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 <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/prom.h> 29 #include <asm/rtas.h> 30 #include <asm/hvcall.h> 31 #include <asm/machdep.h> 32 #include <asm/firmware.h> 33 #include <asm/page.h> 34 #include <asm/param.h> 35 #include <asm/delay.h> 36 #include <linux/uaccess.h> 37 #include <asm/udbg.h> 38 #include <asm/syscalls.h> 39 #include <asm/smp.h> 40 #include <linux/atomic.h> 41 #include <asm/time.h> 42 #include <asm/mmu.h> 43 #include <asm/topology.h> 44 45 /* This is here deliberately so it's only used in this file */ 46 void enter_rtas(unsigned long); 47 48 struct rtas_t rtas = { 49 .lock = __ARCH_SPIN_LOCK_UNLOCKED 50 }; 51 EXPORT_SYMBOL(rtas); 52 53 DEFINE_SPINLOCK(rtas_data_buf_lock); 54 EXPORT_SYMBOL(rtas_data_buf_lock); 55 56 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; 57 EXPORT_SYMBOL(rtas_data_buf); 58 59 unsigned long rtas_rmo_buf; 60 61 /* 62 * If non-NULL, this gets called when the kernel terminates. 63 * This is done like this so rtas_flash can be a module. 64 */ 65 void (*rtas_flash_term_hook)(int); 66 EXPORT_SYMBOL(rtas_flash_term_hook); 67 68 /* RTAS use home made raw locking instead of spin_lock_irqsave 69 * because those can be called from within really nasty contexts 70 * such as having the timebase stopped which would lockup with 71 * normal locks and spinlock debugging enabled 72 */ 73 static unsigned long lock_rtas(void) 74 { 75 unsigned long flags; 76 77 local_irq_save(flags); 78 preempt_disable(); 79 arch_spin_lock(&rtas.lock); 80 return flags; 81 } 82 83 static void unlock_rtas(unsigned long flags) 84 { 85 arch_spin_unlock(&rtas.lock); 86 local_irq_restore(flags); 87 preempt_enable(); 88 } 89 90 /* 91 * call_rtas_display_status and call_rtas_display_status_delay 92 * are designed only for very early low-level debugging, which 93 * is why the token is hard-coded to 10. 94 */ 95 static void call_rtas_display_status(unsigned char c) 96 { 97 unsigned long s; 98 99 if (!rtas.base) 100 return; 101 102 s = lock_rtas(); 103 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c); 104 unlock_rtas(s); 105 } 106 107 static void call_rtas_display_status_delay(char c) 108 { 109 static int pending_newline = 0; /* did last write end with unprinted newline? */ 110 static int width = 16; 111 112 if (c == '\n') { 113 while (width-- > 0) 114 call_rtas_display_status(' '); 115 width = 16; 116 mdelay(500); 117 pending_newline = 1; 118 } else { 119 if (pending_newline) { 120 call_rtas_display_status('\r'); 121 call_rtas_display_status('\n'); 122 } 123 pending_newline = 0; 124 if (width--) { 125 call_rtas_display_status(c); 126 udelay(10000); 127 } 128 } 129 } 130 131 void __init udbg_init_rtas_panel(void) 132 { 133 udbg_putc = call_rtas_display_status_delay; 134 } 135 136 #ifdef CONFIG_UDBG_RTAS_CONSOLE 137 138 /* If you think you're dying before early_init_dt_scan_rtas() does its 139 * work, you can hard code the token values for your firmware here and 140 * hardcode rtas.base/entry etc. 141 */ 142 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE; 143 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE; 144 145 static void udbg_rtascon_putc(char c) 146 { 147 int tries; 148 149 if (!rtas.base) 150 return; 151 152 /* Add CRs before LFs */ 153 if (c == '\n') 154 udbg_rtascon_putc('\r'); 155 156 /* if there is more than one character to be displayed, wait a bit */ 157 for (tries = 0; tries < 16; tries++) { 158 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0) 159 break; 160 udelay(1000); 161 } 162 } 163 164 static int udbg_rtascon_getc_poll(void) 165 { 166 int c; 167 168 if (!rtas.base) 169 return -1; 170 171 if (rtas_call(rtas_getchar_token, 0, 2, &c)) 172 return -1; 173 174 return c; 175 } 176 177 static int udbg_rtascon_getc(void) 178 { 179 int c; 180 181 while ((c = udbg_rtascon_getc_poll()) == -1) 182 ; 183 184 return c; 185 } 186 187 188 void __init udbg_init_rtas_console(void) 189 { 190 udbg_putc = udbg_rtascon_putc; 191 udbg_getc = udbg_rtascon_getc; 192 udbg_getc_poll = udbg_rtascon_getc_poll; 193 } 194 #endif /* CONFIG_UDBG_RTAS_CONSOLE */ 195 196 void rtas_progress(char *s, unsigned short hex) 197 { 198 struct device_node *root; 199 int width; 200 const __be32 *p; 201 char *os; 202 static int display_character, set_indicator; 203 static int display_width, display_lines, form_feed; 204 static const int *row_width; 205 static DEFINE_SPINLOCK(progress_lock); 206 static int current_line; 207 static int pending_newline = 0; /* did last write end with unprinted newline? */ 208 209 if (!rtas.base) 210 return; 211 212 if (display_width == 0) { 213 display_width = 0x10; 214 if ((root = of_find_node_by_path("/rtas"))) { 215 if ((p = of_get_property(root, 216 "ibm,display-line-length", NULL))) 217 display_width = be32_to_cpu(*p); 218 if ((p = of_get_property(root, 219 "ibm,form-feed", NULL))) 220 form_feed = be32_to_cpu(*p); 221 if ((p = of_get_property(root, 222 "ibm,display-number-of-lines", NULL))) 223 display_lines = be32_to_cpu(*p); 224 row_width = of_get_property(root, 225 "ibm,display-truncation-length", NULL); 226 of_node_put(root); 227 } 228 display_character = rtas_token("display-character"); 229 set_indicator = rtas_token("set-indicator"); 230 } 231 232 if (display_character == RTAS_UNKNOWN_SERVICE) { 233 /* use hex display if available */ 234 if (set_indicator != RTAS_UNKNOWN_SERVICE) 235 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); 236 return; 237 } 238 239 spin_lock(&progress_lock); 240 241 /* 242 * Last write ended with newline, but we didn't print it since 243 * it would just clear the bottom line of output. Print it now 244 * instead. 245 * 246 * If no newline is pending and form feed is supported, clear the 247 * display with a form feed; otherwise, print a CR to start output 248 * at the beginning of the line. 249 */ 250 if (pending_newline) { 251 rtas_call(display_character, 1, 1, NULL, '\r'); 252 rtas_call(display_character, 1, 1, NULL, '\n'); 253 pending_newline = 0; 254 } else { 255 current_line = 0; 256 if (form_feed) 257 rtas_call(display_character, 1, 1, NULL, 258 (char)form_feed); 259 else 260 rtas_call(display_character, 1, 1, NULL, '\r'); 261 } 262 263 if (row_width) 264 width = row_width[current_line]; 265 else 266 width = display_width; 267 os = s; 268 while (*os) { 269 if (*os == '\n' || *os == '\r') { 270 /* If newline is the last character, save it 271 * until next call to avoid bumping up the 272 * display output. 273 */ 274 if (*os == '\n' && !os[1]) { 275 pending_newline = 1; 276 current_line++; 277 if (current_line > display_lines-1) 278 current_line = display_lines-1; 279 spin_unlock(&progress_lock); 280 return; 281 } 282 283 /* RTAS wants CR-LF, not just LF */ 284 285 if (*os == '\n') { 286 rtas_call(display_character, 1, 1, NULL, '\r'); 287 rtas_call(display_character, 1, 1, NULL, '\n'); 288 } else { 289 /* CR might be used to re-draw a line, so we'll 290 * leave it alone and not add LF. 291 */ 292 rtas_call(display_character, 1, 1, NULL, *os); 293 } 294 295 if (row_width) 296 width = row_width[current_line]; 297 else 298 width = display_width; 299 } else { 300 width--; 301 rtas_call(display_character, 1, 1, NULL, *os); 302 } 303 304 os++; 305 306 /* if we overwrite the screen length */ 307 if (width <= 0) 308 while ((*os != 0) && (*os != '\n') && (*os != '\r')) 309 os++; 310 } 311 312 spin_unlock(&progress_lock); 313 } 314 EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ 315 316 int rtas_token(const char *service) 317 { 318 const __be32 *tokp; 319 if (rtas.dev == NULL) 320 return RTAS_UNKNOWN_SERVICE; 321 tokp = of_get_property(rtas.dev, service, NULL); 322 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE; 323 } 324 EXPORT_SYMBOL(rtas_token); 325 326 int rtas_service_present(const char *service) 327 { 328 return rtas_token(service) != RTAS_UNKNOWN_SERVICE; 329 } 330 EXPORT_SYMBOL(rtas_service_present); 331 332 #ifdef CONFIG_RTAS_ERROR_LOGGING 333 /* 334 * Return the firmware-specified size of the error log buffer 335 * for all rtas calls that require an error buffer argument. 336 * This includes 'check-exception' and 'rtas-last-error'. 