kernel/arch/powerpc/platforms/powernv/opal.c

   1 /*
   2  * PowerNV OPAL high level interfaces
   3  *
   4  * Copyright 2011 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt)     "opal: " fmt
  13
  14 #include <linux/printk.h>
  15 #include <linux/types.h>
  16 #include <linux/of.h>
  17 #include <linux/of_fdt.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/notifier.h>
  21 #include <linux/slab.h>
  22 #include <linux/sched.h>
  23 #include <linux/kobject.h>
  24 #include <linux/delay.h>
  25 #include <linux/memblock.h>
  26 #include <linux/kthread.h>
  27 #include <linux/freezer.h>
  28
  29 #include <asm/machdep.h>
  30 #include <asm/opal.h>
  31 #include <asm/firmware.h>
  32 #include <asm/mce.h>
  33
  34 #include "powernv.h"
  35
  36 /* /sys/firmware/opal */
  37 struct kobject *opal_kobj;
  38
  39 struct opal {
  40         u64 base;
  41         u64 entry;
  42         u64 size;
  43 } opal;
  44
  45 struct mcheck_recoverable_range {
  46         u64 start_addr;
  47         u64 end_addr;
  48         u64 recover_addr;
  49 };
  50
  51 static struct mcheck_recoverable_range *mc_recoverable_range;
  52 static int mc_recoverable_range_len;
  53
  54 struct device_node *opal_node;
  55 static DEFINE_SPINLOCK(opal_write_lock);
  56 static unsigned int *opal_irqs;
  57 static unsigned int opal_irq_count;
  58 static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);
  59 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
  60 static DEFINE_SPINLOCK(opal_notifier_lock);
  61 static uint64_t last_notified_mask = 0x0ul;
  62 static atomic_t opal_notifier_hold = ATOMIC_INIT(0);
  63 static uint32_t opal_heartbeat;
  64
  65 static void opal_reinit_cores(void)
  66 {
  67         /* Do the actual re-init, This will clobber all FPRs, VRs, etc...
  68          *
  69          * It will preserve non volatile GPRs and HSPRG0/1. It will
  70          * also restore HIDs and other SPRs to their original value
  71          * but it might clobber a bunch.
  72          */
  73 #ifdef __BIG_ENDIAN__
  74         opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_BE);
  75 #else
  76         opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_LE);
  77 #endif
  78 }
  79
  80 int __init early_init_dt_scan_opal(unsigned long node,
  81                                    const char *uname, int depth, void *data)
  82 {
  83         const void *basep, *entryp, *sizep;
  84         int basesz, entrysz, runtimesz;
  85
  86         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
  87                 return 0;
  88
  89         basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
  90         entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
  91         sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);
  92
  93         if (!basep || !entryp || !sizep)
  94                 return 1;
  95
  96         opal.base = of_read_number(basep, basesz/4);
  97         opal.entry = of_read_number(entryp, entrysz/4);
  98         opal.size = of_read_number(sizep, runtimesz/4);
  99
 100         pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
 101                  opal.base, basep, basesz);
 102         pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
 103                  opal.entry, entryp, entrysz);
 104         pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
 105                  opal.size, sizep, runtimesz);
 106
 107         powerpc_firmware_features |= FW_FEATURE_OPAL;
 108         if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
 109                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
 110                 powerpc_firmware_features |= FW_FEATURE_OPALv3;
 111                 pr_info("OPAL V3 detected !\n");
 112         } else if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
 113                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
 114                 pr_info("OPAL V2 detected !\n");
 115         } else {
 116                 pr_info("OPAL V1 detected !\n");
 117         }
 118
 119         /* Reinit all cores with the right endian */
 120         opal_reinit_cores();
 121
 122         /* Restore some bits */
 123         if (cur_cpu_spec->cpu_restore)
 124                 cur_cpu_spec->cpu_restore();
 125
 126         return 1;
 127 }
 128
 129 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
 130                                    const char *uname, int depth, void *data)
 131 {
 132         int i, psize, size;
 133         const __be32 *prop;
 134
 135         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
 136                 return 0;
 137
 138         prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
 139
 140         if (!prop)
 141                 return 1;
 142
 143         pr_debug("Found machine check recoverable ranges.\n");
 144
 145         /*
 146          * Calculate number of available entries.
