drivers/xen/xen-pciback/pci_stub.c

   1 /*
   2  * PCI Stub Driver - Grabs devices in backend to be exported later
   3  *
   4  * Ryan Wilson <hap9@epoch.ncsc.mil>
   5  * Chris Bookholt <hap10@epoch.ncsc.mil>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/rwsem.h>
  10 #include <linux/list.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/kref.h>
  13 #include <linux/pci.h>
  14 #include <linux/wait.h>
  15 #include <linux/sched.h>
  16 #include <linux/atomic.h>
  17 #include <xen/events.h>
  18 #include <asm/xen/pci.h>
  19 #include <asm/xen/hypervisor.h>
  20 #include "pciback.h"
  21 #include "conf_space.h"
  22 #include "conf_space_quirks.h"
  23
  24 static char *pci_devs_to_hide;
  25 wait_queue_head_t xen_pcibk_aer_wait_queue;
  26 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
  27 * We want to avoid in middle of AER ops, xen_pcibk devices is being removed
  28 */
  29 static DECLARE_RWSEM(pcistub_sem);
  30 module_param_named(hide, pci_devs_to_hide, charp, 0444);
  31
  32 struct pcistub_device_id {
  33         struct list_head slot_list;
  34         int domain;
  35         unsigned char bus;
  36         unsigned int devfn;
  37 };
  38 static LIST_HEAD(pcistub_device_ids);
  39 static DEFINE_SPINLOCK(device_ids_lock);
  40
  41 struct pcistub_device {
  42         struct kref kref;
  43         struct list_head dev_list;
  44         spinlock_t lock;
  45
  46         struct pci_dev *dev;
  47         struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */
  48 };
  49
  50 /* Access to pcistub_devices & seized_devices lists and the initialize_devices
  51  * flag must be locked with pcistub_devices_lock
  52  */
  53 static DEFINE_SPINLOCK(pcistub_devices_lock);
  54 static LIST_HEAD(pcistub_devices);
  55
  56 /* wait for device_initcall before initializing our devices
  57  * (see pcistub_init_devices_late)
  58  */
  59 static int initialize_devices;
  60 static LIST_HEAD(seized_devices);
  61
  62 static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
  63 {
  64         struct pcistub_device *psdev;
  65
  66         dev_dbg(&dev->dev, "pcistub_device_alloc\n");
  67
  68         psdev = kzalloc(sizeof(*psdev), GFP_ATOMIC);
  69         if (!psdev)
  70                 return NULL;
  71
  72         psdev->dev = pci_dev_get(dev);
  73         if (!psdev->dev) {
  74                 kfree(psdev);
  75                 return NULL;
  76         }
  77
  78         kref_init(&psdev->kref);
  79         spin_lock_init(&psdev->lock);
  80
  81         return psdev;
  82 }
  83
  84 /* Don't call this directly as it's called by pcistub_device_put */
  85 static void pcistub_device_release(struct kref *kref)
  86 {
  87         struct pcistub_device *psdev;
  88         struct xen_pcibk_dev_data *dev_data;
  89
  90         psdev = container_of(kref, struct pcistub_device, kref);
  91         dev_data = pci_get_drvdata(psdev->dev);
  92
  93         dev_dbg(&psdev->dev->dev, "pcistub_device_release\n");
  94
  95         xen_unregister_device_domain_owner(psdev->dev);
  96
  97         /* Call the reset function which does not take lock as this
  98          * is called from "unbind" which takes a device_lock mutex.