337 */ 338 int rtas_get_error_log_max(void) 339 { 340 static int rtas_error_log_max; 341 if (rtas_error_log_max) 342 return rtas_error_log_max; 343 344 rtas_error_log_max = rtas_token ("rtas-error-log-max"); 345 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || 346 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { 347 printk (KERN_WARNING "RTAS: bad log buffer size %d\n", 348 rtas_error_log_max); 349 rtas_error_log_max = RTAS_ERROR_LOG_MAX; 350 } 351 return rtas_error_log_max; 352 } 353 EXPORT_SYMBOL(rtas_get_error_log_max); 354 355 356 static char rtas_err_buf[RTAS_ERROR_LOG_MAX]; 357 static int rtas_last_error_token; 358 359 /** Return a copy of the detailed error text associated with the 360 * most recent failed call to rtas. Because the error text 361 * might go stale if there are any other intervening rtas calls, 362 * this routine must be called atomically with whatever produced 363 * the error (i.e. with rtas.lock still held from the previous call). 364 */ 365 static char *__fetch_rtas_last_error(char *altbuf) 366 { 367 struct rtas_args err_args, save_args; 368 u32 bufsz; 369 char *buf = NULL; 370 371 if (rtas_last_error_token == -1) 372 return NULL; 373 374 bufsz = rtas_get_error_log_max(); 375 376 err_args.token = cpu_to_be32(rtas_last_error_token); 377 err_args.nargs = cpu_to_be32(2); 378 err_args.nret = cpu_to_be32(1); 379 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf)); 380 err_args.args[1] = cpu_to_be32(bufsz); 381 err_args.args[2] = 0; 382 383 save_args = rtas.args; 384 rtas.args = err_args; 385 386 enter_rtas(__pa(&rtas.args)); 387 388 err_args = rtas.args; 389 rtas.args = save_args; 390 391 /* Log the error in the unlikely case that there was one. */ 392 if (unlikely(err_args.args[2] == 0)) { 393 if (altbuf) { 394 buf = altbuf; 395 } else { 396 buf = rtas_err_buf; 397 if (slab_is_available()) 398 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); 399 } 400 if (buf) 401 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); 402 } 403 404 return buf; 405 } 406 407 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL) 408 409 #else /* CONFIG_RTAS_ERROR_LOGGING */ 410 #define __fetch_rtas_last_error(x) NULL 411 #define get_errorlog_buffer() NULL 412 #endif 413 414 415 static void 416 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, 417 va_list list) 418 { 419 int i; 420 421 args->token = cpu_to_be32(token); 422 args->nargs = cpu_to_be32(nargs); 423 args->nret = cpu_to_be32(nret); 424 args->rets = &(args->args[nargs]); 425 426 for (i = 0; i < nargs; ++i) 427 args->args[i] = cpu_to_be32(va_arg(list, __u32)); 428 429 for (i = 0; i < nret; ++i) 430 args->rets[i] = 0; 431 432 enter_rtas(__pa(args)); 433 } 434 435 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...) 436 { 437 va_list list; 438 439 va_start(list, nret); 440 va_rtas_call_unlocked(args, token, nargs, nret, list); 441 va_end(list); 442 } 443 444 int rtas_call(int token, int nargs, int nret, int *outputs, ...) 445 { 446 va_list list; 447 int i; 448 unsigned long s; 449 struct rtas_args *rtas_args; 450 char *buff_copy = NULL; 451 int ret; 452 453 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) 454 return -1; 455 456 s = lock_rtas(); 457 458 /* We use the global rtas args buffer */ 459 rtas_args = &rtas.args; 460 461 va_start(list, outputs); 462 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list); 463 va_end(list); 464 465 /* A -1 return code indicates that the last command couldn't 466 be completed due to a hardware error. */ 467 if (be32_to_cpu(rtas_args->rets[0]) == -1) 468 buff_copy = __fetch_rtas_last_error(NULL); 469 470 if (nret > 1 && outputs != NULL) 471 for (i = 0; i < nret-1; ++i) 472 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]); 473 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0; 474 475 unlock_rtas(s); 476 477 if (buff_copy) { 478 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); 479 if (slab_is_available()) 480 kfree(buff_copy); 481 } 482 return ret; 483 } 484 EXPORT_SYMBOL(rtas_call); 485 486 /* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status 487 