 147          *
 148          * Each recoverable address range entry is (start address, len,
 149          * recovery address), 2 cells each for start and recovery address,
 150          * 1 cell for len, totalling 5 cells per entry.
 151          */
 152         mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
 153
 154         /* Sanity check */
 155         if (!mc_recoverable_range_len)
 156                 return 1;
 157
 158         /* Size required to hold all the entries. */
 159         size = mc_recoverable_range_len *
 160                         sizeof(struct mcheck_recoverable_range);
 161
 162         /*
 163          * Allocate a buffer to hold the MC recoverable ranges. We would be
 164          * accessing them in real mode, hence it needs to be within
 165          * RMO region.
 166          */
 167         mc_recoverable_range =__va(memblock_alloc_base(size, __alignof__(u64),
 168                                                         ppc64_rma_size));
 169         memset(mc_recoverable_range, 0, size);
 170
 171         for (i = 0; i < mc_recoverable_range_len; i++) {
 172                 mc_recoverable_range[i].start_addr =
 173                                         of_read_number(prop + (i * 5) + 0, 2);
 174                 mc_recoverable_range[i].end_addr =
 175                                         mc_recoverable_range[i].start_addr +
 176                                         of_read_number(prop + (i * 5) + 2, 1);
 177                 mc_recoverable_range[i].recover_addr =
 178                                         of_read_number(prop + (i * 5) + 3, 2);
 179
 180                 pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
 181                                 mc_recoverable_range[i].start_addr,
 182                                 mc_recoverable_range[i].end_addr,
 183                                 mc_recoverable_range[i].recover_addr);
 184         }
 185         return 1;
 186 }
 187
 188 static int __init opal_register_exception_handlers(void)
 189 {
 190 #ifdef __BIG_ENDIAN__
 191         u64 glue;
 192
 193         if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
 194                 return -ENODEV;
 195
 196         /* Hookup some exception handlers except machine check. We use the
 197          * fwnmi area at 0x7000 to provide the glue space to OPAL
 198          */
 199         glue = 0x7000;
 200
 201         /*
 202          * Check if we are running on newer firmware that exports
 203          * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
 204          * the HMI interrupt and we catch it directly in Linux.
 205          *
 206          * For older firmware (i.e currently released POWER8 System Firmware
 207          * as of today <= SV810_087), we fallback to old behavior and let OPAL
 208          * patch the HMI vector and handle it inside OPAL firmware.
 209          *
 210          * For newer firmware (in development/yet to be released) we will
 211          * start catching/handling HMI directly in Linux.
 212          */
 213         if (!opal_check_token(OPAL_HANDLE_HMI)) {
 214                 pr_info("Old firmware detected, OPAL handles HMIs.\n");
 215                 opal_register_exception_handler(
 216                                 OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
 217                                 0, glue);
 218                 glue += 128;
 219         }
 220
 221         opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
 222 #endif
 223
 224         return 0;
 225 }
 226 machine_early_initcall(powernv, opal_register_exception_handlers);
 227
 228 int opal_notifier_register(struct notifier_block *nb)
 229 {
 230         if (!nb) {
 231                 pr_warning("%s: Invalid argument (%p)\n",
 232                            __func__, nb);
 233                 return -EINVAL;
 234         }
 235
 236         atomic_notifier_chain_register(&opal_notifier_head, nb);
 237         return 0;
 238 }
 239 EXPORT_SYMBOL_GPL(opal_notifier_register);
 240
 241 int opal_notifier_unregister(struct notifier_block *nb)
 242 {
 243         if (!nb) {
 244                 pr_warning("%s: Invalid argument (%p)\n",
 245                            __func__, nb);
 246                 return -EINVAL;
 247         }
 248
 249         atomic_notifier_chain_unregister(&opal_notifier_head, nb);
 250         return 0;
 251 }
 252 EXPORT_SYMBOL_GPL(opal_notifier_unregister);
 253
 254 static void opal_do_notifier(uint64_t events)
 255 {
 256         unsigned long flags;
 257         uint64_t changed_mask;
 258
 259         if (atomic_read(&opal_notifier_hold))
 260                 return;
 261
 262         spin_lock_irqsave(&opal_notifier_lock, flags);
 263         changed_mask = last_notified_mask ^ events;
 264         last_notified_mask = events;
 265         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 266
 267         /*
 268          * We feed with the event bits and changed bits for
 269          * enough information to the callback.
