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 #include <linux/capability.h>
  21 #include <linux/delay.h>
  22 #include <linux/smp.h>
  23 #include <linux/completion.h>
  24 #include <linux/cpumask.h>
  25 #include <linux/lmb.h>
  26
  27 #include <asm/prom.h>
  28 #include <asm/rtas.h>
  29 #include <asm/hvcall.h>
  30 #include <asm/machdep.h>
  31 #include <asm/firmware.h>
  32 #include <asm/page.h>
  33 #include <asm/param.h>
  34 #include <asm/system.h>
  35 #include <asm/delay.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/udbg.h>
  38 #include <asm/syscalls.h>
  39 #include <asm/smp.h>
  40 #include <asm/atomic.h>
  41
  42 struct rtas_t rtas = {
  43         .lock = SPIN_LOCK_UNLOCKED
  44 };
  45 EXPORT_SYMBOL(rtas);
  46
  47 struct rtas_suspend_me_data {
  48         atomic_t working; /* number of cpus accessing this struct */
  49         atomic_t done;
  50         int token; /* ibm,suspend-me */
  51         int error;
  52         struct completion *complete; /* wait on this until working == 0 */
  53 };
  54
  55 DEFINE_SPINLOCK(rtas_data_buf_lock);
  56 EXPORT_SYMBOL(rtas_data_buf_lock);
  57
  58 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
  59 EXPORT_SYMBOL(rtas_data_buf);
  60
  61 unsigned long rtas_rmo_buf;
  62
  63 /*
  64  * If non-NULL, this gets called when the kernel terminates.
  65  * This is done like this so rtas_flash can be a module.
  66  */
  67 void (*rtas_flash_term_hook)(int);
  68 EXPORT_SYMBOL(rtas_flash_term_hook);
  69
  70 /*
  71  * call_rtas_display_status and call_rtas_display_status_delay
  72  * are designed only for very early low-level debugging, which
  73  * is why the token is hard-coded to 10.
  74  */
  75 static void call_rtas_display_status(char c)
  76 {
  77         struct rtas_args *args = &rtas.args;
  78         unsigned long s;
  79
  80         if (!rtas.base)
  81                 return;
  82         spin_lock_irqsave(&rtas.lock, s);
  83
  84         args->token = 10;
  85         args->nargs = 1;
  86         args->nret  = 1;
  87         args->rets  = (rtas_arg_t *)&(args->args[1]);
  88         args->args[0] = (unsigned char)c;
  89
  90         enter_rtas(__pa(args));
  91
  92         spin_unlock_irqrestore(&rtas.lock, s);
  93 }
  94
  95 static void call_rtas_display_status_delay(char c)
  96 {
  97         static int pending_newline = 0;  /* did last write end with unprinted newline? */
  98         static int width = 16;
  99
 100         if (c == '\n') {
 101                 while (width-- > 0)
 102                         call_rtas_display_status(' ');
 103                 width = 16;
 104                 mdelay(500);
 105                 pending_newline = 1;
 106         } else {
 107                 if (pending_newline) {
 108                         call_rtas_display_status('\r');
 109                         call_rtas_display_status('\n');
 110                 }
 111                 pending_newline = 0;
 112                 if (width--) {
 113                         call_rtas_display_status(c);
 114                         udelay(10000);
 115                 }
 116         }
 117 }
 118
 119 void __init udbg_init_rtas_panel(void)
 120 {
 121         udbg_putc = call_rtas_display_status_delay;
 122 }
 123
 124 #ifdef CONFIG_UDBG_RTAS_CONSOLE
 125
 126 /* If you think you're dying before early_init_dt_scan_rtas() does its
 127  * work, you can hard code the token values for your firmware here and
 128  * hardcode rtas.base/entry etc.