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds. 488 */ 489 unsigned int rtas_busy_delay_time(int status) 490 { 491 int order; 492 unsigned int ms = 0; 493 494 if (status == RTAS_BUSY) { 495 ms = 1; 496 } else if (status >= RTAS_EXTENDED_DELAY_MIN && 497 status <= RTAS_EXTENDED_DELAY_MAX) { 498 order = status - RTAS_EXTENDED_DELAY_MIN; 499 for (ms = 1; order > 0; order--) 500 ms *= 10; 501 } 502 503 return ms; 504 } 505 EXPORT_SYMBOL(rtas_busy_delay_time); 506 507 /* For an RTAS busy status code, perform the hinted delay. */ 508 unsigned int rtas_busy_delay(int status) 509 { 510 unsigned int ms; 511 512 might_sleep(); 513 ms = rtas_busy_delay_time(status); 514 if (ms && need_resched()) 515 msleep(ms); 516 517 return ms; 518 } 519 EXPORT_SYMBOL(rtas_busy_delay); 520 521 static int rtas_error_rc(int rtas_rc) 522 { 523 int rc; 524 525 switch (rtas_rc) { 526 case -1: /* Hardware Error */ 527 rc = -EIO; 528 break; 529 case -3: /* Bad indicator/domain/etc */ 530 rc = -EINVAL; 531 break; 532 case -9000: /* Isolation error */ 533 rc = -EFAULT; 534 break; 535 case -9001: /* Outstanding TCE/PTE */ 536 rc = -EEXIST; 537 break; 538 case -9002: /* No usable slot */ 539 rc = -ENODEV; 540 break; 541 default: 542 printk(KERN_ERR "%s: unexpected RTAS error %d\n", 543 __func__, rtas_rc); 544 rc = -ERANGE; 545 break; 546 } 547 return rc; 548 } 549 550 int rtas_get_power_level(int powerdomain, int *level) 551 { 552 int token = rtas_token("get-power-level"); 553 int rc; 554 555 if (token == RTAS_UNKNOWN_SERVICE) 556 return -ENOENT; 557 558 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) 559 udelay(1); 560 561 if (rc < 0) 562 return rtas_error_rc(rc); 563 return rc; 564 } 565 EXPORT_SYMBOL(rtas_get_power_level); 566 567 int rtas_set_power_level(int powerdomain, int level, int *setlevel) 568 { 569 int token = rtas_token("set-power-level"); 570 int rc; 571 572 if (token == RTAS_UNKNOWN_SERVICE) 573 return -ENOENT; 574 575 do { 576 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); 577 } while (rtas_busy_delay(rc)); 578 579 if (rc < 0) 580 return rtas_error_rc(rc); 581 return rc; 582 } 583 EXPORT_SYMBOL(rtas_set_power_level); 584 585 int rtas_get_sensor(int sensor, int index, int *state) 586 { 587 int token = rtas_token("get-sensor-state"); 588 int rc; 589 590 if (token == RTAS_UNKNOWN_SERVICE) 591 return -ENOENT; 592 593 do { 594 rc = rtas_call(token, 2, 2, state, sensor, index); 595 } while (rtas_busy_delay(rc)); 596 597 if (rc < 0) 598 return rtas_error_rc(rc); 599 return rc; 600 } 601 EXPORT_SYMBOL(rtas_get_sensor); 602 603 int rtas_get_sensor_fast(int sensor, int index, int *state) 604 { 605 int token = rtas_token("get-sensor-state"); 606 int rc; 607 608 if (token == RTAS_UNKNOWN_SERVICE) 609 return -ENOENT; 610 611 rc = rtas_call(token, 2, 2, state, sensor, index); 612 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 613 rc <= RTAS_EXTENDED_DELAY_MAX)); 614 615 if (rc < 0) 616 return rtas_error_rc(rc); 617 return rc; 618 } 619 620 bool rtas_indicator_present(int token, int *maxindex) 621 { 622 int proplen, count, i; 623 const struct indicator_elem { 624 __be32 token; 625 __be32 maxindex; 626 } *indicators; 627 628 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen); 629 if (!indicators) 630 return false; 631 632 count = proplen / sizeof(struct indicator_elem); 633 634 for (i = 0; i < count; i++) { 635 if (__be32_to_cpu(indicators[i].token) != token) 636 continue; 637 if (maxindex) 638 *maxindex = __be32_to_cpu(indicators[i].maxindex); 639 return true; 640 } 641 642 return false; 643 } 644 EXPORT_SYMBOL(rtas_indicator_present); 645 646 int rtas_set_indicator(int indicator, int index, int new_value) 647 { 648 int token = rtas_token("set-indicator"); 649 int rc; 650 651 if (token == RTAS_UNKNOWN_SERVICE) 652 return -ENOENT; 653 654 do { 655 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 656 } while (rtas_busy_delay(rc)); 657 658 if (rc < 0) 659 return rtas_error_rc(rc); 660 return rc; 661 } 662 EXPORT_SYMBOL(rtas_set_indicator); 663 664 /* 665 * Ignoring RTAS extended delay 666 */ 667 int