1 /* ----------------------------------------------------------------------- 2 ffi_sysv.c - Copyright (C) 2013 IBM 3 Copyright (C) 2011 Anthony Green 4 Copyright (C) 2011 Kyle Moffett 5 Copyright (C) 2008 Red Hat, Inc 6 Copyright (C) 2007, 2008 Free Software Foundation, Inc 7 Copyright (c) 1998 Geoffrey Keating 8 9 PowerPC Foreign Function Interface 10 11 Permission is hereby granted, free of charge, to any person obtaining 12 a copy of this software and associated documentation files (the 13 ``Software''), to deal in the Software without restriction, including 14 without limitation the rights to use, copy, modify, merge, publish, 15 distribute, sublicense, and/or sell copies of the Software, and to 16 permit persons to whom the Software is furnished to do so, subject to 17 the following conditions: 18 19 The above copyright notice and this permission notice shall be included 20 in all copies or substantial portions of the Software. 21 22 THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS 23 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 25 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR 26 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 27 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 28 OTHER DEALINGS IN THE SOFTWARE. 29 ----------------------------------------------------------------------- */ 30 31 #include "ffi.h" 32 33 #ifndef POWERPC64 34 #include "ffi_common.h" 35 #include "ffi_powerpc.h" 36 37 38 /* About the SYSV ABI. */ 39 #define ASM_NEEDS_REGISTERS 4 40 #define NUM_GPR_ARG_REGISTERS 8 41 #define NUM_FPR_ARG_REGISTERS 8 42 43 44 #if HAVE_LONG_DOUBLE_VARIANT && FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 45 /* Adjust size of ffi_type_longdouble. */ 46 void FFI_HIDDEN 47 ffi_prep_types_sysv (ffi_abi abi) 48 { 49 if ((abi & (FFI_SYSV | FFI_SYSV_LONG_DOUBLE_128)) == FFI_SYSV) 50 { 51 ffi_type_longdouble.size = 8; 52 ffi_type_longdouble.alignment = 8; 53 } 54 else 55 { 56 ffi_type_longdouble.size = 16; 57 ffi_type_longdouble.alignment = 16; 58 } 59 } 60 #endif 61 62 /* Transform long double, double and float to other types as per abi. */ 63 static int 64 translate_float (int abi, int type) 65 { 66 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 67 if (type == FFI_TYPE_LONGDOUBLE 68 && (abi & FFI_SYSV_LONG_DOUBLE_128) == 0) 69 type = FFI_TYPE_DOUBLE; 70 #endif 71 if ((abi & FFI_SYSV_SOFT_FLOAT) != 0) 72 { 73 if (type == FFI_TYPE_FLOAT) 74 type = FFI_TYPE_UINT32; 75 else if (type == FFI_TYPE_DOUBLE) 76 type = FFI_TYPE_UINT64; 77 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 78 else if (type == FFI_TYPE_LONGDOUBLE) 79 type = FFI_TYPE_UINT128; 80 } 81 else if ((abi & FFI_SYSV_IBM_LONG_DOUBLE) == 0) 82 { 83 if (type == FFI_TYPE_LONGDOUBLE) 84 type = FFI_TYPE_STRUCT; 85 #endif 86 } 87 return type; 88 } 89 90 /* Perform machine dependent cif processing */ 91 static ffi_status 92 ffi_prep_cif_sysv_core (ffi_cif *cif) 93 { 94 ffi_type **ptr; 95 unsigned bytes; 96 unsigned i, fparg_count = 0, intarg_count = 0; 97 unsigned flags = cif->flags; 98 unsigned struct_copy_size = 0; 99 unsigned type = cif->rtype->type; 100 unsigned size = cif->rtype->size; 101 102 /* The machine-independent calculation of cif->bytes doesn't