 129  */
 130 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
 131 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
 132
 133 static void udbg_rtascon_putc(char c)
 134 {
 135         int tries;
 136
 137         if (!rtas.base)
 138                 return;
 139
 140         /* Add CRs before LFs */
 141         if (c == '\n')
 142                 udbg_rtascon_putc('\r');
 143
 144         /* if there is more than one character to be displayed, wait a bit */
 145         for (tries = 0; tries < 16; tries++) {
 146                 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
 147                         break;
 148                 udelay(1000);
 149         }
 150 }
 151
 152 static int udbg_rtascon_getc_poll(void)
 153 {
 154         int c;
 155
 156         if (!rtas.base)
 157                 return -1;
 158
 159         if (rtas_call(rtas_getchar_token, 0, 2, &c))
 160                 return -1;
 161
 162         return c;
 163 }
 164
 165 static int udbg_rtascon_getc(void)
 166 {
 167         int c;
 168
 169         while ((c = udbg_rtascon_getc_poll()) == -1)
 170                 ;
 171
 172         return c;
 173 }
 174
 175
 176 void __init udbg_init_rtas_console(void)
 177 {
 178         udbg_putc = udbg_rtascon_putc;
 179         udbg_getc = udbg_rtascon_getc;
 180         udbg_getc_poll = udbg_rtascon_getc_poll;
 181 }
 182 #endif /* CONFIG_UDBG_RTAS_CONSOLE */
 183
 184 void rtas_progress(char *s, unsigned short hex)
 185 {
 186         struct device_node *root;
 187         int width;
 188         const int *p;
 189         char *os;
 190         static int display_character, set_indicator;
 191         static int display_width, display_lines, form_feed;
 192         static const int *row_width;
 193         static DEFINE_SPINLOCK(progress_lock);
 194         static int current_line;
 195         static int pending_newline = 0;  /* did last write end with unprinted newline? */
 196
 197         if (!rtas.base)
 198                 return;
 199
 200         if (display_width == 0) {
 201                 display_width = 0x10;
 202                 if ((root = of_find_node_by_path("/rtas"))) {
 203                         if ((p = of_get_property(root,
 204                                         "ibm,display-line-length", NULL)))
 205                                 display_width = *p;
 206                         if ((p = of_get_property(root,
 207                                         "ibm,form-feed", NULL)))
 208                                 form_feed = *p;
 209                         if ((p = of_get_property(root,
 210                                         "ibm,display-number-of-lines", NULL)))
 211                                 display_lines = *p;
 212                         row_width = of_get_property(root,
 213                                         "ibm,display-truncation-length", NULL);
 214                         of_node_put(root);
 215                 }
 216                 display_character = rtas_token("display-character");
 217                 set_indicator = rtas_token("set-indicator");
 218         }
 219
 220         if (display_character == RTAS_UNKNOWN_SERVICE) {
 221                 /* use hex display if available */
 222                 if (set_indicator != RTAS_UNKNOWN_SERVICE)
 223                         rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
 224                 return;
 225         }
 226
 227         spin_lock(&progress_lock);
 228
 229         /*
 230          * Last write ended with newline, but we didn't print it since
 231          * it would just clear the bottom line of output. Print it now
 232          * instead.
 233          *
 234          * If no newline is pending and form feed is supported, clear the
 235          * display with a form feed; otherwise, print a CR to start output
 236          * at the beginning of the line.
 237          */
 238         if (pending_newline) {
 239                 rtas_call(display_character, 1, 1, NULL, '\r');
 240                 rtas_call(display_character, 1, 1, NULL, '\n');
 241                 pending_newline = 0;
 242         } else {
 243                 current_line = 0;
 244                 if (form_feed)
 245                         rtas_call(display_character, 1, 1, NULL,
 246                                   (char)form_feed);
 247                 else
 248                         rtas_call(display_character, 1, 1, NULL, '\r');
 249         }
 250
 251         if (row_width)
 252                 width = row_width[current_line];
 253         else
 254                 width = display_width;
 255         os = s;
 256         while (*os) {
 257                 if (*os == '\n' || *os == '\r') {
 258                         /* If newline is the last character, save it
 259                          * until next call to avoid bumping up the
 260                          * display output.
 261                          */
 262                         if (*os == '\n' && !os[1]) {
 263                                 pending_newline = 1;
 264                                 current_line++;
 265                                 if (current_line > display_lines-1)
 266                                         current_line = display_lines-1;
 267                                 spin_unlock(&progress_lock);
 268                                 return;
 269                         }
 270
 271                         /* RTAS wants CR-LF, not just LF */
 272
 273                         if (*os == '\n') {
 274                                 rtas_call(display_character, 1, 1, NULL, '\r');
 275                                 rtas_call(display_character, 1, 1, NULL, '\n');
 276                         } else {
 277                                 /* CR might be used to re-draw a line, so we'll
 278                                  * leave it alone and not add LF.