rtas_set_indicator_fast(int indicator, int index, int new_value) 668 { 669 int rc; 670 int token = rtas_token("set-indicator"); 671 672 if (token == RTAS_UNKNOWN_SERVICE) 673 return -ENOENT; 674 675 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 676 677 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN && 678 rc <= RTAS_EXTENDED_DELAY_MAX)); 679 680 if (rc < 0) 681 return rtas_error_rc(rc); 682 683 return rc; 684 } 685 686 void __noreturn rtas_restart(char *cmd) 687 { 688 if (rtas_flash_term_hook) 689 rtas_flash_term_hook(SYS_RESTART); 690 printk("RTAS system-reboot returned %d\n", 691 rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); 692 for (;;); 693 } 694 695 void rtas_power_off(void) 696 { 697 if (rtas_flash_term_hook) 698 rtas_flash_term_hook(SYS_POWER_OFF); 699 /* allow power on only with power button press */ 700 printk("RTAS power-off returned %d\n", 701 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 702 for (;;); 703 } 704 705 void __noreturn rtas_halt(void) 706 { 707 if (rtas_flash_term_hook) 708 rtas_flash_term_hook(SYS_HALT); 709 /* allow power on only with power button press */ 710 printk("RTAS power-off returned %d\n", 711 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 712 for (;;); 713 } 714 715 /* Must be in the RMO region, so we place it here */ 716 static char rtas_os_term_buf[2048]; 717 718 void rtas_os_term(char *str) 719 { 720 int status; 721 722 /* 723 * Firmware with the ibm,extended-os-term property is guaranteed 724 * to always return from an ibm,os-term call. Earlier versions without 725 * this property may terminate the partition which we want to avoid 726 * since it interferes with panic_timeout. 727 */ 728 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") || 729 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term")) 730 return; 731 732 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); 733 734 do { 735 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL, 736 __pa(rtas_os_term_buf)); 737 } while (rtas_busy_delay(status)); 738 739 if (status != 0) 740 printk(KERN_EMERG "ibm,os-term call failed %d\n", status); 741 } 742 743 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE; 744 #ifdef CONFIG_PPC_PSERIES 745 static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done) 746 { 747 u16 slb_size = mmu_slb_size; 748 int rc = H_MULTI_THREADS_ACTIVE; 749 int cpu; 750 751 slb_set_size(SLB_MIN_SIZE); 752 printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id()); 753 754 while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) && 755 !atomic_read(&data->error)) 756 rc = rtas_call(data->token, 0, 1, NULL); 757 758 if (rc || atomic_read(&data->error)) { 759 printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc); 760 slb_set_size(slb_size); 761 } 762 763 if (atomic_read(&data->error)) 764 rc = atomic_read(&data->error); 765 766 atomic_set(&data->error, rc); 767 pSeries_coalesce_init(); 768 769 if (wake_when_done) { 770 atomic_set(&data->done, 1); 771 772 for_each_online_cpu(cpu) 773 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu)); 774 } 775 776 if (atomic_dec_return(&data->working) == 0) 777 complete(data->complete); 778 779 return rc; 780 } 781 782 int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data) 783 { 784 atomic_inc(&data->working); 785 return __rtas_suspend_last_cpu(data, 0); 786 } 787 788 static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done) 789 { 790 long rc = H_SUCCESS; 791 unsigned long msr_save; 792 int cpu; 793 794 atomic_inc(&data->working); 795 796 /* really need to ensure MSR.EE is off for H_JOIN */ 797 msr_save = mfmsr(); 798 mtmsr(msr_save & ~(MSR_EE)); 799 800 while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error)) 801 rc = plpar_hcall_norets(H_JOIN); 802 803 mtmsr(msr_save); 804 805 if (rc == H_SUCCESS) { 806 /* This cpu was prodded and the suspend is complete. */ 807 goto out; 808 } else if (rc == H_CONTINUE) { 809 /* All other cpus are in H_JOIN, this cpu does 810 * the suspend. 