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 #undef DEBUG
  13
  14 #include <linux/types.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/notifier.h>
  20 #include <linux/slab.h>
  21 #include <linux/sched.h>
  22 #include <linux/kobject.h>
  23 #include <linux/delay.h>
  24 #include <linux/memblock.h>
  25
  26 #include <asm/machdep.h>
  27 #include <asm/opal.h>
  28 #include <asm/firmware.h>
  29 #include <asm/mce.h>
  30
  31 #include "powernv.h"
  32
  33 /* /sys/firmware/opal */
  34 struct kobject *opal_kobj;
  35
  36 struct opal {
  37         u64 base;
  38         u64 entry;
  39         u64 size;
  40 } opal;
  41
  42 struct mcheck_recoverable_range {
  43         u64 start_addr;
  44         u64 end_addr;
  45         u64 recover_addr;
  46 };
  47
  48 static struct mcheck_recoverable_range *mc_recoverable_range;
  49 static int mc_recoverable_range_len;
  50
  51 struct device_node *opal_node;
  52 static DEFINE_SPINLOCK(opal_write_lock);
  53 extern u64 opal_mc_secondary_handler[];
  54 static unsigned int *opal_irqs;
  55 static unsigned int opal_irq_count;
  56 static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);
  57 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
  58 static DEFINE_SPINLOCK(opal_notifier_lock);
  59 static uint64_t last_notified_mask = 0x0ul;
  60 static atomic_t opal_notifier_hold = ATOMIC_INIT(0);
  61
  62 static void opal_reinit_cores(void)
  63 {
  64         /* Do the actual re-init, This will clobber all FPRs, VRs, etc...
  65          *
  66          * It will preserve non volatile GPRs and HSPRG0/1. It will
  67          * also restore HIDs and other SPRs to their original value
  68          * but it might clobber a bunch.
  69          */
  70 #ifdef __BIG_ENDIAN__
  71         opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_BE);
  72 #else
  73         opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_LE);
  74 #endif
  75 }
  76
  77 int __init early_init_dt_scan_opal(unsigned long node,
  78                                    const char *uname, int depth, void *data)
  79 {
  80         const void *basep, *entryp, *sizep;
  81         int basesz, entrysz, runtimesz;
  82
  83         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
  84                 return 0;
  85
  86         basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
  87         entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
  88         sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);
  89
  90         if (!basep || !entryp || !sizep)
  91                 return 1;
  92
  93         opal.base = of_read_number(basep, basesz/4);
  94         opal.entry = of_read_number(entryp, entrysz/4);
  95         opal.size = of_read_number(sizep, runtimesz/4);
  96
  97         pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
  98                  opal.base, basep, basesz);
  99         pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
 100                  opal.entry, entryp, entrysz);
 101         pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
 102                  opal.size, sizep, runtimesz);
 103
 104         powerpc_firmware_features |= FW_FEATURE_OPAL;
 105         if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
 106                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
 107                 powerpc_firmware_features |= FW_FEATURE_OPALv3;
 108                 printk("OPAL V3 detected !\n");
 109         } else if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
 110                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
 111                 printk("OPAL V2 detected !\n");
 112         } else {
 113                 printk("OPAL V1 detected !\n");
 114         }
 115
 116         /* Reinit all cores with the right endian */
 117         opal_reinit_cores();
 118
 119         /* Restore some bits */
 120         if (cur_cpu_spec->cpu_restore)
 121                 cur_cpu_spec->cpu_restore();
 122
 123         return 1;
 124 }
 125
 126 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
 127                                    const char *uname, int depth, void *data)
 128 {
 129         int i, psize, size;
 130         const __be32 *prop;
 131
 132         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
 133                 return 0;
 134
 135         prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
 136
 137         if (!prop)
 138                 return 1;
 139
 140         pr_debug("Found machine check recoverable ranges.\n");
 141
 142         /*
 143          * Calculate number of available entries.
 144          *
 145          * Each recoverable address range entry is (start address, len,
 146          * recovery address), 2 cells each for start and recovery address,
 147          * 1 cell for len, totalling 5 cells per entry.
