drivers/misc/sgi-xp/xpc_main.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (c) 2004-2009 Silicon Graphics, Inc.  All Rights Reserved.
   7  */
   8
   9 /*
  10  * Cross Partition Communication (XPC) support - standard version.
  11  *
  12  *      XPC provides a message passing capability that crosses partition
  13  *      boundaries. This module is made up of two parts:
  14  *
  15  *          partition   This part detects the presence/absence of other
  16  *                      partitions. It provides a heartbeat and monitors
  17  *                      the heartbeats of other partitions.
  18  *
  19  *          channel     This part manages the channels and sends/receives
  20  *                      messages across them to/from other partitions.
  21  *
  22  *      There are a couple of additional functions residing in XP, which
  23  *      provide an interface to XPC for its users.
  24  *
  25  *
  26  *      Caveats:
  27  *
  28  *        . Currently on sn2, we have no way to determine which nasid an IRQ
  29  *          came from. Thus, xpc_send_IRQ_sn2() does a remote amo write
  30  *          followed by an IPI. The amo indicates where data is to be pulled
  31  *          from, so after the IPI arrives, the remote partition checks the amo
  32  *          word. The IPI can actually arrive before the amo however, so other
  33  *          code must periodically check for this case. Also, remote amo
  34  *          operations do not reliably time out. Thus we do a remote PIO read
  35  *          solely to know whether the remote partition is down and whether we
  36  *          should stop sending IPIs to it. This remote PIO read operation is
  37  *          set up in a special nofault region so SAL knows to ignore (and
  38  *          cleanup) any errors due to the remote amo write, PIO read, and/or
  39  *          PIO write operations.
  40  *
  41  *          If/when new hardware solves this IPI problem, we should abandon
  42  *          the current approach.
  43  *
  44  */
  45
  46 #include <linux/module.h>
  47 #include <linux/slab.h>
  48 #include <linux/sysctl.h>
  49 #include <linux/device.h>
  50 #include <linux/delay.h>
  51 #include <linux/reboot.h>
  52 #include <linux/kdebug.h>
  53 #include <linux/kthread.h>
  54 #include "xpc.h"
  55
  56 /* define two XPC debug device structures to be used with dev_dbg() et al */
  57
  58 struct device_driver xpc_dbg_name = {
  59         .name = "xpc"
  60 };
  61
  62 struct device xpc_part_dbg_subname = {
  63         .init_name = "",        /* set to "part" at xpc_init() time */
  64         .driver = &xpc_dbg_name
  65 };
  66
  67 struct device xpc_chan_dbg_subname = {
  68         .init_name = "",        /* set to "chan" at xpc_init() time */
  69         .driver = &xpc_dbg_name
  70 };
  71
  72 struct device *xpc_part = &xpc_part_dbg_subname;
  73 struct device *xpc_chan = &xpc_chan_dbg_subname;
  74
  75 static int xpc_kdebug_ignore;
  76
  77 /* systune related variables for /proc/sys directories */
  78
  79 static int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
  80 static int xpc_hb_min_interval = 1;
  81 static int xpc_hb_max_interval = 10;
  82
  83 static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
  84 static int xpc_hb_check_min_interval = 10;
  85 static int xpc_hb_check_max_interval = 120;
  86
  87 int xpc_disengage_timelimit = XPC_DISENGAGE_DEFAULT_TIMELIMIT;
  88 static int xpc_disengage_min_timelimit; /* = 0 */
  89 static int xpc_disengage_max_timelimit = 120;
  90
  91 static ctl_table xpc_sys_xpc_hb_dir[] = {
  92         {
  93          .procname = "hb_interval",
  94          .data = &xpc_hb_interval,
  95          .maxlen = sizeof(int),
  96          .mode = 0644,
  97          .proc_handler = proc_dointvec_minmax,
  98          .extra1 = &xpc_hb_min_interval,
  99          .extra2 = &xpc_hb_max_interval},
 100         {
 101          .procname = "hb_check_interval",
 102          .data = &xpc_hb_check_interval,
 103          .maxlen = sizeof(int),
 104          .mode = 0644,
 105          .proc_handler = proc_dointvec_minmax,
 106          .extra1 = &xpc_hb_check_min_interval,
 107          .extra2 = &xpc_hb_check_max_interval},
 108         {}
 109 };
 110 static ctl_table xpc_sys_xpc_dir[] = {
 111         {
 112          .procname = "hb",
 113          .mode = 0555,
 114          .child = xpc_sys_xpc_hb_dir},
 115         {
 116          .procname = "disengage_timelimit",
 117          .data = &xpc_disengage_timelimit,
 118          .maxlen = sizeof(int),
 119          .mode = 0644,
 120          .proc_handler = proc_dointvec_minmax,
 121          .extra1 = &xpc_disengage_min_timelimit,
 122          .extra2 = &xpc_disengage_max_timelimit},
 123         {}
 124 };
 125 static ctl_table xpc_sys_dir[] = {
 126         {
 127          .procname = "xpc",
 128          .mode = 0555,
 129          .child = xpc_sys_xpc_dir},
 130         {}
 131 };
 132 static struct ctl_table_header *xpc_sysctl;
 133
 134 /* non-zero if any remote partition disengage was timed out */
 135 int xpc_disengage_timedout;
 136
 137 /* #of activate IRQs received and not yet processed */
 138 int xpc_activate_IRQ_rcvd;
 139 DEFINE_SPINLOCK(xpc_activate_IRQ_rcvd_lock);
 140
 141 /* IRQ handler notifies this wait queue on receipt of an IRQ */
 142 DECLARE_WAIT_QUEUE_HEAD(xpc_activate_IRQ_wq);
 143
 144 static unsigned long xpc_hb_check_timeout;
 145 static struct timer_list xpc_hb_timer;
 146
 147 /* notification that the xpc_hb_checker thread has exited */
 148 static DECLARE_COMPLETION(xpc_hb_checker_exited);
 149
 150 /* notification that the xpc_discovery thread has exited */
 151 static DECLARE_COMPLETION(xpc_discovery_exited);
 152
 153 static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
 154
 155 static int xpc_system_reboot(struct notifier_block *, unsigned long, void *);
 156 static struct notifier_block xpc_reboot_notifier = {
 157         .notifier_call = xpc_system_reboot,
 158 };
 159
 160 static int xpc_system_die(struct notifier_block *, unsigned long, void *);
 161 static struct notifier_block xpc_die_notifier = {
 162         .notifier_call = xpc_system_die,
 163 };
 164
 165 struct xpc_arch_operations xpc_arch_ops;
 166
 167 /*
 168  * Timer function to enforce the timelimit on the partition disengage.
