1 /* $NetBSD: Locore.c,v 1.7 2000/08/20 07:04:59 tsubai Exp $ */ 2 3 /*- 4 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 5 * Copyright (C) 1995, 1996 TooLs GmbH. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by TooLs GmbH. 19 * 4. The name of TooLs GmbH may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 /*- 34 * Copyright (C) 2000 Benno Rice. 35 * All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 46 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR 47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 49 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 50 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 52 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 53 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 54 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 55 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 56 */ 57 58 #include <sys/cdefs.h> 59 __FBSDID("$FreeBSD$"); 60 61 #include "opt_platform.h" 62 63 #include <sys/param.h> 64 #include <sys/kernel.h> 65 #include <sys/lock.h> 66 #include <sys/malloc.h> 67 #include <sys/mutex.h> 68 #include <sys/queue.h> 69 #include <sys/systm.h> 70 #include <sys/endian.h> 71 72 #include <machine/stdarg.h> 73 74 #include <dev/ofw/ofwvar.h> 75 #include <dev/ofw/openfirm.h> 76 77 #include "ofw_if.h" 78 79 static void OF_putchar(int c, void *arg); 80 81 MALLOC_DEFINE(M_OFWPROP, "openfirm", "Open Firmware properties"); 82 83 static ihandle_t stdout; 84 85 static ofw_def_t *ofw_def_impl = NULL; 86 static ofw_t ofw_obj; 87 static struct ofw_kobj ofw_kernel_obj; 88 static struct kobj_ops ofw_kernel_kops; 89 90 struct xrefinfo { 91 phandle_t xref; 92 phandle_t node; 93 device_t dev; 94 SLIST_ENTRY(xrefinfo) next_entry; 95 }; 96 97 static SLIST_HEAD(, xrefinfo) xreflist = SLIST_HEAD_INITIALIZER(xreflist); 98 static struct mtx xreflist_lock; 99 static boolean_t xref_init_done; 100 101 #define FIND_BY_XREF 0 102 #define FIND_BY_NODE 1 103 #define FIND_BY_DEV 2 104 105 /* 106 * xref-phandle-device lookup helper routines. 107 * 108 * As soon as we are able to use malloc(), walk the node tree and build a list 109 * of info that cross-references node handles, xref handles, and device_t 110 * instances. This list exists primarily to allow association of a device_t 111 * with an xref handle, but it is also used to speed up translation between xref 112 * and node handles. Before malloc() is available we have to recursively search 113 * the node tree each time we want to translate between a node and xref handle. 114 * Afterwards we can do the translations by searching this much shorter list. 115 */ 116 static void 117 xrefinfo_create(phandle_t node) 118 { 119 struct xrefinfo * xi; 120 phandle_t child, xref; 121 122 /* 123 * Recursively descend from parent, looking for nodes with a property 124 * named either "phandle", "ibm,phandle", or "linux,phandle". For each 125 * such node found create an entry in the xreflist. 126 */ 127 for (child = OF_child(node); child != 0; child = OF_peer(child)) { 128 xrefinfo_create(child); 129 if (OF_getencprop(child, "phandle", &xref, sizeof(xref)) == 130 -1 && OF_getencprop(child, "ibm,phandle", &xref, 131 sizeof(xref)) == -1 && OF_getencprop(child, 132 "linux,phandle", &xref, sizeof(xref)) == -1) 133 continue; 134 xi = malloc(sizeof(*xi), M_OFWPROP, M_WAITOK | M_ZERO); 135 xi->node = child; 136 xi->xref = xref; 137 SLIST_INSERT_HEAD(&xreflist, xi, next_entry); 138 } 139 } 140 141 static void 142 xrefinfo_init(void *unsed) 143 { 144 145 /* 146 * There is no locking during this init because it runs much earlier 147 * than any of the clients/consumers of the xref list data, but we do 148 * initialize the mutex that will be used for access later. 