811 */ 812 return __rtas_suspend_last_cpu(data, wake_when_done); 813 } else { 814 printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n", 815 smp_processor_id(), rc); 816 atomic_set(&data->error, rc); 817 } 818 819 if (wake_when_done) { 820 atomic_set(&data->done, 1); 821 822 /* This cpu did the suspend or got an error; in either case, 823 * we need to prod all other other cpus out of join state. 824 * Extra prods are harmless. 825 */ 826 for_each_online_cpu(cpu) 827 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu)); 828 } 829 out: 830 if (atomic_dec_return(&data->working) == 0) 831 complete(data->complete); 832 return rc; 833 } 834 835 int rtas_suspend_cpu(struct rtas_suspend_me_data *data) 836 { 837 return __rtas_suspend_cpu(data, 0); 838 } 839 840 static void rtas_percpu_suspend_me(void *info) 841 { 842 __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1); 843 } 844 845 enum rtas_cpu_state { 846 DOWN, 847 UP, 848 }; 849 850 #ifndef CONFIG_SMP 851 static int rtas_cpu_state_change_mask(enum rtas_cpu_state state, 852 cpumask_var_t cpus) 853 { 854 if (!cpumask_empty(cpus)) { 855 cpumask_clear(cpus); 856 return -EINVAL; 857 } else 858 return 0; 859 } 860 #else 861 /* On return cpumask will be altered to indicate CPUs changed. 862 * CPUs with states changed will be set in the mask, 863 * CPUs with status unchanged will be unset in the mask. */ 864 static int rtas_cpu_state_change_mask(enum rtas_cpu_state state, 865 cpumask_var_t cpus) 866 { 867 int cpu; 868 int cpuret = 0; 869 int ret = 0; 870 871 if (cpumask_empty(cpus)) 872 return 0; 873 874 for_each_cpu(cpu, cpus) { 875 struct device *dev = get_cpu_device(cpu); 876 877 switch (state) { 878 case DOWN: 879 cpuret = device_offline(dev); 880 break; 881 case UP: 882 cpuret = device_online(dev); 883 break; 884 } 885 if (cpuret < 0) { 886 pr_debug("%s: cpu_%s for cpu#%d returned %d.\n", 887 __func__, 888 ((state == UP) ? "up" : "down"), 889 cpu, cpuret); 890 if (!ret) 891 ret = cpuret; 892 if (state == UP) { 893 /* clear bits for unchanged cpus, return */ 894 cpumask_shift_right(cpus, cpus, cpu); 895 cpumask_shift_left(cpus, cpus, cpu); 896 break; 897 } else { 898 /* clear bit for unchanged cpu, continue */ 899 cpumask_clear_cpu(cpu, cpus); 900 } 901 } 902 cond_resched(); 903 } 904 905 return ret; 906 } 907 #endif 908 909 int rtas_online_cpus_mask(cpumask_var_t cpus) 910 { 911 int ret; 912 913 ret = rtas_cpu_state_change_mask(UP, cpus); 914 915 if (ret) { 916 cpumask_var_t tmp_mask; 917 918 if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL)) 919 return ret; 920 921 /* Use tmp_mask to preserve cpus mask from first failure */ 922 cpumask_copy(tmp_mask, cpus); 923 rtas_offline_cpus_mask(tmp_mask); 924 free_cpumask_var(tmp_mask); 925 } 926 927 return ret; 928 } 929 930 int rtas_offline_cpus_mask(cpumask_var_t cpus) 931 { 932 return rtas_cpu_state_change_mask(DOWN, cpus); 933 } 934 935 int rtas_ibm_suspend_me(u64 handle) 936 { 937 long state; 938 long rc; 939 unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; 940 struct rtas_suspend_me_data data; 941 DECLARE_COMPLETION_ONSTACK(done); 942 cpumask_var_t offline_mask; 943 int cpuret; 944 945 if (!rtas_service_present("ibm,suspend-me")) 946 return -ENOSYS; 947 948 /* Make sure the state is valid */ 949 rc = plpar_hcall(H_VASI_STATE, retbuf, handle); 950 951 state = retbuf[0]; 952 953 if (rc) { 954 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc); 955 return rc; 956 } else if (state == H_VASI_ENABLED) { 957 return -EAGAIN; 958 } else if (state != H_VASI_SUSPENDING) { 959 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n", 960 state); 961 return -EIO; 962 } 963 964 if (!alloc_cpumask_var(&offline_mask, GFP_KERNEL)) 965 return -ENOMEM; 966 967 atomic_set(&data.working, 0); 968 atomic_set(&data.done, 0); 969 atomic_set(&data.error, 0); 970 data.token = rtas_token("ibm,suspend-me"); 971 data.complete = &done; 972 973 lock_device_hotplug(); 974 975 /* All present CPUs must be online */ 976 cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask); 977 cpuret = rtas_online_cpus_mask(offline_mask); 978 if (cpuret) { 979 pr_err("%s: Could not bring present CPUs online.