work 103 for us. Redo the calculation. */ 104 105 /* Space for the frame pointer, callee's LR, and the asm's temp regs. */ 106 bytes = (2 + ASM_NEEDS_REGISTERS) * sizeof (int); 107 108 /* Space for the GPR registers. */ 109 bytes += NUM_GPR_ARG_REGISTERS * sizeof (int); 110 111 /* Return value handling. The rules for SYSV are as follows: 112 - 32-bit (or less) integer values are returned in gpr3; 113 - Structures of size <= 4 bytes also returned in gpr3; 114 - 64-bit integer values and structures between 5 and 8 bytes are returned 115 in gpr3 and gpr4; 116 - Larger structures are allocated space and a pointer is passed as 117 the first argument. 118 - Single/double FP values are returned in fpr1; 119 - long doubles (if not equivalent to double) are returned in 120 fpr1,fpr2 for Linux and as for large structs for SysV. */ 121 122 type = translate_float (cif->abi, type); 123 124 switch (type) 125 { 126 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 127 case FFI_TYPE_LONGDOUBLE: 128 flags |= FLAG_RETURNS_128BITS; 129 /* Fall through. */ 130 #endif 131 case FFI_TYPE_DOUBLE: 132 flags |= FLAG_RETURNS_64BITS; 133 /* Fall through. */ 134 case FFI_TYPE_FLOAT: 135 flags |= FLAG_RETURNS_FP; 136 #ifdef __NO_FPRS__ 137 return FFI_BAD_ABI; 138 #endif 139 break; 140 141 case FFI_TYPE_UINT128: 142 flags |= FLAG_RETURNS_128BITS; 143 /* Fall through. */ 144 case FFI_TYPE_UINT64: 145 case FFI_TYPE_SINT64: 146 flags |= FLAG_RETURNS_64BITS; 147 break; 148 149 case FFI_TYPE_STRUCT: 150 /* The final SYSV ABI says that structures smaller or equal 8 bytes 151 are returned in r3/r4. A draft ABI used by linux instead 152 returns them in memory. */ 153 if ((cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8) 154 { 155 flags |= FLAG_RETURNS_SMST; 156 break; 157 } 158 intarg_count++; 159 flags |= FLAG_RETVAL_REFERENCE; 160 /* Fall through. */ 161 case FFI_TYPE_VOID: 162 flags |= FLAG_RETURNS_NOTHING; 163 break; 164 165 default: 166 /* Returns 32-bit integer, or similar. Nothing to do here. */ 167 break; 168 } 169 170 /* The first NUM_GPR_ARG_REGISTERS words of integer arguments, and the 171 first NUM_FPR_ARG_REGISTERS fp arguments, go in registers; the rest 172 goes on the stack. Structures and long doubles (if not equivalent 173 to double) are passed as a pointer to a copy of the structure. 174 Stuff on the stack needs to keep proper alignment. */ 175 for (ptr = cif->arg_types, i = cif->nargs; i > 0; i--, ptr++) 176 { 177 unsigned short typenum = (*ptr)->type; 178 179 typenum = translate_float (cif->abi, typenum); 180 181 switch (typenum) 182 { 183 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 184 case FFI_TYPE_LONGDOUBLE: 185 fparg_count++; 186 /* Fall thru */ 187 #endif 188 case FFI_TYPE_DOUBLE: 189 fparg_count++; 190 /* If this FP arg is going on the stack, it must be 191 8-byte-aligned. */ 192 if (fparg_count > NUM_FPR_ARG_REGISTERS 193 && intarg_count >= NUM_GPR_ARG_REGISTERS 194 && intarg_count % 2 != 0) 195 intarg_count++; 196 #ifdef __NO_FPRS__ 197 return FFI_BAD_ABI; 198 #endif 199 break; 200 201 case FFI_TYPE_FLOAT: 202 fparg_count++; 203 #ifdef __NO_FPRS__ 204 return FFI_BAD_ABI; 205 #endif 206 break; 207 208 case FFI_TYPE_UINT128: 209 /* A long double in