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