1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Procedures for interfacing to the RTAS on CHRP machines. 5 * 6 * Peter Bergner, IBM March 2001. 7 * Copyright (C) 2001 IBM. 8 */ 9 10 #include <linux/stdarg.h> 11 #include <linux/kernel.h> 12 #include <linux/types.h> 13 #include <linux/spinlock.h> 14 #include <linux/export.h> 15 #include <linux/init.h> 16 #include <linux/capability.h> 17 #include <linux/delay.h> 18 #include <linux/cpu.h> 19 #include <linux/sched.h> 20 #include <linux/smp.h> 21 #include <linux/completion.h> 22 #include <linux/cpumask.h> 23 #include <linux/memblock.h> 24 #include <linux/slab.h> 25 #include <linux/reboot.h> 26 #include <linux/security.h> 27 #include <linux/syscalls.h> 28 #include <linux/of.h> 29 #include <linux/of_fdt.h> 30 31 #include <asm/interrupt.h> 32 #include <asm/rtas.h> 33 #include <asm/hvcall.h> 34 #include <asm/machdep.h> 35 #include <asm/firmware.h> 36 #include <asm/page.h> 37 #include <asm/param.h> 38 #include <asm/delay.h> 39 #include <linux/uaccess.h> 40 #include <asm/udbg.h> 41 #include <asm/syscalls.h> 42 #include <asm/smp.h> 43 #include <linux/atomic.h> 44 #include <asm/time.h> 45 #include <asm/mmu.h> 46 #include <asm/topology.h> 47 48 /* This is here deliberately so it's only used in this file */ 49 void enter_rtas(unsigned long); 50 51 static inline void do_enter_rtas(unsigned long args) 52 { 53 unsigned long msr; 54 55 /* 56 * Make sure MSR[RI] is currently enabled as it will be forced later 57 * in enter_rtas. 58 */ 59 msr = mfmsr(); 60 BUG_ON(!(msr & MSR_RI)); 61 62 BUG_ON(!irqs_disabled()); 63 64 hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */ 65 66 enter_rtas(args); 67 68 srr_regs_clobbered(); /* rtas uses SRRs, invalidate */ 69 } 70 71 struct rtas_t rtas = { 72 .lock = __ARCH_SPIN_LOCK_UNLOCKED 73 }; 74 EXPORT_SYMBOL(rtas); 75 76 DEFINE_SPINLOCK(rtas_data_buf_lock); 77 EXPORT_SYMBOL(rtas_data_buf_lock); 78 79 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; 80 EXPORT_SYMBOL(rtas_data_buf); 81 82 unsigned long rtas_rmo_buf; 83 84 /* 85 * If non-NULL, this gets called when the kernel terminates. 86 * This is done like this so rtas_flash can be a module. 87 */ 88 void (*rtas_flash_term_hook)(int); 89 EXPORT_SYMBOL(rtas_flash_term_hook); 90 91 /* RTAS use home made raw locking instead of spin_lock_irqsave 92 * because those can be called from within really nasty contexts 93 * such as having the timebase stopped which would lockup with 94 * normal locks and spinlock debugging enabled 95 */ 96 static unsigned long lock_rtas(void) 97 { 98 unsigned long flags; 99 100 local_irq_save(flags); 101 preempt_disable(); 102 arch_spin_lock(&rtas.lock); 103 return flags; 104 } 105 106 static void unlock_rtas(unsigned long flags) 107 { 108 arch_spin_unlock(&rtas.lock); 109 local_irq_restore(flags); 110 preempt_enable(); 111 } 112 113 /* 114 * call_rtas_display_status and call_rtas_display_status_delay 115 * are designed only for very early low-level debugging, which 116 * is why the token is hard-coded to 10. 117 */ 118 static void call_rtas_display_status(unsigned char c) 119 { 120 unsigned long s; 121 122 if (!rtas.base) 123 return; 124 125 s = lock_rtas(); 126 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c); 127 unlock_rtas(s); 128 } 129 130 static void call_rtas_display_status_delay(char c) 131 { 132 static int pending_newline = 0; /* did last write end with unprinted newline? */ 133 static int width = 16; 134 135 if (c == '\n') { 136 while (width-- > 0) 137 call_rtas_display_status(' '); 138 width = 16; 139 mdelay(500); 140 pending_newline = 1; 141 } else { 142 if (pending_newline) { 143 call_rtas_display_status('\r'); 144 call_rtas_display_status('\n'); 145 } 146 pending_newline = 0; 147 if (width--) { 148 call_rtas_display_status(c); 149 udelay(10000); 150 } 151 } 152 } 153 154 void __init udbg_init_rtas_panel(void) 155 { 156 udbg_putc = call_rtas_display_status_delay; 157 } 158 159 #ifdef CONFIG_UDBG_RTAS_CONSOLE 160 161 /* If you think you're dying before early_init_dt_scan_rtas() does its 162 * work, you can hard code the token values for your firmware here and 163 * hardcode rtas.base/entry etc. 164 */ 165 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE; 166 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE; 167 168 static void udbg_rtascon_putc(char c) 169 { 170 int tries; 171 172 if (!rtas.base) 173 return; 174 175 /* Add CRs before LFs */ 176 if (c == '\n') 177 udbg_rtascon_putc('\r'); 178 179 /* if there is more than one character to be displayed, wait a bit */ 180 for (tries = 0; tries < 16; tries++) { 181 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0) 182 break; 183 udelay(1000); 184 } 185 } 186 187 static int udbg_rtascon_getc_poll(void) 188 { 189 int c; 190 191 if (!rtas.base) 192 return -1; 193 194 if (rtas_call(rtas_getchar_token, 0, 2, &c)) 195 return -1; 196 197 return c; 198 } 199 200 static int udbg_rtascon_getc(void) 201 { 202 int c; 203 204 while ((c = udbg_rtascon_getc_poll()) == -1) 205 ; 206 207 return c; 208 } 209 210 211 void __init udbg_init_rtas_console(void) 212 { 213 udbg_putc = udbg_rtascon_putc; 214 udbg_getc = udbg_rtascon_getc; 215 udbg_getc_poll = udbg_rtascon_getc_poll; 216 } 217 #endif /* CONFIG_UDBG_RTAS_CONSOLE */ 218 219 void rtas_progress(char *s, unsigned short hex) 220 { 221 struct device_node *root; 222 int width; 223 const __be32 *p; 224 char *os; 225 static int display_character, set_indicator; 226 static int display_width, display_lines, form_feed; 227 static const int *row_width; 228 static DEFINE_SPINLOCK(progress_lock); 229 static int current_line; 230 static int pending_newline = 0; /* did last write end with unprinted newline? */ 231 232 if (!rtas.base) 233 return; 234 235 if (display_width == 0) { 236 display_width = 0x10; 237 if ((root = of_find_node_by_path("/rtas"))) { 238 if ((p = of_get_property(root, 239 "ibm,display-line-length", NULL))) 240 display_width = be32_to_cpu(*p); 241 if ((p = of_get_property(root, 242 "ibm,form-feed", NULL))) 243 form_feed = be32_to_cpu(*p); 244 if ((p = of_get_property(root, 245 "ibm,display-number-of-lines", NULL))) 246 display_lines = be32_to_cpu(*p); 247 row_width = of_get_property(root, 248 "ibm,display-truncation-length", NULL); 249 of_node_put(root); 250 } 251 display_character = rtas_token("display-character"); 252 set_indicator = rtas_token("set-indicator"); 253 } 254 255 if (display_character == RTAS_UNKNOWN_SERVICE) { 256 /* use hex display if available */ 257 if (set_indicator != RTAS_UNKNOWN_SERVICE) 258 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); 259 return; 260 } 261 262 spin_lock(&progress_lock); 263 264 /* 265 * Last write ended with newline, but we didn't print it since 266 * it would just clear the bottom line of output. Print it now 267 * instead. 268 * 269 * If no newline is pending and form feed is supported, clear the 270 * display with a form feed; otherwise, print a CR to start output 271 * at the beginning of the line. 272 */ 273 if (pending_newline) { 274 rtas_call(display_character, 1, 1, NULL, '\r'); 275 rtas_call(display_character, 1, 1, NULL, '\n'); 276 pending_newline = 0; 277 } else { 278 current_line = 0; 279 if (form_feed) 280 rtas_call(display_character, 1, 1, NULL, 281 (char)form_feed); 282 else 283 rtas_call(display_character, 1, 1, NULL, '\r'); 284 } 285 286 if (row_width) 287 width = row_width[current_line]; 288 else 289 width = display_width; 290 os = s; 291 while (*os) { 292 if (*os == '\n' || *os == '\r') { 293 /* If newline is the last character, save it 294 * until next call to avoid bumping up the 295 * display output. 296 */ 297 if (*os == '\n' && !os[1]) { 298 pending_newline = 1; 299 current_line++; 300 if (current_line > display_lines-1) 301 current_line = display_lines-1; 302 spin_unlock(&progress_lock); 303 return; 304 } 305 306 /* RTAS wants CR-LF, not just LF */ 307 308 if (*os == '\n') { 309 rtas_call(display_character, 1, 1, NULL, '\r'); 310 rtas_call(display_character, 1, 1, NULL, '\n'); 311 } else { 312 /* CR might be used to re-draw a line, so we'll 313 * leave it alone and not add LF. 314 */ 315 rtas_call(display_character, 1, 1, NULL, *os); 316 } 317 318 if (row_width) 319 width = row_width[current_line]; 320 else 321 width = display_width; 322 } else { 323 width--; 324 rtas_call(display_character, 1, 1, NULL, *os); 325 } 326 327 os++; 328 329 /* if we overwrite the screen length */ 330 if (width <= 0) 331 while ((*os != 0) && (*os != '\n') && (*os != '\r')) 332 os++; 333 } 334 335 spin_unlock(&progress_lock); 336 } 337 EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ 338 339 int rtas_token(const char *service) 340 { 341 const __be32 *tokp; 342 if (rtas.dev == NULL) 343 return RTAS_UNKNOWN_SERVICE; 344 tokp = of_get_property(rtas.dev, service, NULL); 345 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; 346 } 347 EXPORT_SYMBOL(rtas_token); 348 349 int rtas_service_present(const char *service) 350 { 351 return rtas_token(service) != RTAS_UNKNOWN_SERVICE; 352 } 353 EXPORT_SYMBOL(rtas_service_present); 354 355 #ifdef CONFIG_RTAS_ERROR_LOGGING 356 /* 357 * Return the firmware-specified size of the error log buffer 358 * for all rtas calls that require an error buffer argument. 359 * This includes 'check-exception' and 'rtas-last-error'. 360 */ 361 int rtas_get_error_log_max(void) 362 { 363 static int rtas_error_log_max; 364 if (rtas_error_log_max) 365 return rtas_error_log_max; 366 367 rtas_error_log_max = rtas_token ("rtas-error-log-max"); 368 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || 369 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { 370 printk (KERN_WARNING "RTAS: bad log buffer size %d\n", 371 rtas_error_log_max); 372 rtas_error_log_max = RTAS_ERROR_LOG_MAX; 373 } 374 return rtas_error_log_max; 375 } 376 EXPORT_SYMBOL(rtas_get_error_log_max); 377 378 379 static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; 380 static int rtas_last_error_token; 381 382 /** Return a copy of the detailed error text associated with the 383 * most recent failed call to rtas. Because the error text 384 * might go stale if there are any other intervening rtas calls, 385 * this routine must be called atomically with whatever produced 386 * the error (i.e. with rtas.lock still held from the previous call). 