 279                                  */
 280                                 rtas_call(display_character, 1, 1, NULL, *os);
 281                         }
 282
 283                         if (row_width)
 284                                 width = row_width[current_line];
 285                         else
 286                                 width = display_width;
 287                 } else {
 288                         width--;
 289                         rtas_call(display_character, 1, 1, NULL, *os);
 290                 }
 291
 292                 os++;
 293
 294                 /* if we overwrite the screen length */
 295                 if (width <= 0)
 296                         while ((*os != 0) && (*os != '\n') && (*os != '\r'))
 297                                 os++;
 298         }
 299
 300         spin_unlock(&progress_lock);
 301 }
 302 EXPORT_SYMBOL(rtas_progress);           /* needed by rtas_flash module */
 303
 304 int rtas_token(const char *service)
 305 {
 306         const int *tokp;
 307         if (rtas.dev == NULL)
 308                 return RTAS_UNKNOWN_SERVICE;
 309         tokp = of_get_property(rtas.dev, service, NULL);
 310         return tokp ? *tokp : RTAS_UNKNOWN_SERVICE;
 311 }
 312 EXPORT_SYMBOL(rtas_token);
 313
 314 int rtas_service_present(const char *service)
 315 {
 316         return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
 317 }
 318 EXPORT_SYMBOL(rtas_service_present);
 319
 320 #ifdef CONFIG_RTAS_ERROR_LOGGING
 321 /*
 322  * Return the firmware-specified size of the error log buffer
 323  *  for all rtas calls that require an error buffer argument.
 324  *  This includes 'check-exception' and 'rtas-last-error'.
 325  */
 326 int rtas_get_error_log_max(void)
 327 {
 328         static int rtas_error_log_max;
 329         if (rtas_error_log_max)
 330                 return rtas_error_log_max;
 331
 332         rtas_error_log_max = rtas_token ("rtas-error-log-max");
 333         if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
 334             (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
 335                 printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
 336                         rtas_error_log_max);
 337                 rtas_error_log_max = RTAS_ERROR_LOG_MAX;
 338         }
 339         return rtas_error_log_max;
 340 }
 341 EXPORT_SYMBOL(rtas_get_error_log_max);
 342
 343
 344 static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
 345 static int rtas_last_error_token;
 346
 347 /** Return a copy of the detailed error text associated with the
 348  *  most recent failed call to rtas.  Because the error text
 349  *  might go stale if there are any other intervening rtas calls,
 350  *  this routine must be called atomically with whatever produced
 351  *  the error (i.e. with rtas.lock still held from the previous call).
 352  */
 353 static char *__fetch_rtas_last_error(char *altbuf)
 354 {
 355         struct rtas_args err_args, save_args;
 356         u32 bufsz;
 357         char *buf = NULL;
 358
 359         if (rtas_last_error_token == -1)
 360                 return NULL;
 361
 362         bufsz = rtas_get_error_log_max();
 363
 364         err_args.token = rtas_last_error_token;
 365         err_args.nargs = 2;
 366         err_args.nret = 1;
 367         err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
 368         err_args.args[1] = bufsz;
 369         err_args.args[2] = 0;
 370
 371         save_args = rtas.args;
 372         rtas.args = err_args;
 373
 374         enter_rtas(__pa(&rtas.args));
 375
 376         err_args = rtas.args;
 377         rtas.args = save_args;
 378
 379         /* Log the error in the unlikely case that there was one. */
 380         if (unlikely(err_args.args[2] == 0)) {
 381                 if (altbuf) {
 382                         buf = altbuf;
 383                 } else {
 384                         buf = rtas_err_buf;
 385                         if (mem_init_done)
 386                                 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
 387                 }
 388                 if (buf)
 389                         memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
 390         }
 391
 392         return buf;
 393 }
 394
 395 #define get_errorlog_buffer()   kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
 396
 397 #else /* CONFIG_RTAS_ERROR_LOGGING */
 398 #define __fetch_rtas_last_error(x)      NULL
 399 #define get_errorlog_buffer()           NULL
 400 #endif
 401
 402 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
 403 {
 404         va_list list;
 405         int i;
 406         unsigned long s;
 407         struct rtas_args *rtas_args;
 408         char *buff_copy = NULL;
 409         int ret;
 410
 411         if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
 412                 return -1;
 413
 414         /* Gotta do something different here, use global lock for now... */