 169  */
 170 static void
 171 xpc_timeout_partition_disengage(unsigned long data)
 172 {
 173         struct xpc_partition *part = (struct xpc_partition *)data;
 174
 175         DBUG_ON(time_is_after_jiffies(part->disengage_timeout));
 176
 177         (void)xpc_partition_disengaged(part);
 178
 179         DBUG_ON(part->disengage_timeout != 0);
 180         DBUG_ON(xpc_arch_ops.partition_engaged(XPC_PARTID(part)));
 181 }
 182
 183 /*
 184  * Timer to produce the heartbeat.  The timer structures function is
 185  * already set when this is initially called.  A tunable is used to
 186  * specify when the next timeout should occur.
 187  */
 188 static void
 189 xpc_hb_beater(unsigned long dummy)
 190 {
 191         xpc_arch_ops.increment_heartbeat();
 192
 193         if (time_is_before_eq_jiffies(xpc_hb_check_timeout))
 194                 wake_up_interruptible(&xpc_activate_IRQ_wq);
 195
 196         xpc_hb_timer.expires = jiffies + (xpc_hb_interval * HZ);
 197         add_timer(&xpc_hb_timer);
 198 }
 199
 200 static void
 201 xpc_start_hb_beater(void)
 202 {
 203         xpc_arch_ops.heartbeat_init();
 204         init_timer(&xpc_hb_timer);
 205         xpc_hb_timer.function = xpc_hb_beater;
 206         xpc_hb_beater(0);
 207 }
 208
 209 static void
 210 xpc_stop_hb_beater(void)
 211 {
 212         del_timer_sync(&xpc_hb_timer);
 213         xpc_arch_ops.heartbeat_exit();
 214 }
 215
 216 /*
 217  * At periodic intervals, scan through all active partitions and ensure
 218  * their heartbeat is still active.  If not, the partition is deactivated.
 219  */
 220 static void
 221 xpc_check_remote_hb(void)
 222 {
 223         struct xpc_partition *part;
 224         short partid;
 225         enum xp_retval ret;
 226
 227         for (partid = 0; partid < xp_max_npartitions; partid++) {
 228
 229                 if (xpc_exiting)
 230                         break;
 231
 232                 if (partid == xp_partition_id)
 233                         continue;
 234
 235                 part = &xpc_partitions[partid];
 236
 237                 if (part->act_state == XPC_P_AS_INACTIVE ||
 238                     part->act_state == XPC_P_AS_DEACTIVATING) {
 239                         continue;
 240                 }
 241
 242                 ret = xpc_arch_ops.get_remote_heartbeat(part);
 243                 if (ret != xpSuccess)
 244                         XPC_DEACTIVATE_PARTITION(part, ret);
 245         }
 246 }
 247
 248 /*
 249  * This thread is responsible for nearly all of the partition
 250  * activation/deactivation.
 251  */
 252 static int
 253 xpc_hb_checker(void *ignore)
 254 {
 255         int force_IRQ = 0;
 256
 257         /* this thread was marked active by xpc_hb_init() */
 258
 259         set_cpus_allowed_ptr(current, cpumask_of(XPC_HB_CHECK_CPU));
 260
 261         /* set our heartbeating to other partitions into motion */
 262         xpc_hb_check_timeout = jiffies + (xpc_hb_check_interval * HZ);
 263         xpc_start_hb_beater();
 264
 265         while (!xpc_exiting) {
 266
 267                 dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
 268                         "been received\n",
 269                         (int)(xpc_hb_check_timeout - jiffies),
 270                         xpc_activate_IRQ_rcvd);
 271
 272                 /* checking of remote heartbeats is skewed by IRQ handling */
 273                 if (time_is_before_eq_jiffies(xpc_hb_check_timeout)) {
 274                         xpc_hb_check_timeout = jiffies +
 275                             (xpc_hb_check_interval * HZ);
 276
 277                         dev_dbg(xpc_part, "checking remote heartbeats\n");
 278                         xpc_check_remote_hb();
 279
 280                         /*
 281                          * On sn2 we need to periodically recheck to ensure no
 282                          * IRQ/amo pairs have been missed.
 283                          */
 284                         if (is_shub())
 285                                 force_IRQ = 1;
 286                 }
 287
 288                 /* check for outstanding IRQs */
 289                 if (xpc_activate_IRQ_rcvd > 0 || force_IRQ != 0) {
 290                         force_IRQ = 0;
 291                         dev_dbg(xpc_part, "processing activate IRQs "
 292                                 "received\n");
 293                         xpc_arch_ops.process_activate_IRQ_rcvd();
 294                 }
 295
 296                 /* wait for IRQ or timeout */
 297                 (void)wait_event_interruptible(xpc_activate_IRQ_wq,
 298                                                (time_is_before_eq_jiffies(
 299                                                 xpc_hb_check_timeout) ||
 300                                                 xpc_activate_IRQ_rcvd > 0 ||
 301                                                 xpc_exiting));
 302         }
 303
 304         xpc_stop_hb_beater();
 305
 306         dev_dbg(xpc_part, "heartbeat checker is exiting\n");
 307
 308         /* mark this thread as having exited */
 309         complete(&xpc_hb_checker_exited);
 310         return 0;
 311 }
 312
 313 /*
 314  * This thread will attempt to discover other partitions to activate
 315  * based on info provided by SAL. This new thread is short lived and
 316  * will exit once discovery is complete.
 317  */
 318 static int
 319 xpc_initiate_discovery(void *ignore)
 320 {
 321         xpc_discovery();
 322
 323         dev_dbg(xpc_part, "discovery thread is exiting\n");
 324
 325         /* mark this thread as having exited */
 326         complete(&xpc_discovery_exited);
 327         return 0;
 328 }
 329
 330 /*
 331  * The first kthread assigned to a newly activated partition is the one
 332  * created by XPC HB with which it calls xpc_activating(). XPC hangs on to
 333  * that kthread until the partition is brought down, at which time that kthread
 334  * returns back to XPC HB. (The return of that kthread will signify to XPC HB
 335  * that XPC has dismantled all communication infrastructure for the associated
 336  * partition.) This kthread becomes the channel manager for that partition.