FFI_LINUX_SOFT_FLOAT can use only a set 210 of four consecutive gprs. If we do not have enough, we 211 have to adjust the intarg_count value. */ 212 if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3 213 && intarg_count < NUM_GPR_ARG_REGISTERS) 214 intarg_count = NUM_GPR_ARG_REGISTERS; 215 intarg_count += 4; 216 break; 217 218 case FFI_TYPE_UINT64: 219 case FFI_TYPE_SINT64: 220 /* 'long long' arguments are passed as two words, but 221 either both words must fit in registers or both go 222 on the stack. If they go on the stack, they must 223 be 8-byte-aligned. 224 225 Also, only certain register pairs can be used for 226 passing long long int -- specifically (r3,r4), (r5,r6), 227 (r7,r8), (r9,r10). */ 228 if (intarg_count == NUM_GPR_ARG_REGISTERS-1 229 || intarg_count % 2 != 0) 230 intarg_count++; 231 intarg_count += 2; 232 break; 233 234 case FFI_TYPE_STRUCT: 235 /* We must allocate space for a copy of these to enforce 236 pass-by-value. Pad the space up to a multiple of 16 237 bytes (the maximum alignment required for anything under 238 the SYSV ABI). */ 239 struct_copy_size += ((*ptr)->size + 15) & ~0xF; 240 /* Fall through (allocate space for the pointer). */ 241 242 case FFI_TYPE_POINTER: 243 case FFI_TYPE_INT: 244 case FFI_TYPE_UINT32: 245 case FFI_TYPE_SINT32: 246 case FFI_TYPE_UINT16: 247 case FFI_TYPE_SINT16: 248 case FFI_TYPE_UINT8: 249 case FFI_TYPE_SINT8: 250 /* Everything else is passed as a 4-byte word in a GPR, either 251 the object itself or a pointer to it. */ 252 intarg_count++; 253 break; 254 255 default: 256 FFI_ASSERT (0); 257 } 258 } 259 260 if (fparg_count != 0) 261 flags |= FLAG_FP_ARGUMENTS; 262 if (intarg_count > 4) 263 flags |= FLAG_4_GPR_ARGUMENTS; 264 if (struct_copy_size != 0) 265 flags |= FLAG_ARG_NEEDS_COPY; 266 267 /* Space for the FPR registers, if needed. */ 268 if (fparg_count != 0) 269 bytes += NUM_FPR_ARG_REGISTERS * sizeof (double); 270 271 /* Stack space. */ 272 if (intarg_count > NUM_GPR_ARG_REGISTERS) 273 bytes += (intarg_count - NUM_GPR_ARG_REGISTERS) * sizeof (int); 274 if (fparg_count > NUM_FPR_ARG_REGISTERS) 275 bytes += (fparg_count - NUM_FPR_ARG_REGISTERS) * sizeof (double); 276 277 /* The stack space allocated needs to be a multiple of 16 bytes. */ 278 bytes = (bytes + 15) & ~0xF; 279 280 /* Add in the space for the copied structures. */ 281 bytes += struct_copy_size; 282 283 cif->flags = flags; 284 cif->bytes = bytes; 285 286 return FFI_OK; 287 } 288 289 ffi_status FFI_HIDDEN 290 ffi_prep_cif_sysv (ffi_cif *cif) 291 { 292 if ((cif->abi & FFI_SYSV) == 0) 293 { 294 /* This call is from old code. Translate to new ABI values. */ 295 cif->flags |= FLAG_COMPAT; 296 switch (cif->abi) 297 { 298 default: 299 return FFI_BAD_ABI; 300 301 case FFI_COMPAT_SYSV: 302 cif->abi = FFI_SYSV | FFI_SYSV_STRUCT_RET | FFI_SYSV_LONG_DOUBLE_128; 303 break; 304 305 case FFI_COMPAT_GCC_SYSV: 306 cif->abi = FFI_SYSV | FFI_SYSV_LONG_DOUBLE_128; 307 break; 308 309 case FFI_COMPAT_LINUX: 310 cif->abi = (FFI_SYSV | FFI_SYSV_IBM_LONG_DOUBLE 311 | FFI_SYSV_LONG_DOUBLE_128); 312 break; 313 314 case FFI_COMPAT_LINUX_SOFT_FLOAT: 315 cif->abi = (FFI_SYSV | FFI_SYSV_SOFT_FLOAT | FFI_SYSV_IBM_LONG_DOUBLE 316 | FFI_SYSV_LONG_DOUBLE_128); 317 break; 318 } 319 } 320 return ffi_prep_cif_sysv_core (cif); 321 } 322 323 /* ffi_prep_args_SYSV is called by the assembly routine once stack space 324 has been allocated for the function's arguments. 