149 */ 150 mtx_init(&xreflist_lock, "OF xreflist lock", NULL, MTX_DEF); 151 xrefinfo_create(OF_peer(0)); 152 xref_init_done = true; 153 } 154 SYSINIT(xrefinfo, SI_SUB_KMEM, SI_ORDER_ANY, xrefinfo_init, NULL); 155 156 static struct xrefinfo * 157 xrefinfo_find(uintptr_t key, int find_by) 158 { 159 struct xrefinfo *rv, *xi; 160 161 rv = NULL; 162 mtx_lock(&xreflist_lock); 163 SLIST_FOREACH(xi, &xreflist, next_entry) { 164 if ((find_by == FIND_BY_XREF && (phandle_t)key == xi->xref) || 165 (find_by == FIND_BY_NODE && (phandle_t)key == xi->node) || 166 (find_by == FIND_BY_DEV && key == (uintptr_t)xi->dev)) { 167 rv = xi; 168 break; 169 } 170 } 171 mtx_unlock(&xreflist_lock); 172 return (rv); 173 } 174 175 static struct xrefinfo * 176 xrefinfo_add(phandle_t node, phandle_t xref, device_t dev) 177 { 178 struct xrefinfo *xi; 179 180 xi = malloc(sizeof(*xi), M_OFWPROP, M_WAITOK); 181 xi->node = node; 182 xi->xref = xref; 183 xi->dev = dev; 184 mtx_lock(&xreflist_lock); 185 SLIST_INSERT_HEAD(&xreflist, xi, next_entry); 186 mtx_unlock(&xreflist_lock); 187 return (xi); 188 } 189 190 /* 191 * OFW install routines. Highest priority wins, equal priority also 192 * overrides allowing last-set to win. 193 */ 194 SET_DECLARE(ofw_set, ofw_def_t); 195 196 boolean_t 197 OF_install(char *name, int prio) 198 { 199 ofw_def_t *ofwp, **ofwpp; 200 static int curr_prio = 0; 201 202 /* 203 * Try and locate the OFW kobj corresponding to the name. 204 */ 205 SET_FOREACH(ofwpp, ofw_set) { 206 ofwp = *ofwpp; 207 208 if (ofwp->name && 209 !strcmp(ofwp->name, name) && 210 prio >= curr_prio) { 211 curr_prio = prio; 212 ofw_def_impl = ofwp; 213 return (TRUE); 214 } 215 } 216 217 return (FALSE); 218 } 219 220 /* Initializer */ 221 int 222 OF_init(void *cookie) 223 { 224 phandle_t chosen; 225 int rv; 226 227 if (ofw_def_impl == NULL) 228 return (-1); 229 230 ofw_obj = &ofw_kernel_obj; 231 /* 232 * Take care of compiling the selected class, and 233 * then statically initialize the OFW object. 234 */ 235 kobj_class_compile_static(ofw_def_impl, &ofw_kernel_kops); 236 kobj_init_static((kobj_t)ofw_obj, ofw_def_impl); 237 238 rv = OFW_INIT(ofw_obj, cookie); 239 240 if ((chosen = OF_finddevice("/chosen")) != -1) 241 if (OF_getencprop(chosen, "stdout", &stdout, 242 sizeof(stdout)) == -1) 243 stdout = -1; 244 245 return (rv); 246 } 247 248 static void 249 OF_putchar(int c, void *arg __unused) 250 { 251 char cbuf; 252 253 if (c == '\n') { 254 cbuf = '\r'; 255 OF_write(stdout, &cbuf, 1); 256 } 257 258 cbuf = c; 259 OF_write(stdout, &cbuf, 1); 260 } 261 262 void 263 OF_printf(const char *fmt, ...) 264 { 265 va_list va; 266 267 va_start(va, fmt); 268 (void)kvprintf(fmt, OF_putchar, NULL, 10, va); 269 va_end(va); 270 } 271 272 /* 273 * Generic functions 274 */ 275 276 /* Test to see if a service exists. */ 277 int 278 OF_test(const char *name) 279 { 280 281 if (ofw_def_impl == NULL) 282 return (-1); 283 284 return (OFW_TEST(ofw_obj, name)); 285 } 286 287 int 288 OF_interpret(const char *cmd, int nreturns, ...) 289 { 290 va_list ap; 291 cell_t slots[16]; 292 int i = 0; 293 int status; 294 295 if (ofw_def_impl == NULL) 296 return (-1); 297 298 status = OFW_INTERPRET(ofw_obj, cmd, nreturns, slots); 299 if (status == -1) 300 return (status); 301 302 va_start(ap, nreturns); 303 while (i < nreturns) 304 *va_arg(ap, cell_t *) = slots[i++]; 305 va_end(ap); 306 307 return (status); 308 } 309 310 /* 311 * Device tree functions 312 */ 313 314 /* Return the next sibling of this node or 0. */ 315 phandle_t 316 OF_peer(phandle_t node) 317 { 318 319 if (ofw_def_impl == NULL) 320 return (0); 321 