 337  *
 338  * Each active partition has a channel manager, who, besides connecting and
 339  * disconnecting channels, will ensure that each of the partition's connected
 340  * channels has the required number of assigned kthreads to get the work done.
 341  */
 342 static void
 343 xpc_channel_mgr(struct xpc_partition *part)
 344 {
 345         while (part->act_state != XPC_P_AS_DEACTIVATING ||
 346                atomic_read(&part->nchannels_active) > 0 ||
 347                !xpc_partition_disengaged(part)) {
 348
 349                 xpc_process_sent_chctl_flags(part);
 350
 351                 /*
 352                  * Wait until we've been requested to activate kthreads or
 353                  * all of the channel's message queues have been torn down or
 354                  * a signal is pending.
 355                  *
 356                  * The channel_mgr_requests is set to 1 after being awakened,
 357                  * This is done to prevent the channel mgr from making one pass
 358                  * through the loop for each request, since he will
 359                  * be servicing all the requests in one pass. The reason it's
 360                  * set to 1 instead of 0 is so that other kthreads will know
 361                  * that the channel mgr is running and won't bother trying to
 362                  * wake him up.
 363                  */
 364                 atomic_dec(&part->channel_mgr_requests);
 365                 (void)wait_event_interruptible(part->channel_mgr_wq,
 366                                 (atomic_read(&part->channel_mgr_requests) > 0 ||
 367                                  part->chctl.all_flags != 0 ||
 368                                  (part->act_state == XPC_P_AS_DEACTIVATING &&
 369                                  atomic_read(&part->nchannels_active) == 0 &&
 370                                  xpc_partition_disengaged(part))));
 371                 atomic_set(&part->channel_mgr_requests, 1);
 372         }
 373 }
 374
 375 /*
 376  * Guarantee that the kzalloc'd memory is cacheline aligned.
 377  */
 378 void *
 379 xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
 380 {
 381         /* see if kzalloc will give us cachline aligned memory by default */
 382         *base = kzalloc(size, flags);
 383         if (*base == NULL)
 384                 return NULL;
 385
 386         if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
 387                 return *base;
 388
 389         kfree(*base);
 390
 391         /* nope, we'll have to do it ourselves */
 392         *base = kzalloc(size + L1_CACHE_BYTES, flags);
 393         if (*base == NULL)
 394                 return NULL;
 395
 396         return (void *)L1_CACHE_ALIGN((u64)*base);
 397 }
 398
 399 /*
 400  * Setup the channel structures necessary to support XPartition Communication
 401  * between the specified remote partition and the local one.
 402  */
 403 static enum xp_retval
 404 xpc_setup_ch_structures(struct xpc_partition *part)
 405 {
 406         enum xp_retval ret;
 407         int ch_number;
 408         struct xpc_channel *ch;
 409         short partid = XPC_PARTID(part);
 410
 411         /*
 412          * Allocate all of the channel structures as a contiguous chunk of
 413          * memory.
 414          */
 415         DBUG_ON(part->channels != NULL);
 416         part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_MAX_NCHANNELS,
 417                                  GFP_KERNEL);
 418         if (part->channels == NULL) {
 419                 dev_err(xpc_chan, "can't get memory for channels\n");
 420                 return xpNoMemory;
 421         }
 422
 423         /* allocate the remote open and close args */
 424
 425         part->remote_openclose_args =
 426             xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
 427                                           GFP_KERNEL, &part->
 428                                           remote_openclose_args_base);
 429         if (part->remote_openclose_args == NULL) {
 430                 dev_err(xpc_chan, "can't get memory for remote connect args\n");
 431                 ret = xpNoMemory;
 432                 goto out_1;
 433         }
 434
 435         part->chctl.all_flags = 0;
 436         spin_lock_init(&part->chctl_lock);
 437
 438         atomic_set(&part->channel_mgr_requests, 1);
 439         init_waitqueue_head(&part->channel_mgr_wq);
 440
 441         part->nchannels = XPC_MAX_NCHANNELS;
 442
 443         atomic_set(&part->nchannels_active, 0);
 444         atomic_set(&part->nchannels_engaged, 0);
 445
 446         for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
 447                 ch = &part->channels[ch_number];
 448
 449                 ch->partid = partid;
 450                 ch->number = ch_number;
 451                 ch->flags = XPC_C_DISCONNECTED;
 452
 453                 atomic_set(&ch->kthreads_assigned, 0);
 454                 atomic_set(&ch->kthreads_idle, 0);
 455                 atomic_set(&ch->kthreads_active, 0);
 456
 457                 atomic_set(&ch->references, 0);
 458                 atomic_set(&ch->n_to_notify, 0);
 459
 460                 spin_lock_init(&ch->lock);
 461                 init_completion(&ch->wdisconnect_wait);
 462
 463                 atomic_set(&ch->n_on_msg_allocate_wq, 0);
 464                 init_waitqueue_head(&ch->msg_allocate_wq);
 465                 init_waitqueue_head(&ch->idle_wq);
 466         }
 467
 468         ret = xpc_arch_ops.setup_ch_structures(part);
 469         if (ret != xpSuccess)
 470                 goto out_2;
 471
 472         /*
 473          * With the setting of the partition setup_state to XPC_P_SS_SETUP,
 474          * we're declaring that this partition is ready to go.
 475          */
 476         part->setup_state = XPC_P_SS_SETUP;
 477
 478         return xpSuccess;
 479
 480         /* setup of ch structures failed */
 481 out_2:
 482         kfree(part->remote_openclose_args_base);
 483         part->remote_openclose_args = NULL;
 484 out_1:
 485         kfree(part->channels);
 486         part->channels = NULL;
 487         return ret;
 488 }
 489
 490 /*
 491  * Teardown the channel structures necessary to support XPartition Communication
 492  * between the specified remote partition and the local one.