325 326 The stack layout we want looks like this: 327 328 | Return address from ffi_call_SYSV 4bytes | higher addresses 329 |--------------------------------------------| 330 | Previous backchain pointer 4 | stack pointer here 331 |--------------------------------------------|<+ <<< on entry to 332 | Saved r28-r31 4*4 | | ffi_call_SYSV 333 |--------------------------------------------| | 334 | GPR registers r3-r10 8*4 | | ffi_call_SYSV 335 |--------------------------------------------| | 336 | FPR registers f1-f8 (optional) 8*8 | | 337 |--------------------------------------------| | stack | 338 | Space for copied structures | | grows | 339 |--------------------------------------------| | down V 340 | Parameters that didn't fit in registers | | 341 |--------------------------------------------| | lower addresses 342 | Space for callee's LR 4 | | 343 |--------------------------------------------| | stack pointer here 344 | Current backchain pointer 4 |-/ during 345 |--------------------------------------------| <<< ffi_call_SYSV 346 347 */ 348 349 void FFI_HIDDEN 350 ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) 351 { 352 const unsigned bytes = ecif->cif->bytes; 353 const unsigned flags = ecif->cif->flags; 354 355 typedef union 356 { 357 char *c; 358 unsigned *u; 359 long long *ll; 360 float *f; 361 double *d; 362 } valp; 363 364 /* 'stacktop' points at the previous backchain pointer. */ 365 valp stacktop; 366 367 /* 'gpr_base' points at the space for gpr3, and grows upwards as 368 we use GPR registers. */ 369 valp gpr_base; 370 int intarg_count; 371 372 #ifndef __NO_FPRS__ 373 /* 'fpr_base' points at the space for fpr1, and grows upwards as 374 we use FPR registers. */ 375 valp fpr_base; 376 int fparg_count; 377 #endif 378 379 /* 'copy_space' grows down as we put structures in it. It should 380 stay 16-byte aligned. */ 381 valp copy_space; 382 383 /* 'next_arg' grows up as we put parameters in it. */ 384 valp next_arg; 385 386 int i; 387 ffi_type **ptr; 388 #ifndef __NO_FPRS__ 389 double double_tmp; 390 #endif 391 union 392 { 393 void **v; 394 char **c; 395 signed char **sc; 396 unsigned char **uc; 397 signed short **ss; 398 unsigned short **us; 399 unsigned int **ui; 400 long long **ll; 401 float **f; 402 double **d; 403 } p_argv; 404 size_t struct_copy_size; 405 unsigned gprvalue; 406 407 stacktop.c = (char *) stack + bytes; 408 gpr_base.u = stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS; 409 intarg_count = 0; 410 #ifndef __NO_FPRS__ 411 fpr_base.d = gpr_base.d - NUM_FPR_ARG_REGISTERS; 412 fparg_count = 0; 413 copy_space.c = ((flags & FLAG_FP_ARGUMENTS) ? fpr_base.c : gpr_base.c); 414 #else 415 copy_space.c = gpr_base.c; 416 #endif 417 next_arg.u = stack + 2; 418 419 /* Check that everything starts aligned properly. */ 420 FFI_ASSERT (((unsigned long) (char *) stack & 0xF) == 0); 421 FFI_ASSERT (((unsigned long) copy_space.c & 0xF) == 0); 422 FFI_ASSERT (((unsigned long) stacktop.c & 0xF) == 0); 423 FFI_ASSERT ((bytes & 0xF) == 0); 424 FFI_ASSERT (copy_space.c >= next_arg.c); 