drivers/pci/hotplug/cpci_hotplug_core.c

   1 /*
   2  * CompactPCI Hot Plug Driver
   3  *
   4  * Copyright (C) 2002,2005 SOMA Networks, Inc.
   5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
   6  * Copyright (C) 2001 IBM Corp.
   7  *
   8  * All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or (at
  13  * your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  18  * NON INFRINGEMENT.  See the GNU General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  *
  25  * Send feedback to <scottm@somanetworks.com>
  26  */
  27
  28 #include <linux/config.h>
  29 #include <linux/module.h>
  30 #include <linux/kernel.h>
  31 #include <linux/slab.h>
  32 #include <linux/pci.h>
  33 #include <linux/init.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/smp_lock.h>
  36 #include <asm/atomic.h>
  37 #include <linux/delay.h>
  38 #include "pci_hotplug.h"
  39 #include "cpci_hotplug.h"
  40
  41 #define DRIVER_AUTHOR   "Scott Murray <scottm@somanetworks.com>"
  42 #define DRIVER_DESC     "CompactPCI Hot Plug Core"
  43
  44 #define MY_NAME "cpci_hotplug"
  45
  46 #define dbg(format, arg...)                                     \
  47         do {                                                    \
  48                 if (cpci_debug)                                 \
  49                         printk (KERN_DEBUG "%s: " format "\n",  \
  50                                 MY_NAME , ## arg);              \
  51         } while (0)
  52 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
  53 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
  54 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)
  55
  56 /* local variables */
  57 static DECLARE_RWSEM(list_rwsem);
  58 static LIST_HEAD(slot_list);
  59 static int slots;
  60 static atomic_t extracting;
  61 int cpci_debug;
  62 static struct cpci_hp_controller *controller;
  63 static struct semaphore event_semaphore;        /* mutex for process loop (up if something to process) */
  64 static struct semaphore thread_exit;            /* guard ensure thread has exited before calling it quits */
  65 static int thread_finished = 1;
  66
  67 static int enable_slot(struct hotplug_slot *slot);
  68 static int disable_slot(struct hotplug_slot *slot);
  69 static int set_attention_status(struct hotplug_slot *slot, u8 value);
  70 static int get_power_status(struct hotplug_slot *slot, u8 * value);
  71 static int get_attention_status(struct hotplug_slot *slot, u8 * value);
  72 static int get_adapter_status(struct hotplug_slot *slot, u8 * value);
  73 static int get_latch_status(struct hotplug_slot *slot, u8 * value);
  74
  75 static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
  76         .owner = THIS_MODULE,
  77         .enable_slot = enable_slot,
  78         .disable_slot = disable_slot,
  79         .set_attention_status = set_attention_status,
  80         .get_power_status = get_power_status,
  81         .get_attention_status = get_attention_status,
  82         .get_adapter_status = get_adapter_status,
  83         .get_latch_status = get_latch_status,
  84 };
  85
  86 static int
  87 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
  88 {
  89         struct hotplug_slot_info info;
  90
  91         memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
  92         info.latch_status = value;
  93         return pci_hp_change_slot_info(hotplug_slot, &info);
  94 }
  95
  96 static int
  97 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
  98 {
  99         struct hotplug_slot_info info;
 100
 101         memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
 102         info.adapter_status = value;
 103         return pci_hp_change_slot_info(hotplug_slot, &info);
 104 }
 105
 106 static int
 107 enable_slot(struct hotplug_slot *hotplug_slot)
 108 {
 109         struct slot *slot = hotplug_slot->private;
 110         int retval = 0;
 111
 112         dbg("%s - physical_slot = %s", __FUNCTION__, hotplug_slot->name);
 113
 114         if (controller->ops->set_power)
 115                 retval = controller->ops->set_power(slot, 1);