\n", __func__); 980 atomic_set(&data.error, cpuret); 981 goto out; 982 } 983 984 cpu_hotplug_disable(); 985 986 /* Check if we raced with a CPU-Offline Operation */ 987 if (!cpumask_equal(cpu_present_mask, cpu_online_mask)) { 988 pr_info("%s: Raced against a concurrent CPU-Offline\n", __func__); 989 atomic_set(&data.error, -EAGAIN); 990 goto out_hotplug_enable; 991 } 992 993 /* Call function on all CPUs. One of us will make the 994 * rtas call 995 */ 996 on_each_cpu(rtas_percpu_suspend_me, &data, 0); 997 998 wait_for_completion(&done); 999 1000 if (atomic_read(&data.error) != 0) 1001 printk(KERN_ERR "Error doing global join\n"); 1002 1003 out_hotplug_enable: 1004 cpu_hotplug_enable(); 1005 1006 /* Take down CPUs not online prior to suspend */ 1007 cpuret = rtas_offline_cpus_mask(offline_mask); 1008 if (cpuret) 1009 pr_warn("%s: Could not restore CPUs to offline state.\n", 1010 __func__); 1011 1012 out: 1013 unlock_device_hotplug(); 1014 free_cpumask_var(offline_mask); 1015 return atomic_read(&data.error); 1016 } 1017 #else /* CONFIG_PPC_PSERIES */ 1018 int rtas_ibm_suspend_me(u64 handle) 1019 { 1020 return -ENOSYS; 1021 } 1022 #endif 1023 1024 /** 1025 * Find a specific pseries error log in an RTAS extended event log. 1026 * @log: RTAS error/event log 1027 * @section_id: two character section identifier 1028 * 1029 * Returns a pointer to the specified errorlog or NULL if not found. 1030 */ 1031 struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, 1032 uint16_t section_id) 1033 { 1034 struct rtas_ext_event_log_v6 *ext_log = 1035 (struct rtas_ext_event_log_v6 *)log->buffer; 1036 struct pseries_errorlog *sect; 1037 unsigned char *p, *log_end; 1038 uint32_t ext_log_length = rtas_error_extended_log_length(log); 1039 uint8_t log_format = rtas_ext_event_log_format(ext_log); 1040 uint32_t company_id = rtas_ext_event_company_id(ext_log); 1041 1042 /* Check that we understand the format */ 1043 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) || 1044 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || 1045 company_id != RTAS_V6EXT_COMPANY_ID_IBM) 1046 return NULL; 1047 1048 log_end = log->buffer + ext_log_length; 1049 p = ext_log->vendor_log; 1050 1051 while (p < log_end) { 1052 sect = (struct pseries_errorlog *)p; 1053 if (pseries_errorlog_id(sect) == section_id) 1054 return sect; 1055 p += pseries_errorlog_length(sect); 1056 } 1057 1058 return NULL; 1059 } 1060 1061 /* We assume to be passed big endian arguments */ 1062 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) 1063 { 1064 struct rtas_args args; 1065 unsigned long flags; 1066 char *buff_copy, *errbuf = NULL; 1067 int nargs, nret, token; 1068 1069 if (!capable(CAP_SYS_ADMIN)) 1070 return -EPERM; 1071 1072 if (!rtas.entry) 1073 return -EINVAL; 1074 1075 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) 1076 return -EFAULT; 1077 1078 nargs = be32_to_cpu(args.nargs); 1079 nret = be32_to_cpu(args.nret); 1080 token = be32_to_cpu(args.token); 1081 1082 if (nargs >= ARRAY_SIZE(args.args) 1083 || nret > ARRAY_SIZE(args.args) 1084 || nargs + nret > ARRAY_SIZE(args.args)) 1085 return -EINVAL; 1086 1087 /* Copy in args. */ 1088 if (copy_from_user(args.args, uargs->args, 1089 nargs * sizeof(rtas_arg_t)) != 0) 1090 return -EFAULT; 1091 1092 if (token == RTAS_UNKNOWN_SERVICE) 1093 return -EINVAL; 1094 1095 args.rets = &args.args[nargs]; 1096 memset(args.rets, 0, nret * sizeof(rtas_arg_t)); 1097 1098 /* Need to handle ibm,suspend_me call specially */ 1099 if (token == ibm_suspend_me_token) { 1100 1101 /* 1102 * rtas_ibm_suspend_me assumes the streamid handle is in cpu 1103 * endian, or at least the hcall within it requires it. 1104 */ 1105 int rc = 0; 1106 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) 1107 | be32_to_cpu(args.args[1]); 1108 rc = rtas_ibm_suspend_me(handle); 1109 if (rc == -EAGAIN) 1110 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); 1111 else if (rc == -EIO) 1112 args.rets[0] = cpu_to_be32(-1); 1113 else if (rc) 1114 return rc; 1115 goto copy_return; 1116 } 1117 1118 buff_copy = get_errorlog_buffer(); 1119 1120 