425 426 /* Deal with return values that are actually pass-by-reference. */ 427 if (flags & FLAG_RETVAL_REFERENCE) 428 { 429 *gpr_base.u++ = (unsigned long) (char *) ecif->rvalue; 430 intarg_count++; 431 } 432 433 /* Now for the arguments. */ 434 p_argv.v = ecif->avalue; 435 for (ptr = ecif->cif->arg_types, i = ecif->cif->nargs; 436 i > 0; 437 i--, ptr++, p_argv.v++) 438 { 439 unsigned int typenum = (*ptr)->type; 440 441 typenum = translate_float (ecif->cif->abi, typenum); 442 443 /* Now test the translated value */ 444 switch (typenum) 445 { 446 #ifndef __NO_FPRS__ 447 # if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 448 case FFI_TYPE_LONGDOUBLE: 449 double_tmp = (*p_argv.d)[0]; 450 451 if (fparg_count >= NUM_FPR_ARG_REGISTERS - 1) 452 { 453 if (intarg_count >= NUM_GPR_ARG_REGISTERS 454 && intarg_count % 2 != 0) 455 { 456 intarg_count++; 457 next_arg.u++; 458 } 459 *next_arg.d = double_tmp; 460 next_arg.u += 2; 461 double_tmp = (*p_argv.d)[1]; 462 *next_arg.d = double_tmp; 463 next_arg.u += 2; 464 } 465 else 466 { 467 *fpr_base.d++ = double_tmp; 468 double_tmp = (*p_argv.d)[1]; 469 *fpr_base.d++ = double_tmp; 470 } 471 472 fparg_count += 2; 473 FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 474 break; 475 # endif 476 case FFI_TYPE_DOUBLE: 477 double_tmp = **p_argv.d; 478 479 if (fparg_count >= NUM_FPR_ARG_REGISTERS) 480 { 481 if (intarg_count >= NUM_GPR_ARG_REGISTERS 482 && intarg_count % 2 != 0) 483 { 484 intarg_count++; 485 next_arg.u++; 486 } 487 *next_arg.d = double_tmp; 488 next_arg.u += 2; 489 } 490 else 491 *fpr_base.d++ = double_tmp; 492 fparg_count++; 493 FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 494 break; 495 496 case FFI_TYPE_FLOAT: 497 double_tmp = **p_argv.f; 498 if (fparg_count >= NUM_FPR_ARG_REGISTERS) 499 { 500 *next_arg.f = (float) double_tmp; 501 next_arg.u += 1; 502 intarg_count++; 503 } 504 else 505 *fpr_base.d++ = double_tmp; 506 fparg_count++; 507 FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); 508 break; 509 #endif /* have FPRs */ 510 511 case FFI_TYPE_UINT128: 512 /* The soft float ABI for long doubles works like this, a long double 513 is passed in four consecutive GPRs if available. A maximum of 2 514 long doubles can be passed in gprs. If we do not have 4 GPRs 515 left, the long double is passed on the stack, 4-byte aligned. */ 516 { 517 unsigned int int_tmp; 518 unsigned int ii; 519 if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3) 520 { 521 if (intarg_count < NUM_GPR_ARG_REGISTERS) 522 intarg_count = NUM_GPR_ARG_REGISTERS; 523 for (ii = 0; ii < 4; ii++) 524 { 525 int_tmp = (*p_argv.ui)[ii]; 526 *next_arg.u++ = int_tmp; 527 } 528 } 529 else 530 { 531 for (ii = 0; ii < 4; ii++) 532 { 533 int_tmp = (*p_argv.ui)[ii]; 534 *gpr_base.u++ = int_tmp; 535 } 536 } 537 intarg_count += 4; 538 break; 539 } 540 541 case FFI_TYPE_UINT64: 542 case FFI_TYPE_SINT64: 543 if (intarg_count == NUM_GPR_ARG_REGISTERS-1) 544 intarg_count++; 545 if (intarg_count >= NUM_GPR_ARG_REGISTERS) 546 { 547 if (intarg_count % 2 != 0) 548 { 549 intarg_count++; 550 next_arg.u++; 551 } 552 *next_arg.ll = **p_argv.ll; 553 next_arg.u += 2; 554 } 555 else 556 { 557 /* The abi states only certain register pairs can be 558 used for