1 /* 2 * 3 * Procedures for interfacing to the RTAS on CHRP machines. 4 * 5 * Peter Bergner, IBM March 2001. 6 * Copyright (C) 2001 IBM. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <stdarg.h> 15 #include <linux/kernel.h> 16 #include <linux/types.h> 17 #include <linux/spinlock.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 21 #include <asm/prom.h> 22 #include <asm/rtas.h> 23 #include <asm/semaphore.h> 24 #include <asm/machdep.h> 25 #include <asm/page.h> 26 #include <asm/param.h> 27 #include <asm/system.h> 28 #include <asm/delay.h> 29 #include <asm/uaccess.h> 30 #include <asm/lmb.h> 31 #ifdef CONFIG_PPC64 32 #include <asm/systemcfg.h> 33 #endif 34 35 struct rtas_t rtas = { 36 .lock = SPIN_LOCK_UNLOCKED 37 }; 38 39 EXPORT_SYMBOL(rtas); 40 41 DEFINE_SPINLOCK(rtas_data_buf_lock); 42 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; 43 unsigned long rtas_rmo_buf; 44 45 /* 46 * If non-NULL, this gets called when the kernel terminates. 47 * This is done like this so rtas_flash can be a module. 48 */ 49 void (*rtas_flash_term_hook)(int); 50 EXPORT_SYMBOL(rtas_flash_term_hook); 51 52 /* 53 * call_rtas_display_status and call_rtas_display_status_delay 54 * are designed only for very early low-level debugging, which 55 * is why the token is hard-coded to 10. 56 */ 57 void call_rtas_display_status(unsigned char c) 58 { 59 struct rtas_args *args = &rtas.args; 60 unsigned long s; 61 62 if (!rtas.base) 63 return; 64 spin_lock_irqsave(&rtas.lock, s); 65 66 args->token = 10; 67 args->nargs = 1; 68 args->nret = 1; 69 args->rets = (rtas_arg_t *)&(args->args[1]); 70 args->args[0] = (int)c; 71 72 enter_rtas(__pa(args)); 73 74 spin_unlock_irqrestore(&rtas.lock, s); 75 } 76 77 void call_rtas_display_status_delay(unsigned char c) 78 { 79 static int pending_newline = 0; /* did last write end with unprinted newline? */ 80 static int width = 16; 81 82 if (c == '\n') { 83 while (width-- > 0) 84 call_rtas_display_status(' '); 85 width = 16; 86 udelay(500000); 87 pending_newline = 1; 88 } else { 89 if (pending_newline) { 90 call_rtas_display_status('\r'); 91 call_rtas_display_status('\n'); 92 } 93 pending_newline = 0; 94 if (width--) { 95 call_rtas_display_status(c); 96 udelay(10000); 97 } 98 } 99 } 100 101 void rtas_progress(char *s, unsigned short hex) 102 { 103 struct device_node *root; 104 int width, *p; 105 char *os; 106 static int display_character, set_indicator; 107 static int display_width, display_lines, *row_width, form_feed; 108 static DEFINE_SPINLOCK(progress_lock); 109 static int current_line; 110 static int pending_newline = 0; /* did last write end with unprinted newline? */ 111 112 if (!rtas.base) 113 return; 114 115 if (display_width == 0) { 116 display_width = 0x10; 117 if ((root = find_path_device("/rtas"))) { 118 if ((p = (unsigned int *)get_property(root, 119 "ibm,display-line-length", NULL))) 120 display_width = *p; 121 if ((p = (unsigned int *)get_property(root, 122 "ibm,form-feed", NULL))) 123 form_feed = *p; 124 if ((p = (unsigned int *)get_property(root, 125 "ibm,display-number-of-lines", NULL))) 126 display_lines = *p; 127 row_width = (unsigned int *)get_property(root, 128 "ibm,display-truncation-length", NULL); 129 } 130 display_character = rtas_token("display-character"); 131 set_indicator = rtas_token("set-indicator"); 132 } 133 134 if (display_character == RTAS_UNKNOWN_SERVICE) { 135 /* use hex display if available */ 136 if (set_indicator != RTAS_UNKNOWN_SERVICE) 137 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex); 138 return; 139 } 140 141 spin_lock(&progress_lock); 142 143 /* 144 * Last write ended with newline, but we didn't print it since 145 * it would just clear the bottom line of output. Print it now 146 * instead. 