flags = lock_rtas(); 1121 1122 rtas.args = args; 1123 enter_rtas(__pa(&rtas.args)); 1124 args = rtas.args; 1125 1126 /* A -1 return code indicates that the last command couldn't 1127 be completed due to a hardware error. */ 1128 if (be32_to_cpu(args.rets[0]) == -1) 1129 errbuf = __fetch_rtas_last_error(buff_copy); 1130 1131 unlock_rtas(flags); 1132 1133 if (buff_copy) { 1134 if (errbuf) 1135 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); 1136 kfree(buff_copy); 1137 } 1138 1139 copy_return: 1140 /* Copy out args. */ 1141 if (copy_to_user(uargs->args + nargs, 1142 args.args + nargs, 1143 nret * sizeof(rtas_arg_t)) != 0) 1144 return -EFAULT; 1145 1146 return 0; 1147 } 1148 1149 /* 1150 * Call early during boot, before mem init, to retrieve the RTAS 1151 * information from the device-tree and allocate the RMO buffer for userland 1152 * accesses. 1153 */ 1154 void __init rtas_initialize(void) 1155 { 1156 unsigned long rtas_region = RTAS_INSTANTIATE_MAX; 1157 u32 base, size, entry; 1158 int no_base, no_size, no_entry; 1159 1160 /* Get RTAS dev node and fill up our "rtas" structure with infos 1161 * about it. 1162 */ 1163 rtas.dev = of_find_node_by_name(NULL, "rtas"); 1164 if (!rtas.dev) 1165 return; 1166 1167 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base); 1168 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size); 1169 if (no_base || no_size) { 1170 of_node_put(rtas.dev); 1171 rtas.dev = NULL; 1172 return; 1173 } 1174 1175 rtas.base = base; 1176 rtas.size = size; 1177 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry); 1178 rtas.entry = no_entry ? rtas.base : entry; 1179 1180 /* If RTAS was found, allocate the RMO buffer for it and look for 1181 * the stop-self token if any 1182 */ 1183 #ifdef CONFIG_PPC64 1184 if (firmware_has_feature(FW_FEATURE_LPAR)) { 1185 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX); 1186 ibm_suspend_me_token = rtas_token("ibm,suspend-me"); 1187 } 1188 #endif 1189 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_RMOBUF_MAX, PAGE_SIZE, 1190 0, rtas_region); 1191 if (!rtas_rmo_buf) 1192 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n", 1193 PAGE_SIZE, &rtas_region); 1194 1195 #ifdef CONFIG_RTAS_ERROR_LOGGING 1196 rtas_last_error_token = rtas_token("rtas-last-error"); 1197 #endif 1198 } 1199 1200 int __init early_init_dt_scan_rtas(unsigned long node, 1201 const char *uname, int depth, void *data) 1202 { 1203 const u32 *basep, *entryp, *sizep; 1204 1205 if (depth != 1 || strcmp(uname, "rtas") != 0) 1206 return 0; 1207 1208 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL); 1209 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL); 1210 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL); 1211 1212 if (basep && entryp && sizep) { 1213 rtas.base = *basep; 1214 rtas.entry = *entryp; 1215 rtas.size = *sizep; 1216 } 1217 1218 #ifdef CONFIG_UDBG_RTAS_CONSOLE 1219 basep = of_get_flat_dt_prop(node, "put-term-char", NULL); 1220 if (basep) 1221 rtas_putchar_token = *basep; 1222 1223 basep = of_get_flat_dt_prop(node, "get-term-char", NULL); 1224 if (basep) 1225 rtas_getchar_token = *basep; 1226 1227 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE && 1228 rtas_getchar_token != RTAS_UNKNOWN_SERVICE) 1229 udbg_init_rtas_console(); 1230 1231 #endif 1232 1233 /* break now */ 1234 return 1; 1235 } 1236 1237 static arch_spinlock_t timebase_lock; 1238 static u64 timebase = 0; 1239 1240 void rtas_give_timebase(void) 1241 { 1242 unsigned long flags; 1243 1244 local_irq_save(flags); 1245 hard_irq_disable(); 1246 arch_spin_lock(&timebase_lock); 1247 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 1248 timebase = get_tb(); 1249 arch_spin_unlock(&timebase_lock); 1250 1251 while (timebase) 1252 barrier(); 1253 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 1254 local_irq_restore(flags); 1255 } 1256 1257 void rtas_take_timebase(void) 1258 { 1259 while (!timebase) 1260 barrier(); 1261 arch_spin_lock(&timebase_lock); 1262 set_tb(timebase >> 32, timebase & 0xffffffff); 1263 timebase = 0; 1264 arch_spin_unlock(&timebase_lock); 1265 } 1266