passing long long int specifically (r3,r4), 559 (r5,r6), (r7,r8), (r9,r10). If next arg is long long 560 but not correct starting register of pair then skip 561 until the proper starting register. */ 562 if (intarg_count % 2 != 0) 563 { 564 intarg_count ++; 565 gpr_base.u++; 566 } 567 *gpr_base.ll++ = **p_argv.ll; 568 } 569 intarg_count += 2; 570 break; 571 572 case FFI_TYPE_STRUCT: 573 struct_copy_size = ((*ptr)->size + 15) & ~0xF; 574 copy_space.c -= struct_copy_size; 575 memcpy (copy_space.c, *p_argv.c, (*ptr)->size); 576 577 gprvalue = (unsigned long) copy_space.c; 578 579 FFI_ASSERT (copy_space.c > next_arg.c); 580 FFI_ASSERT (flags & FLAG_ARG_NEEDS_COPY); 581 goto putgpr; 582 583 case FFI_TYPE_UINT8: 584 gprvalue = **p_argv.uc; 585 goto putgpr; 586 case FFI_TYPE_SINT8: 587 gprvalue = **p_argv.sc; 588 goto putgpr; 589 case FFI_TYPE_UINT16: 590 gprvalue = **p_argv.us; 591 goto putgpr; 592 case FFI_TYPE_SINT16: 593 gprvalue = **p_argv.ss; 594 goto putgpr; 595 596 case FFI_TYPE_INT: 597 case FFI_TYPE_UINT32: 598 case FFI_TYPE_SINT32: 599 case FFI_TYPE_POINTER: 600 601 gprvalue = **p_argv.ui; 602 603 putgpr: 604 if (intarg_count >= NUM_GPR_ARG_REGISTERS) 605 *next_arg.u++ = gprvalue; 606 else 607 *gpr_base.u++ = gprvalue; 608 intarg_count++; 609 break; 610 } 611 } 612 613 /* Check that we didn't overrun the stack... */ 614 FFI_ASSERT (copy_space.c >= next_arg.c); 615 FFI_ASSERT (gpr_base.u <= stacktop.u - ASM_NEEDS_REGISTERS); 616 /* The assert below is testing that the number of integer arguments agrees 617 with the number found in ffi_prep_cif_machdep(). However, intarg_count 618 is incremented whenever we place an FP arg on the stack, so account for 619 that before our assert test. */ 620 #ifndef __NO_FPRS__ 621 if (fparg_count > NUM_FPR_ARG_REGISTERS) 622 intarg_count -= fparg_count - NUM_FPR_ARG_REGISTERS; 623 FFI_ASSERT (fpr_base.u 624 <= stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS); 625 #endif 626 FFI_ASSERT (flags & FLAG_4_GPR_ARGUMENTS || intarg_count <= 4); 627 } 628 629 #define MIN_CACHE_LINE_SIZE 8 630 631 static void 632 flush_icache (char *wraddr, char *xaddr, int size) 633 { 634 int i; 635 for (i = 0; i < size; i += MIN_CACHE_LINE_SIZE) 636 __asm__ volatile ("icbi 0,%0;" "dcbf 0,%1;" 637 : : "r" (xaddr + i), "r" (wraddr + i) : "memory"); 638 __asm__ volatile ("icbi 0,%0;" "dcbf 0,%1;" "sync;" "isync;" 639 : : "r"(xaddr + size - 1), "r"(wraddr + size - 1) 640 : "memory"); 641 } 642 643 ffi_status FFI_HIDDEN 644 ffi_prep_closure_loc_sysv (ffi_closure *closure, 645 ffi_cif *cif, 646 void (*fun) (ffi_cif *, void *, void **, void *), 647 void *user_data, 648 void *codeloc) 649 { 650 unsigned int *tramp; 651 652 if (cif->abi < FFI_SYSV || cif->abi >= FFI_LAST_ABI) 653 return FFI_BAD_ABI; 654 655 tramp = (unsigned int *) &closure->tramp[0]; 656 tramp[0] = 0x7c0802a6; /* mflr r0 */ 657 tramp[1] = 0x4800000d; /* bl 10 <trampoline_initial+0x10> */ 658 tramp[4] = 0x7d6802a6; /* mflr r11 */ 659 tramp[5] = 0x7c0803a6; /* mtlr r0 */ 660 tramp[6] = 0x800b0000; /* lwz r0,0(r11) */ 661 tramp[7] = 0x816b0004; /* lwz r11,4(r11) */ 662 tramp[8] = 0x7c0903a6; /* mtctr r0 */ 663 tramp[9] = 0x4e800420; /* bctr */ 664 *(void **) &tramp[2] = (void *) ffi_closure_SYSV; /* function */ 665 *(void **) &tramp[3] = codeloc; /* context */ 666 667 /* Flush the icache. */ 668 flush_icache ((char *)tramp, (char *)codeloc, FFI_TRAMPOLINE_SIZE); 669 670 closure->cif = cif; 671 closure->fun = fun; 672 closure->user_data = user_data; 673 674 return FFI_OK; 675 } 676 677 /* Basically the trampoline invokes ffi_closure_SYSV, and on 678 entry, r11 holds the address of the closure. 