  99          */
 100         __pci_reset_function_locked(psdev->dev);
 101         if (pci_load_and_free_saved_state(psdev->dev,
 102                                           &dev_data->pci_saved_state)) {
 103                 dev_dbg(&psdev->dev->dev, "Could not reload PCI state\n");
 104         } else
 105                 pci_restore_state(psdev->dev);
 106
 107         /* Disable the device */
 108         xen_pcibk_reset_device(psdev->dev);
 109
 110         kfree(dev_data);
 111         pci_set_drvdata(psdev->dev, NULL);
 112
 113         /* Clean-up the device */
 114         xen_pcibk_config_free_dyn_fields(psdev->dev);
 115         xen_pcibk_config_free_dev(psdev->dev);
 116
 117         psdev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
 118         pci_dev_put(psdev->dev);
 119
 120         kfree(psdev);
 121 }
 122
 123 static inline void pcistub_device_get(struct pcistub_device *psdev)
 124 {
 125         kref_get(&psdev->kref);
 126 }
 127
 128 static inline void pcistub_device_put(struct pcistub_device *psdev)
 129 {
 130         kref_put(&psdev->kref, pcistub_device_release);
 131 }
 132
 133 static struct pcistub_device *pcistub_device_find(int domain, int bus,
 134                                                   int slot, int func)
 135 {
 136         struct pcistub_device *psdev = NULL;
 137         unsigned long flags;
 138
 139         spin_lock_irqsave(&pcistub_devices_lock, flags);
 140
 141         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 142                 if (psdev->dev != NULL
 143                     && domain == pci_domain_nr(psdev->dev->bus)
 144                     && bus == psdev->dev->bus->number
 145                     && PCI_DEVFN(slot, func) == psdev->dev->devfn) {
 146                         pcistub_device_get(psdev);
 147                         goto out;
 148                 }
 149         }
 150
 151         /* didn't find it */
 152         psdev = NULL;
 153
 154 out:
 155         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 156         return psdev;
 157 }
 158
 159 static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
 160                                                   struct pcistub_device *psdev)
 161 {
 162         struct pci_dev *pci_dev = NULL;
 163         unsigned long flags;
 164
 165         pcistub_device_get(psdev);
 166
 167         spin_lock_irqsave(&psdev->lock, flags);
 168         if (!psdev->pdev) {
 169                 psdev->pdev = pdev;
 170                 pci_dev = psdev->dev;
 171         }
 172         spin_unlock_irqrestore(&psdev->lock, flags);
 173
 174         if (!pci_dev)
 175                 pcistub_device_put(psdev);
 176
 177         return pci_dev;
 178 }
 179
 180 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 181                                             int domain, int bus,
 182                                             int slot, int func)
 183 {
 184         struct pcistub_device *psdev;
 185         struct pci_dev *found_dev = NULL;
 186         unsigned long flags;
 187
 188         spin_lock_irqsave(&pcistub_devices_lock, flags);
 189
 190         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 191                 if (psdev->dev != NULL
 192                     && domain == pci_domain_nr(psdev->dev->bus)
 193                     && bus == psdev->dev->bus->number
 194                     && PCI_DEVFN(slot, func) == psdev->dev->devfn) {
 195                         found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 196                         break;
 197                 }
 198         }
 199
 200         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 201         return found_dev;
 202 }
 203
 204 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 205                                     struct pci_dev *dev)
 206 {
 207         struct pcistub_device *psdev;
 208         struct pci_dev *found_dev = NULL;
 209         unsigned long flags;
 210
 211         spin_lock_irqsave(&pcistub_devices_lock, flags);
 212
 213         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 214                 if (psdev->dev == dev) {
 215                         found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 216                         break;
 217                 }
 218         }
 219
 220         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 221         return found_dev;
 222 }
 223
 224 void pcistub_put_pci_dev(struct pci_dev *dev)
 225 {
 226         struct pcistub_device *psdev, *found_psdev = NULL;
 227         unsigned long flags;
 228
 229         spin_lock_irqsave(&pcistub_devices_lock, flags);
 230
 231         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 232                 if (psdev->dev == dev) {
 233                         found_psdev = psdev;
 234                         break;
 235                 }
 236         }
 237
 238         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 239         if (WARN_ON(!found_psdev))
 240                 return;
 241
 242         /*hold this lock for avoiding breaking link between
 243         * pcistub and xen_pcibk when AER is in processing
 244         */
 245         down_write(&pcistub_sem);
 246         /* Cleanup our device
 247          * (so it's ready for the next domain)
 248          */
 249
 250         /* This is OK - we are running from workqueue context
 251          * and want to inhibit the user from fiddling with 'reset'
 252          */
 253         pci_reset_function(dev);
 254         pci_restore_state(psdev->dev);
 255
 256         /* This disables the device. */
 257         xen_pcibk_reset_device(found_psdev->dev);
 258
 259         /* And cleanup up our emulated fields. */
 260         xen_pcibk_config_free_dyn_fields(found_psdev->dev);
 261         xen_pcibk_config_reset_dev(found_psdev->dev);
 262
 263         xen_unregister_device_domain_owner(found_psdev->dev);
 264
 265         spin_lock_irqsave(&found_psdev->lock, flags);
 266         found_psdev->pdev = NULL;
 267         spin_unlock_irqrestore(&found_psdev->lock, flags);
 268
 269         pcistub_device_put(found_psdev);
 270         up_write(&pcistub_sem);
 271 }
 272
 273 static int __devinit pcistub_match_one(struct pci_dev *dev,
 274                                        struct pcistub_device_id *pdev_id)
 275 {
 276         /* Match the specified device by domain, bus, slot, func and also if
 277          * any of the device's parent bridges match.