 116         return retval;
 117 }
 118
 119 static int
 120 disable_slot(struct hotplug_slot *hotplug_slot)
 121 {
 122         struct slot *slot = hotplug_slot->private;
 123         int retval = 0;
 124
 125         dbg("%s - physical_slot = %s", __FUNCTION__, hotplug_slot->name);
 126
 127         down_write(&list_rwsem);
 128
 129         /* Unconfigure device */
 130         dbg("%s - unconfiguring slot %s",
 131             __FUNCTION__, slot->hotplug_slot->name);
 132         if ((retval = cpci_unconfigure_slot(slot))) {
 133                 err("%s - could not unconfigure slot %s",
 134                     __FUNCTION__, slot->hotplug_slot->name);
 135                 goto disable_error;
 136         }
 137         dbg("%s - finished unconfiguring slot %s",
 138             __FUNCTION__, slot->hotplug_slot->name);
 139
 140         /* Clear EXT (by setting it) */
 141         if (cpci_clear_ext(slot)) {
 142                 err("%s - could not clear EXT for slot %s",
 143                     __FUNCTION__, slot->hotplug_slot->name);
 144                 retval = -ENODEV;
 145                 goto disable_error;
 146         }
 147         cpci_led_on(slot);
 148
 149         if (controller->ops->set_power)
 150                 if ((retval = controller->ops->set_power(slot, 0)))
 151                         goto disable_error;
 152
 153         if (update_adapter_status(slot->hotplug_slot, 0))
 154                 warn("failure to update adapter file");
 155
 156         if (slot->extracting) {
 157                 slot->extracting = 0;
 158                 atomic_dec(&extracting);
 159         }
 160 disable_error:
 161         up_write(&list_rwsem);
 162         return retval;
 163 }
 164
 165 static u8
 166 cpci_get_power_status(struct slot *slot)
 167 {
 168         u8 power = 1;
 169
 170         if (controller->ops->get_power)
 171                 power = controller->ops->get_power(slot);
 172         return power;
 173 }
 174
 175 static int
 176 get_power_status(struct hotplug_slot *hotplug_slot, u8 * value)
 177 {
 178         struct slot *slot = hotplug_slot->private;
 179
 180         *value = cpci_get_power_status(slot);
 181         return 0;
 182 }
 183
 184 static int
 185 get_attention_status(struct hotplug_slot *hotplug_slot, u8 * value)
 186 {
 187         struct slot *slot = hotplug_slot->private;
 188
 189         *value = cpci_get_attention_status(slot);
 190         return 0;
 191 }
 192
 193 static int
 194 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 195 {
 196         return cpci_set_attention_status(hotplug_slot->private, status);
 197 }
 198
 199 static int
 200 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 * value)
 201 {
 202         *value = hotplug_slot->info->adapter_status;
 203         return 0;
 204 }
 205
 206 static int
 207 get_latch_status(struct hotplug_slot *hotplug_slot, u8 * value)
 208 {
 209         *value = hotplug_slot->info->latch_status;
 210         return 0;
 211 }
 212
 213 static void release_slot(struct hotplug_slot *hotplug_slot)
 214 {
 215         struct slot *slot = hotplug_slot->private;
 216
 217         kfree(slot->hotplug_slot->info);
 218         kfree(slot->hotplug_slot->name);
 219         kfree(slot->hotplug_slot);
 220         if (slot->dev)
 221                 pci_dev_put(slot->dev);
 222         kfree(slot);
 223 }
 224
 225 #define SLOT_NAME_SIZE  6
 226 static void
 227 make_slot_name(struct slot *slot)
 228 {
 229         snprintf(slot->hotplug_slot->name,
 230                  SLOT_NAME_SIZE, "%02x:%02x", slot->bus->number, slot->number);
 231 }
 232
 233 int
 234 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
 235 {
 236         struct slot *slot;
 237         struct hotplug_slot *hotplug_slot;
 238         struct hotplug_slot_info *info;
 239         char *name;
 240         int status = -ENOMEM;
 241         int i;
 242
 243         if (!(controller && bus))
 244                 return -ENODEV;
 245
 246         /*
 247          * Create a structure for each slot, and register that slot
 248          * with the pci_hotplug subsystem.