322 return (OFW_PEER(ofw_obj, node)); 323 } 324 325 /* Return the first child of this node or 0. */ 326 phandle_t 327 OF_child(phandle_t node) 328 { 329 330 if (ofw_def_impl == NULL) 331 return (0); 332 333 return (OFW_CHILD(ofw_obj, node)); 334 } 335 336 /* Return the parent of this node or 0. */ 337 phandle_t 338 OF_parent(phandle_t node) 339 { 340 341 if (ofw_def_impl == NULL) 342 return (0); 343 344 return (OFW_PARENT(ofw_obj, node)); 345 } 346 347 /* Return the package handle that corresponds to an instance handle. */ 348 phandle_t 349 OF_instance_to_package(ihandle_t instance) 350 { 351 352 if (ofw_def_impl == NULL) 353 return (-1); 354 355 return (OFW_INSTANCE_TO_PACKAGE(ofw_obj, instance)); 356 } 357 358 /* Get the length of a property of a package. */ 359 ssize_t 360 OF_getproplen(phandle_t package, const char *propname) 361 { 362 363 if (ofw_def_impl == NULL) 364 return (-1); 365 366 return (OFW_GETPROPLEN(ofw_obj, package, propname)); 367 } 368 369 /* Check existence of a property of a package. */ 370 int 371 OF_hasprop(phandle_t package, const char *propname) 372 { 373 374 return (OF_getproplen(package, propname) >= 0 ? 1 : 0); 375 } 376 377 /* Get the value of a property of a package. */ 378 ssize_t 379 OF_getprop(phandle_t package, const char *propname, void *buf, size_t buflen) 380 { 381 382 if (ofw_def_impl == NULL) 383 return (-1); 384 385 return (OFW_GETPROP(ofw_obj, package, propname, buf, buflen)); 386 } 387 388 ssize_t 389 OF_getencprop(phandle_t node, const char *propname, pcell_t *buf, size_t len) 390 { 391 ssize_t retval; 392 int i; 393 394 KASSERT(len % 4 == 0, ("Need a multiple of 4 bytes")); 395 396 retval = OF_getprop(node, propname, buf, len); 397 for (i = 0; i < len/4; i++) 398 buf[i] = be32toh(buf[i]); 399 400 return (retval); 401 } 402 403 /* 404 * Recursively search the node and its parent for the given property, working 405 * downward from the node to the device tree root. Returns the value of the 406 * first match. 407 */ 408 ssize_t 409 OF_searchprop(phandle_t node, const char *propname, void *buf, size_t len) 410 { 411 ssize_t rv; 412 413 for (; node != 0; node = OF_parent(node)) 414 if ((rv = OF_getprop(node, propname, buf, len)) != -1) 415 return (rv); 416 return (-1); 417 } 418 419 ssize_t 420 OF_searchencprop(phandle_t node, const char *propname, void *buf, size_t len) 421 { 422 ssize_t rv; 423 424 for (; node != 0; node = OF_parent(node)) 425 if ((rv = OF_getencprop(node, propname, buf, len)) != -1) 426 return (rv); 427 return (-1); 428 } 429 430 /* 431 * Store the value of a property of a package into newly allocated memory 432 * (using the M_OFWPROP malloc pool and M_WAITOK). elsz is the size of a 433 * single element, the number of elements is return in number. 434 */ 435 ssize_t 436 OF_getprop_alloc(phandle_t package, const char *propname, int elsz, void **buf) 437 { 438 int len; 439 440 *buf = NULL; 441 if ((len = OF_getproplen(package, propname)) == -1 || 442 len % elsz != 0) 443 return (-1); 444 445 *buf = malloc(len, M_OFWPROP, M_WAITOK); 446 if (OF_getprop(package, propname, *buf, len) == -1) { 447 free(*buf, M_OFWPROP); 448 *buf = NULL; 449 return (-1); 450 } 451 return (len / elsz); 452 } 453 454 ssize_t 455 OF_getencprop_alloc(phandle_t package, const char *name, int elsz, void **buf) 456 { 457 ssize_t retval; 458 pcell_t *cell; 459 int i; 460 461 retval = OF_getprop_alloc(package, name, elsz, buf); 462 if (retval == -1) 463 return (-1); 464 if (retval * elsz % 4 != 0) { 465 free(*buf, M_OFWPROP); 466 *buf = NULL; 467 return (-1); 468 } 469 470 cell = *buf; 471 for (i = 0; i < retval * elsz / 4; i++) 472 cell[i] = be32toh(cell[i]); 473 474 