387 */ 388 static char *__fetch_rtas_last_error(char *altbuf) 389 { 390 struct rtas_args err_args, save_args; 391 u32 bufsz; 392 char *buf = NULL; 393 394 if (rtas_last_error_token == -1) 395 return NULL; 396 397 bufsz = rtas_get_error_log_max(); 398 399 err_args.token = cpu_to_be32(rtas_last_error_token); 400 err_args.nargs = cpu_to_be32(2); 401 err_args.nret = cpu_to_be32(1); 402 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf)); 403 err_args.args[1] = cpu_to_be32(bufsz); 404 err_args.args[2] = 0; 405 406 save_args = rtas.args; 407 rtas.args = err_args; 408 409 do_enter_rtas(__pa(&rtas.args)); 410 411 err_args = rtas.args; 412 rtas.args = save_args; 413 414 /* Log the error in the unlikely case that there was one. */ 415 if (unlikely(err_args.args[2] == 0)) { 416 if (altbuf) { 417 buf = altbuf; 418 } else { 419 buf = rtas_err_buf; 420 if (slab_is_available()) 421 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); 422 } 423 if (buf) 424 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); 425 } 426 427 return buf; 428 } 429 430 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL) 431 432 #else /* CONFIG_RTAS_ERROR_LOGGING */ 433 #define __fetch_rtas_last_error(x) NULL 434 #define get_errorlog_buffer() NULL 435 #endif 436 437 438 static void 439 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, 440 va_list list) 441 { 442 int i; 443 444 args->token = cpu_to_be32(token); 445 args->nargs = cpu_to_be32(nargs); 446 args->nret = cpu_to_be32(nret); 447 args->rets = &(args->args[nargs]); 448 449 for (i = 0; i < nargs; ++i) 450 args->args[i] = cpu_to_be32(va_arg(list, __u32)); 451 452 for (i = 0; i < nret; ++i) 453 args->rets[i] = 0; 454 455 do_enter_rtas(__pa(args)); 456 } 457 458 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...) 459 { 460 va_list list; 461 462 va_start(list, nret); 463 va_rtas_call_unlocked(args, token, nargs, nret, list); 464 va_end(list); 465 } 466 467 static int ibm_open_errinjct_token; 468 static int ibm_errinjct_token; 469 470 /** 471 * rtas_call() - Invoke an RTAS firmware function. 472 * @token: Identifies the function being invoked. 473 * @nargs: Number of input parameters. Does not include token. 474 * @nret: Number of output parameters, including the call status. 475 * @outputs: Array of @nret output words. 476 * @....: List of @nargs input parameters. 477 * 478 * Invokes the RTAS function indicated by @token, which the caller 479 * should obtain via rtas_token(). 480 * 481 * The @nargs and @nret arguments must match the number of input and 482 * output parameters specified for the RTAS function. 483 * 484 * rtas_call() returns RTAS status codes, not conventional Linux errno 485 * values. Callers must translate any failure to an appropriate errno 486 * in syscall context. Most callers of RTAS functions that can return 487 * -2 or 990x should use rtas_busy_delay() to correctly handle those 488 * statuses before calling again. 489 * 490 * The return value descriptions are adapted from 7.2.8 [RTAS] Return 491 * Codes of the PAPR and CHRP specifications. 492 * 493 * Context: Process context preferably, interrupt context if 494 * necessary. Acquires an internal spinlock and may perform 495 * GFP_ATOMIC slab allocation in error path. Unsafe for NMI 496 * context. 497 * Return: 498 * * 0 - RTAS function call succeeded. 499 * * -1 - RTAS function encountered a hardware or 500 * platform error, or the token is invalid, 501 * or the function is restricted by kernel policy. 502 * * -2 - Specs say "A necessary hardware device was busy, 503 * and the requested function could not be 504 * performed. The operation should be retried at 505 * a later time." This is misleading, at least with 506 * respect to current RTAS implementations. What it 507 * usually means in practice is that the function 508 * could not be completed while meeting RTAS's 509 * deadline for returning control to the OS (250us 510 * for PAPR/PowerVM, typically), but the call may be 511 * immediately reattempted to resume work on it. 512 * * -3 - Parameter error. 513 * * -7 - Unexpected state change. 514 * * 9000...9899 - Vendor-specific success codes. 515 * * 9900...9905 - Advisory extended delay. Caller should try 516 * again after ~10^x ms has elapsed, where x is 517 * the last digit of the status [0-5]. Again going 518 * beyond the PAPR text, 990x on PowerVM indicates 519 * contention for RTAS-internal resources. Other 520 * RTAS call sequences in progress should be 521 * allowed to complete before reattempting the 522 * call. 523 * * -9000 - Multi-level isolation error. 524 * * -9999...-9004 - Vendor-specific error codes. 525 * * Additional negative values - Function-specific error. 526 * * Additional positive values - Function-specific success. 527 */ 528 int rtas_call(int token, int nargs, int nret, int *outputs, ...) 