 249          */
 250         for (i = first; i <= last; ++i) {
 251                 slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
 252                 if (!slot)
 253                         goto error;
 254
 255                 hotplug_slot =
 256                         kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL);
 257                 if (!hotplug_slot)
 258                         goto error_slot;
 259                 slot->hotplug_slot = hotplug_slot;
 260
 261                 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
 262                 if (!info)
 263                         goto error_hpslot;
 264                 hotplug_slot->info = info;
 265
 266                 name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
 267                 if (!name)
 268                         goto error_info;
 269                 hotplug_slot->name = name;
 270
 271                 slot->bus = bus;
 272                 slot->number = i;
 273                 slot->devfn = PCI_DEVFN(i, 0);
 274
 275                 hotplug_slot->private = slot;
 276                 hotplug_slot->release = &release_slot;
 277                 make_slot_name(slot);
 278                 hotplug_slot->ops = &cpci_hotplug_slot_ops;
 279
 280                 /*
 281                  * Initialize the slot info structure with some known
 282                  * good values.
 283                  */
 284                 dbg("initializing slot %s", slot->hotplug_slot->name);
 285                 info->power_status = cpci_get_power_status(slot);
 286                 info->attention_status = cpci_get_attention_status(slot);
 287
 288                 dbg("registering slot %s", slot->hotplug_slot->name);
 289                 status = pci_hp_register(slot->hotplug_slot);
 290                 if (status) {
 291                         err("pci_hp_register failed with error %d", status);
 292                         goto error_name;
 293                 }
 294
 295                 /* Add slot to our internal list */
 296                 down_write(&list_rwsem);
 297                 list_add(&slot->slot_list, &slot_list);
 298                 slots++;
 299                 up_write(&list_rwsem);
 300         }
 301         return 0;
 302 error_name:
 303         kfree(name);
 304 error_info:
 305         kfree(info);
 306 error_hpslot:
 307         kfree(hotplug_slot);
 308 error_slot:
 309         kfree(slot);
 310 error:
 311         return status;
 312 }
 313
 314 int
 315 cpci_hp_unregister_bus(struct pci_bus *bus)
 316 {
 317         struct slot *slot;
 318         struct slot *tmp;
 319         int status = 0;
 320
 321         down_write(&list_rwsem);
 322         if (!slots) {
 323                 up_write(&list_rwsem);
 324                 return -1;
 325         }
 326         list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
 327                 if (slot->bus == bus) {
 328                         list_del(&slot->slot_list);
 329                         slots--;
 330
 331                         dbg("deregistering slot %s", slot->hotplug_slot->name);
 332                         status = pci_hp_deregister(slot->hotplug_slot);
 333                         if (status) {
 334                                 err("pci_hp_deregister failed with error %d",
 335                                     status);
 336                                 break;
 337                         }
 338                 }
 339         }
 340         up_write(&list_rwsem);
 341         return status;
 342 }
 343
 344 /* This is the interrupt mode interrupt handler */
 345 static irqreturn_t
 346 cpci_hp_intr(int irq, void *data, struct pt_regs *regs)
 347 {
 348         dbg("entered cpci_hp_intr");
 349
 350         /* Check to see if it was our interrupt */
 351         if ((controller->irq_flags & SA_SHIRQ) &&
 352             !controller->ops->check_irq(controller->dev_id)) {
 353                 dbg("exited cpci_hp_intr, not our interrupt");
 354                 return IRQ_NONE;
 355         }
 356
 357         /* Disable ENUM interrupt */
 358         controller->ops->disable_irq();
 359
 360         /* Trigger processing by the event thread */
 361         dbg("Signal event_semaphore");
 362         up(&event_semaphore);
 363         dbg("exited cpci_hp_intr");
 364         return IRQ_HANDLED;
 365 }
 366
 367 /*
 368  * According to PICMG 2.1 R2.0, section 6.3.2, upon
 369  * initialization, the system driver shall clear the
 370  * INS bits of the cold-inserted devices.