 278          */
 279         for (; dev != NULL; dev = dev->bus->self) {
 280                 if (pci_domain_nr(dev->bus) == pdev_id->domain
 281                     && dev->bus->number == pdev_id->bus
 282                     && dev->devfn == pdev_id->devfn)
 283                         return 1;
 284
 285                 /* Sometimes topmost bridge links to itself. */
 286                 if (dev == dev->bus->self)
 287                         break;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int __devinit pcistub_match(struct pci_dev *dev)
 294 {
 295         struct pcistub_device_id *pdev_id;
 296         unsigned long flags;
 297         int found = 0;
 298
 299         spin_lock_irqsave(&device_ids_lock, flags);
 300         list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) {
 301                 if (pcistub_match_one(dev, pdev_id)) {
 302                         found = 1;
 303                         break;
 304                 }
 305         }
 306         spin_unlock_irqrestore(&device_ids_lock, flags);
 307
 308         return found;
 309 }
 310
 311 static int __devinit pcistub_init_device(struct pci_dev *dev)
 312 {
 313         struct xen_pcibk_dev_data *dev_data;
 314         int err = 0;
 315
 316         dev_dbg(&dev->dev, "initializing...\n");
 317
 318         /* The PCI backend is not intended to be a module (or to work with
 319          * removable PCI devices (yet). If it were, xen_pcibk_config_free()
 320          * would need to be called somewhere to free the memory allocated
 321          * here and then to call kfree(pci_get_drvdata(psdev->dev)).
 322          */
 323         dev_data = kzalloc(sizeof(*dev_data) +  strlen(DRV_NAME "[]")
 324                                 + strlen(pci_name(dev)) + 1, GFP_ATOMIC);
 325         if (!dev_data) {
 326                 err = -ENOMEM;
 327                 goto out;
 328         }
 329         pci_set_drvdata(dev, dev_data);
 330
 331         /*
 332          * Setup name for fake IRQ handler. It will only be enabled
 333          * once the device is turned on by the guest.
 334          */
 335         sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev));
 336
 337         dev_dbg(&dev->dev, "initializing config\n");
 338
 339         init_waitqueue_head(&xen_pcibk_aer_wait_queue);
 340         err = xen_pcibk_config_init_dev(dev);
 341         if (err)
 342                 goto out;
 343
 344         /* HACK: Force device (& ACPI) to determine what IRQ it's on - we
 345          * must do this here because pcibios_enable_device may specify
 346          * the pci device's true irq (and possibly its other resources)
 347          * if they differ from what's in the configuration space.
 348          * This makes the assumption that the device's resources won't
 349          * change after this point (otherwise this code may break!)