529 { 530 va_list list; 531 int i; 532 unsigned long s; 533 struct rtas_args *rtas_args; 534 char *buff_copy = NULL; 535 int ret; 536 537 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) 538 return -1; 539 540 if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) { 541 /* 542 * It would be nicer to not discard the error value 543 * from security_locked_down(), but callers expect an 544 * RTAS status, not an errno. 545 */ 546 if (security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION)) 547 return -1; 548 } 549 550 if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) { 551 WARN_ON_ONCE(1); 552 return -1; 553 } 554 555 s = lock_rtas(); 556 557 /* We use the global rtas args buffer */ 558 rtas_args = &rtas.args; 559 560 va_start(list, outputs); 561 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list); 562 va_end(list); 563 564 /* A -1 return code indicates that the last command couldn't 565 be completed due to a hardware error. */ 566 if (be32_to_cpu(rtas_args->rets[0]) == -1) 567 buff_copy = __fetch_rtas_last_error(NULL); 568 569 if (nret > 1 && outputs != NULL) 570 for (i = 0; i < nret-1; ++i) 571 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]); 572 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0; 573 574 unlock_rtas(s); 575 576 if (buff_copy) { 577 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); 578 if (slab_is_available()) 579 kfree(buff_copy); 580 } 581 return ret; 582 } 583 EXPORT_SYMBOL(rtas_call); 584 585 /** 586 * rtas_busy_delay_time() - From an RTAS status value, calculate the 587 * suggested delay time in milliseconds. 588 * 589 * @status: a value returned from rtas_call() or similar APIs which return 590 * the status of a RTAS function call. 591 * 592 * Context: Any context. 593 * 594 * Return: 595 * * 100000 - If @status is 9905. 596 * * 10000 - If @status is 9904. 597 * * 1000 - If @status is 9903. 598 * * 100 - If @status is 9902. 599 * * 10 - If @status is 9901. 600 * * 1 - If @status is either 9900 or -2. This is "wrong" for -2, but 601 * some callers depend on this behavior, and the worst outcome 602 * is that they will delay for longer than necessary. 603 * * 0 - If @status is not a busy or extended delay value. 604 */ 605 unsigned int rtas_busy_delay_time(int status) 606 { 607 int order; 608 unsigned int ms = 0; 609 610 if (status == RTAS_BUSY) { 611 ms = 1; 612 } else if (status >= RTAS_EXTENDED_DELAY_MIN && 613 status <= RTAS_EXTENDED_DELAY_MAX) { 614 order = status - RTAS_EXTENDED_DELAY_MIN; 615 for (ms = 1; order > 0; order--) 616 ms *= 10; 617 } 618 619 return ms; 620 } 621 EXPORT_SYMBOL(rtas_busy_delay_time); 622 623 /** 624 * rtas_busy_delay() - helper for RTAS busy and extended delay statuses 625 * 626 * @status: a value returned from rtas_call() or similar APIs which return 627 * the status of a RTAS function call. 628 * 629 * Context: Process context. May sleep or schedule. 630 * 631 * Return: 632 * * true - @status is RTAS_BUSY or an extended delay hint. The 633 * caller may assume that the CPU has been yielded if necessary, 634 * and that an appropriate delay for @status has elapsed. 635 * Generally the caller should reattempt the RTAS call which 636 * yielded @status. 637 * 638 * * false - @status is not @RTAS_BUSY nor an extended delay hint. The 639 * caller is responsible for handling @status. 640 */ 641 bool rtas_busy_delay(int status) 642 { 643 unsigned int ms; 644 bool ret; 645 646 switch (status) { 647 case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: 648 ret = true; 649 ms = rtas_busy_delay_time(status); 650 /* 651 * The extended delay hint can be as high as 100 seconds. 652 * Surely any function returning such a status is either 653 * buggy or isn't going to be significantly slowed by us 654 * polling at 1HZ. Clamp the sleep time to one second. 655 */ 656 ms = clamp(ms, 1U, 1000U); 657 /* 658 * The delay hint is an order-of-magnitude suggestion, not 659 * a minimum. It is fine, possibly even advantageous, for 660 * us to pause for less time than hinted. For small values, 661 * use usleep_range() to ensure we don't sleep much longer 662 * than actually needed. 663 * 664 * See Documentation/timers/timers-howto.rst for 665 * explanation of the threshold used here. In effect we use 666 * usleep_range() for 9900 and 9901, msleep() for 667 * 9902-9905. 668 */ 669 if (ms <= 20) 670 usleep_range(ms * 100, ms * 1000); 671 else 672 msleep(ms); 673 break; 674 case RTAS_BUSY: 675 ret = true; 676 /* 677 * We should call again immediately if there's no other 678 * work to do. 679 */ 680 cond_resched(); 681 break; 682 default: 683 ret = false; 684 /* 685 * Not a busy or extended delay status; the caller should 686 * handle @status itself. Ensure we warn on misuses in 687 * atomic context regardless. 