 371  */
 372 static int
 373 init_slots(int clear_ins)
 374 {
 375         struct slot *slot;
 376         struct pci_dev* dev;
 377
 378         dbg("%s - enter", __FUNCTION__);
 379         down_read(&list_rwsem);
 380         if (!slots) {
 381                 up_read(&list_rwsem);
 382                 return -1;
 383         }
 384         list_for_each_entry(slot, &slot_list, slot_list) {
 385                 dbg("%s - looking at slot %s",
 386                     __FUNCTION__, slot->hotplug_slot->name);
 387                 if (clear_ins && cpci_check_and_clear_ins(slot))
 388                         dbg("%s - cleared INS for slot %s",
 389                             __FUNCTION__, slot->hotplug_slot->name);
 390                 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
 391                 if (dev) {
 392                         if (update_adapter_status(slot->hotplug_slot, 1))
 393                                 warn("failure to update adapter file");
 394                         if (update_latch_status(slot->hotplug_slot, 1))
 395                                 warn("failure to update latch file");
 396                         slot->dev = dev;
 397                 }
 398         }
 399         up_read(&list_rwsem);
 400         dbg("%s - exit", __FUNCTION__);
 401         return 0;
 402 }
 403
 404 static int
 405 check_slots(void)
 406 {
 407         struct slot *slot;
 408         int extracted;
 409         int inserted;
 410         u16 hs_csr;
 411
 412         down_read(&list_rwsem);
 413         if (!slots) {
 414                 up_read(&list_rwsem);
 415                 err("no slots registered, shutting down");
 416                 return -1;
 417         }
 418         extracted = inserted = 0;
 419         list_for_each_entry(slot, &slot_list, slot_list) {
 420                 dbg("%s - looking at slot %s",
 421                     __FUNCTION__, slot->hotplug_slot->name);
 422                 if (cpci_check_and_clear_ins(slot)) {
 423                         /*
 424                          * Some broken hardware (e.g. PLX 9054AB) asserts
 425                          * ENUM# twice...
 426                          */
 427                         if (slot->dev) {
 428                                 warn("slot %s already inserted",
 429                                      slot->hotplug_slot->name);
 430                                 inserted++;
 431                                 continue;
 432                         }
 433
 434                         /* Process insertion */
 435                         dbg("%s - slot %s inserted",
 436                             __FUNCTION__, slot->hotplug_slot->name);
 437
 438                         /* GSM, debug */
 439                         hs_csr = cpci_get_hs_csr(slot);
 440                         dbg("%s - slot %s HS_CSR (1) = %04x",
 441                             __FUNCTION__, slot->hotplug_slot->name, hs_csr);
 442
 443                         /* Configure device */
 444                         dbg("%s - configuring slot %s",
 445                             __FUNCTION__, slot->hotplug_slot->name);
 446                         if (cpci_configure_slot(slot)) {
 447                                 err("%s - could not configure slot %s",
 448                                     __FUNCTION__, slot->hotplug_slot->name);
 449                                 continue;
 450                         }
 451                         dbg("%s - finished configuring slot %s",
 452                             __FUNCTION__, slot->hotplug_slot->name);
 453
 454                         /* GSM, debug */
 455                         hs_csr = cpci_get_hs_csr(slot);
 456                         dbg("%s - slot %s HS_CSR (2) = %04x",
 457                             __FUNCTION__, slot->hotplug_slot->name, hs_csr);
 458
 459                         if (update_latch_status(slot->hotplug_slot, 1))
 460                                 warn("failure to update latch file");
 461
 462                         if (update_adapter_status(slot->hotplug_slot, 1))
 463                                 warn("failure to update adapter file");
 464
 465                         cpci_led_off(slot);
 466
 467                         /* GSM, debug */
 468                         hs_csr = cpci_get_hs_csr(slot);
 469                         dbg("%s - slot %s HS_CSR (3) = %04x",
 470                             __FUNCTION__, slot->hotplug_slot->name, hs_csr);
 471
 472                         inserted++;
 473                 } else if (cpci_check_ext(slot)) {
 474                         /* Process extraction request */
 475                         dbg("%s - slot %s extracted",
 476                             __FUNCTION__, slot->hotplug_slot->name);
 477
 478                         /* GSM, debug */
 479                         hs_csr = cpci_get_hs_csr(slot);
 480                         dbg("%s - slot %s HS_CSR = %04x",
 481                             __FUNCTION__, slot->hotplug_slot->name, hs_csr);
 482
 483                         if (!slot->extracting) {
 484                                 if (update_latch_status(slot->hotplug_slot, 0)) {
 485                                         warn("failure to update latch file");
 486                                 }
 487                                 slot->extracting = 1;
 488                                 atomic_inc(&extracting);
 489                         }
 490                         extracted++;
 491                 } else if (slot->extracting) {
 492                         hs_csr = cpci_get_hs_csr(slot);
 493                         if (hs_csr == 0xffff) {
 494                                 /*
 495                                  * Hmmm, we're likely hosed at this point, should we
 496                                  * bother trying to tell the driver or not?
