1 /* ----------------------------------------------------------------------- 2 ffi.c - Copyright (C) 2012, 2013 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 : 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 = 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 $r7. We must save this 163 pointer in a place that will persist while we do our work. */ 164 register ffi_closure *creg __asm__ ("$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 avalue[i] = ptr; 219 ptr += 4; 220 break; 221 } 222 ptr += 4; 223 224 /* If we've handled more arguments than fit in registers, 225 start looking at the those passed on the stack. */ 226 if (ptr == ®ister_args[6]) 227 ptr = stack_args; 228 } 229 230 /* Invoke the closure. */ 231 if (cif->rtype && (cif->rtype->type == FFI_TYPE_STRUCT)) 232 { 233 (closure->fun) (cif, struct_rvalue, avalue, closure->user_data); 234 } 235 else 236 { 237 /* Allocate space for the return value and call the function. */ 238 long long rvalue; 239 (closure->fun) (cif, &rvalue, avalue, closure->user_data); 240 asm ("mov $r12, %0\n ld.l $r0, ($r12)\n ldo.l $r1, 4($r12)" : : "r" (&rvalue)); 241 } 242 } 243 244 ffi_status 245 ffi_prep_closure_loc (ffi_closure* closure, 246 ffi_cif* cif, 247 void (*fun)(ffi_cif*, void*, void**, void*), 248 void *user_data, 249 void *codeloc) 250 { 251 unsigned short *tramp = (unsigned short *) &closure->tramp[0]; 252 unsigned long fn = (long) ffi_closure_eabi; 253 unsigned long cls = (long) codeloc; 254 255 if (cif->abi != FFI_EABI) 256 return FFI_BAD_ABI; 257 258 fn = (unsigned long) ffi_closure_eabi; 259 260 tramp[0] = 0x01e0; /* ldi.l $r7, .... */ 261 tramp[1] = cls >> 16; 262 tramp[2] = cls & 0xffff; 263 tramp[3] = 0x1a00; /* jmpa .... */ 264 tramp[4] = fn >> 16; 265 tramp[5] = fn & 0xffff; 266 267 closure->cif = cif; 268 closure->fun = fun; 269 closure->user_data = user_data; 270 271 return FFI_OK; 272 } 273