 415         spin_lock_irqsave(&rtas.lock, s);
 416         rtas_args = &rtas.args;
 417
 418         rtas_args->token = token;
 419         rtas_args->nargs = nargs;
 420         rtas_args->nret  = nret;
 421         rtas_args->rets  = (rtas_arg_t *)&(rtas_args->args[nargs]);
 422         va_start(list, outputs);
 423         for (i = 0; i < nargs; ++i)
 424                 rtas_args->args[i] = va_arg(list, rtas_arg_t);
 425         va_end(list);
 426
 427         for (i = 0; i < nret; ++i)
 428                 rtas_args->rets[i] = 0;
 429
 430         enter_rtas(__pa(rtas_args));
 431
 432         /* A -1 return code indicates that the last command couldn't
 433            be completed due to a hardware error. */
 434         if (rtas_args->rets[0] == -1)
 435                 buff_copy = __fetch_rtas_last_error(NULL);
 436
 437         if (nret > 1 && outputs != NULL)
 438                 for (i = 0; i < nret-1; ++i)
 439                         outputs[i] = rtas_args->rets[i+1];
 440         ret = (nret > 0)? rtas_args->rets[0]: 0;
 441
 442         /* Gotta do something different here, use global lock for now... */
 443         spin_unlock_irqrestore(&rtas.lock, s);
 444
 445         if (buff_copy) {
 446                 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
 447                 if (mem_init_done)
 448                         kfree(buff_copy);
 449         }
 450         return ret;
 451 }
 452 EXPORT_SYMBOL(rtas_call);
 453
 454 /* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
 455  * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
 456  */
 457 unsigned int rtas_busy_delay_time(int status)
 458 {
 459         int order;
 460         unsigned int ms = 0;
 461
 462         if (status == RTAS_BUSY) {
 463                 ms = 1;
 464         } else if (status >= 9900 && status <= 9905) {
 465                 order = status - 9900;
 466                 for (ms = 1; order > 0; order--)
 467                         ms *= 10;
 468         }
 469
 470         return ms;
 471 }
 472 EXPORT_SYMBOL(rtas_busy_delay_time);
 473
 474 /* For an RTAS busy status code, perform the hinted delay. */
 475 unsigned int rtas_busy_delay(int status)
 476 {
 477         unsigned int ms;
 478
 479         might_sleep();
 480         ms = rtas_busy_delay_time(status);
 481         if (ms)
 482                 msleep(ms);
 483
 484         return ms;
 485 }
 486 EXPORT_SYMBOL(rtas_busy_delay);
 487
 488 static int rtas_error_rc(int rtas_rc)
 489 {
 490         int rc;
 491
 492         switch (rtas_rc) {
 493                 case -1:                /* Hardware Error */
 494                         rc = -EIO;
 495                         break;
 496                 case -3:                /* Bad indicator/domain/etc */
 497                         rc = -EINVAL;
 498                         break;
 499                 case -9000:             /* Isolation error */
 500                         rc = -EFAULT;
 501                         break;
 502                 case -9001:             /* Outstanding TCE/PTE */
 503                         rc = -EEXIST;
 504                         break;
 505                 case -9002:             /* No usable slot */
 506                         rc = -ENODEV;
 507                         break;
 508                 default:
 509                         printk(KERN_ERR "%s: unexpected RTAS error %d\n",
 510                                         __func__, rtas_rc);
 511                         rc = -ERANGE;
 512                         break;
 513         }
 514         return rc;
 515 }
 516
 517 int rtas_get_power_level(int powerdomain, int *level)
 518 {
 519         int token = rtas_token("get-power-level");
 520         int rc;
 521
 522         if (token == RTAS_UNKNOWN_SERVICE)
 523                 return -ENOENT;
 524
 525         while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
 526                 udelay(1);
 527
 528         if (rc < 0)
 529                 return rtas_error_rc(rc);
 530         return rc;
 531 }
 532 EXPORT_SYMBOL(rtas_get_power_level);
 533
 534 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
 535 {
 536         int token = rtas_token("set-power-level");
 537         int rc;
 538
 539         if (token == RTAS_UNKNOWN_SERVICE)
 540                 return -ENOENT;
 541
 542         do {
 543                 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
 544         } while (rtas_busy_delay(rc));
 545
 546         if (rc < 0)
 547                 return rtas_error_rc(rc);
 548         return rc;
 549 }
 550 EXPORT_SYMBOL(rtas_set_power_level);
 551
 552 int rtas_get_sensor(int sensor, int index, int *state)
 553 {
 554         int token = rtas_token("get-sensor-state");
 555         int rc;
 556
 557         if (token == RTAS_UNKNOWN_SERVICE)
 558                 return -ENOENT;
 559
 560         do {
 561                 rc = rtas_call(token, 2, 2, state, sensor, index);