return (retval); 475 } 476 477 /* Get the next property of a package. */ 478 int 479 OF_nextprop(phandle_t package, const char *previous, char *buf, size_t size) 480 { 481 482 if (ofw_def_impl == NULL) 483 return (-1); 484 485 return (OFW_NEXTPROP(ofw_obj, package, previous, buf, size)); 486 } 487 488 /* Set the value of a property of a package. */ 489 int 490 OF_setprop(phandle_t package, const char *propname, const void *buf, size_t len) 491 { 492 493 if (ofw_def_impl == NULL) 494 return (-1); 495 496 return (OFW_SETPROP(ofw_obj, package, propname, buf,len)); 497 } 498 499 /* Convert a device specifier to a fully qualified pathname. */ 500 ssize_t 501 OF_canon(const char *device, char *buf, size_t len) 502 { 503 504 if (ofw_def_impl == NULL) 505 return (-1); 506 507 return (OFW_CANON(ofw_obj, device, buf, len)); 508 } 509 510 /* Return a package handle for the specified device. */ 511 phandle_t 512 OF_finddevice(const char *device) 513 { 514 515 if (ofw_def_impl == NULL) 516 return (-1); 517 518 return (OFW_FINDDEVICE(ofw_obj, device)); 519 } 520 521 /* Return the fully qualified pathname corresponding to an instance. */ 522 ssize_t 523 OF_instance_to_path(ihandle_t instance, char *buf, size_t len) 524 { 525 526 if (ofw_def_impl == NULL) 527 return (-1); 528 529 return (OFW_INSTANCE_TO_PATH(ofw_obj, instance, buf, len)); 530 } 531 532 /* Return the fully qualified pathname corresponding to a package. */ 533 ssize_t 534 OF_package_to_path(phandle_t package, char *buf, size_t len) 535 { 536 537 if (ofw_def_impl == NULL) 538 return (-1); 539 540 return (OFW_PACKAGE_TO_PATH(ofw_obj, package, buf, len)); 541 } 542 543 /* Look up effective phandle (see FDT/PAPR spec) */ 544 static phandle_t 545 OF_child_xref_phandle(phandle_t parent, phandle_t xref) 546 { 547 phandle_t child, rxref; 548 549 /* 550 * Recursively descend from parent, looking for a node with a property 551 * named either "phandle", "ibm,phandle", or "linux,phandle" that 552 * matches the xref we are looking for. 553 */ 554 555 for (child = OF_child(parent); child != 0; child = OF_peer(child)) { 556 rxref = OF_child_xref_phandle(child, xref); 557 if (rxref != -1) 558 return (rxref); 559 560 if (OF_getencprop(child, "phandle", &rxref, sizeof(rxref)) == 561 -1 && OF_getencprop(child, "ibm,phandle", &rxref, 562 sizeof(rxref)) == -1 && OF_getencprop(child, 563 "linux,phandle", &rxref, sizeof(rxref)) == -1) 564 continue; 565 566 if (rxref == xref) 567 return (child); 568 } 569 570 return (-1); 571 } 572 573 phandle_t 574 OF_node_from_xref(phandle_t xref) 575 { 576 struct xrefinfo *xi; 577 phandle_t node; 578 579 if (xref_init_done) { 580 if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL) 581 return (xref); 582 return (xi->node); 583 } 584 585 if ((node = OF_child_xref_phandle(OF_peer(0), xref)) == -1) 586 return (xref); 587 return (node); 588 } 589 590 phandle_t 591 OF_xref_from_node(phandle_t node) 592 { 593 struct xrefinfo *xi; 594 phandle_t xref; 595 596 if (xref_init_done) { 597 if ((xi = xrefinfo_find(node, FIND_BY_NODE)) == NULL) 598 return (node); 599 return (xi->xref); 600 } 601 602 if (OF_getencprop(node, "phandle", &xref, sizeof(xref)) == 603 -1 && OF_getencprop(node, "ibm,phandle", &xref, 604 sizeof(xref)) == -1 && OF_getencprop(node, 605 "linux,phandle", &xref, sizeof(xref)) == -1) 606 return (node); 607 return (xref); 608 } 609 610 device_t 611 OF_device_from_xref(phandle_t xref) 612 { 613 struct xrefinfo *xi; 614 615 if (xref_init_done) { 616 if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL) 617 return (NULL); 618 return (xi->dev); 619 } 620 panic("Attempt to find device before xreflist_init"); 621 } 622 623 