 270          */
 271         atomic_notifier_call_chain(&opal_notifier_head,
 272                                    events, (void *)changed_mask);
 273 }
 274
 275 void opal_notifier_update_evt(uint64_t evt_mask,
 276                               uint64_t evt_val)
 277 {
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&opal_notifier_lock, flags);
 281         last_notified_mask &= ~evt_mask;
 282         last_notified_mask |= evt_val;
 283         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 284 }
 285
 286 void opal_notifier_enable(void)
 287 {
 288         int64_t rc;
 289         __be64 evt = 0;
 290
 291         atomic_set(&opal_notifier_hold, 0);
 292
 293         /* Process pending events */
 294         rc = opal_poll_events(&evt);
 295         if (rc == OPAL_SUCCESS && evt)
 296                 opal_do_notifier(be64_to_cpu(evt));
 297 }
 298
 299 void opal_notifier_disable(void)
 300 {
 301         atomic_set(&opal_notifier_hold, 1);
 302 }
 303
 304 /*
 305  * Opal message notifier based on message type. Allow subscribers to get
 306  * notified for specific messgae type.
 307  */
 308 int opal_message_notifier_register(enum opal_msg_type msg_type,
 309                                         struct notifier_block *nb)
 310 {
 311         if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
 312                 pr_warning("%s: Invalid arguments, msg_type:%d\n",
 313                            __func__, msg_type);
 314                 return -EINVAL;
 315         }
 316
 317         return atomic_notifier_chain_register(
 318                                 &opal_msg_notifier_head[msg_type], nb);
 319 }
 320
 321 int opal_message_notifier_unregister(enum opal_msg_type msg_type,
 322                                      struct notifier_block *nb)
 323 {
 324         return atomic_notifier_chain_unregister(
 325                         &opal_msg_notifier_head[msg_type], nb);
 326 }
 327
 328 static void opal_message_do_notify(uint32_t msg_type, void *msg)
 329 {
 330         /* notify subscribers */
 331         atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
 332                                         msg_type, msg);
 333 }
 334
 335 static void opal_handle_message(void)
 336 {
 337         s64 ret;
 338         /*
 339          * TODO: pre-allocate a message buffer depending on opal-msg-size
 340          * value in /proc/device-tree.
 341          */
 342         static struct opal_msg msg;
 343         u32 type;
 344
 345         ret = opal_get_msg(__pa(&msg), sizeof(msg));
 346         /* No opal message pending. */
 347         if (ret == OPAL_RESOURCE)
 348                 return;
 349
 350         /* check for errors. */
 351         if (ret) {
 352                 pr_warning("%s: Failed to retrieve opal message, err=%lld\n",
 353                                 __func__, ret);
 354                 return;
 355         }
 356
 357         type = be32_to_cpu(msg.msg_type);
 358
 359         /* Sanity check */
 360         if (type >= OPAL_MSG_TYPE_MAX) {
 361                 pr_warning("%s: Unknown message type: %u\n", __func__, type);
 362                 return;
 363         }
 364         opal_message_do_notify(type, (void *)&msg);
 365 }
 366
 367 static int opal_message_notify(struct notifier_block *nb,
 368                           unsigned long events, void *change)
 369 {
 370         if (events & OPAL_EVENT_MSG_PENDING)
 371                 opal_handle_message();
 372         return 0;
 373 }
 374
 375 static struct notifier_block opal_message_nb = {
 376         .notifier_call  = opal_message_notify,
 377         .next           = NULL,
 378         .priority       = 0,
 379 };
 380
 381 static int __init opal_message_init(void)
 382 {
 383         int ret, i;
 384
 385         for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
 386                 ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
 387
 388         ret = opal_notifier_register(&opal_message_nb);
 389         if (ret) {
 390                 pr_err("%s: Can't register OPAL event notifier (%d)\n",
 391                        __func__, ret);
 392                 return ret;
 393         }
 394         return 0;
 395 }
 396 machine_early_initcall(powernv, opal_message_init);