 562         } while (rtas_busy_delay(rc));
 563
 564         if (rc < 0)
 565                 return rtas_error_rc(rc);
 566         return rc;
 567 }
 568 EXPORT_SYMBOL(rtas_get_sensor);
 569
 570 bool rtas_indicator_present(int token, int *maxindex)
 571 {
 572         int proplen, count, i;
 573         const struct indicator_elem {
 574                 u32 token;
 575                 u32 maxindex;
 576         } *indicators;
 577
 578         indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
 579         if (!indicators)
 580                 return false;
 581
 582         count = proplen / sizeof(struct indicator_elem);
 583
 584         for (i = 0; i < count; i++) {
 585                 if (indicators[i].token != token)
 586                         continue;
 587                 if (maxindex)
 588                         *maxindex = indicators[i].maxindex;
 589                 return true;
 590         }
 591
 592         return false;
 593 }
 594 EXPORT_SYMBOL(rtas_indicator_present);
 595
 596 int rtas_set_indicator(int indicator, int index, int new_value)
 597 {
 598         int token = rtas_token("set-indicator");
 599         int rc;
 600
 601         if (token == RTAS_UNKNOWN_SERVICE)
 602                 return -ENOENT;
 603
 604         do {
 605                 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
 606         } while (rtas_busy_delay(rc));
 607
 608         if (rc < 0)
 609                 return rtas_error_rc(rc);
 610         return rc;
 611 }
 612 EXPORT_SYMBOL(rtas_set_indicator);
 613
 614 /*
 615  * Ignoring RTAS extended delay
 616  */
 617 int rtas_set_indicator_fast(int indicator, int index, int new_value)
 618 {
 619         int rc;
 620         int token = rtas_token("set-indicator");
 621
 622         if (token == RTAS_UNKNOWN_SERVICE)
 623                 return -ENOENT;
 624
 625         rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
 626
 627         WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
 628
 629         if (rc < 0)
 630                 return rtas_error_rc(rc);
 631
 632         return rc;
 633 }
 634
 635 void rtas_restart(char *cmd)
 636 {
 637         if (rtas_flash_term_hook)
 638                 rtas_flash_term_hook(SYS_RESTART);
 639         printk("RTAS system-reboot returned %d\n",
 640                rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
 641         for (;;);
 642 }
 643
 644 void rtas_power_off(void)
 645 {
 646         if (rtas_flash_term_hook)
 647                 rtas_flash_term_hook(SYS_POWER_OFF);
 648         /* allow power on only with power button press */
 649         printk("RTAS power-off returned %d\n",
 650                rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
 651         for (;;);
 652 }
 653
 654 void rtas_halt(void)
 655 {
 656         if (rtas_flash_term_hook)
 657                 rtas_flash_term_hook(SYS_HALT);
 658         /* allow power on only with power button press */
 659         printk("RTAS power-off returned %d\n",
 660                rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
 661         for (;;);
 662 }
 663
 664 /* Must be in the RMO region, so we place it here */
 665 static char rtas_os_term_buf[2048];
 666
 667 void rtas_os_term(char *str)
 668 {
 669         int status;
 670
 671         if (panic_timeout)
 672                 return;
 673
 674         if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
 675                 return;
 676
 677         snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
 678
 679         do {
 680                 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
 681                                    __pa(rtas_os_term_buf));
 682         } while (rtas_busy_delay(status));
 683
 684         if (status != 0)
 685                 printk(KERN_EMERG "ibm,os-term call failed %d\n",
 686                                status);
 687 }
 688
 689 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
 690 #ifdef CONFIG_PPC_PSERIES
 691 static void rtas_percpu_suspend_me(void *info)
 692 {
 693         long rc = H_SUCCESS;
 694         unsigned long msr_save;
 695         int cpu;
 696         struct rtas_suspend_me_data *data =
 697                 (struct rtas_suspend_me_data *)info;
 698
 699         atomic_inc(&data->working);
 700
 701         /* really need to ensure MSR.EE is off for H_JOIN */
 702         msr_save = mfmsr();
 703         mtmsr(msr_save & ~(MSR_EE));
 704
 705         while (rc == H_SUCCESS && !atomic_read(&data->done))
 706                 rc = plpar_hcall_norets(H_JOIN);
 707
 708         mtmsr(msr_save);
 709
 710         if (rc == H_SUCCESS) {
 711                 /* This cpu was prodded and the suspend is complete. */
 712                 goto out;
 713         } else if (rc == H_CONTINUE) {
 714                 /* All other cpus are in H_JOIN, this cpu does
 715                  * the suspend.