 148          */
 149         mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
 150
 151         /* Sanity check */
 152         if (!mc_recoverable_range_len)
 153                 return 1;
 154
 155         /* Size required to hold all the entries. */
 156         size = mc_recoverable_range_len *
 157                         sizeof(struct mcheck_recoverable_range);
 158
 159         /*
 160          * Allocate a buffer to hold the MC recoverable ranges. We would be
 161          * accessing them in real mode, hence it needs to be within
 162          * RMO region.
 163          */
 164         mc_recoverable_range =__va(memblock_alloc_base(size, __alignof__(u64),
 165                                                         ppc64_rma_size));
 166         memset(mc_recoverable_range, 0, size);
 167
 168         for (i = 0; i < mc_recoverable_range_len; i++) {
 169                 mc_recoverable_range[i].start_addr =
 170                                         of_read_number(prop + (i * 5) + 0, 2);
 171                 mc_recoverable_range[i].end_addr =
 172                                         mc_recoverable_range[i].start_addr +
 173                                         of_read_number(prop + (i * 5) + 2, 1);
 174                 mc_recoverable_range[i].recover_addr =
 175                                         of_read_number(prop + (i * 5) + 3, 2);
 176
 177                 pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
 178                                 mc_recoverable_range[i].start_addr,
 179                                 mc_recoverable_range[i].end_addr,
 180                                 mc_recoverable_range[i].recover_addr);
 181         }
 182         return 1;
 183 }
 184
 185 static int __init opal_register_exception_handlers(void)
 186 {
 187 #ifdef __BIG_ENDIAN__
 188         u64 glue;
 189
 190         if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
 191                 return -ENODEV;
 192
 193         /* Hookup some exception handlers except machine check. We use the
 194          * fwnmi area at 0x7000 to provide the glue space to OPAL
 195          */
 196         glue = 0x7000;
 197         opal_register_exception_handler(OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
 198                                         0, glue);
 199         glue += 128;
 200         opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
 201 #endif
 202
 203         return 0;
 204 }
 205 machine_early_initcall(powernv, opal_register_exception_handlers);
 206
 207 int opal_notifier_register(struct notifier_block *nb)
 208 {
 209         if (!nb) {
 210                 pr_warning("%s: Invalid argument (%p)\n",
 211                            __func__, nb);
 212                 return -EINVAL;
 213         }
 214
 215         atomic_notifier_chain_register(&opal_notifier_head, nb);
 216         return 0;
 217 }
 218 EXPORT_SYMBOL_GPL(opal_notifier_register);
 219
 220 int opal_notifier_unregister(struct notifier_block *nb)
 221 {
 222         if (!nb) {
 223                 pr_warning("%s: Invalid argument (%p)\n",
 224                            __func__, nb);
 225                 return -EINVAL;
 226         }
 227
 228         atomic_notifier_chain_unregister(&opal_notifier_head, nb);
 229         return 0;
 230 }
 231 EXPORT_SYMBOL_GPL(opal_notifier_unregister);
 232
 233 static void opal_do_notifier(uint64_t events)
 234 {
 235         unsigned long flags;
 236         uint64_t changed_mask;
 237
 238         if (atomic_read(&opal_notifier_hold))
 239                 return;
 240
 241         spin_lock_irqsave(&opal_notifier_lock, flags);
 242         changed_mask = last_notified_mask ^ events;
 243         last_notified_mask = events;
 244         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 245
 246         /*
 247          * We feed with the event bits and changed bits for
 248          * enough information to the callback.