 493  */
 494 static void
 495 xpc_teardown_ch_structures(struct xpc_partition *part)
 496 {
 497         DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
 498         DBUG_ON(atomic_read(&part->nchannels_active) != 0);
 499
 500         /*
 501          * Make this partition inaccessible to local processes by marking it
 502          * as no longer setup. Then wait before proceeding with the teardown
 503          * until all existing references cease.
 504          */
 505         DBUG_ON(part->setup_state != XPC_P_SS_SETUP);
 506         part->setup_state = XPC_P_SS_WTEARDOWN;
 507
 508         wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
 509
 510         /* now we can begin tearing down the infrastructure */
 511
 512         xpc_arch_ops.teardown_ch_structures(part);
 513
 514         kfree(part->remote_openclose_args_base);
 515         part->remote_openclose_args = NULL;
 516         kfree(part->channels);
 517         part->channels = NULL;
 518
 519         part->setup_state = XPC_P_SS_TORNDOWN;
 520 }
 521
 522 /*
 523  * When XPC HB determines that a partition has come up, it will create a new
 524  * kthread and that kthread will call this function to attempt to set up the
 525  * basic infrastructure used for Cross Partition Communication with the newly
 526  * upped partition.
 527  *
 528  * The kthread that was created by XPC HB and which setup the XPC
 529  * infrastructure will remain assigned to the partition becoming the channel
 530  * manager for that partition until the partition is deactivating, at which
 531  * time the kthread will teardown the XPC infrastructure and then exit.
 532  */
 533 static int
 534 xpc_activating(void *__partid)
 535 {
 536         short partid = (u64)__partid;
 537         struct xpc_partition *part = &xpc_partitions[partid];
 538         unsigned long irq_flags;
 539
 540         DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 541
 542         spin_lock_irqsave(&part->act_lock, irq_flags);
 543
 544         if (part->act_state == XPC_P_AS_DEACTIVATING) {
 545                 part->act_state = XPC_P_AS_INACTIVE;
 546                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 547                 part->remote_rp_pa = 0;
 548                 return 0;
 549         }
 550
 551         /* indicate the thread is activating */
 552         DBUG_ON(part->act_state != XPC_P_AS_ACTIVATION_REQ);
 553         part->act_state = XPC_P_AS_ACTIVATING;
 554
 555         XPC_SET_REASON(part, 0, 0);
 556         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 557
 558         dev_dbg(xpc_part, "activating partition %d\n", partid);
 559
 560         xpc_arch_ops.allow_hb(partid);
 561
 562         if (xpc_setup_ch_structures(part) == xpSuccess) {
 563                 (void)xpc_part_ref(part);       /* this will always succeed */
 564
 565                 if (xpc_arch_ops.make_first_contact(part) == xpSuccess) {
 566                         xpc_mark_partition_active(part);
 567                         xpc_channel_mgr(part);
 568                         /* won't return until partition is deactivating */
 569                 }
 570
 571                 xpc_part_deref(part);
 572                 xpc_teardown_ch_structures(part);
 573         }
 574
 575         xpc_arch_ops.disallow_hb(partid);
 576         xpc_mark_partition_inactive(part);
 577
 578         if (part->reason == xpReactivating) {
 579                 /* interrupting ourselves results in activating partition */
 580                 xpc_arch_ops.request_partition_reactivation(part);
 581         }
 582
 583         return 0;
 584 }
 585
 586 void
 587 xpc_activate_partition(struct xpc_partition *part)
 588 {
 589         short partid = XPC_PARTID(part);
 590         unsigned long irq_flags;
 591         struct task_struct *kthread;
 592
 593         spin_lock_irqsave(&part->act_lock, irq_flags);
 594
 595         DBUG_ON(part->act_state != XPC_P_AS_INACTIVE);
 596
 597         part->act_state = XPC_P_AS_ACTIVATION_REQ;
 598         XPC_SET_REASON(part, xpCloneKThread, __LINE__);
 599
 600         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 601
 602         kthread = kthread_run(xpc_activating, (void *)((u64)partid), "xpc%02d",
 603                               partid);
 604         if (IS_ERR(kthread)) {
 605                 spin_lock_irqsave(&part->act_lock, irq_flags);
 606                 part->act_state = XPC_P_AS_INACTIVE;
 607                 XPC_SET_REASON(part, xpCloneKThreadFailed, __LINE__);
 608                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 609         }
 610 }
 611
 612 void
 613 xpc_activate_kthreads(struct xpc_channel *ch, int needed)
 614 {
 615         int idle = atomic_read(&ch->kthreads_idle);
 616         int assigned = atomic_read(&ch->kthreads_assigned);
 617         int wakeup;
 618
 619         DBUG_ON(needed <= 0);
 620
 621         if (idle > 0) {
 622                 wakeup = (needed > idle) ? idle : needed;
 623                 needed -= wakeup;
 624
 625                 dev_dbg(xpc_chan, "wakeup %d idle kthreads, partid=%d, "
 626                         "channel=%d\n", wakeup, ch->partid, ch->number);
 627
 628                 /* only wakeup the requested number of kthreads */
 629                 wake_up_nr(&ch->idle_wq, wakeup);
 630         }
 631
 632         if (needed <= 0)
 633                 return;
 634
 635         if (needed + assigned > ch->kthreads_assigned_limit) {
 636                 needed = ch->kthreads_assigned_limit - assigned;
 637                 if (needed <= 0)
 638                         return;
 639         }
 640
 641         dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n",
 642                 needed, ch->partid, ch->number);
 643
 644         xpc_create_kthreads(ch, needed, 0);
 645 }
 646
 647 /*
 648  * This function is where XPC's kthreads wait for messages to deliver.
