM 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 42 argp = stack; 43 44 if ( ecif->cif->flags == FFI_TYPE_STRUCT ) { 45 *(void **) argp = ecif->rvalue; 46 argp += 4; 47 } 48 49 p_argv = ecif->avalue; 50 51 for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types; 52 (i != 0); 53 i--, p_arg++) 54 { 55 size_t z; 56 57 /* Align if necessary */ 58 if (((*p_arg)->alignment - 1) & (unsigned) argp) { 59 argp = (char *) ALIGN(argp, (*p_arg)->alignment); 60 } 61 62 if ((*p_arg)->type == FFI_TYPE_STRUCT) 63 argp = (char *) ALIGN(argp, 4); 64 65 z = (*p_arg)->size; 66 if (z < sizeof(int)) 67 { 68 z = sizeof(int); 69 switch ((*p_arg)->type) 70 { 71 case FFI_TYPE_SINT8: 72 *(signed int *) argp = (signed int)*(SINT8 *)(* p_argv); 73 break; 74 75 case FFI_TYPE_UINT8: 76 *(unsigned int *) argp = (unsigned int)*(UINT8 *)(* p_argv); 77 break; 78 79 case FFI_TYPE_SINT16: 80 *(signed int *) argp = (signed int)*(SINT16 *)(* p_argv); 81 break; 82 83 case FFI_TYPE_UINT16: 84 *(unsigned int *) argp = (unsigned int)*(UINT16 *)(* p_argv); 85 break; 86 87 case FFI_TYPE_STRUCT: 88 memcpy(argp, *p_argv, (*p_arg)->size); 89 break; 90 91 default: 92 FFI_ASSERT(0); 93 } 94 } 95 else if (z == sizeof(int)) 96 { 97 *(unsigned int *) argp = (unsigned int)*(UINT32 *)(* p_argv); 98 } 99 else 100 { 101 memcpy(argp, *p_argv, z); 102 } 103 p_argv++; 104 argp += z; 105 } 106 107 return; 108 } 109 110 /* Perform machine dependent cif processing */ 111 ffi_status ffi_prep_cif_machdep(ffi_cif *cif) 112 { 113 /* Round the stack up to a multiple of 8 bytes. This isn't needed 114 everywhere, but it is on some platforms, and it doesn't harm anything 115 when it isn't needed. */ 116 cif->bytes = (cif->bytes + 7) & ~7; 117 118 /* Set the return type flag */ 119 switch (cif->rtype->type) 120 { 121 case FFI_TYPE_VOID: 122 case FFI_TYPE_FLOAT: 123 case FFI_TYPE_DOUBLE: 124 cif->flags = (unsigned) cif->rtype->type; 125 break; 126 127 case FFI_TYPE_SINT64: 128 case FFI_TYPE_UINT64: 129 cif->flags = (unsigned) FFI_TYPE_SINT64; 130 break; 131 132 case FFI_TYPE_STRUCT: 133 if (cif->rtype->size <= 4) 134 /* A Composite Type not larger than 4 bytes is returned in r0. */ 135 cif->flags = (unsigned)FFI_TYPE_INT; 136 else 137 /* A Composite Type larger than 4 bytes, or whose size cannot 138 be determined statically ... is stored in memory at an 139 address passed [in r0]. */ 140 cif->flags = (unsigned)FFI_TYPE_STRUCT; 141 break; 142 143 default: 144 cif->flags = FFI_TYPE_INT; 145 break; 146 } 147 148 return FFI_OK; 149 } 150 151 extern void ffi_call_SYSV(void (*)(char *, extended_cif *), extended_cif *, 152 unsigned, unsigned, unsigned *, void (*fn)(void)); 153 154 void ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue) 155 { 156 extended_cif ecif; 157 158 int small_struct = (cif->flags == FFI_TYPE_INT 159 && cif->rtype->type == FFI_TYPE_STRUCT); 160 161 ecif.cif = cif; 162 ecif.avalue = avalue; 163 164 unsigned int temp; 165 166 /* If the return value is a struct and we don't have a return */ 167 /* value address then we need to make one */ 168 169 if ((rvalue == NULL) && 170 (cif->flags == FFI_TYPE_STRUCT)) 171 { 172 ecif.rvalue = alloca(cif->rtype->size); 173 } 174 else if (small_struct) 175 ecif.rvalue = &temp; 176 else 177 ecif.rvalue = rvalue; 