 397
 398 int opal_get_chars(uint32_t vtermno, char *buf, int count)
 399 {
 400         s64 rc;
 401         __be64 evt, len;
 402
 403         if (!opal.entry)
 404                 return -ENODEV;
 405         opal_poll_events(&evt);
 406         if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
 407                 return 0;
 408         len = cpu_to_be64(count);
 409         rc = opal_console_read(vtermno, &len, buf);
 410         if (rc == OPAL_SUCCESS)
 411                 return be64_to_cpu(len);
 412         return 0;
 413 }
 414
 415 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
 416 {
 417         int written = 0;
 418         __be64 olen;
 419         s64 len, rc;
 420         unsigned long flags;
 421         __be64 evt;
 422
 423         if (!opal.entry)
 424                 return -ENODEV;
 425
 426         /* We want put_chars to be atomic to avoid mangling of hvsi
 427          * packets. To do that, we first test for room and return
 428          * -EAGAIN if there isn't enough.
 429          *
 430          * Unfortunately, opal_console_write_buffer_space() doesn't
 431          * appear to work on opal v1, so we just assume there is
 432          * enough room and be done with it
 433          */
 434         spin_lock_irqsave(&opal_write_lock, flags);
 435         if (firmware_has_feature(FW_FEATURE_OPALv2)) {
 436                 rc = opal_console_write_buffer_space(vtermno, &olen);
 437                 len = be64_to_cpu(olen);
 438                 if (rc || len < total_len) {
 439                         spin_unlock_irqrestore(&opal_write_lock, flags);
 440                         /* Closed -> drop characters */
 441                         if (rc)
 442                                 return total_len;
 443                         opal_poll_events(NULL);
 444                         return -EAGAIN;
 445                 }
 446         }
 447
 448         /* We still try to handle partial completions, though they
 449          * should no longer happen.
 450          */
 451         rc = OPAL_BUSY;
 452         while(total_len > 0 && (rc == OPAL_BUSY ||
 453                                 rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
 454                 olen = cpu_to_be64(total_len);
 455                 rc = opal_console_write(vtermno, &olen, data);
 456                 len = be64_to_cpu(olen);
 457
 458                 /* Closed or other error drop */
 459                 if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
 460                     rc != OPAL_BUSY_EVENT) {
 461                         written = total_len;
 462                         break;
 463                 }
 464                 if (rc == OPAL_SUCCESS) {
 465                         total_len -= len;
 466                         data += len;
 467                         written += len;
 468                 }
 469                 /* This is a bit nasty but we need that for the console to
 470                  * flush when there aren't any interrupts. We will clean
 471                  * things a bit later to limit that to synchronous path
 472                  * such as the kernel console and xmon/udbg
 473                  */
 474                 do
 475                         opal_poll_events(&evt);
 476                 while(rc == OPAL_SUCCESS &&
 477                         (be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
 478         }
 479         spin_unlock_irqrestore(&opal_write_lock, flags);
 480         return written;
 481 }
 482
 483 static int opal_recover_mce(struct pt_regs *regs,
 484                                         struct machine_check_event *evt)
 485 {
 486         int recovered = 0;
 487         uint64_t ea = get_mce_fault_addr(evt);
 488
 489         if (!(regs->msr & MSR_RI)) {
 490                 /* If MSR_RI isn't set, we cannot recover */
 491                 recovered = 0;
 492         } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
 493                 /* Platform corrected itself */
 494                 recovered = 1;
 495         } else if (ea && !is_kernel_addr(ea)) {
 496                 /*
 497                  * Faulting address is not in kernel text. We should be fine.
