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