 350          */
 351         dev_dbg(&dev->dev, "enabling device\n");
 352         err = pci_enable_device(dev);
 353         if (err)
 354                 goto config_release;
 355
 356         dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
 357         __pci_reset_function_locked(dev);
 358
 359         /* We need the device active to save the state. */
 360         dev_dbg(&dev->dev, "save state of device\n");
 361         pci_save_state(dev);
 362         dev_data->pci_saved_state = pci_store_saved_state(dev);
 363         if (!dev_data->pci_saved_state)
 364                 dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
 365
 366         /* Now disable the device (this also ensures some private device
 367          * data is setup before we export)
 368          */
 369         dev_dbg(&dev->dev, "reset device\n");
 370         xen_pcibk_reset_device(dev);
 371
 372         dev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
 373         return 0;
 374
 375 config_release:
 376         xen_pcibk_config_free_dev(dev);
 377
 378 out:
 379         pci_set_drvdata(dev, NULL);
 380         kfree(dev_data);
 381         return err;
 382 }
 383
 384 /*
 385  * Because some initialization still happens on
 386  * devices during fs_initcall, we need to defer
 387  * full initialization of our devices until
 388  * device_initcall.
 389  */
 390 static int __init pcistub_init_devices_late(void)
 391 {
 392         struct pcistub_device *psdev;
 393         unsigned long flags;
 394         int err = 0;
 395
 396         pr_debug(DRV_NAME ": pcistub_init_devices_late\n");
 397
 398         spin_lock_irqsave(&pcistub_devices_lock, flags);
 399
 400         while (!list_empty(&seized_devices)) {
 401                 psdev = container_of(seized_devices.next,
 402                                      struct pcistub_device, dev_list);
 403                 list_del(&psdev->dev_list);
 404
 405                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 406
 407                 err = pcistub_init_device(psdev->dev);
 408                 if (err) {
 409                         dev_err(&psdev->dev->dev,
 410                                 "error %d initializing device\n", err);
 411                         kfree(psdev);
 412                         psdev = NULL;
 413                 }
 414
 415                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 416
 417                 if (psdev)
 418                         list_add_tail(&psdev->dev_list, &pcistub_devices);
 419         }
 420
 421         initialize_devices = 1;
 422
 423         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 424
 425         return 0;
 426 }
 427
 428 static int __devinit pcistub_seize(struct pci_dev *dev)
 429 {
 430         struct pcistub_device *psdev;
 431         unsigned long flags;
 432         int err = 0;
 433
 434         psdev = pcistub_device_alloc(dev);
 435         if (!psdev)
 436                 return -ENOMEM;
 437
 438         spin_lock_irqsave(&pcistub_devices_lock, flags);
 439
 440         if (initialize_devices) {
 441                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 442
 443                 /* don't want irqs disabled when calling pcistub_init_device */
 444                 err = pcistub_init_device(psdev->dev);
 445
 446                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 447
 448                 if (!err)
 449                         list_add(&psdev->dev_list, &pcistub_devices);
 450         } else {
 451                 dev_dbg(&dev->dev, "deferring initialization\n");
 452                 list_add(&psdev->dev_list, &seized_devices);
 453         }
 454
 455         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 456
 457         if (err)
 458                 pcistub_device_put(psdev);
 459
 460         return err;
 461 }
 462
 463 static int __devinit pcistub_probe(struct pci_dev *dev,
 464                                    const struct pci_device_id *id)
 465 {
 466         int err = 0;
 467
 468         dev_dbg(&dev->dev, "probing...\n");
 469
 470         if (pcistub_match(dev)) {
 471
 472                 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
 473                     && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 474                         dev_err(&dev->dev, "can't export pci devices that "
 475                                 "don't have a normal (0) or bridge (1) "
 476                                 "header type!\n");
 477                         err = -ENODEV;
 478                         goto out;
 479                 }
 480
 481                 dev_info(&dev->dev, "seizing device\n");
 482                 err = pcistub_seize(dev);
 483         } else
 484                 /* Didn't find the device */
 485                 err = -ENODEV;
 486
 487 out:
 488         return err;
 489 }
 490
 491 static void pcistub_remove(struct pci_dev *dev)
 492 {
 493         struct pcistub_device *psdev, *found_psdev = NULL;
 494         unsigned long flags;
 495
 496         dev_dbg(&dev->dev, "removing\n");