 249          */
 250         atomic_notifier_call_chain(&opal_notifier_head,
 251                                    events, (void *)changed_mask);
 252 }
 253
 254 void opal_notifier_update_evt(uint64_t evt_mask,
 255                               uint64_t evt_val)
 256 {
 257         unsigned long flags;
 258
 259         spin_lock_irqsave(&opal_notifier_lock, flags);
 260         last_notified_mask &= ~evt_mask;
 261         last_notified_mask |= evt_val;
 262         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 263 }
 264
 265 void opal_notifier_enable(void)
 266 {
 267         int64_t rc;
 268         __be64 evt = 0;
 269
 270         atomic_set(&opal_notifier_hold, 0);
 271
 272         /* Process pending events */
 273         rc = opal_poll_events(&evt);
 274         if (rc == OPAL_SUCCESS && evt)
 275                 opal_do_notifier(be64_to_cpu(evt));
 276 }
 277
 278 void opal_notifier_disable(void)
 279 {
 280         atomic_set(&opal_notifier_hold, 1);
 281 }
 282
 283 /*
 284  * Opal message notifier based on message type. Allow subscribers to get
 285  * notified for specific messgae type.
 286  */
 287 int opal_message_notifier_register(enum OpalMessageType msg_type,
 288                                         struct notifier_block *nb)
 289 {
 290         if (!nb) {
 291                 pr_warning("%s: Invalid argument (%p)\n",
 292                            __func__, nb);
 293                 return -EINVAL;
 294         }
 295         if (msg_type > OPAL_MSG_TYPE_MAX) {
 296                 pr_warning("%s: Invalid message type argument (%d)\n",
 297                            __func__, msg_type);
 298                 return -EINVAL;
 299         }
 300         return atomic_notifier_chain_register(
 301                                 &opal_msg_notifier_head[msg_type], nb);
 302 }
 303
 304 static void opal_message_do_notify(uint32_t msg_type, void *msg)
 305 {
 306         /* notify subscribers */
 307         atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
 308                                         msg_type, msg);
 309 }
 310
 311 static void opal_handle_message(void)
 312 {
 313         s64 ret;
 314         /*
 315          * TODO: pre-allocate a message buffer depending on opal-msg-size
 316          * value in /proc/device-tree.
 317          */
 318         static struct opal_msg msg;
 319         u32 type;
 320
 321         ret = opal_get_msg(__pa(&msg), sizeof(msg));
 322         /* No opal message pending. */
 323         if (ret == OPAL_RESOURCE)
 324                 return;
 325
 326         /* check for errors. */
 327         if (ret) {
 328                 pr_warning("%s: Failed to retrive opal message, err=%lld\n",
 329                                 __func__, ret);
 330                 return;
 331         }
 332
 333         type = be32_to_cpu(msg.msg_type);
 334
 335         /* Sanity check */
 336         if (type > OPAL_MSG_TYPE_MAX) {
 337                 pr_warning("%s: Unknown message type: %u\n", __func__, type);
 338                 return;
 339         }
 340         opal_message_do_notify(type, (void *)&msg);
 341 }
 342
 343 static int opal_message_notify(struct notifier_block *nb,
 344                           unsigned long events, void *change)
 345 {
 346         if (events & OPAL_EVENT_MSG_PENDING)
 347                 opal_handle_message();
 348         return 0;
 349 }
 350
 351 static struct notifier_block opal_message_nb = {
 352         .notifier_call  = opal_message_notify,
 353         .next           = NULL,
 354         .priority       = 0,
 355 };
 356
 357 static int __init opal_message_init(void)
 358 {
 359         int ret, i;
 360
 361         for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
 362                 ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
 363
 364         ret = opal_notifier_register(&opal_message_nb);
 365         if (ret) {
 366                 pr_err("%s: Can't register OPAL event notifier (%d)\n",
 367                        __func__, ret);
 368                 return ret;
 369         }
 370         return 0;
 371 }
 372 machine_early_initcall(powernv, opal_message_init);
 373
 374 int opal_get_chars(uint32_t vtermno, char *buf, int count)
 375 {
 376         s64 rc;
 377         __be64 evt, len;
 378
 379         if (!opal.entry)
 380                 return -ENODEV;
 381         opal_poll_events(&evt);
 382         if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
 383                 return 0;
 384         len = cpu_to_be64(count);
 385         rc = opal_console_read(vtermno, &len, buf);
 386         if (rc == OPAL_SUCCESS)
 387                 return be64_to_cpu(len);
 388         return 0;
 389 }
 390
 391 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
 392 {
 393         int written = 0;
 394         __be64 olen;
 395         s64 len, rc;
 396         unsigned long flags;
 397         __be64 evt;
 398
 399         if (!opal.entry)
 400                 return -ENODEV;
 401
 402         /* We want put_chars to be atomic to avoid mangling of hvsi
 403          * packets. To do that, we first test for room and return
 404          * -EAGAIN if there isn't enough.