688 */ 689 might_sleep(); 690 break; 691 } 692 693 return ret; 694 } 695 EXPORT_SYMBOL(rtas_busy_delay); 696 697 static int rtas_error_rc(int rtas_rc) 698 { 699 int rc; 700 701 switch (rtas_rc) { 702 case -1: /* Hardware Error */ 703 rc = -EIO; 704 break; 705 case -3: /* Bad indicator/domain/etc */ 706 rc = -EINVAL; 707 break; 708 case -9000: /* Isolation error */ 709 rc = -EFAULT; 710 break; 711 case -9001: /* Outstanding TCE/PTE */ 712 rc = -EEXIST; 713 break; 714 case -9002: /* No usable slot */ 715 rc = -ENODEV; 716 break; 717 default: 718 printk(KERN_ERR "%s: unexpected RTAS error %d\n", 719 __func__, rtas_rc); 720 rc = -ERANGE; 721 break; 722 } 723 return rc; 724 } 725 726 int rtas_get_power_level(int powerdomain, int *level) 727 { 728 int token = rtas_token("get-power-level"); 729 int rc; 730 731 if (token == RTAS_UNKNOWN_SERVICE) 732 return -ENOENT; 733 734 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) 735 udelay(1); 736 737 if (rc < 0) 738 return rtas_error_rc(rc); 739 return rc; 740 } 741 EXPORT_SYMBOL(rtas_get_power_level); 742 743 int rtas_set_power_level(int powerdomain, int level, int *setlevel) 744 { 745 int token = rtas_token("set-power-level"); 746 int rc; 747 748 if (token == RTAS_UNKNOWN_SERVICE) 749 return -ENOENT; 750 751 do { 752 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); 753 } while (rtas_busy_delay(rc)); 754 755 if (rc < 0) 756 return rtas_error_rc(rc); 757 return rc; 758 } 759 EXPORT_SYMBOL(rtas_set_power_level); 760 761 int rtas_get_sensor(int sensor, int index, int *state) 762 { 763 int token = rtas_token("get-sensor-state"); 764 int rc; 765 766 if (token == RTAS_UNKNOWN_SERVICE) 767 return -ENOENT; 768 769 do { 770 rc = rtas_call(token, 2, 2, state, sensor, index); 771 } while (rtas_busy_delay(rc)); 772 773 if (rc < 0) 774 return rtas_error_rc(rc); 775 return rc; 776 } 777 EXPORT_SYMBOL(rtas_get_sensor); 778 779 int rtas_get_sensor_fast(int sensor, int index, int *state) 780 { 781 int token = rtas_token("get-sensor-state"); 782 int rc; 783 784 if (token == RTAS_UNKNOWN_SERVICE) 785 return -ENOENT; 786 787 rc = rtas_call(token, 2, 2, state, sensor, index); 788 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 789 rc <= RTAS_EXTENDED_DELAY_MAX)); 790 791 if (rc < 0) 792 return rtas_error_rc(rc); 793 return rc; 794 } 795 796 bool rtas_indicator_present(int token, int *maxindex) 797 { 798 int proplen, count, i; 799 const struct indicator_elem { 800 __be32 token; 801 __be32 maxindex; 802 } *indicators; 803 804 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen); 805 if (!indicators) 806 return false; 807 808 count = proplen / sizeof(struct indicator_elem); 809 810 for (i = 0; i < count; i++) { 811 if (__be32_to_cpu(indicators[i].token) != token) 812 continue; 813 if (maxindex) 814 *maxindex = __be32_to_cpu(indicators[i].maxindex); 815 return true; 816 } 817 818 return false; 819 } 820 EXPORT_SYMBOL(rtas_indicator_present); 821 822 int rtas_set_indicator(int indicator, int index, int new_value) 823 { 824 int token = rtas_token("set-indicator"); 825 int rc; 826 827 if (token == RTAS_UNKNOWN_SERVICE) 828 return -ENOENT; 829 830 do { 831 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 832 } while (rtas_busy_delay(rc)); 833 834 if (rc < 0) 835 return rtas_error_rc(rc); 836 return rc; 837 } 838 EXPORT_SYMBOL(rtas_set_indicator); 839 840 /* 841 * Ignoring RTAS extended delay 842 */ 843 int rtas_set_indicator_fast(int indicator, int index, int new_value) 844 { 845 int rc; 846 int token = rtas_token("set-indicator"); 847 848 if (token == RTAS_UNKNOWN_SERVICE) 849 return -ENOENT; 850 851 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 852 853 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 854 rc <= RTAS_EXTENDED_DELAY_MAX)); 855 856 if (rc < 0) 857 return rtas_error_rc(rc); 858 859 return rc; 860 } 861 862 /** 863 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR. 864 * 865 * @fw_status: RTAS call status will be placed here if not NULL. 866 * 867 * rtas_ibm_suspend_me() should be called only on a CPU which has 868 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs 869 * should be waiting to return from H_JOIN. 870 * 871 * rtas_ibm_suspend_me() may suspend execution of the OS 872 * indefinitely. Callers should take appropriate measures upon return, such as 873 * resetting watchdog facilities. 874 * 875 * Callers may choose to retry this call if @fw_status is 876 * %RTAS_THREADS_ACTIVE. 877 * 878 * Return: 879 * 0 - The partition has resumed from suspend, possibly after 880 * migration to a different host. 881 * -ECANCELED - The operation was aborted. 882 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call. 883 * -EBUSY - Some other condition prevented the suspend from succeeding. 884 * -EIO - Hardware/platform error. 885 */ 886 int rtas_ibm_suspend_me(int *fw_status) 887 { 888 int fwrc; 889 int ret; 890 891 fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL); 892 893 switch (fwrc) { 894 case 0: 895 ret = 0; 896 break; 897 case RTAS_SUSPEND_ABORTED: 898 ret = -ECANCELED; 899 break; 900 case RTAS_THREADS_ACTIVE: 901 ret = -EAGAIN; 902 break; 903 case RTAS_NOT_SUSPENDABLE: 904 case RTAS_OUTSTANDING_COPROC: 905 ret = -EBUSY; 906 break; 907 case -1: 908 default: 909 ret = -EIO; 910 break; 911 } 912 913 if (fw_status) 914 *fw_status = fwrc; 915 916 return ret; 917 } 918 919 void __noreturn rtas_restart(char *cmd) 920 { 921 if (rtas_flash_term_hook) 922 rtas_flash_term_hook(SYS_RESTART); 923 printk("RTAS system-reboot returned %d\n", 924 rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); 925 for (;;); 926 } 927 928 void