 498                  * We need to find which process uses this address.
 499                  * For now, kill the task if we have received exception when
 500                  * in userspace.
 501                  *
 502                  * TODO: Queue up this address for hwpoisioning later.
 503                  */
 504                 if (user_mode(regs) && !is_global_init(current)) {
 505                         _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 506                         recovered = 1;
 507                 } else
 508                         recovered = 0;
 509         } else if (user_mode(regs) && !is_global_init(current) &&
 510                 evt->severity == MCE_SEV_ERROR_SYNC) {
 511                 /*
 512                  * If we have received a synchronous error when in userspace
 513                  * kill the task.
 514                  */
 515                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 516                 recovered = 1;
 517         }
 518         return recovered;
 519 }
 520
 521 int opal_machine_check(struct pt_regs *regs)
 522 {
 523         struct machine_check_event evt;
 524
 525         if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
 526                 return 0;
 527
 528         /* Print things out */
 529         if (evt.version != MCE_V1) {
 530                 pr_err("Machine Check Exception, Unknown event version %d !\n",
 531                        evt.version);
 532                 return 0;
 533         }
 534         machine_check_print_event_info(&evt);
 535
 536         if (opal_recover_mce(regs, &evt))
 537                 return 1;
 538         return 0;
 539 }
 540
 541 /* Early hmi handler called in real mode. */
 542 int opal_hmi_exception_early(struct pt_regs *regs)
 543 {
 544         s64 rc;
 545
 546         /*
 547          * call opal hmi handler. Pass paca address as token.
 548          * The return value OPAL_SUCCESS is an indication that there is
 549          * an HMI event generated waiting to pull by Linux.
 550          */
 551         rc = opal_handle_hmi();
 552         if (rc == OPAL_SUCCESS) {
 553                 local_paca->hmi_event_available = 1;
 554                 return 1;
 555         }
 556         return 0;
 557 }
 558
 559 /* HMI exception handler called in virtual mode during check_irq_replay. */
 560 int opal_handle_hmi_exception(struct pt_regs *regs)
 561 {
 562         s64 rc;
 563         __be64 evt = 0;
 564
 565         /*
 566          * Check if HMI event is available.
 567          * if Yes, then call opal_poll_events to pull opal messages and
 568          * process them.
 569          */
 570         if (!local_paca->hmi_event_available)
 571                 return 0;
 572
 573         local_paca->hmi_event_available = 0;
 574         rc = opal_poll_events(&evt);
 575         if (rc == OPAL_SUCCESS && evt)
 576                 opal_do_notifier(be64_to_cpu(evt));
 577
 578         return 1;
 579 }
 580
 581 static uint64_t find_recovery_address(uint64_t nip)
 582 {
 583         int i;
 584
 585         for (i = 0; i < mc_recoverable_range_len; i++)
 586                 if ((nip >= mc_recoverable_range[i].start_addr) &&
 587                     (nip < mc_recoverable_range[i].end_addr))
 588                     return mc_recoverable_range[i].recover_addr;
 589         return 0;
 590 }
 591
 592 bool opal_mce_check_early_recovery(struct pt_regs *regs)
 593 {
 594         uint64_t recover_addr = 0;
 595
 596         if (!opal.base || !opal.size)
 597                 goto out;
 598
 599         if ((regs->nip >= opal.base) &&
 600                         (regs->nip <= (opal.base + opal.size)))
 601                 recover_addr = find_recovery_address(regs->nip);
 602
 603         /*
 604          * Setup regs->nip to rfi into fixup address.