 405          *
 406          * Unfortunately, opal_console_write_buffer_space() doesn't
 407          * appear to work on opal v1, so we just assume there is
 408          * enough room and be done with it
 409          */
 410         spin_lock_irqsave(&opal_write_lock, flags);
 411         if (firmware_has_feature(FW_FEATURE_OPALv2)) {
 412                 rc = opal_console_write_buffer_space(vtermno, &olen);
 413                 len = be64_to_cpu(olen);
 414                 if (rc || len < total_len) {
 415                         spin_unlock_irqrestore(&opal_write_lock, flags);
 416                         /* Closed -> drop characters */
 417                         if (rc)
 418                                 return total_len;
 419                         opal_poll_events(NULL);
 420                         return -EAGAIN;
 421                 }
 422         }
 423
 424         /* We still try to handle partial completions, though they
 425          * should no longer happen.
 426          */
 427         rc = OPAL_BUSY;
 428         while(total_len > 0 && (rc == OPAL_BUSY ||
 429                                 rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
 430                 olen = cpu_to_be64(total_len);
 431                 rc = opal_console_write(vtermno, &olen, data);
 432                 len = be64_to_cpu(olen);
 433
 434                 /* Closed or other error drop */
 435                 if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
 436                     rc != OPAL_BUSY_EVENT) {
 437                         written = total_len;
 438                         break;
 439                 }
 440                 if (rc == OPAL_SUCCESS) {
 441                         total_len -= len;
 442                         data += len;
 443                         written += len;
 444                 }
 445                 /* This is a bit nasty but we need that for the console to
 446                  * flush when there aren't any interrupts. We will clean
 447                  * things a bit later to limit that to synchronous path
 448                  * such as the kernel console and xmon/udbg
 449                  */
 450                 do
 451                         opal_poll_events(&evt);
 452                 while(rc == OPAL_SUCCESS &&
 453                         (be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
 454         }
 455         spin_unlock_irqrestore(&opal_write_lock, flags);
 456         return written;
 457 }
 458
 459 static int opal_recover_mce(struct pt_regs *regs,
 460                                         struct machine_check_event *evt)
 461 {
 462         int recovered = 0;
 463         uint64_t ea = get_mce_fault_addr(evt);
 464
 465         if (!(regs->msr & MSR_RI)) {
 466                 /* If MSR_RI isn't set, we cannot recover */
 467                 recovered = 0;
 468         } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
 469                 /* Platform corrected itself */
 470                 recovered = 1;
 471         } else if (ea && !is_kernel_addr(ea)) {
 472                 /*
 473                  * Faulting address is not in kernel text. We should be fine.
 474                  * We need to find which process uses this address.
 475                  * For now, kill the task if we have received exception when
 476                  * in userspace.
 477                  *
 478                  * TODO: Queue up this address for hwpoisioning later.
 479                  */
 480                 if (user_mode(regs) && !is_global_init(current)) {
 481                         _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 482                         recovered = 1;
 483                 } else
 484                         recovered = 0;
 485         } else if (user_mode(regs) && !is_global_init(current) &&
 486                 evt->severity == MCE_SEV_ERROR_SYNC) {
 487                 /*
 488                  * If we have received a synchronous error when in userspace
 489                  * kill the task.