 497                                  */
 498                                 err("card in slot %s was improperly removed",
 499                                     slot->hotplug_slot->name);
 500                                 if (update_adapter_status(slot->hotplug_slot, 0))
 501                                         warn("failure to update adapter file");
 502                                 slot->extracting = 0;
 503                                 atomic_dec(&extracting);
 504                         }
 505                 }
 506         }
 507         up_read(&list_rwsem);
 508         dbg("inserted=%d, extracted=%d, extracting=%d",
 509             inserted, extracted, atomic_read(&extracting));
 510         if (inserted || extracted)
 511                 return extracted;
 512         else if (!atomic_read(&extracting)) {
 513                 err("cannot find ENUM# source, shutting down");
 514                 return -1;
 515         }
 516         return 0;
 517 }
 518
 519 /* This is the interrupt mode worker thread body */
 520 static int
 521 event_thread(void *data)
 522 {
 523         int rc;
 524
 525         lock_kernel();
 526         daemonize("cpci_hp_eventd");
 527         unlock_kernel();
 528
 529         dbg("%s - event thread started", __FUNCTION__);
 530         while (1) {
 531                 dbg("event thread sleeping");
 532                 down_interruptible(&event_semaphore);
 533                 dbg("event thread woken, thread_finished = %d",
 534                     thread_finished);
 535                 if (thread_finished || signal_pending(current))
 536                         break;
 537                 do {
 538                         rc = check_slots();
 539                         if (rc > 0) {
 540                                 /* Give userspace a chance to handle extraction */
 541                                 msleep(500);
 542                         } else if (rc < 0) {
 543                                 dbg("%s - error checking slots", __FUNCTION__);
 544                                 thread_finished = 1;
 545                                 break;
 546                         }
 547                 } while (atomic_read(&extracting) && !thread_finished);
 548                 if (thread_finished)
 549                         break;
 550
 551                 /* Re-enable ENUM# interrupt */
 552                 dbg("%s - re-enabling irq", __FUNCTION__);
 553                 controller->ops->enable_irq();
 554         }
 555         dbg("%s - event thread signals exit", __FUNCTION__);
 556         up(&thread_exit);
 557         return 0;
 558 }
 559
 560 /* This is the polling mode worker thread body */
 561 static int
 562 poll_thread(void *data)
 563 {
 564         int rc;
 565
 566         lock_kernel();
 567         daemonize("cpci_hp_polld");
 568         unlock_kernel();
 569
 570         while (1) {
 571                 if (thread_finished || signal_pending(current))
 572                         break;
 573                 if (controller->ops->query_enum()) {
 574                         do {
 575                                 rc = check_slots();
 576                                 if (rc > 0) {
 577                                         /* Give userspace a chance to handle extraction */
 578                                         msleep(500);
 579                                 } else if (rc < 0) {
 580                                         dbg("%s - error checking slots", __FUNCTION__);
 581                                         thread_finished = 1;
 582                                         break;
 583                                 }
 584                         } while (atomic_read(&extracting) && !thread_finished);
 585                 }
 586                 msleep(100);
 587         }
 588         dbg("poll thread signals exit");
 589         up(&thread_exit);
 590         return 0;
 591 }
 592
 593 static int
 594 cpci_start_thread(void)
 595 {
 596         int pid;
 597
 598         /* initialize our semaphores */
 599         init_MUTEX_LOCKED(&event_semaphore);
 600         init_MUTEX_LOCKED(&thread_exit);
 601         thread_finished = 0;
 602
 603         if (controller->irq)
 604                 pid = kernel_thread(event_thread, NULL, 0);
 605         else
 606                 pid = kernel_thread(poll_thread, NULL, 0);
 607         if (pid < 0) {
 608                 err("Can't start up our thread");
 609                 return -1;
 610         }
 611         dbg("Our thread pid = %d", pid);
 612         return 0;
 613 }
 614
 615 static void
 616 cpci_stop_thread(void)
 617 {
 618         thread_finished = 1;
 619         dbg("thread finish command given");