 605          */
 606         if (recover_addr)
 607                 regs->nip = recover_addr;
 608
 609 out:
 610         return !!recover_addr;
 611 }
 612
 613 static irqreturn_t opal_interrupt(int irq, void *data)
 614 {
 615         __be64 events;
 616
 617         opal_handle_interrupt(virq_to_hw(irq), &events);
 618
 619         opal_do_notifier(be64_to_cpu(events));
 620
 621         return IRQ_HANDLED;
 622 }
 623
 624 static int opal_sysfs_init(void)
 625 {
 626         opal_kobj = kobject_create_and_add("opal", firmware_kobj);
 627         if (!opal_kobj) {
 628                 pr_warn("kobject_create_and_add opal failed\n");
 629                 return -ENOMEM;
 630         }
 631
 632         return 0;
 633 }
 634
 635 static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
 636                                struct bin_attribute *bin_attr,
 637                                char *buf, loff_t off, size_t count)
 638 {
 639         return memory_read_from_buffer(buf, count, &off, bin_attr->private,
 640                                        bin_attr->size);
 641 }
 642
 643 static BIN_ATTR_RO(symbol_map, 0);
 644
 645 static void opal_export_symmap(void)
 646 {
 647         const __be64 *syms;
 648         unsigned int size;
 649         struct device_node *fw;
 650         int rc;
 651
 652         fw = of_find_node_by_path("/ibm,opal/firmware");
 653         if (!fw)
 654                 return;
 655         syms = of_get_property(fw, "symbol-map", &size);
 656         if (!syms || size != 2 * sizeof(__be64))
 657                 return;
 658
 659         /* Setup attributes */
 660         bin_attr_symbol_map.private = __va(be64_to_cpu(syms[0]));
 661         bin_attr_symbol_map.size = be64_to_cpu(syms[1]);
 662
 663         rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map);
 664         if (rc)
 665                 pr_warn("Error %d creating OPAL symbols file\n", rc);
 666 }
 667
 668 static void __init opal_dump_region_init(void)
 669 {
 670         void *addr;
 671         uint64_t size;
 672         int rc;
 673
 674         if (!opal_check_token(OPAL_REGISTER_DUMP_REGION))
 675                 return;
 676
 677         /* Register kernel log buffer */
 678         addr = log_buf_addr_get();
 679         if (addr == NULL)
 680                 return;
 681
 682         size = log_buf_len_get();
 683         if (size == 0)
 684                 return;
 685
 686         rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF,
 687                                        __pa(addr), size);
 688         /* Don't warn if this is just an older OPAL that doesn't
 689          * know about that call
 690          */
 691         if (rc && rc != OPAL_UNSUPPORTED)
 692                 pr_warn("DUMP: Failed to register kernel log buffer. "
 693                         "rc = %d\n", rc);
 694 }
 695
 696 static void opal_flash_init(struct device_node *opal_node)
 697 {
 698         struct device_node *np;
 699
 700         for_each_child_of_node(opal_node, np)
 701                 if (of_device_is_compatible(np, "ibm,opal-flash"))
 702                         of_platform_device_create(np, NULL, NULL);
 703 }
 704
 705 static void opal_ipmi_init(struct device_node *opal_node)
 706 {
 707         struct device_node *np;
 708
 709         for_each_child_of_node(opal_node, np)
 710                 if (of_device_is_compatible(np, "ibm,opal-ipmi"))
 711                         of_platform_device_create(np, NULL, NULL);
 712 }
 713
 714 static void opal_i2c_create_devs(void)
 715 {
 716         struct device_node *np;
 717
 718         for_each_compatible_node(np, NULL, "ibm,opal-i2c")
 719                 of_platform_device_create(np, NULL, NULL);
 720 }
 721
 722 static void __init opal_irq_init(struct device_node *dn)
 723 {
 724         const __be32 *irqs;
 725         int i, irqlen;
 726
 727         /* Get interrupt property */
 728         irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
 729         opal_irq_count = irqs ? (irqlen / 4) : 0;
 730         pr_debug("Found %d interrupts reserved for OPAL\n", opal_irq_count);
 731         if (!opal_irq_count)
 732                 return;
 733
 734         /* Install interrupt handlers */
 735         opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