 490                  */
 491                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 492                 recovered = 1;
 493         }
 494         return recovered;
 495 }
 496
 497 int opal_machine_check(struct pt_regs *regs)
 498 {
 499         struct machine_check_event evt;
 500
 501         if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
 502                 return 0;
 503
 504         /* Print things out */
 505         if (evt.version != MCE_V1) {
 506                 pr_err("Machine Check Exception, Unknown event version %d !\n",
 507                        evt.version);
 508                 return 0;
 509         }
 510         machine_check_print_event_info(&evt);
 511
 512         if (opal_recover_mce(regs, &evt))
 513                 return 1;
 514         return 0;
 515 }
 516
 517 /* Early hmi handler called in real mode. */
 518 int opal_hmi_exception_early(struct pt_regs *regs)
 519 {
 520         /* TODO: Call opal hmi handler. */
 521         return 0;
 522 }
 523
 524 /* HMI exception handler called in virtual mode during check_irq_replay. */
 525 int opal_handle_hmi_exception(struct pt_regs *regs)
 526 {
 527         /* TODO: Retrive and print HMI event from OPAL. */
 528         return 0;
 529 }
 530
 531 static uint64_t find_recovery_address(uint64_t nip)
 532 {
 533         int i;
 534
 535         for (i = 0; i < mc_recoverable_range_len; i++)
 536                 if ((nip >= mc_recoverable_range[i].start_addr) &&
 537                     (nip < mc_recoverable_range[i].end_addr))
 538                     return mc_recoverable_range[i].recover_addr;
 539         return 0;
 540 }
 541
 542 bool opal_mce_check_early_recovery(struct pt_regs *regs)
 543 {
 544         uint64_t recover_addr = 0;
 545
 546         if (!opal.base || !opal.size)
 547                 goto out;
 548
 549         if ((regs->nip >= opal.base) &&
 550                         (regs->nip <= (opal.base + opal.size)))
 551                 recover_addr = find_recovery_address(regs->nip);
 552
 553         /*
 554          * Setup regs->nip to rfi into fixup address.
 555          */
 556         if (recover_addr)
 557                 regs->nip = recover_addr;
 558
 559 out:
 560         return !!recover_addr;
 561 }
 562
 563 static irqreturn_t opal_interrupt(int irq, void *data)
 564 {
 565         __be64 events;
 566
 567         opal_handle_interrupt(virq_to_hw(irq), &events);
 568
 569         opal_do_notifier(be64_to_cpu(events));
 570
 571         return IRQ_HANDLED;
 572 }
 573
 574 static int opal_sysfs_init(void)
 575 {
 576         opal_kobj = kobject_create_and_add("opal", firmware_kobj);
 577         if (!opal_kobj) {
 578                 pr_warn("kobject_create_and_add opal failed\n");
 579                 return -ENOMEM;
 580         }
 581
 582         return 0;
 583 }
 584
 585 static int __init opal_init(void)
 586 {
 587         struct device_node *np, *consoles;
 588         const __be32 *irqs;
 589         int rc, i, irqlen;
 590
 591         opal_node = of_find_node_by_path("/ibm,opal");
 592         if (!opal_node) {
 593                 pr_warn("opal: Node not found\n");
 594                 return -ENODEV;
 595         }
 596
 597         /* Register OPAL consoles if any ports */
 598         if (firmware_has_feature(FW_FEATURE_OPALv2))
 599                 consoles = of_find_node_by_path("/ibm,opal/consoles");
 600         else
 601                 consoles = of_node_get(opal_node);
 602         if (consoles) {
 603                 for_each_child_of_node(consoles, np) {
 604                         if (strcmp(np->name, "serial"))
 605                                 continue;
 606                         of_platform_device_create(np, NULL, NULL);
 607                 }
 608                 of_node_put(consoles);
 609         }
 610
 611         /* Find all OPAL interrupts and request them */
 612         irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
 613         pr_debug("opal: Found %d interrupts reserved for OPAL\n",
 614                  irqs ? (irqlen / 4) : 0);
 615         opal_irq_count = irqlen / 4;
 616         opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
 617         for (i = 0; irqs && i < (irqlen / 4); i++, irqs++) {
 618                 unsigned int hwirq = be32_to_cpup(irqs);
 619                 unsigned int irq = irq_create_mapping(NULL, hwirq);
