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