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