 649  */
 650 static void
 651 xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 652 {
 653         int (*n_of_deliverable_payloads) (struct xpc_channel *) =
 654                 xpc_arch_ops.n_of_deliverable_payloads;
 655
 656         do {
 657                 /* deliver messages to their intended recipients */
 658
 659                 while (n_of_deliverable_payloads(ch) > 0 &&
 660                        !(ch->flags & XPC_C_DISCONNECTING)) {
 661                         xpc_deliver_payload(ch);
 662                 }
 663
 664                 if (atomic_inc_return(&ch->kthreads_idle) >
 665                     ch->kthreads_idle_limit) {
 666                         /* too many idle kthreads on this channel */
 667                         atomic_dec(&ch->kthreads_idle);
 668                         break;
 669                 }
 670
 671                 dev_dbg(xpc_chan, "idle kthread calling "
 672                         "wait_event_interruptible_exclusive()\n");
 673
 674                 (void)wait_event_interruptible_exclusive(ch->idle_wq,
 675                                 (n_of_deliverable_payloads(ch) > 0 ||
 676                                  (ch->flags & XPC_C_DISCONNECTING)));
 677
 678                 atomic_dec(&ch->kthreads_idle);
 679
 680         } while (!(ch->flags & XPC_C_DISCONNECTING));
 681 }
 682
 683 static int
 684 xpc_kthread_start(void *args)
 685 {
 686         short partid = XPC_UNPACK_ARG1(args);
 687         u16 ch_number = XPC_UNPACK_ARG2(args);
 688         struct xpc_partition *part = &xpc_partitions[partid];
 689         struct xpc_channel *ch;
 690         int n_needed;
 691         unsigned long irq_flags;
 692         int (*n_of_deliverable_payloads) (struct xpc_channel *) =
 693                 xpc_arch_ops.n_of_deliverable_payloads;
 694
 695         dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n",
 696                 partid, ch_number);
 697
 698         ch = &part->channels[ch_number];
 699
 700         if (!(ch->flags & XPC_C_DISCONNECTING)) {
 701
 702                 /* let registerer know that connection has been established */
 703
 704                 spin_lock_irqsave(&ch->lock, irq_flags);
 705                 if (!(ch->flags & XPC_C_CONNECTEDCALLOUT)) {
 706                         ch->flags |= XPC_C_CONNECTEDCALLOUT;
 707                         spin_unlock_irqrestore(&ch->lock, irq_flags);
 708
 709                         xpc_connected_callout(ch);
 710
 711                         spin_lock_irqsave(&ch->lock, irq_flags);
 712                         ch->flags |= XPC_C_CONNECTEDCALLOUT_MADE;
 713                         spin_unlock_irqrestore(&ch->lock, irq_flags);
 714
 715                         /*
 716                          * It is possible that while the callout was being
 717                          * made that the remote partition sent some messages.
 718                          * If that is the case, we may need to activate
 719                          * additional kthreads to help deliver them. We only
 720                          * need one less than total #of messages to deliver.
 721                          */
 722                         n_needed = n_of_deliverable_payloads(ch) - 1;
 723                         if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
 724                                 xpc_activate_kthreads(ch, n_needed);
 725
 726                 } else {
 727                         spin_unlock_irqrestore(&ch->lock, irq_flags);
 728                 }
 729
 730                 xpc_kthread_waitmsgs(part, ch);
 731         }
 732
 733         /* let registerer know that connection is disconnecting */
 734
 735         spin_lock_irqsave(&ch->lock, irq_flags);
 736         if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
 737             !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
 738                 ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
 739                 spin_unlock_irqrestore(&ch->lock, irq_flags);
 740
 741                 xpc_disconnect_callout(ch, xpDisconnecting);
 742
 743                 spin_lock_irqsave(&ch->lock, irq_flags);
 744                 ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
 745         }
 746         spin_unlock_irqrestore(&ch->lock, irq_flags);
 747
 748         if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
 749             atomic_dec_return(&part->nchannels_engaged) == 0) {
 750                 xpc_arch_ops.indicate_partition_disengaged(part);
 751         }
 752
 753         xpc_msgqueue_deref(ch);
 754
 755         dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
 756                 partid, ch_number);
 757
 758         xpc_part_deref(part);
 759         return 0;
 760 }
 761
 762 /*
 763  * For each partition that XPC has established communications with, there is
 764  * a minimum of one kernel thread assigned to perform any operation that
 765  * may potentially sleep or block (basically the callouts to the asynchronous
 766  * functions registered via xpc_connect()).
 767  *
 768  * Additional kthreads are created and destroyed by XPC as the workload
 769  * demands.
 770  *
 771  * A kthread is assigned to one of the active channels that exists for a given
 772  * partition.
 773  */
 774 void
 775 xpc_create_kthreads(struct xpc_channel *ch, int needed,
 776                     int ignore_disconnecting)
 777 {
 778         unsigned long irq_flags;
 779         u64 args = XPC_PACK_ARGS(ch->partid, ch->number);
 780         struct xpc_partition *part = &xpc_partitions[ch->partid];
 781         struct task_struct *kthread;
 782         void (*indicate_partition_disengaged) (struct xpc_partition *) =
 783                 xpc_arch_ops.indicate_partition_disengaged;
 784
 785         while (needed-- > 0) {
 786
 787                 /*
 788                  * The following is done on behalf of the newly created
 789                  * kthread. That kthread is responsible for doing the
 790                  * counterpart to the following before it exits.
 791                  */
 792                 if (ignore_disconnecting) {
 793                         if (!atomic_inc_not_zero(&ch->kthreads_assigned)) {
 794                                 /* kthreads assigned had gone to zero */
 795                                 BUG_ON(!(ch->flags &
 796                                          XPC_C_DISCONNECTINGCALLOUT_MADE));
 797                                 break;
 798                         }
 799
 800                 } else if (ch->flags & XPC_C_DISCONNECTING) {
 801                         break;
 802
 803                 } else if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
 804                            atomic_inc_return(&part->nchannels_engaged) == 1) {
 805                         xpc_arch_ops.indicate_partition_engaged(part);
 806                 }
 807                 (void)xpc_part_ref(part);
 808                 xpc_msgqueue_ref(ch);
 809
 810                 kthread = kthread_run(xpc_kthread_start, (void *)args,
 811                                       "xpc%02dc%d", ch->partid, ch->number);
 812                 if (IS_ERR(kthread)) {
 813                         /* the fork failed */
 814
 815                         /*
 816                          * NOTE: if (ignore_disconnecting &&
 817                          * !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) is true,
 818                          * then we'll deadlock if all other kthreads assigned
 819                          * to this channel are blocked in the channel's
 820                          * registerer, because the only thing that will unblock
 821                          * them is the xpDisconnecting callout that this
 822                          * failed kthread_run() would have made.