 620                 if (irq == NO_IRQ) {
 621                         pr_warning("opal: Failed to map irq 0x%x\n", hwirq);
 622                         continue;
 623                 }
 624                 rc = request_irq(irq, opal_interrupt, 0, "opal", NULL);
 625                 if (rc)
 626                         pr_warning("opal: Error %d requesting irq %d"
 627                                    " (0x%x)\n", rc, irq, hwirq);
 628                 opal_irqs[i] = irq;
 629         }
 630
 631         /* Create "opal" kobject under /sys/firmware */
 632         rc = opal_sysfs_init();
 633         if (rc == 0) {
 634                 /* Setup error log interface */
 635                 rc = opal_elog_init();
 636                 /* Setup code update interface */
 637                 opal_flash_init();
 638                 /* Setup platform dump extract interface */
 639                 opal_platform_dump_init();
 640                 /* Setup system parameters interface */
 641                 opal_sys_param_init();
 642                 /* Setup message log interface. */
 643                 opal_msglog_init();
 644         }
 645
 646         return 0;
 647 }
 648 machine_subsys_initcall(powernv, opal_init);
 649
 650 void opal_shutdown(void)
 651 {
 652         unsigned int i;
 653         long rc = OPAL_BUSY;
 654
 655         /* First free interrupts, which will also mask them */
 656         for (i = 0; i < opal_irq_count; i++) {
 657                 if (opal_irqs[i])
 658                         free_irq(opal_irqs[i], NULL);
 659                 opal_irqs[i] = 0;
 660         }
 661
 662         /*
 663          * Then sync with OPAL which ensure anything that can
 664          * potentially write to our memory has completed such
 665          * as an ongoing dump retrieval
 666          */
 667         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 668                 rc = opal_sync_host_reboot();
 669                 if (rc == OPAL_BUSY)
 670                         opal_poll_events(NULL);
 671                 else
 672                         mdelay(10);
 673         }
 674 }
 675
 676 /* Export this so that test modules can use it */
 677 EXPORT_SYMBOL_GPL(opal_invalid_call);
 678
 679 /* Convert a region of vmalloc memory to an opal sg list */
 680 struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
 681                                              unsigned long vmalloc_size)
 682 {
 683         struct opal_sg_list *sg, *first = NULL;
 684         unsigned long i = 0;
 685
 686         sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 687         if (!sg)
 688                 goto nomem;
 689
 690         first = sg;
 691
 692         while (vmalloc_size > 0) {
 693                 uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
 694                 uint64_t length = min(vmalloc_size, PAGE_SIZE);
 695
 696                 sg->entry[i].data = cpu_to_be64(data);
 697                 sg->entry[i].length = cpu_to_be64(length);
 698                 i++;
 699
 700                 if (i >= SG_ENTRIES_PER_NODE) {
 701                         struct opal_sg_list *next;
 702
 703                         next = kzalloc(PAGE_SIZE, GFP_KERNEL);
 704                         if (!next)
 705                                 goto nomem;
 706
 707                         sg->length = cpu_to_be64(
 708                                         i * sizeof(struct opal_sg_entry) + 16);
 709                         i = 0;
 710                         sg->next = cpu_to_be64(__pa(next));
 711                         sg = next;
 712                 }
 713
 714                 vmalloc_addr += length;
 715                 vmalloc_size -= length;
 716         }
 717
 718         sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);
 719
 720         return first;
 721
 722 nomem:
 723         pr_err("%s : Failed to allocate memory\n", __func__);
 724         opal_free_sg_list(first);
 725         return NULL;
 726 }
 727
 728 void opal_free_sg_list(struct opal_sg_list *sg)
 729 {
 730         while (sg) {
 731                 uint64_t next = be64_to_cpu(sg->next);
 732
 733                 kfree(sg);
 734
 735                 if (next)
 736                         sg = __va(next);
 737                 else
 738                         sg = NULL;
 739         }
 740 }