rtas_power_off(void) 929 { 930 if (rtas_flash_term_hook) 931 rtas_flash_term_hook(SYS_POWER_OFF); 932 /* allow power on only with power button press */ 933 printk("RTAS power-off returned %d\n", 934 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 935 for (;;); 936 } 937 938 void __noreturn rtas_halt(void) 939 { 940 if (rtas_flash_term_hook) 941 rtas_flash_term_hook(SYS_HALT); 942 /* allow power on only with power button press */ 943 printk("RTAS power-off returned %d\n", 944 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 945 for (;;); 946 } 947 948 /* Must be in the RMO region, so we place it here */ 949 static char rtas_os_term_buf[2048]; 950 951 void rtas_os_term(char *str) 952 { 953 int status; 954 955 /* 956 * Firmware with the ibm,extended-os-term property is guaranteed 957 * to always return from an ibm,os-term call. Earlier versions without 958 * this property may terminate the partition which we want to avoid 959 * since it interferes with panic_timeout. 960 */ 961 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") || 962 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term")) 963 return; 964 965 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); 966 967 do { 968 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL, 969 __pa(rtas_os_term_buf)); 970 } while (rtas_busy_delay(status)); 971 972 if (status != 0) 973 printk(KERN_EMERG "ibm,os-term call failed %d\n", status); 974 } 975 976 /** 977 * rtas_activate_firmware() - Activate a new version of firmware. 978 * 979 * Context: This function may sleep. 980 * 981 * Activate a new version of partition firmware. The OS must call this 982 * after resuming from a partition hibernation or migration in order 983 * to maintain the ability to perform live firmware updates. It's not 984 * catastrophic for this method to be absent or to fail; just log the 985 * condition in that case. 986 */ 987 void rtas_activate_firmware(void) 988 { 989 int token; 990 int fwrc; 991 992 token = rtas_token("ibm,activate-firmware"); 993 if (token == RTAS_UNKNOWN_SERVICE) { 994 pr_notice("ibm,activate-firmware method unavailable\n"); 995 return; 996 } 997 998 do { 999 fwrc = rtas_call(token, 0, 1, NULL); 1000 } while (rtas_busy_delay(fwrc)); 1001 1002 if (fwrc) 1003 pr_err("ibm,activate-firmware failed (%i)\n", fwrc); 1004 } 1005 1006 /** 1007 * get_pseries_errorlog() - Find a specific pseries error log in an RTAS 1008 * extended event log. 1009 * @log: RTAS error/event log 1010 * @section_id: two character section identifier 1011 * 1012 * Return: A pointer to the specified errorlog or NULL if not found. 1013 */ 1014 noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, 1015 uint16_t section_id) 1016 { 1017 struct rtas_ext_event_log_v6 *ext_log = 1018 (struct rtas_ext_event_log_v6 *)log->buffer; 1019 struct pseries_errorlog *sect; 1020 unsigned char *p, *log_end; 1021 uint32_t ext_log_length = rtas_error_extended_log_length(log); 1022 uint8_t log_format = rtas_ext_event_log_format(ext_log); 1023 uint32_t company_id = rtas_ext_event_company_id(ext_log); 1024 1025 /* Check that we understand the format */ 1026 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) || 1027 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || 1028 company_id != RTAS_V6EXT_COMPANY_ID_IBM) 1029 return NULL; 1030 1031 log_end = log->buffer + ext_log_length; 1032 p = ext_log->vendor_log; 1033 1034 while (p < log_end) { 1035 sect = (struct pseries_errorlog *)p; 1036 if (pseries_errorlog_id(sect) == section_id) 1037 return sect; 1038 p += pseries_errorlog_length(sect); 1039 } 1040 1041 return NULL; 1042 } 1043 1044 #ifdef CONFIG_PPC_RTAS_FILTER 1045 1046 /* 1047 * The sys_rtas syscall, as originally designed, allows root to pass 1048 * arbitrary physical addresses to RTAS calls. A number of RTAS calls 1049 * can be abused to write to arbitrary memory and do other things that 1050 * are potentially harmful to system integrity, and thus should only 1051 * be used inside the kernel and not exposed to userspace. 1052 * 1053 * All known legitimate users of the sys_rtas syscall will only ever 1054 * pass addresses that fall within the RMO buffer, and use a known 1055 * subset of RTAS calls. 1056 * 1057 * Accordingly, we filter RTAS requests to check that the call is 1058 * permitted, and that provided pointers fall within the RMO buffer. 1059 * The rtas_filters list contains an entry for each permitted call, 1060 * with the indexes of the parameters which are expected to contain 1061 * addresses and sizes of buffers allocated inside the RMO buffer. 