 823                          */
 824
 825                         if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
 826                             atomic_dec_return(&part->nchannels_engaged) == 0) {
 827                                 indicate_partition_disengaged(part);
 828                         }
 829                         xpc_msgqueue_deref(ch);
 830                         xpc_part_deref(part);
 831
 832                         if (atomic_read(&ch->kthreads_assigned) <
 833                             ch->kthreads_idle_limit) {
 834                                 /*
 835                                  * Flag this as an error only if we have an
 836                                  * insufficient #of kthreads for the channel
 837                                  * to function.
 838                                  */
 839                                 spin_lock_irqsave(&ch->lock, irq_flags);
 840                                 XPC_DISCONNECT_CHANNEL(ch, xpLackOfResources,
 841                                                        &irq_flags);
 842                                 spin_unlock_irqrestore(&ch->lock, irq_flags);
 843                         }
 844                         break;
 845                 }
 846         }
 847 }
 848
 849 void
 850 xpc_disconnect_wait(int ch_number)
 851 {
 852         unsigned long irq_flags;
 853         short partid;
 854         struct xpc_partition *part;
 855         struct xpc_channel *ch;
 856         int wakeup_channel_mgr;
 857
 858         /* now wait for all callouts to the caller's function to cease */
 859         for (partid = 0; partid < xp_max_npartitions; partid++) {
 860                 part = &xpc_partitions[partid];
 861
 862                 if (!xpc_part_ref(part))
 863                         continue;
 864
 865                 ch = &part->channels[ch_number];
 866
 867                 if (!(ch->flags & XPC_C_WDISCONNECT)) {
 868                         xpc_part_deref(part);
 869                         continue;
 870                 }
 871
 872                 wait_for_completion(&ch->wdisconnect_wait);
 873
 874                 spin_lock_irqsave(&ch->lock, irq_flags);
 875                 DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
 876                 wakeup_channel_mgr = 0;
 877
 878                 if (ch->delayed_chctl_flags) {
 879                         if (part->act_state != XPC_P_AS_DEACTIVATING) {
 880                                 spin_lock(&part->chctl_lock);
 881                                 part->chctl.flags[ch->number] |=
 882                                     ch->delayed_chctl_flags;
 883                                 spin_unlock(&part->chctl_lock);
 884                                 wakeup_channel_mgr = 1;
 885                         }
 886                         ch->delayed_chctl_flags = 0;
 887                 }
 888
 889                 ch->flags &= ~XPC_C_WDISCONNECT;
 890                 spin_unlock_irqrestore(&ch->lock, irq_flags);
 891
 892                 if (wakeup_channel_mgr)
 893                         xpc_wakeup_channel_mgr(part);
 894
 895                 xpc_part_deref(part);
 896         }
 897 }
 898
 899 static int
 900 xpc_setup_partitions(void)
 901 {
 902         short partid;
 903         struct xpc_partition *part;
 904
 905         xpc_partitions = kzalloc(sizeof(struct xpc_partition) *
 906                                  xp_max_npartitions, GFP_KERNEL);
 907         if (xpc_partitions == NULL) {
 908                 dev_err(xpc_part, "can't get memory for partition structure\n");
 909                 return -ENOMEM;
 910         }
 911
 912         /*
 913          * The first few fields of each entry of xpc_partitions[] need to
 914          * be initialized now so that calls to xpc_connect() and
 915          * xpc_disconnect() can be made prior to the activation of any remote
 916          * partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE
 917          * ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING
 918          * PARTITION HAS BEEN ACTIVATED.
 919          */
 920         for (partid = 0; partid < xp_max_npartitions; partid++) {
 921                 part = &xpc_partitions[partid];
 922
 923                 DBUG_ON((u64)part != L1_CACHE_ALIGN((u64)part));
 924
 925                 part->activate_IRQ_rcvd = 0;
 926                 spin_lock_init(&part->act_lock);
 927                 part->act_state = XPC_P_AS_INACTIVE;
 928                 XPC_SET_REASON(part, 0, 0);
 929
 930                 init_timer(&part->disengage_timer);
 931                 part->disengage_timer.function =
 932                     xpc_timeout_partition_disengage;
 933                 part->disengage_timer.data = (unsigned long)part;
 934
 935                 part->setup_state = XPC_P_SS_UNSET;
 936                 init_waitqueue_head(&part->teardown_wq);
 937                 atomic_set(&part->references, 0);
 938         }
 939
 940         return xpc_arch_ops.setup_partitions();
 941 }
 942
 943 static void
 944 xpc_teardown_partitions(void)
 945 {
 946         xpc_arch_ops.teardown_partitions();
 947         kfree(xpc_partitions);
 948 }
 949
 950 static void
 951 xpc_do_exit(enum xp_retval reason)
 952 {
 953         short partid;
 954         int active_part_count, printed_waiting_msg = 0;
 955         struct xpc_partition *part;
 956         unsigned long printmsg_time, disengage_timeout = 0;
 957
 958         /* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
 959         DBUG_ON(xpc_exiting == 1);
 960
 961         /*
 962          * Let the heartbeat checker thread and the discovery thread
 963          * (if one is running) know that they should exit. Also wake up
 964          * the heartbeat checker thread in case it's sleeping.