147 * 148 * If no newline is pending and form feed is supported, clear the 149 * display with a form feed; otherwise, print a CR to start output 150 * at the beginning of the line. 151 */ 152 if (pending_newline) { 153 rtas_call(display_character, 1, 1, NULL, '\r'); 154 rtas_call(display_character, 1, 1, NULL, '\n'); 155 pending_newline = 0; 156 } else { 157 current_line = 0; 158 if (form_feed) 159 rtas_call(display_character, 1, 1, NULL, 160 (char)form_feed); 161 else 162 rtas_call(display_character, 1, 1, NULL, '\r'); 163 } 164 165 if (row_width) 166 width = row_width[current_line]; 167 else 168 width = display_width; 169 os = s; 170 while (*os) { 171 if (*os == '\n' || *os == '\r') { 172 /* If newline is the last character, save it 173 * until next call to avoid bumping up the 174 * display output. 175 */ 176 if (*os == '\n' && !os[1]) { 177 pending_newline = 1; 178 current_line++; 179 if (current_line > display_lines-1) 180 current_line = display_lines-1; 181 spin_unlock(&progress_lock); 182 return; 183 } 184 185 /* RTAS wants CR-LF, not just LF */ 186 187 if (*os == '\n') { 188 rtas_call(display_character, 1, 1, NULL, '\r'); 189 rtas_call(display_character, 1, 1, NULL, '\n'); 190 } else { 191 /* CR might be used to re-draw a line, so we'll 192 * leave it alone and not add LF. 193 */ 194 rtas_call(display_character, 1, 1, NULL, *os); 195 } 196 197 if (row_width) 198 width = row_width[current_line]; 199 else 200 width = display_width; 201 } else { 202 width--; 203 rtas_call(display_character, 1, 1, NULL, *os); 204 } 205 206 os++; 207 208 /* if we overwrite the screen length */ 209 if (width <= 0) 210 while ((*os != 0) && (*os != '\n') && (*os != '\r')) 211 os++; 212 } 213 214 spin_unlock(&progress_lock); 215 } 216 EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */ 217 218 int rtas_token(const char *service) 219 { 220 int *tokp; 221 if (rtas.dev == NULL) 222 return RTAS_UNKNOWN_SERVICE; 223 tokp = (int *) get_property(rtas.dev, service, NULL); 224 return tokp ? *tokp : RTAS_UNKNOWN_SERVICE; 225 } 226 227 #ifdef CONFIG_RTAS_ERROR_LOGGING 228 /* 229 * Return the firmware-specified size of the error log buffer 230 * for all rtas calls that require an error buffer argument. 231 * This includes 'check-exception' and 'rtas-last-error'. 232 */ 233 int rtas_get_error_log_max(void) 234 { 235 static int rtas_error_log_max; 236 if (rtas_error_log_max) 237 return rtas_error_log_max; 238 239 rtas_error_log_max = rtas_token ("rtas-error-log-max"); 240 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) || 241 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) { 242 printk (KERN_WARNING "RTAS: bad log buffer size %d\n", 243 rtas_error_log_max); 244 rtas_error_log_max = RTAS_ERROR_LOG_MAX; 245 } 246 return rtas_error_log_max; 247 } 248 EXPORT_SYMBOL(rtas_get_error_log_max); 249 250 251 char rtas_err_buf[RTAS_ERROR_LOG_MAX]; 252 int rtas_last_error_token; 253 254 /** Return a copy of the detailed error text associated with the 255 * most recent failed call to rtas. Because the error text 256 * might go stale if there are any other intervening rtas calls, 257 * this routine must be called atomically with whatever produced 258 * the error (i.e. with rtas.lock still held from the previous call). 