 716                  */
 717                 printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n",
 718                        smp_processor_id());
 719                 data->error = rtas_call(data->token, 0, 1, NULL);
 720
 721                 if (data->error)
 722                         printk(KERN_DEBUG "ibm,suspend-me returned %d\n",
 723                                data->error);
 724         } else {
 725                 printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
 726                        smp_processor_id(), rc);
 727                 data->error = rc;
 728         }
 729
 730         atomic_set(&data->done, 1);
 731
 732         /* This cpu did the suspend or got an error; in either case,
 733          * we need to prod all other other cpus out of join state.
 734          * Extra prods are harmless.
 735          */
 736         for_each_online_cpu(cpu)
 737                 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
 738 out:
 739         if (atomic_dec_return(&data->working) == 0)
 740                 complete(data->complete);
 741 }
 742
 743 static int rtas_ibm_suspend_me(struct rtas_args *args)
 744 {
 745         long state;
 746         long rc;
 747         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
 748         struct rtas_suspend_me_data data;
 749         DECLARE_COMPLETION_ONSTACK(done);
 750
 751         if (!rtas_service_present("ibm,suspend-me"))
 752                 return -ENOSYS;
 753
 754         /* Make sure the state is valid */
 755         rc = plpar_hcall(H_VASI_STATE, retbuf,
 756                          ((u64)args->args[0] << 32) | args->args[1]);
 757
 758         state = retbuf[0];
 759
 760         if (rc) {
 761                 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
 762                 return rc;
 763         } else if (state == H_VASI_ENABLED) {
 764                 args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
 765                 return 0;
 766         } else if (state != H_VASI_SUSPENDING) {
 767                 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
 768                        state);
 769                 args->args[args->nargs] = -1;
 770                 return 0;
 771         }
 772
 773         atomic_set(&data.working, 0);
 774         atomic_set(&data.done, 0);
 775         data.token = rtas_token("ibm,suspend-me");
 776         data.error = 0;
 777         data.complete = &done;
 778
 779         /* Call function on all CPUs.  One of us will make the
 780          * rtas call
 781          */
 782         if (on_each_cpu(rtas_percpu_suspend_me, &data, 0))
 783                 data.error = -EINVAL;
 784
 785         wait_for_completion(&done);
 786
 787         if (data.error != 0)
 788                 printk(KERN_ERR "Error doing global join\n");
 789
 790         return data.error;
 791 }
 792 #else /* CONFIG_PPC_PSERIES */
 793 static int rtas_ibm_suspend_me(struct rtas_args *args)
 794 {
 795         return -ENOSYS;
 796 }
 797 #endif
 798
 799 asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
 800 {
 801         struct rtas_args args;
 802         unsigned long flags;
 803         char *buff_copy, *errbuf = NULL;
 804         int nargs;
 805         int rc;
 806
 807         if (!capable(CAP_SYS_ADMIN))
 808                 return -EPERM;
 809
 810         if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
 811                 return -EFAULT;
 812
 813         nargs = args.nargs;
 814         if (nargs > ARRAY_SIZE(args.args)
 815             || args.nret > ARRAY_SIZE(args.args)
 816             || nargs + args.nret > ARRAY_SIZE(args.args))
 817                 return -EINVAL;
 818
 819         /* Copy in args. */
 820         if (copy_from_user(args.args, uargs->args,
 821                            nargs * sizeof(rtas_arg_t)) != 0)
 822                 return -EFAULT;
 823
 824         if (args.token == RTAS_UNKNOWN_SERVICE)
 825                 return -EINVAL;
 826
 827         args.rets = &args.args[nargs];
 828         memset(args.rets, 0, args.nret * sizeof(rtas_arg_t));
 829
 830         /* Need to handle ibm,suspend_me call specially */
 831         if (args.token == ibm_suspend_me_token) {
 832                 rc = rtas_ibm_suspend_me(&args);
 833                 if (rc)
 834                         return rc;