phandle_t 624 OF_xref_from_device(device_t dev) 625 { 626 struct xrefinfo *xi; 627 628 if (xref_init_done) { 629 if ((xi = xrefinfo_find((uintptr_t)dev, FIND_BY_DEV)) == NULL) 630 return (0); 631 return (xi->xref); 632 } 633 panic("Attempt to find xref before xreflist_init"); 634 } 635 636 int 637 OF_device_register_xref(phandle_t xref, device_t dev) 638 { 639 struct xrefinfo *xi; 640 641 /* 642 * If the given xref handle doesn't already exist in the list then we 643 * add a list entry. In theory this can only happen on a system where 644 * nodes don't contain phandle properties and xref and node handles are 645 * synonymous, so the xref handle is added as the node handle as well. 646 */ 647 if (xref_init_done) { 648 if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL) 649 xrefinfo_add(xref, xref, dev); 650 else 651 xi->dev = dev; 652 return (0); 653 } 654 panic("Attempt to register device before xreflist_init"); 655 } 656 657 /* Call the method in the scope of a given instance. */ 658 int 659 OF_call_method(const char *method, ihandle_t instance, int nargs, int nreturns, 660 ...) 661 { 662 va_list ap; 663 cell_t args_n_results[12]; 664 int n, status; 665 666 if (nargs > 6 || ofw_def_impl == NULL) 667 return (-1); 668 va_start(ap, nreturns); 669 for (n = 0; n < nargs; n++) 670 args_n_results[n] = va_arg(ap, cell_t); 671 672 status = OFW_CALL_METHOD(ofw_obj, instance, method, nargs, nreturns, 673 args_n_results); 674 if (status != 0) 675 return (status); 676 677 for (; n < nargs + nreturns; n++) 678 *va_arg(ap, cell_t *) = args_n_results[n]; 679 va_end(ap); 680 return (0); 681 } 682 683 /* 684 * Device I/O functions 685 */ 686 687 /* Open an instance for a device. */ 688 ihandle_t 689 OF_open(const char *device) 690 { 691 692 if (ofw_def_impl == NULL) 693 return (0); 694 695 return (OFW_OPEN(ofw_obj, device)); 696 } 697 698 /* Close an instance. */ 699 void 700 OF_close(ihandle_t instance) 701 { 702 703 if (ofw_def_impl == NULL) 704 return; 705 706 OFW_CLOSE(ofw_obj, instance); 707 } 708 709 /* Read from an instance. */ 710 ssize_t 711 OF_read(ihandle_t instance, void *addr, size_t len) 712 { 713 714 if (ofw_def_impl == NULL) 715 return (-1); 716 717 return (OFW_READ(ofw_obj, instance, addr, len)); 718 } 719 720 /* Write to an instance. */ 721 ssize_t 722 OF_write(ihandle_t instance, const void *addr, size_t len) 723 { 724 725 if (ofw_def_impl == NULL) 726 return (-1); 727 728 return (OFW_WRITE(ofw_obj, instance, addr, len)); 729 } 730 731 /* Seek to a position. */ 732 int 733 OF_seek(ihandle_t instance, uint64_t pos) 734 { 735 736 if (ofw_def_impl == NULL) 737 return (-1); 738 739 return (OFW_SEEK(ofw_obj, instance, pos)); 740 } 741 742 /* 743 * Memory functions 744 */ 745 746 /* Claim an area of memory. */ 747 void * 748 OF_claim(void *virt, size_t size, u_int align) 749 { 750 751 if (ofw_def_impl == NULL) 752 return ((void *)-1); 753 754 return (OFW_CLAIM(ofw_obj, virt, size, align)); 755 } 756 757 /* Release an area of memory. */ 758 void 759 OF_release(void *virt, size_t size) 760 { 761 762 if (ofw_def_impl == NULL) 763 return; 764 765 OFW_RELEASE(ofw_obj, virt, size); 766 } 767 768 /* 769 * Control transfer functions 770 */ 771 772 /* Suspend and drop back to the Open Firmware interface. */ 773 void 774 OF_enter() 775 { 776 777 if (ofw_def_impl == NULL) 778 return; 779 780 OFW_ENTER(ofw_obj); 781 } 782 783 /* Shut down and drop back to the Open Firmware interface. */ 784 void 785 OF_exit() 786 { 787 788 if (ofw_def_impl == NULL) 789 panic("OF_exit: Open Firmware not available"); 790 791 /* Should not return */ 792 OFW_EXIT(ofw_obj); 793 794 for (;;) /* just in case */ 795 ; 796 } 797