 497
 498         spin_lock_irqsave(&pcistub_devices_lock, flags);
 499
 500         xen_pcibk_config_quirk_release(dev);
 501
 502         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 503                 if (psdev->dev == dev) {
 504                         found_psdev = psdev;
 505                         break;
 506                 }
 507         }
 508
 509         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 510
 511         if (found_psdev) {
 512                 dev_dbg(&dev->dev, "found device to remove - in use? %p\n",
 513                         found_psdev->pdev);
 514
 515                 if (found_psdev->pdev) {
 516                         printk(KERN_WARNING DRV_NAME ": ****** removing device "
 517                                "%s while still in-use! ******\n",
 518                                pci_name(found_psdev->dev));
 519                         printk(KERN_WARNING DRV_NAME ": ****** driver domain may"
 520                                " still access this device's i/o resources!\n");
 521                         printk(KERN_WARNING DRV_NAME ": ****** shutdown driver "
 522                                "domain before binding device\n");
 523                         printk(KERN_WARNING DRV_NAME ": ****** to other drivers "
 524                                "or domains\n");
 525
 526                         xen_pcibk_release_pci_dev(found_psdev->pdev,
 527                                                 found_psdev->dev);
 528                 }
 529
 530                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 531                 list_del(&found_psdev->dev_list);
 532                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 533
 534                 /* the final put for releasing from the list */
 535                 pcistub_device_put(found_psdev);
 536         }
 537 }
 538
 539 static DEFINE_PCI_DEVICE_TABLE(pcistub_ids) = {
 540         {
 541          .vendor = PCI_ANY_ID,
 542          .device = PCI_ANY_ID,
 543          .subvendor = PCI_ANY_ID,
 544          .subdevice = PCI_ANY_ID,
 545          },
 546         {0,},
 547 };
 548
 549 #define PCI_NODENAME_MAX 40
 550 static void kill_domain_by_device(struct pcistub_device *psdev)
 551 {
 552         struct xenbus_transaction xbt;
 553         int err;
 554         char nodename[PCI_NODENAME_MAX];
 555
 556         BUG_ON(!psdev);
 557         snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
 558                 psdev->pdev->xdev->otherend_id);
 559
 560 again:
 561         err = xenbus_transaction_start(&xbt);
 562         if (err) {
 563                 dev_err(&psdev->dev->dev,
 564                         "error %d when start xenbus transaction\n", err);
 565                 return;
 566         }
 567         /*PV AER handlers will set this flag*/
 568         xenbus_printf(xbt, nodename, "aerState" , "aerfail");
 569         err = xenbus_transaction_end(xbt, 0);
 570         if (err) {
 571                 if (err == -EAGAIN)
 572                         goto again;
 573                 dev_err(&psdev->dev->dev,
 574                         "error %d when end xenbus transaction\n", err);
 575                 return;
 576         }
 577 }
 578
 579 /* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
 580  * backend need to have cooperation. In xen_pcibk, those steps will do similar
 581  * jobs: send service request and waiting for front_end response.
 582 */
 583 static pci_ers_result_t common_process(struct pcistub_device *psdev,
 584                                        pci_channel_state_t state, int aer_cmd,
 585                                        pci_ers_result_t result)
 586 {
 587         pci_ers_result_t res = result;
 588         struct xen_pcie_aer_op *aer_op;
 589         int ret;
 590
 591         /*with PV AER drivers*/
 592         aer_op = &(psdev->pdev->sh_info->aer_op);
 593         aer_op->cmd = aer_cmd ;
 594         /*useful for error_detected callback*/
 595         aer_op->err = state;
 596         /*pcifront_end BDF*/
 597         ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
 598                 &aer_op->domain, &aer_op->bus, &aer_op->devfn);
 599         if (!ret) {
 600                 dev_err(&psdev->dev->dev,
 601                         DRV_NAME ": failed to get pcifront device\n");
 602                 return PCI_ERS_RESULT_NONE;
 603         }
 604         wmb();
 605
 606         dev_dbg(&psdev->dev->dev,
 607                         DRV_NAME ": aer_op %x dom %x bus %x devfn %x\n",
 608                         aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
 609         /*local flag to mark there's aer request, xen_pcibk callback will use
 610         * this flag to judge whether we need to check pci-front give aer
 611         * service ack signal
 612         */
 613         set_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
 614
 615         /*It is possible that a pcifront conf_read_write ops request invokes
 616         * the callback which cause the spurious execution of wake_up.