1062 */ 1063 struct rtas_filter { 1064 const char *name; 1065 int token; 1066 /* Indexes into the args buffer, -1 if not used */ 1067 int buf_idx1; 1068 int size_idx1; 1069 int buf_idx2; 1070 int size_idx2; 1071 1072 int fixed_size; 1073 }; 1074 1075 static struct rtas_filter rtas_filters[] __ro_after_init = { 1076 { "ibm,activate-firmware", -1, -1, -1, -1, -1 }, 1077 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */ 1078 { "display-character", -1, -1, -1, -1, -1 }, 1079 { "ibm,display-message", -1, 0, -1, -1, -1 }, 1080 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 }, 1081 { "ibm,close-errinjct", -1, -1, -1, -1, -1 }, 1082 { "ibm,open-errinjct", -1, -1, -1, -1, -1 }, 1083 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 }, 1084 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 }, 1085 { "ibm,get-indices", -1, 2, 3, -1, -1 }, 1086 { "get-power-level", -1, -1, -1, -1, -1 }, 1087 { "get-sensor-state", -1, -1, -1, -1, -1 }, 1088 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 }, 1089 { "get-time-of-day", -1, -1, -1, -1, -1 }, 1090 { "ibm,get-vpd", -1, 0, -1, 1, 2 }, 1091 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 }, 1092 { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */ 1093 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 }, 1094 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 }, 1095 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 }, 1096 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 }, 1097 { "set-indicator", -1, -1, -1, -1, -1 }, 1098 { "set-power-level", -1, -1, -1, -1, -1 }, 1099 { "set-time-for-power-on", -1, -1, -1, -1, -1 }, 1100 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 }, 1101 { "set-time-of-day", -1, -1, -1, -1, -1 }, 1102 #ifdef CONFIG_CPU_BIG_ENDIAN 1103 { "ibm,suspend-me", -1, -1, -1, -1, -1 }, 1104 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 }, 1105 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 }, 1106 #endif 1107 { "ibm,physical-attestation", -1, 0, 1, -1, -1 }, 1108 }; 1109 1110 static bool in_rmo_buf(u32 base, u32 end) 1111 { 1112 return base >= rtas_rmo_buf && 1113 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) && 1114 base <= end && 1115 end >= rtas_rmo_buf && 1116 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE); 1117 } 1118 1119 static bool block_rtas_call(int token, int nargs, 1120 struct rtas_args *args) 1121 { 1122 int i; 1123 1124 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) { 1125 struct rtas_filter *f = &rtas_filters[i]; 1126 u32 base, size, end; 1127 1128 if (token != f->token) 1129 continue; 1130 1131 if (f->buf_idx1 != -1) { 1132 base = be32_to_cpu(args->args[f->buf_idx1]); 1133 if (f->size_idx1 != -1) 1134 size = be32_to_cpu(args->args[f->size_idx1]); 1135 else if (f->fixed_size) 1136 size = f->fixed_size; 1137 else 1138 size = 1; 1139 1140 end = base + size - 1; 1141 1142 /* 1143 * Special case for ibm,platform-dump - NULL buffer 1144 * address is used to indicate end of dump processing 1145 */ 1146 if (!strcmp(f->name, "ibm,platform-dump") && 1147 base == 0) 1148 return false; 1149 1150 if (!in_rmo_buf(base, end)) 1151 goto err; 1152 } 1153 1154 if (f->buf_idx2 != -1) { 1155 base = be32_to_cpu(args->args[f->buf_idx2]); 1156 if (f->size_idx2 != -1) 1157 size = be32_to_cpu(args->args[f->size_idx2]); 1158 else if (f->fixed_size) 1159 size = f->fixed_size; 1160 else 1161 size = 1; 1162 end = base + size - 1; 1163 1164 /* 1165 * Special case for ibm,configure-connector where the 1166 * address can be 0 1167 */ 1168 if (!strcmp(f->name, "ibm,configure-connector") && 1169 base == 0) 1170 return false; 1171 1172 if (!in_rmo_buf(base, end)) 1173 goto err; 1174 } 1175 1176 return false; 1177 } 1178 1179 err: 1180 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n"); 1181 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n", 1182 token, nargs, current->comm); 1183 return true; 1184 } 1185 1186 static void __init rtas_syscall_filter_init(void) 1187 { 1188 unsigned int i; 1189 1190 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) 1191 rtas_filters[i].token = rtas_token(rtas_filters[i].name); 1192 } 1193 1194 #else 1195 1196 static bool block_rtas_call(int token, int nargs, 1197 struct rtas_args *args) 1198 { 1199 return false; 1200 } 1201 1202 static void __init rtas_syscall_filter_init(void) 1203 { 1204 } 1205 1206 #endif /* CONFIG_PPC_RTAS_FILTER */ 1207 1208 /* We assume to be passed big endian arguments */ 1209 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) 1210 { 1211 struct rtas_args args; 1212 unsigned long flags; 1213 char *buff_copy, *errbuf = NULL; 1214 int nargs, nret, token; 1215 1216 if (!capable(CAP_SYS_ADMIN)) 1217 return -EPERM; 1218 1219 if (!rtas.entry) 1220 return -EINVAL; 1221 1222 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) 1223 return -EFAULT; 1224 1225 nargs = be32_to_cpu(args.nargs); 1226 nret = be32_to_cpu(args.nret); 1227 token = be32_to_cpu(args.token); 1228 1229 if (nargs >= ARRAY_SIZE(args.args) 1230 || nret > ARRAY_SIZE(args.args) 1231 || nargs + nret > ARRAY_SIZE(args.args)) 1232 return -EINVAL; 1233 1234 /* Copy in args. */ 1235 if (copy_from_user(args.args, uargs->args, 1236 nargs * sizeof(rtas_arg_t)) != 0) 1237 return -EFAULT; 1238 1239 if (token == RTAS_UNKNOWN_SERVICE) 1240 return -EINVAL; 1241 1242 args.rets = &args.args[nargs]; 1243 memset(args.rets, 0, nret * sizeof(rtas_arg_t)); 1244 1245 if (block_rtas_call(token, nargs, &args)) 1246 return -EINVAL; 1247 1248 if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) { 1249 int err; 1250 1251 err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION); 