 965          */
 966         xpc_exiting = 1;
 967         wake_up_interruptible(&xpc_activate_IRQ_wq);
 968
 969         /* wait for the discovery thread to exit */
 970         wait_for_completion(&xpc_discovery_exited);
 971
 972         /* wait for the heartbeat checker thread to exit */
 973         wait_for_completion(&xpc_hb_checker_exited);
 974
 975         /* sleep for a 1/3 of a second or so */
 976         (void)msleep_interruptible(300);
 977
 978         /* wait for all partitions to become inactive */
 979
 980         printmsg_time = jiffies + (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
 981         xpc_disengage_timedout = 0;
 982
 983         do {
 984                 active_part_count = 0;
 985
 986                 for (partid = 0; partid < xp_max_npartitions; partid++) {
 987                         part = &xpc_partitions[partid];
 988
 989                         if (xpc_partition_disengaged(part) &&
 990                             part->act_state == XPC_P_AS_INACTIVE) {
 991                                 continue;
 992                         }
 993
 994                         active_part_count++;
 995
 996                         XPC_DEACTIVATE_PARTITION(part, reason);
 997
 998                         if (part->disengage_timeout > disengage_timeout)
 999                                 disengage_timeout = part->disengage_timeout;
1000                 }
1001
1002                 if (xpc_arch_ops.any_partition_engaged()) {
1003                         if (time_is_before_jiffies(printmsg_time)) {
1004                                 dev_info(xpc_part, "waiting for remote "
1005                                          "partitions to deactivate, timeout in "
1006                                          "%ld seconds\n", (disengage_timeout -
1007                                          jiffies) / HZ);
1008                                 printmsg_time = jiffies +
1009                                     (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
1010                                 printed_waiting_msg = 1;
1011                         }
1012
1013                 } else if (active_part_count > 0) {
1014                         if (printed_waiting_msg) {
1015                                 dev_info(xpc_part, "waiting for local partition"
1016                                          " to deactivate\n");
1017                                 printed_waiting_msg = 0;
1018                         }
1019
1020                 } else {
1021                         if (!xpc_disengage_timedout) {
1022                                 dev_info(xpc_part, "all partitions have "
1023                                          "deactivated\n");
1024                         }
1025                         break;
1026                 }
1027
1028                 /* sleep for a 1/3 of a second or so */
1029                 (void)msleep_interruptible(300);
1030
1031         } while (1);
1032
1033         DBUG_ON(xpc_arch_ops.any_partition_engaged());
1034
1035         xpc_teardown_rsvd_page();
1036
1037         if (reason == xpUnloading) {
1038                 (void)unregister_die_notifier(&xpc_die_notifier);
1039                 (void)unregister_reboot_notifier(&xpc_reboot_notifier);
1040         }
1041
1042         /* clear the interface to XPC's functions */
1043         xpc_clear_interface();
1044
1045         if (xpc_sysctl)
1046                 unregister_sysctl_table(xpc_sysctl);
1047
1048         xpc_teardown_partitions();
1049
1050         if (is_shub())
1051                 xpc_exit_sn2();
1052         else if (is_uv())
1053                 xpc_exit_uv();
1054 }
1055
1056 /*
1057  * This function is called when the system is being rebooted.
1058  */
1059 static int
1060 xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
1061 {
1062         enum xp_retval reason;
1063
1064         switch (event) {
1065         case SYS_RESTART:
1066                 reason = xpSystemReboot;
1067                 break;
1068         case SYS_HALT:
1069                 reason = xpSystemHalt;
1070                 break;
1071         case SYS_POWER_OFF:
1072                 reason = xpSystemPoweroff;
1073                 break;
1074         default:
1075                 reason = xpSystemGoingDown;
1076         }
1077
1078         xpc_do_exit(reason);
1079         return NOTIFY_DONE;
1080 }
1081
1082 /*
1083  * Notify other partitions to deactivate from us by first disengaging from all
1084  * references to our memory.
1085  */
1086 static void
1087 xpc_die_deactivate(void)
1088 {
1089         struct xpc_partition *part;
1090         short partid;
1091         int any_engaged;
1092         long keep_waiting;
1093         long wait_to_print;
1094
1095         /* keep xpc_hb_checker thread from doing anything (just in case) */
1096         xpc_exiting = 1;
1097
1098         xpc_arch_ops.disallow_all_hbs();   /*indicate we're deactivated */
1099
1100         for (partid = 0; partid < xp_max_npartitions; partid++) {
1101                 part = &xpc_partitions[partid];
1102
1103                 if (xpc_arch_ops.partition_engaged(partid) ||
1104                     part->act_state != XPC_P_AS_INACTIVE) {
1105                         xpc_arch_ops.request_partition_deactivation(part);
1106                         xpc_arch_ops.indicate_partition_disengaged(part);
1107                 }
1108         }
1109
1110         /*
1111          * Though we requested that all other partitions deactivate from us,
1112          * we only wait until they've all disengaged or we've reached the
1113          * defined timelimit.
1114          *
1115          * Given that one iteration through the following while-loop takes
1116          * approximately 200 microseconds, calculate the #of loops to take
1117          * before bailing and the #of loops before printing a waiting message.
1118          */
1119         keep_waiting = xpc_disengage_timelimit * 1000 * 5;
1120         wait_to_print = XPC_DEACTIVATE_PRINTMSG_INTERVAL * 1000 * 5;
1121
1122         while (1) {
1123                 any_engaged = xpc_arch_ops.any_partition_engaged();
1124                 if (!any_engaged) {
1125                         dev_info(xpc_part, "all partitions have deactivated\n");
1126                         break;
1127                 }
1128
1129                 if (!keep_waiting--) {
1130                         for (partid = 0; partid < xp_max_npartitions;
1131                              partid++) {
1132                                 if (xpc_arch_ops.partition_engaged(partid)) {
1133                                         dev_info(xpc_part, "deactivate from "
1134                                                  "remote partition %d timed "
1135                                                  "out\n", partid);
1136                                 }
1137                         }
1138                         break;
1139                 }
1140
1141                 if (!wait_to_print--) {
1142                         dev_info(xpc_part, "waiting for remote partitions to "
1143                                  "deactivate, timeout in %ld seconds\n",
1144                                  keep_waiting / (1000 * 5));
1145                         wait_to_print = XPC_DEACTIVATE_PRINTMSG_INTERVAL *
1146                             1000 * 5;
1147                 }
1148
1149                 udelay(200);
1150         }
1151 }
1152
1153 /*
1154  * This function is called when the system is being restarted or halted due
1155  * to some sort of system failure. If this is the case we need to notify the
1156  * other partitions to disengage from all references to our memory.
1157  * This function can also be called when our heartbeater could be offlined
1158  * for a time. In this case we need to notify other partitions to not worry
1159  * about the lack of a heartbeat.