679 After storing the registers that could possibly contain 680 parameters to be passed into the stack frame and setting 681 up space for a return value, ffi_closure_SYSV invokes the 682 following helper function to do most of the work. */ 683 684 int 685 ffi_closure_helper_SYSV (ffi_closure *closure, void *rvalue, 686 unsigned long *pgr, ffi_dblfl *pfr, 687 unsigned long *pst) 688 { 689 /* rvalue is the pointer to space for return value in closure assembly */ 690 /* pgr is the pointer to where r3-r10 are stored in ffi_closure_SYSV */ 691 /* pfr is the pointer to where f1-f8 are stored in ffi_closure_SYSV */ 692 /* pst is the pointer to outgoing parameter stack in original caller */ 693 694 void ** avalue; 695 ffi_type ** arg_types; 696 long i, avn; 697 #ifndef __NO_FPRS__ 698 long nf = 0; /* number of floating registers already used */ 699 #endif 700 long ng = 0; /* number of general registers already used */ 701 702 ffi_cif *cif = closure->cif; 703 unsigned size = cif->rtype->size; 704 unsigned short rtypenum = cif->rtype->type; 705 706 avalue = alloca (cif->nargs * sizeof (void *)); 707 708 /* First translate for softfloat/nonlinux */ 709 rtypenum = translate_float (cif->abi, rtypenum); 710 711 /* Copy the caller's structure return value address so that the closure 712 returns the data directly to the caller. 713 For FFI_SYSV the result is passed in r3/r4 if the struct size is less 714 or equal 8 bytes. */ 715 if (rtypenum == FFI_TYPE_STRUCT 716 && !((cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8)) 717 { 718 rvalue = (void *) *pgr; 719 ng++; 720 pgr++; 721 } 722 723 i = 0; 724 avn = cif->nargs; 725 arg_types = cif->arg_types; 726 727 /* Grab the addresses of the arguments from the stack frame. */ 728 while (i < avn) { 729 unsigned short typenum = arg_types[i]->type; 730 731 /* We may need to handle some values depending on ABI. */ 732 typenum = translate_float (cif->abi, typenum); 733 734 switch (typenum) 735 { 736 #ifndef __NO_FPRS__ 737 case FFI_TYPE_FLOAT: 738 /* Unfortunately float values are stored as doubles 739 in the ffi_closure_SYSV code (since we don't check 740 the type in that routine). */ 741 if (nf < NUM_FPR_ARG_REGISTERS) 742 { 743 /* FIXME? here we are really changing the values 744 stored in the original calling routines outgoing 745 parameter stack. This is probably a really 746 naughty thing to do but... */ 747 double temp = pfr->d; 748 pfr->f = (float) temp; 749 avalue[i] = pfr; 750 nf++; 751 pfr++; 752 } 753 else 754 { 755 avalue[i] = pst; 756 pst += 1; 757 } 758 break; 759 760 case FFI_TYPE_DOUBLE: 761 if (nf < NUM_FPR_ARG_REGISTERS) 762 { 763 avalue[i] = pfr; 764 nf++; 765 pfr++; 766 } 767 else 768 { 769 if (((long) pst) & 4) 770 pst++; 771 avalue[i] = pst; 772 pst += 2; 773 } 774 break; 775 776 # if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE 777 case FFI_TYPE_LONGDOUBLE: 778 if (nf < NUM_FPR_ARG_REGISTERS - 1) 779 { 780 avalue[i] = pfr; 781 pfr += 2; 782 nf += 2; 783 } 784 else 785 { 786 if (((long) pst) & 4) 787 pst++; 788 avalue[i] = pst; 789 pst += 4; 790 nf = 8; 791 } 792 break; 793 # endif 794 #endif 795 796 case FFI_TYPE_UINT128: 797 /* Test if for the whole long double, 4 gprs are available. 