259 */ 260 static char *__fetch_rtas_last_error(char *altbuf) 261 { 262 struct rtas_args err_args, save_args; 263 u32 bufsz; 264 char *buf = NULL; 265 266 if (rtas_last_error_token == -1) 267 return NULL; 268 269 bufsz = rtas_get_error_log_max(); 270 271 err_args.token = rtas_last_error_token; 272 err_args.nargs = 2; 273 err_args.nret = 1; 274 err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf); 275 err_args.args[1] = bufsz; 276 err_args.args[2] = 0; 277 278 save_args = rtas.args; 279 rtas.args = err_args; 280 281 enter_rtas(__pa(&rtas.args)); 282 283 err_args = rtas.args; 284 rtas.args = save_args; 285 286 /* Log the error in the unlikely case that there was one. */ 287 if (unlikely(err_args.args[2] == 0)) { 288 if (altbuf) { 289 buf = altbuf; 290 } else { 291 buf = rtas_err_buf; 292 if (mem_init_done) 293 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); 294 } 295 if (buf) 296 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); 297 } 298 299 return buf; 300 } 301 302 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL) 303 304 #else /* CONFIG_RTAS_ERROR_LOGGING */ 305 #define __fetch_rtas_last_error(x) NULL 306 #define get_errorlog_buffer() NULL 307 #endif 308 309 int rtas_call(int token, int nargs, int nret, int *outputs, ...) 310 { 311 va_list list; 312 int i; 313 unsigned long s; 314 struct rtas_args *rtas_args; 315 char *buff_copy = NULL; 316 int ret; 317 318 if (token == RTAS_UNKNOWN_SERVICE) 319 return -1; 320 321 /* Gotta do something different here, use global lock for now... */ 322 spin_lock_irqsave(&rtas.lock, s); 323 rtas_args = &rtas.args; 324 325 rtas_args->token = token; 326 rtas_args->nargs = nargs; 327 rtas_args->nret = nret; 328 rtas_args->rets = (rtas_arg_t *)&(rtas_args->args[nargs]); 329 va_start(list, outputs); 330 for (i = 0; i < nargs; ++i) 331 rtas_args->args[i] = va_arg(list, rtas_arg_t); 332 va_end(list); 333 334 for (i = 0; i < nret; ++i) 335 rtas_args->rets[i] = 0; 336 337 enter_rtas(__pa(rtas_args)); 338 339 /* A -1 return code indicates that the last command couldn't 340 be completed due to a hardware error. */ 341 if (rtas_args->rets[0] == -1) 342 buff_copy = __fetch_rtas_last_error(NULL); 343 344 if (nret > 1 && outputs != NULL) 345 for (i = 0; i < nret-1; ++i) 346 outputs[i] = rtas_args->rets[i+1]; 347 ret = (nret > 0)? rtas_args->rets[0]: 0; 348 349 /* Gotta do something different here, use global lock for now... */ 350 spin_unlock_irqrestore(&rtas.lock, s); 351 352 if (buff_copy) { 353 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); 354 if (mem_init_done) 355 kfree(buff_copy); 356 } 357 return ret; 358 } 359 360 /* Given an RTAS status code of 990n compute the hinted delay of 10^n 361 * (last digit) milliseconds. For now we bound at n=5 (100 sec). 362 */ 363 unsigned int rtas_extended_busy_delay_time(int status) 364 { 365 int order = status - 9900; 366 unsigned long ms; 367 368 if (order < 0) 369 order = 0; /* RTC depends on this for -2 clock busy */ 370 else if (order > 5) 371 order = 5; /* bound */ 372 373 /* Use microseconds for reasonable accuracy */ 374 for (ms = 1; order > 0; order--) 375 ms *= 10; 376 377 return ms; 378 } 379 380 int rtas_error_rc(int rtas_rc) 381 { 382 int rc; 383 384 switch (rtas_rc) { 385 case -1: /* Hardware Error */ 386 rc = -EIO; 387 break; 388 case -3: /* Bad indicator/domain/etc */ 389 rc = -EINVAL; 390 break; 391 case -9000: /* Isolation error */ 392 rc = -EFAULT; 393 break; 394 case -9001: /* Outstanding TCE/PTE */ 395 rc = -EEXIST; 396 break; 397 case -9002: /* No usable slot */ 398 rc = -ENODEV; 399 break; 400 default: 401 printk(KERN_ERR "%s: unexpected RTAS error %d\n", 402 __FUNCTION__, rtas_rc); 403 rc = -ERANGE; 404 break; 405 } 406 return rc; 407 } 408 409 int rtas_get_power_level(int powerdomain, int *level) 410 { 411 int token = rtas_token("get-power-level"); 412 int rc; 413 414 if (token == RTAS_UNKNOWN_SERVICE) 415 