 617         * Yet it is harmless and better than a spinlock here
 618         */
 619         set_bit(_XEN_PCIB_active,
 620                 (unsigned long *)&psdev->pdev->sh_info->flags);
 621         wmb();
 622         notify_remote_via_irq(psdev->pdev->evtchn_irq);
 623
 624         ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
 625                                  !(test_bit(_XEN_PCIB_active, (unsigned long *)
 626                                  &psdev->pdev->sh_info->flags)), 300*HZ);
 627
 628         if (!ret) {
 629                 if (test_bit(_XEN_PCIB_active,
 630                         (unsigned long *)&psdev->pdev->sh_info->flags)) {
 631                         dev_err(&psdev->dev->dev,
 632                                 "pcifront aer process not responding!\n");
 633                         clear_bit(_XEN_PCIB_active,
 634                           (unsigned long *)&psdev->pdev->sh_info->flags);
 635                         aer_op->err = PCI_ERS_RESULT_NONE;
 636                         return res;
 637                 }
 638         }
 639         clear_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
 640
 641         if (test_bit(_XEN_PCIF_active,
 642                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 643                 dev_dbg(&psdev->dev->dev,
 644                         "schedule pci_conf service in " DRV_NAME "\n");
 645                 xen_pcibk_test_and_schedule_op(psdev->pdev);
 646         }
 647
 648         res = (pci_ers_result_t)aer_op->err;
 649         return res;
 650 }
 651
 652 /*
 653 * xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
 654 * of the device driver could provide this service, and then wait for pcifront
 655 * ack.
 656 * @dev: pointer to PCI devices
 657 * return value is used by aer_core do_recovery policy
 658 */
 659 static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
 660 {
 661         struct pcistub_device *psdev;
 662         pci_ers_result_t result;
 663
 664         result = PCI_ERS_RESULT_RECOVERED;
 665         dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
 666                 dev->bus->number, dev->devfn);
 667
 668         down_write(&pcistub_sem);
 669         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 670                                 dev->bus->number,
 671                                 PCI_SLOT(dev->devfn),
 672                                 PCI_FUNC(dev->devfn));
 673
 674         if (!psdev || !psdev->pdev) {
 675                 dev_err(&dev->dev,
 676                         DRV_NAME " device is not found/assigned\n");
 677                 goto end;
 678         }
 679
 680         if (!psdev->pdev->sh_info) {
 681                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 682                         " by HVM, kill it\n");
 683                 kill_domain_by_device(psdev);
 684                 goto release;
 685         }
 686
 687         if (!test_bit(_XEN_PCIB_AERHANDLER,
 688                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 689                 dev_err(&dev->dev,
 690                         "guest with no AER driver should have been killed\n");
 691                 goto release;
 692         }
 693         result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
 694
 695         if (result == PCI_ERS_RESULT_NONE ||
 696                 result == PCI_ERS_RESULT_DISCONNECT) {
 697                 dev_dbg(&dev->dev,
 698                         "No AER slot_reset service or disconnected!\n");
 699                 kill_domain_by_device(psdev);
 700         }
 701 release:
 702         pcistub_device_put(psdev);
 703 end:
 704         up_write(&pcistub_sem);
 705         return result;
 706
 707 }
 708
 709
 710 /*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
 711 * in case of the device driver could provide this service, and then wait
 712 * for pcifront ack
 713 * @dev: pointer to PCI devices
 714 * return value is used by aer_core do_recovery policy
 715 */
 716
 717 static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
 718 {
 719         struct pcistub_device *psdev;
 720         pci_ers_result_t result;
 721
 722         result = PCI_ERS_RESULT_RECOVERED;