1160  */
1161 static int
1162 xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
1163 {
1164 #ifdef CONFIG_IA64              /* !!! temporary kludge */
1165         switch (event) {
1166         case DIE_MACHINE_RESTART:
1167         case DIE_MACHINE_HALT:
1168                 xpc_die_deactivate();
1169                 break;
1170
1171         case DIE_KDEBUG_ENTER:
1172                 /* Should lack of heartbeat be ignored by other partitions? */
1173                 if (!xpc_kdebug_ignore)
1174                         break;
1175
1176                 /* fall through */
1177         case DIE_MCA_MONARCH_ENTER:
1178         case DIE_INIT_MONARCH_ENTER:
1179                 xpc_arch_ops.offline_heartbeat();
1180                 break;
1181
1182         case DIE_KDEBUG_LEAVE:
1183                 /* Is lack of heartbeat being ignored by other partitions? */
1184                 if (!xpc_kdebug_ignore)
1185                         break;
1186
1187                 /* fall through */
1188         case DIE_MCA_MONARCH_LEAVE:
1189         case DIE_INIT_MONARCH_LEAVE:
1190                 xpc_arch_ops.online_heartbeat();
1191                 break;
1192         }
1193 #else
1194         xpc_die_deactivate();
1195 #endif
1196
1197         return NOTIFY_DONE;
1198 }
1199
1200 int __init
1201 xpc_init(void)
1202 {
1203         int ret;
1204         struct task_struct *kthread;
1205
1206         dev_set_name(xpc_part, "part");
1207         dev_set_name(xpc_chan, "chan");
1208
1209         if (is_shub()) {
1210                 /*
1211                  * The ia64-sn2 architecture supports at most 64 partitions.
1212                  * And the inability to unregister remote amos restricts us
1213                  * further to only support exactly 64 partitions on this
1214                  * architecture, no less.
1215                  */
1216                 if (xp_max_npartitions != 64) {
1217                         dev_err(xpc_part, "max #of partitions not set to 64\n");
1218                         ret = -EINVAL;
1219                 } else {
1220                         ret = xpc_init_sn2();
1221                 }
1222
1223         } else if (is_uv()) {
1224                 ret = xpc_init_uv();
1225
1226         } else {
1227                 ret = -ENODEV;
1228         }
1229
1230         if (ret != 0)
1231                 return ret;
1232
1233         ret = xpc_setup_partitions();
1234         if (ret != 0) {
1235                 dev_err(xpc_part, "can't get memory for partition structure\n");
1236                 goto out_1;
1237         }
1238
1239         xpc_sysctl = register_sysctl_table(xpc_sys_dir);
1240
1241         /*
1242          * Fill the partition reserved page with the information needed by
1243          * other partitions to discover we are alive and establish initial
1244          * communications.
1245          */
1246         ret = xpc_setup_rsvd_page();
1247         if (ret != 0) {
1248                 dev_err(xpc_part, "can't setup our reserved page\n");
1249                 goto out_2;
1250         }
1251
1252         /* add ourselves to the reboot_notifier_list */
1253         ret = register_reboot_notifier(&xpc_reboot_notifier);
1254         if (ret != 0)
1255                 dev_warn(xpc_part, "can't register reboot notifier\n");
1256
1257         /* add ourselves to the die_notifier list */
1258         ret = register_die_notifier(&xpc_die_notifier);
1259         if (ret != 0)
1260                 dev_warn(xpc_part, "can't register die notifier\n");
1261
1262         /*
1263          * The real work-horse behind xpc.  This processes incoming
1264          * interrupts and monitors remote heartbeats.
1265          */
1266         kthread = kthread_run(xpc_hb_checker, NULL, XPC_HB_CHECK_THREAD_NAME);
1267         if (IS_ERR(kthread)) {
1268                 dev_err(xpc_part, "failed while forking hb check thread\n");
1269                 ret = -EBUSY;
1270                 goto out_3;
1271         }
1272
1273         /*
1274          * Startup a thread that will attempt to discover other partitions to
1275          * activate based on info provided by SAL. This new thread is short
1276          * lived and will exit once discovery is complete.
1277          */
1278         kthread = kthread_run(xpc_initiate_discovery, NULL,
1279                               XPC_DISCOVERY_THREAD_NAME);
1280         if (IS_ERR(kthread)) {
1281                 dev_err(xpc_part, "failed while forking discovery thread\n");
1282
1283                 /* mark this new thread as a non-starter */
1284                 complete(&xpc_discovery_exited);
1285
1286                 xpc_do_exit(xpUnloading);
1287                 return -EBUSY;
1288         }
1289
1290         /* set the interface to point at XPC's functions */
1291         xpc_set_interface(xpc_initiate_connect, xpc_initiate_disconnect,
1292                           xpc_initiate_send, xpc_initiate_send_notify,
1293                           xpc_initiate_received, xpc_initiate_partid_to_nasids);
1294
1295         return 0;
1296
1297         /* initialization was not successful */
1298 out_3:
1299         xpc_teardown_rsvd_page();
1300
1301         (void)unregister_die_notifier(&xpc_die_notifier);
1302         (void)unregister_reboot_notifier(&xpc_reboot_notifier);
1303 out_2:
1304         if (xpc_sysctl)
1305                 unregister_sysctl_table(xpc_sysctl);
1306
1307         xpc_teardown_partitions();
1308 out_1:
1309         if (is_shub())
1310                 xpc_exit_sn2();
1311         else if (is_uv())
1312                 xpc_exit_uv();
1313         return ret;
1314 }
1315
1316 module_init(xpc_init);
1317
1318 void __exit
1319 xpc_exit(void)
1320 {
1321         xpc_do_exit(xpUnloading);
1322 }
1323
1324 module_exit(xpc_exit);
1325
1326 MODULE_AUTHOR("Silicon Graphics, Inc.");
1327 MODULE_DESCRIPTION("Cross Partition Communication (XPC) support");
1328 MODULE_LICENSE("GPL");
1329
1330 module_param(xpc_hb_interval, int, 0);
1331 MODULE_PARM_DESC(xpc_hb_interval, "Number of seconds between "
1332                  "heartbeat increments.");
1333
1334 module_param(xpc_hb_check_interval, int, 0);
1335 MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
1336                  "heartbeat checks.");
1337
1338 module_param(xpc_disengage_timelimit, int, 0);
1339 MODULE_PARM_DESC(xpc_disengage_timelimit, "Number of seconds to wait "
1340                  "for disengage to complete.");
1341
1342 module_param(xpc_kdebug_ignore, int, 0);
1343 MODULE_PARM_DESC(xpc_kdebug_ignore, "Should lack of heartbeat be ignored by "
1344                  "other partitions when dropping into kdebug.");