 620         if (controller->irq)
 621                 up(&event_semaphore);
 622         dbg("wait for thread to exit");
 623         down(&thread_exit);
 624 }
 625
 626 int
 627 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
 628 {
 629         int status = 0;
 630
 631         if (controller)
 632                 return -1;
 633         if (!(new_controller && new_controller->ops))
 634                 return -EINVAL;
 635         if (new_controller->irq) {
 636                 if (!(new_controller->ops->enable_irq &&
 637                      new_controller->ops->disable_irq))
 638                         status = -EINVAL;
 639                 if (request_irq(new_controller->irq,
 640                                cpci_hp_intr,
 641                                new_controller->irq_flags,
 642                                MY_NAME,
 643                                new_controller->dev_id)) {
 644                         err("Can't get irq %d for the hotplug cPCI controller",
 645                             new_controller->irq);
 646                         status = -ENODEV;
 647                 }
 648                 dbg("%s - acquired controller irq %d",
 649                     __FUNCTION__, new_controller->irq);
 650         }
 651         if (!status)
 652                 controller = new_controller;
 653         return status;
 654 }
 655
 656 static void
 657 cleanup_slots(void)
 658 {
 659         struct slot *slot;
 660         struct slot *tmp;
 661
 662         /*
 663          * Unregister all of our slots with the pci_hotplug subsystem,
 664          * and free up all memory that we had allocated.
 665          */
 666         down_write(&list_rwsem);
 667         if (!slots)
 668                 goto cleanup_null;
 669         list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
 670                 list_del(&slot->slot_list);
 671                 pci_hp_deregister(slot->hotplug_slot);
 672         }
 673 cleanup_null:
 674         up_write(&list_rwsem);
 675         return;
 676 }
 677
 678 int
 679 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
 680 {
 681         int status = 0;
 682
 683         if (controller) {
 684                 if (!thread_finished)
 685                         cpci_stop_thread();
 686                 if (controller->irq)
 687                         free_irq(controller->irq, controller->dev_id);
 688                 controller = NULL;
 689                 cleanup_slots();
 690         } else
 691                 status = -ENODEV;
 692         return status;
 693 }
 694
 695 int
 696 cpci_hp_start(void)
 697 {
 698         static int first = 1;
 699         int status;
 700
 701         dbg("%s - enter", __FUNCTION__);
 702         if (!controller)
 703                 return -ENODEV;
 704
 705         down_read(&list_rwsem);
 706         if (list_empty(&slot_list)) {
 707                 up_read(&list_rwsem);
 708                 return -ENODEV;
 709         }
 710         up_read(&list_rwsem);
 711
 712         status = init_slots(first);
 713         if (first)
 714                 first = 0;
 715         if (status)
 716                 return status;
 717
 718         status = cpci_start_thread();
 719         if (status)
 720                 return status;
 721         dbg("%s - thread started", __FUNCTION__);
 722
 723         if (controller->irq) {
 724                 /* Start enum interrupt processing */
 725                 dbg("%s - enabling irq", __FUNCTION__);
 726                 controller->ops->enable_irq();
 727         }
 728         dbg("%s - exit", __FUNCTION__);
 729         return 0;
 730 }
 731
 732 int
 733 cpci_hp_stop(void)
 734 {
 735         if (!controller)
 736                 return -ENODEV;
 737         if (controller->irq) {
 738                 /* Stop enum interrupt processing */
 739                 dbg("%s - disabling irq", __FUNCTION__);
 740                 controller->ops->disable_irq();
 741         }
 742         cpci_stop_thread();
 743         return 0;
 744 }
 745
 746 int __init
 747 cpci_hotplug_init(int debug)
 748 {
 749         cpci_debug = debug;
 750         return 0;
 751 }
 752
 753 void __exit
 754 cpci_hotplug_exit(void)
 755 {
 756         /*
 757          * Clean everything up.
 758          */
 759         cpci_hp_stop();
 760         cpci_hp_unregister_controller(controller);
 761 }
 762
 763 EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
 764 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
 765 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
 766 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
 767 EXPORT_SYMBOL_GPL(cpci_hp_start);
 768 EXPORT_SYMBOL_GPL(cpci_hp_stop);