178 179 switch (cif->abi) 180 { 181 case FFI_SYSV: 182 ffi_call_SYSV(ffi_prep_args, &ecif, cif->bytes, cif->flags, ecif.rvalue, 183 fn); 184 185 break; 186 default: 187 FFI_ASSERT(0); 188 break; 189 } 190 if (small_struct) 191 memcpy (rvalue, &temp, cif->rtype->size); 192 } 193 194 /** private members **/ 195 196 static void ffi_prep_incoming_args_SYSV (char *stack, void **ret, 197 void** args, ffi_cif* cif); 198 199 void ffi_closure_SYSV (ffi_closure *); 200 201 /* This function is jumped to by the trampoline */ 202 203 unsigned int 204 ffi_closure_SYSV_inner (closure, respp, args) 205 ffi_closure *closure; 206 void **respp; 207 void *args; 208 { 209 // our various things... 210 ffi_cif *cif; 211 void **arg_area; 212 213 cif = closure->cif; 214 arg_area = (void**) alloca (cif->nargs * sizeof (void*)); 215 216 /* this call will initialize ARG_AREA, such that each 217 * element in that array points to the corresponding 218 * value on the stack; and if the function returns 219 * a structure, it will re-set RESP to point to the 220 * structure return address. */ 221 222 ffi_prep_incoming_args_SYSV(args, respp, arg_area, cif); 223 224 (closure->fun) (cif, *respp, arg_area, closure->user_data); 225 226 return cif->flags; 227 } 228 229 /*@-exportheader@*/ 230 static void 231 ffi_prep_incoming_args_SYSV(char *stack, void **rvalue, 232 void **avalue, ffi_cif *cif) 233 /*@=exportheader@*/ 234 { 235 register unsigned int i; 236 register void **p_argv; 237 register char *argp; 238 register ffi_type **p_arg; 239 240 argp = stack; 241 242 if ( cif->flags == FFI_TYPE_STRUCT ) { 243 *rvalue = *(void **) argp; 244 argp += 4; 245 } 246 247 p_argv = avalue; 248 249 for (i = cif->nargs, p_arg = cif->arg_types; (i != 0); i--, p_arg++) 250 { 251 size_t z; 252 253 size_t alignment = (*p_arg)->alignment; 254 if (alignment < 4) 255 alignment = 4; 256 /* Align if necessary */ 257 if ((alignment - 1) & (unsigned) argp) { 258 argp = (char *) ALIGN(argp, alignment); 259 } 260 261 z = (*p_arg)->size; 262 263 /* because we're little endian, this is what it turns into. */ 264 265 *p_argv = (void*) argp; 266 267 p_argv++; 268 argp += z; 269 } 270 271 return; 272 } 273 274 /* How to make a trampoline. */ 275 276 #define FFI_INIT_TRAMPOLINE(TRAMP,FUN,CTX) \ 277 ({ unsigned char *__tramp = (unsigned char*)(TRAMP); \ 278 unsigned int __fun = (unsigned int)(FUN); \ 279 unsigned int __ctx = (unsigned int)(CTX); \ 280 *(unsigned int*) &__tramp[0] = 0xe92d000f; /* stmfd sp!, {r0-r3} */ \ 281 *(unsigned int*) &__tramp[4] = 0xe59f0000; /* ldr r0, [pc] */ \ 282 *(unsigned int*) &__tramp[8] = 0xe59ff000; /* ldr pc, [pc] */ \ 283 *(unsigned int*) &__tramp[12] = __ctx; \ 284 *(unsigned int*) &__tramp[16] = __fun; \ 285 __clear_cache((&__tramp[0]), (&__tramp[19])); \ 286 }) 287 288 289 /* the cif must already be prep'ed */ 290 291 ffi_status 292 ffi_prep_closure_loc (ffi_closure* closure, 293 ffi_cif* cif, 294 void (*fun)(ffi_cif*,void*,void**,void*), 295 void *user_data, 296 void *codeloc) 297 { 298 FFI_ASSERT (cif->abi == FFI_SYSV); 299 300 FFI_INIT_TRAMPOLINE (&closure->tramp[0], \ 301 &ffi_closure_SYSV, \ 302 codeloc); 303 304 closure->cif = cif; 305 closure->user_data = user_data; 306 closure->fun = fun; 307 308 return FFI_OK; 309 } 310