 723         dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n",
 724                 dev->bus->number, dev->devfn);
 725
 726         down_write(&pcistub_sem);
 727         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 728                                 dev->bus->number,
 729                                 PCI_SLOT(dev->devfn),
 730                                 PCI_FUNC(dev->devfn));
 731
 732         if (!psdev || !psdev->pdev) {
 733                 dev_err(&dev->dev,
 734                         DRV_NAME " device is not found/assigned\n");
 735                 goto end;
 736         }
 737
 738         if (!psdev->pdev->sh_info) {
 739                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 740                         " by HVM, kill it\n");
 741                 kill_domain_by_device(psdev);
 742                 goto release;
 743         }
 744
 745         if (!test_bit(_XEN_PCIB_AERHANDLER,
 746                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 747                 dev_err(&dev->dev,
 748                         "guest with no AER driver should have been killed\n");
 749                 goto release;
 750         }
 751         result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
 752
 753         if (result == PCI_ERS_RESULT_NONE ||
 754                 result == PCI_ERS_RESULT_DISCONNECT) {
 755                 dev_dbg(&dev->dev,
 756                         "No AER mmio_enabled service or disconnected!\n");
 757                 kill_domain_by_device(psdev);
 758         }
 759 release:
 760         pcistub_device_put(psdev);
 761 end:
 762         up_write(&pcistub_sem);
 763         return result;
 764 }
 765
 766 /*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
 767 * in case of the device driver could provide this service, and then wait
 768 * for pcifront ack.
 769 * @dev: pointer to PCI devices
 770 * @error: the current PCI connection state
 771 * return value is used by aer_core do_recovery policy
 772 */
 773
 774 static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
 775         pci_channel_state_t error)
 776 {
 777         struct pcistub_device *psdev;
 778         pci_ers_result_t result;
 779
 780         result = PCI_ERS_RESULT_CAN_RECOVER;
 781         dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
 782                 dev->bus->number, dev->devfn);
 783
 784         down_write(&pcistub_sem);
 785         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 786                                 dev->bus->number,
 787                                 PCI_SLOT(dev->devfn),
 788                                 PCI_FUNC(dev->devfn));
 789
 790         if (!psdev || !psdev->pdev) {
 791                 dev_err(&dev->dev,
 792                         DRV_NAME " device is not found/assigned\n");
 793                 goto end;
 794         }
 795
 796         if (!psdev->pdev->sh_info) {
 797                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 798                         " by HVM, kill it\n");
 799                 kill_domain_by_device(psdev);
 800                 goto release;
 801         }
 802
 803         /*Guest owns the device yet no aer handler regiested, kill guest*/
 804         if (!test_bit(_XEN_PCIB_AERHANDLER,
 805                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 806                 dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
 807                 kill_domain_by_device(psdev);
 808                 goto release;
 809         }
 810         result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
 811
 812         if (result == PCI_ERS_RESULT_NONE ||
 813                 result == PCI_ERS_RESULT_DISCONNECT) {
 814                 dev_dbg(&dev->dev,
 815                         "No AER error_detected service or disconnected!\n");
 816                 kill_domain_by_device(psdev);
 817         }
 818 release:
 819         pcistub_device_put(psdev);
 820 end:
 821         up_write(&pcistub_sem);
 822         return result;
 823 }
 824
 825 /*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
 826 * in case of the device driver could provide this service, and then wait
 827 * for pcifront ack.