return -ENOENT; 416 417 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY) 418 udelay(1); 419 420 if (rc < 0) 421 return rtas_error_rc(rc); 422 return rc; 423 } 424 425 int rtas_set_power_level(int powerdomain, int level, int *setlevel) 426 { 427 int token = rtas_token("set-power-level"); 428 unsigned int wait_time; 429 int rc; 430 431 if (token == RTAS_UNKNOWN_SERVICE) 432 return -ENOENT; 433 434 while (1) { 435 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level); 436 if (rc == RTAS_BUSY) 437 udelay(1); 438 else if (rtas_is_extended_busy(rc)) { 439 wait_time = rtas_extended_busy_delay_time(rc); 440 udelay(wait_time * 1000); 441 } else 442 break; 443 } 444 445 if (rc < 0) 446 return rtas_error_rc(rc); 447 return rc; 448 } 449 450 int rtas_get_sensor(int sensor, int index, int *state) 451 { 452 int token = rtas_token("get-sensor-state"); 453 unsigned int wait_time; 454 int rc; 455 456 if (token == RTAS_UNKNOWN_SERVICE) 457 return -ENOENT; 458 459 while (1) { 460 rc = rtas_call(token, 2, 2, state, sensor, index); 461 if (rc == RTAS_BUSY) 462 udelay(1); 463 else if (rtas_is_extended_busy(rc)) { 464 wait_time = rtas_extended_busy_delay_time(rc); 465 udelay(wait_time * 1000); 466 } else 467 break; 468 } 469 470 if (rc < 0) 471 return rtas_error_rc(rc); 472 return rc; 473 } 474 475 int rtas_set_indicator(int indicator, int index, int new_value) 476 { 477 int token = rtas_token("set-indicator"); 478 unsigned int wait_time; 479 int rc; 480 481 if (token == RTAS_UNKNOWN_SERVICE) 482 return -ENOENT; 483 484 while (1) { 485 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value); 486 if (rc == RTAS_BUSY) 487 udelay(1); 488 else if (rtas_is_extended_busy(rc)) { 489 wait_time = rtas_extended_busy_delay_time(rc); 490 udelay(wait_time * 1000); 491 } 492 else 493 break; 494 } 495 496 if (rc < 0) 497 return rtas_error_rc(rc); 498 return rc; 499 } 500 501 void rtas_restart(char *cmd) 502 { 503 if (rtas_flash_term_hook) 504 rtas_flash_term_hook(SYS_RESTART); 505 printk("RTAS system-reboot returned %d\n", 506 rtas_call(rtas_token("system-reboot"), 0, 1, NULL)); 507 for (;;); 508 } 509 510 void rtas_power_off(void) 511 { 512 if (rtas_flash_term_hook) 513 rtas_flash_term_hook(SYS_POWER_OFF); 514 /* allow power on only with power button press */ 515 printk("RTAS power-off returned %d\n", 516 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 517 for (;;); 518 } 519 520 void rtas_halt(void) 521 { 522 if (rtas_flash_term_hook) 523 rtas_flash_term_hook(SYS_HALT); 524 /* allow power on only with power button press */ 525 printk("RTAS power-off returned %d\n", 526 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1)); 527 for (;;); 528 } 529 530 /* Must be in the RMO region, so we place it here */ 531 static char rtas_os_term_buf[2048]; 532 533 void rtas_os_term(char *str) 534 { 535 int status; 536 537 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term")) 538 return; 539 540 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str); 541 542 do { 543 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL, 544 __pa(rtas_os_term_buf)); 545 546 if (status == RTAS_BUSY) 547 udelay(1); 548 else if (status != 0) 549 printk(KERN_EMERG "ibm,os-term call failed %d\n", 550 status); 551 } while (status == RTAS_BUSY); 552 } 553 554 555 asmlinkage int ppc_rtas(struct rtas_args __user *uargs) 556 { 557 struct rtas_args args; 558 unsigned long flags; 559 char *buff_copy, *errbuf = NULL; 560 int nargs; 561 562 if (!capable(CAP_SYS_ADMIN)) 563 return -EPERM; 564 565 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) 566 return -EFAULT; 567 568 nargs = args.nargs; 569 