798 otherwise the stuff ends up on the stack. */ 799 if (ng < NUM_GPR_ARG_REGISTERS - 3) 800 { 801 avalue[i] = pgr; 802 pgr += 4; 803 ng += 4; 804 } 805 else 806 { 807 avalue[i] = pst; 808 pst += 4; 809 ng = 8+4; 810 } 811 break; 812 813 case FFI_TYPE_SINT8: 814 case FFI_TYPE_UINT8: 815 #ifndef __LITTLE_ENDIAN__ 816 if (ng < NUM_GPR_ARG_REGISTERS) 817 { 818 avalue[i] = (char *) pgr + 3; 819 ng++; 820 pgr++; 821 } 822 else 823 { 824 avalue[i] = (char *) pst + 3; 825 pst++; 826 } 827 break; 828 #endif 829 830 case FFI_TYPE_SINT16: 831 case FFI_TYPE_UINT16: 832 #ifndef __LITTLE_ENDIAN__ 833 if (ng < NUM_GPR_ARG_REGISTERS) 834 { 835 avalue[i] = (char *) pgr + 2; 836 ng++; 837 pgr++; 838 } 839 else 840 { 841 avalue[i] = (char *) pst + 2; 842 pst++; 843 } 844 break; 845 #endif 846 847 case FFI_TYPE_SINT32: 848 case FFI_TYPE_UINT32: 849 case FFI_TYPE_POINTER: 850 if (ng < NUM_GPR_ARG_REGISTERS) 851 { 852 avalue[i] = pgr; 853 ng++; 854 pgr++; 855 } 856 else 857 { 858 avalue[i] = pst; 859 pst++; 860 } 861 break; 862 863 case FFI_TYPE_STRUCT: 864 /* Structs are passed by reference. The address will appear in a 865 gpr if it is one of the first 8 arguments. */ 866 if (ng < NUM_GPR_ARG_REGISTERS) 867 { 868 avalue[i] = (void *) *pgr; 869 ng++; 870 pgr++; 871 } 872 else 873 { 874 avalue[i] = (void *) *pst; 875 pst++; 876 } 877 break; 878 879 case FFI_TYPE_SINT64: 880 case FFI_TYPE_UINT64: 881 /* Passing long long ints are complex, they must 882 be passed in suitable register pairs such as 883 (r3,r4) or (r5,r6) or (r6,r7), or (r7,r8) or (r9,r10) 884 and if the entire pair aren't available then the outgoing 885 parameter stack is used for both but an alignment of 8 886 must will be kept. So we must either look in pgr 887 or pst to find the correct address for this type 888 of parameter. */ 889 if (ng < NUM_GPR_ARG_REGISTERS - 1) 890 { 891 if (ng & 1) 892 { 893 /* skip r4, r6, r8 as starting points */ 894 ng++; 895 pgr++; 896 } 897 avalue[i] = pgr; 898 ng += 2; 899 pgr += 2; 900 } 901 else 902 { 903 if (((long) pst) & 4) 904 pst++; 905 avalue[i] = pst; 906 pst += 2; 907 ng = NUM_GPR_ARG_REGISTERS; 908 } 909 break; 910 911 default: 912 FFI_ASSERT (0); 913 } 914 915 i++; 916 } 917 918 (closure->fun) (cif, rvalue, avalue, closure->user_data); 919 920 /* Tell ffi_closure_SYSV how to perform return type promotions. 921 Because the FFI_SYSV ABI returns the structures <= 8 bytes in 922 r3/r4 we have to tell ffi_closure_SYSV how to treat them. We 923 combine the base type FFI_SYSV_TYPE_SMALL_STRUCT with the size of 924 the struct less one. We never have a struct with size zero. 925 See the comment in ffitarget.h about ordering. */ 926 if (rtypenum == FFI_TYPE_STRUCT 927 && (cif->abi & FFI_SYSV_STRUCT_RET) != 0 && size <= 8) 928 return FFI_SYSV_TYPE_SMALL_STRUCT - 1 + size; 929 return rtypenum; 930 } 931 #endif 932