1252 if (err) 1253 return err; 1254 } 1255 1256 /* Need to handle ibm,suspend_me call specially */ 1257 if (token == rtas_token("ibm,suspend-me")) { 1258 1259 /* 1260 * rtas_ibm_suspend_me assumes the streamid handle is in cpu 1261 * endian, or at least the hcall within it requires it. 1262 */ 1263 int rc = 0; 1264 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) 1265 | be32_to_cpu(args.args[1]); 1266 rc = rtas_syscall_dispatch_ibm_suspend_me(handle); 1267 if (rc == -EAGAIN) 1268 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); 1269 else if (rc == -EIO) 1270 args.rets[0] = cpu_to_be32(-1); 1271 else if (rc) 1272 return rc; 1273 goto copy_return; 1274 } 1275 1276 buff_copy = get_errorlog_buffer(); 1277 1278 flags = lock_rtas(); 1279 1280 rtas.args = args; 1281 do_enter_rtas(__pa(&rtas.args)); 1282 args = rtas.args; 1283 1284 /* A -1 return code indicates that the last command couldn't 1285 be completed due to a hardware error. */ 1286 if (be32_to_cpu(args.rets[0]) == -1) 1287 errbuf = __fetch_rtas_last_error(buff_copy); 1288 1289 unlock_rtas(flags); 1290 1291 if (buff_copy) { 1292 if (errbuf) 1293 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); 1294 kfree(buff_copy); 1295 } 1296 1297 copy_return: 1298 /* Copy out args. */ 1299 if (copy_to_user(uargs->args + nargs, 1300 args.args + nargs, 1301 nret * sizeof(rtas_arg_t)) != 0) 1302 return -EFAULT; 1303 1304 return 0; 1305 } 1306 1307 /* 1308 * Call early during boot, before mem init, to retrieve the RTAS 1309 * information from the device-tree and allocate the RMO buffer for userland 1310 * accesses. 1311 */ 1312 void __init rtas_initialize(void) 1313 { 1314 unsigned long rtas_region = RTAS_INSTANTIATE_MAX; 1315 u32 base, size, entry; 1316 int no_base, no_size, no_entry; 1317 1318 /* Get RTAS dev node and fill up our "rtas" structure with infos 1319 * about it. 1320 */ 1321 rtas.dev = of_find_node_by_name(NULL, "rtas"); 1322 if (!rtas.dev) 1323 return; 1324 1325 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base); 1326 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size); 1327 if (no_base || no_size) { 1328 of_node_put(rtas.dev); 1329 rtas.dev = NULL; 1330 return; 1331 } 1332 1333 rtas.base = base; 1334 rtas.size = size; 1335 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); 1336 rtas.entry = no_entry ? rtas.base : entry; 1337 1338 /* If RTAS was found, allocate the RMO buffer for it and look for 1339 * the stop-self token if any 1340 */ 1341 #ifdef CONFIG_PPC64 1342 if (firmware_has_feature(FW_FEATURE_LPAR)) 1343 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX); 1344 #endif 1345 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE, 1346 0, rtas_region); 1347 if (!rtas_rmo_buf) 1348 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", 1349 PAGE_SIZE, &rtas_region); 1350 1351 #ifdef CONFIG_RTAS_ERROR_LOGGING 1352 rtas_last_error_token = rtas_token("rtas-last-error"); 1353 #endif 1354 ibm_open_errinjct_token = rtas_token("ibm,open-errinjct"); 1355 ibm_errinjct_token = rtas_token("ibm,errinjct"); 1356 rtas_syscall_filter_init(); 1357 } 1358 1359 int __init early_init_dt_scan_rtas(unsigned long node, 1360 const char *uname, int depth, void *data) 1361 { 1362 const u32 *basep, *entryp, *sizep; 1363 1364 if (depth != 1 || strcmp(uname, "rtas") != 0) 1365 return 0; 1366 1367 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL); 1368 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL); 1369 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL); 1370 1371 #ifdef CONFIG_PPC64 1372 /* need this feature to decide the crashkernel offset */ 1373 if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL)) 1374 powerpc_firmware_features |= FW_FEATURE_LPAR; 1375 #endif 1376 1377 if (basep && entryp && sizep) { 1378 rtas.base = *basep; 1379 rtas.entry = *entryp; 1380 rtas.size = *sizep; 1381 } 1382 1383 #ifdef CONFIG_UDBG_RTAS_CONSOLE 1384 basep = of_get_flat_dt_prop(node, "put-term-char", NULL); 1385 if (basep) 1386 rtas_putchar_token = *basep; 1387 1388 basep = of_get_flat_dt_prop(node, "get-term-char", NULL); 1389 if (basep) 1390 rtas_getchar_token = *basep; 1391 1392 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE && 1393 rtas_getchar_token != RTAS_UNKNOWN_SERVICE) 1394 udbg_init_rtas_console(); 1395 1396 #endif 1397 1398 /* break now */ 1399 return 1; 1400 } 1401 1402 static arch_spinlock_t timebase_lock; 1403 static u64 timebase = 0; 1404 1405 void rtas_give_timebase(void) 1406 { 1407 unsigned long flags; 1408 1409 local_irq_save(flags); 1410 hard_irq_disable(); 1411 arch_spin_lock(&timebase_lock); 1412 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 1413 timebase = get_tb(); 1414 arch_spin_unlock(&timebase_lock); 1415 1416 while (timebase) 1417 barrier(); 1418 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 1419 local_irq_restore(flags); 1420 } 1421 1422 void rtas_take_timebase(void) 1423 { 1424 while (!timebase) 1425 barrier(); 1426 arch_spin_lock(&timebase_lock); 1427 set_tb(timebase >> 32, timebase & 0xffffffff); 1428 timebase = 0; 1429 arch_spin_unlock(&timebase_lock); 1430 } 1431