 835                 goto copy_return;
 836         }
 837
 838         buff_copy = get_errorlog_buffer();
 839
 840         spin_lock_irqsave(&rtas.lock, flags);
 841
 842         rtas.args = args;
 843         enter_rtas(__pa(&rtas.args));
 844         args = rtas.args;
 845
 846         /* A -1 return code indicates that the last command couldn't
 847            be completed due to a hardware error. */
 848         if (args.rets[0] == -1)
 849                 errbuf = __fetch_rtas_last_error(buff_copy);
 850
 851         spin_unlock_irqrestore(&rtas.lock, flags);
 852
 853         if (buff_copy) {
 854                 if (errbuf)
 855                         log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
 856                 kfree(buff_copy);
 857         }
 858
 859  copy_return:
 860         /* Copy out args. */
 861         if (copy_to_user(uargs->args + nargs,
 862                          args.args + nargs,
 863                          args.nret * sizeof(rtas_arg_t)) != 0)
 864                 return -EFAULT;
 865
 866         return 0;
 867 }
 868
 869 /*
 870  * Call early during boot, before mem init or bootmem, to retrieve the RTAS
 871  * informations from the device-tree and allocate the RMO buffer for userland
 872  * accesses.
 873  */
 874 void __init rtas_initialize(void)
 875 {
 876         unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
 877
 878         /* Get RTAS dev node and fill up our "rtas" structure with infos
 879          * about it.
 880          */
 881         rtas.dev = of_find_node_by_name(NULL, "rtas");
 882         if (rtas.dev) {
 883                 const u32 *basep, *entryp, *sizep;
 884
 885                 basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
 886                 sizep = of_get_property(rtas.dev, "rtas-size", NULL);
 887                 if (basep != NULL && sizep != NULL) {
 888                         rtas.base = *basep;
 889                         rtas.size = *sizep;
 890                         entryp = of_get_property(rtas.dev,
 891                                         "linux,rtas-entry", NULL);
 892                         if (entryp == NULL) /* Ugh */
 893                                 rtas.entry = rtas.base;
 894                         else
 895                                 rtas.entry = *entryp;
 896                 } else
 897                         rtas.dev = NULL;
 898         }
 899         if (!rtas.dev)
 900                 return;
 901
 902         /* If RTAS was found, allocate the RMO buffer for it and look for
 903          * the stop-self token if any
 904          */
 905 #ifdef CONFIG_PPC64
 906         if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
 907                 rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
 908                 ibm_suspend_me_token = rtas_token("ibm,suspend-me");
 909         }
 910 #endif
 911         rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
 912
 913 #ifdef CONFIG_RTAS_ERROR_LOGGING
 914         rtas_last_error_token = rtas_token("rtas-last-error");
 915 #endif
 916 }
 917
 918 int __init early_init_dt_scan_rtas(unsigned long node,
 919                 const char *uname, int depth, void *data)
 920 {
 921         u32 *basep, *entryp, *sizep;
 922
 923         if (depth != 1 || strcmp(uname, "rtas") != 0)
 924                 return 0;
 925
 926         basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
 927         entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
 928         sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
 929
 930         if (basep && entryp && sizep) {
 931                 rtas.base = *basep;
 932                 rtas.entry = *entryp;
 933                 rtas.size = *sizep;
 934         }
 935
 936 #ifdef CONFIG_UDBG_RTAS_CONSOLE
 937         basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
 938         if (basep)
 939                 rtas_putchar_token = *basep;
 940
 941         basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
 942         if (basep)
 943                 rtas_getchar_token = *basep;
 944
 945         if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
 946             rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
 947                 udbg_init_rtas_console();
 948
 949 #endif
 950
 951         /* break now */
 952         return 1;
 953 }