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