arch/powerpc/kernel/rtas.c

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