 736         for (i = 0; irqs && i < opal_irq_count; i++, irqs++) {
 737                 unsigned int irq, virq;
 738                 int rc;
 739
 740                 /* Get hardware and virtual IRQ */
 741                 irq = be32_to_cpup(irqs);
 742                 virq = irq_create_mapping(NULL, irq);
 743                 if (virq == NO_IRQ) {
 744                         pr_warn("Failed to map irq 0x%x\n", irq);
 745                         continue;
 746                 }
 747
 748                 /* Install interrupt handler */
 749                 rc = request_irq(virq, opal_interrupt, 0, "opal", NULL);
 750                 if (rc) {
 751                         irq_dispose_mapping(virq);
 752                         pr_warn("Error %d requesting irq %d (0x%x)\n",
 753                                  rc, virq, irq);
 754                         continue;
 755                 }
 756
 757                 /* Cache IRQ */
 758                 opal_irqs[i] = virq;
 759         }
 760 }
 761
 762 static int kopald(void *unused)
 763 {
 764         set_freezable();
 765         do {
 766                 try_to_freeze();
 767                 opal_poll_events(NULL);
 768                 msleep_interruptible(opal_heartbeat);
 769         } while (!kthread_should_stop());
 770
 771         return 0;
 772 }
 773
 774 static void opal_init_heartbeat(void)
 775 {
 776         /* Old firwmware, we assume the HVC heartbeat is sufficient */
 777         if (of_property_read_u32(opal_node, "ibm,heartbeat-ms",
 778                                  &opal_heartbeat) != 0)
 779                 opal_heartbeat = 0;
 780
 781         if (opal_heartbeat)
 782                 kthread_run(kopald, NULL, "kopald");
 783 }
 784
 785 static int __init opal_init(void)
 786 {
 787         struct device_node *np, *consoles;
 788         int rc;
 789
 790         opal_node = of_find_node_by_path("/ibm,opal");
 791         if (!opal_node) {
 792                 pr_warn("Device node not found\n");
 793                 return -ENODEV;
 794         }
 795
 796         /* Register OPAL consoles if any ports */
 797         if (firmware_has_feature(FW_FEATURE_OPALv2))
 798                 consoles = of_find_node_by_path("/ibm,opal/consoles");
 799         else
 800                 consoles = of_node_get(opal_node);
 801         if (consoles) {
 802                 for_each_child_of_node(consoles, np) {
 803                         if (strcmp(np->name, "serial"))
 804                                 continue;
 805                         of_platform_device_create(np, NULL, NULL);
 806                 }
 807                 of_node_put(consoles);
 808         }
 809
 810         /* Create i2c platform devices */
 811         opal_i2c_create_devs();
 812
 813         /* Setup a heatbeat thread if requested by OPAL */
 814         opal_init_heartbeat();
 815
 816         /* Find all OPAL interrupts and request them */
 817         opal_irq_init(opal_node);
 818
 819         /* Create "opal" kobject under /sys/firmware */
 820         rc = opal_sysfs_init();
 821         if (rc == 0) {
 822                 /* Export symbol map to userspace */
 823                 opal_export_symmap();
 824                 /* Setup dump region interface */
 825                 opal_dump_region_init();
 826                 /* Setup error log interface */
 827                 rc = opal_elog_init();
 828                 /* Setup code update interface */
 829                 opal_flash_update_init();
 830                 /* Setup platform dump extract interface */
 831                 opal_platform_dump_init();
 832                 /* Setup system parameters interface */
 833                 opal_sys_param_init();
 834                 /* Setup message log interface. */
 835                 opal_msglog_init();
 836         }
 837
 838         /* Initialize OPAL IPMI backend */
 839         opal_ipmi_init(opal_node);
 840
 841         opal_flash_init(opal_node);
 842
 843         return 0;
 844 }
 845 machine_subsys_initcall(powernv, opal_init);
 846
 847 void opal_shutdown(void)
 848 {
 849         unsigned int i;
 850         long rc = OPAL_BUSY;
 851
 852         /* First free interrupts, which will also mask them */
