1 /* ----------------------------------------------------------------------- 2 ffi.c - Copyright (c) 2014 Sebastian Macke <sebastian (at) 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 } 329