if (nargs > ARRAY_SIZE(args.args) 570 || args.nret > ARRAY_SIZE(args.args) 571 || nargs + args.nret > ARRAY_SIZE(args.args)) 572 return -EINVAL; 573 574 /* Copy in args. */ 575 if (copy_from_user(args.args, uargs->args, 576 nargs * sizeof(rtas_arg_t)) != 0) 577 return -EFAULT; 578 579 buff_copy = get_errorlog_buffer(); 580 581 spin_lock_irqsave(&rtas.lock, flags); 582 583 rtas.args = args; 584 enter_rtas(__pa(&rtas.args)); 585 args = rtas.args; 586 587 args.rets = &args.args[nargs]; 588 589 /* A -1 return code indicates that the last command couldn't 590 be completed due to a hardware error. */ 591 if (args.rets[0] == -1) 592 errbuf = __fetch_rtas_last_error(buff_copy); 593 594 spin_unlock_irqrestore(&rtas.lock, flags); 595 596 if (buff_copy) { 597 if (errbuf) 598 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0); 599 kfree(buff_copy); 600 } 601 602 /* Copy out args. */ 603 if (copy_to_user(uargs->args + nargs, 604 args.args + nargs, 605 args.nret * sizeof(rtas_arg_t)) != 0) 606 return -EFAULT; 607 608 return 0; 609 } 610 611 #ifdef CONFIG_SMP 612 /* This version can't take the spinlock, because it never returns */ 613 614 struct rtas_args rtas_stop_self_args = { 615 /* The token is initialized for real in setup_system() */ 616 .token = RTAS_UNKNOWN_SERVICE, 617 .nargs = 0, 618 .nret = 1, 619 .rets = &rtas_stop_self_args.args[0], 620 }; 621 622 void rtas_stop_self(void) 623 { 624 struct rtas_args *rtas_args = &rtas_stop_self_args; 625 626 local_irq_disable(); 627 628 BUG_ON(rtas_args->token == RTAS_UNKNOWN_SERVICE); 629 630 printk("cpu %u (hwid %u) Ready to die...\n", 631 smp_processor_id(), hard_smp_processor_id()); 632 enter_rtas(__pa(rtas_args)); 633 634 panic("Alas, I survived.\n"); 635 } 636 #endif 637 638 /* 639 * Call early during boot, before mem init or bootmem, to retreive the RTAS 640 * informations from the device-tree and allocate the RMO buffer for userland 641 * accesses. 642 */ 643 void __init rtas_initialize(void) 644 { 645 unsigned long rtas_region = RTAS_INSTANTIATE_MAX; 646 647 /* Get RTAS dev node and fill up our "rtas" structure with infos 648 * about it. 649 */ 650 rtas.dev = of_find_node_by_name(NULL, "rtas"); 651 if (rtas.dev) { 652 u32 *basep, *entryp; 653 u32 *sizep; 654 655 basep = (u32 *)get_property(rtas.dev, "linux,rtas-base", NULL); 656 sizep = (u32 *)get_property(rtas.dev, "rtas-size", NULL); 657 if (basep != NULL && sizep != NULL) { 658 rtas.base = *basep; 659 rtas.size = *sizep; 660 entryp = (u32 *)get_property(rtas.dev, "linux,rtas-entry", NULL); 661 if (entryp == NULL) /* Ugh */ 662 rtas.entry = rtas.base; 663 else 664 rtas.entry = *entryp; 665 } else 666 rtas.dev = NULL; 667 } 668 if (!rtas.dev) 669 return; 670 671 /* If RTAS was found, allocate the RMO buffer for it and look for 672 * the stop-self token if any 673 */ 674 #ifdef CONFIG_PPC64 675 if (systemcfg->platform == PLATFORM_PSERIES_LPAR) 676 rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX); 677 #endif 678 rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region); 679 680 #ifdef CONFIG_HOTPLUG_CPU 681 rtas_stop_self_args.token = rtas_token("stop-self"); 682 #endif /* CONFIG_HOTPLUG_CPU */ 683 #ifdef CONFIG_RTAS_ERROR_LOGGING 684 rtas_last_error_token = rtas_token("rtas-last-error"); 685 #endif 686 } 687 688 689 EXPORT_SYMBOL(rtas_token); 690 EXPORT_SYMBOL(rtas_call); 691 EXPORT_SYMBOL(rtas_data_buf); 692 EXPORT_SYMBOL(rtas_data_buf_lock); 693 EXPORT_SYMBOL(rtas_extended_busy_delay_time); 694 EXPORT_SYMBOL(rtas_get_sensor); 695 EXPORT_SYMBOL(rtas_get_power_level); 696 EXPORT_SYMBOL(rtas_set_power_level); 697 EXPORT_SYMBOL(rtas_set_indicator); 698