 853         for (i = 0; i < opal_irq_count; i++) {
 854                 if (opal_irqs[i])
 855                         free_irq(opal_irqs[i], NULL);
 856                 opal_irqs[i] = 0;
 857         }
 858
 859         /*
 860          * Then sync with OPAL which ensure anything that can
 861          * potentially write to our memory has completed such
 862          * as an ongoing dump retrieval
 863          */
 864         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 865                 rc = opal_sync_host_reboot();
 866                 if (rc == OPAL_BUSY)
 867                         opal_poll_events(NULL);
 868                 else
 869                         mdelay(10);
 870         }
 871
 872         /* Unregister memory dump region */
 873         if (opal_check_token(OPAL_UNREGISTER_DUMP_REGION))
 874                 opal_unregister_dump_region(OPAL_DUMP_REGION_LOG_BUF);
 875 }
 876
 877 /* Export this so that test modules can use it */
 878 EXPORT_SYMBOL_GPL(opal_invalid_call);
 879 EXPORT_SYMBOL_GPL(opal_ipmi_send);
 880 EXPORT_SYMBOL_GPL(opal_ipmi_recv);
 881 EXPORT_SYMBOL_GPL(opal_flash_read);
 882 EXPORT_SYMBOL_GPL(opal_flash_write);
 883 EXPORT_SYMBOL_GPL(opal_flash_erase);
 884
 885 /* Convert a region of vmalloc memory to an opal sg list */
 886 struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
 887                                              unsigned long vmalloc_size)
 888 {
 889         struct opal_sg_list *sg, *first = NULL;
 890         unsigned long i = 0;
 891
 892         sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 893         if (!sg)
 894                 goto nomem;
 895
 896         first = sg;
 897
 898         while (vmalloc_size > 0) {
 899                 uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
 900                 uint64_t length = min(vmalloc_size, PAGE_SIZE);
 901
 902                 sg->entry[i].data = cpu_to_be64(data);
 903                 sg->entry[i].length = cpu_to_be64(length);
 904                 i++;
 905
 906                 if (i >= SG_ENTRIES_PER_NODE) {
 907                         struct opal_sg_list *next;
 908
 909                         next = kzalloc(PAGE_SIZE, GFP_KERNEL);
 910                         if (!next)
 911                                 goto nomem;
 912
 913                         sg->length = cpu_to_be64(
 914                                         i * sizeof(struct opal_sg_entry) + 16);
 915                         i = 0;
 916                         sg->next = cpu_to_be64(__pa(next));
 917                         sg = next;
 918                 }
 919
 920                 vmalloc_addr += length;
 921                 vmalloc_size -= length;
 922         }
 923
 924         sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);
 925
 926         return first;
 927
 928 nomem:
 929         pr_err("%s : Failed to allocate memory\n", __func__);
 930         opal_free_sg_list(first);
 931         return NULL;
 932 }
 933
 934 void opal_free_sg_list(struct opal_sg_list *sg)
 935 {
 936         while (sg) {
 937                 uint64_t next = be64_to_cpu(sg->next);
 938
 939                 kfree(sg);
 940
 941                 if (next)
 942                         sg = __va(next);
 943                 else
 944                         sg = NULL;
 945         }
 946 }
 947
 948 int opal_error_code(int rc)
 949 {
 950         switch (rc) {
 951         case OPAL_SUCCESS:              return 0;
 952
 953         case OPAL_PARAMETER:            return -EINVAL;
 954         case OPAL_ASYNC_COMPLETION:     return -EINPROGRESS;
 955         case OPAL_BUSY_EVENT:           return -EBUSY;
 956         case OPAL_NO_MEM:               return -ENOMEM;
 957
 958         case OPAL_UNSUPPORTED:          return -EIO;
 959         case OPAL_HARDWARE:             return -EIO;
 960         case OPAL_INTERNAL_ERROR:       return -EIO;
 961         default:
 962                 pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
 963                 return -EIO;
 964         }
 965 }
 966
 967 EXPORT_SYMBOL_GPL(opal_poll_events);
 968 EXPORT_SYMBOL_GPL(opal_rtc_read);
 969 EXPORT_SYMBOL_GPL(opal_rtc_write);
 970 EXPORT_SYMBOL_GPL(opal_tpo_read);
 971 EXPORT_SYMBOL_GPL(opal_tpo_write);
 972 EXPORT_SYMBOL_GPL(opal_i2c_request);