 828 * @dev: pointer to PCI devices
 829 */
 830
 831 static void xen_pcibk_error_resume(struct pci_dev *dev)
 832 {
 833         struct pcistub_device *psdev;
 834
 835         dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
 836                 dev->bus->number, dev->devfn);
 837
 838         down_write(&pcistub_sem);
 839         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 840                                 dev->bus->number,
 841                                 PCI_SLOT(dev->devfn),
 842                                 PCI_FUNC(dev->devfn));
 843
 844         if (!psdev || !psdev->pdev) {
 845                 dev_err(&dev->dev,
 846                         DRV_NAME " device is not found/assigned\n");
 847                 goto end;
 848         }
 849
 850         if (!psdev->pdev->sh_info) {
 851                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 852                         " by HVM, kill it\n");
 853                 kill_domain_by_device(psdev);
 854                 goto release;
 855         }
 856
 857         if (!test_bit(_XEN_PCIB_AERHANDLER,
 858                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 859                 dev_err(&dev->dev,
 860                         "guest with no AER driver should have been killed\n");
 861                 kill_domain_by_device(psdev);
 862                 goto release;
 863         }
 864         common_process(psdev, 1, XEN_PCI_OP_aer_resume,
 865                        PCI_ERS_RESULT_RECOVERED);
 866 release:
 867         pcistub_device_put(psdev);
 868 end:
 869         up_write(&pcistub_sem);
 870         return;
 871 }
 872
 873 /*add xen_pcibk AER handling*/
 874 static struct pci_error_handlers xen_pcibk_error_handler = {
 875         .error_detected = xen_pcibk_error_detected,
 876         .mmio_enabled = xen_pcibk_mmio_enabled,
 877         .slot_reset = xen_pcibk_slot_reset,
 878         .resume = xen_pcibk_error_resume,
 879 };
 880
 881 /*
 882  * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
 883  * for a normal device. I don't want it to be loaded automatically.
 884  */
 885
 886 static struct pci_driver xen_pcibk_pci_driver = {
 887         /* The name should be xen_pciback, but until the tools are updated
 888          * we will keep it as pciback. */
 889         .name = "pciback",
 890         .id_table = pcistub_ids,
 891         .probe = pcistub_probe,
 892         .remove = pcistub_remove,
 893         .err_handler = &xen_pcibk_error_handler,
 894 };
 895
 896 static inline int str_to_slot(const char *buf, int *domain, int *bus,
 897                               int *slot, int *func)
 898 {
 899         int err;
 900
 901         err = sscanf(buf, " %x:%x:%x.%x", domain, bus, slot, func);
 902         if (err == 4)
 903                 return 0;
 904         else if (err < 0)
 905                 return -EINVAL;
 906
 907         /* try again without domain */
 908         *domain = 0;
 909         err = sscanf(buf, " %x:%x.%x", bus, slot, func);
 910         if (err == 3)
 911                 return 0;
 912
 913         return -EINVAL;
 914 }
 915
 916 static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
 917                                *slot, int *func, int *reg, int *size, int *mask)
 918 {
 919         int err;
 920
 921         err =
 922             sscanf(buf, " %04x:%02x:%02x.%d-%08x:%1x:%08x", domain, bus, slot,
 923                    func, reg, size, mask);
 924         if (err == 7)
 925                 return 0;
 926         return -EINVAL;
 927 }
 928
 929 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
 930 {
 931         struct pcistub_device_id *pci_dev_id;
 932         unsigned long flags;
 933
 934         pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
 935         if (!pci_dev_id)
 936                 return -ENOMEM;
 937
 938         pci_dev_id->domain = domain;
 939         pci_dev_id->bus = bus;
 940         pci_dev_id->devfn = PCI_DEVFN(slot, func);
 941
 942         pr_debug(DRV_NAME ": wants to seize %04x:%02x:%02x.%d\n",
 943                  domain, bus, slot, func);
 944
 945         spin_lock_irqsave(&device_ids_lock, flags);
 946         list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
 947         spin_unlock_irqrestore(&device_ids_lock, flags);
 948
 949         return 0;
 950 }
 951
 952 static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
 953 {
 954         struct pcistub_device_id *pci_dev_id, *t;
 955         int devfn = PCI_DEVFN(slot, func);
 956         int err = -ENOENT;
 957         unsigned long flags;
 958
 959         spin_lock_irqsave(&device_ids_lock, flags);
 960         list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
 961                                  slot_list) {
 962                 if (pci_dev_id->domain == domain
 963                     && pci_dev_id->bus == bus && pci_dev_id->devfn == devfn) {
 964                         /* Don't break; here because it's possible the same
 965                          * slot could be in the list more than once
 966                          */
 967                         list_del(&pci_dev_id->slot_list);
 968                         kfree(pci_dev_id);
 969
 970                         err = 0;
 971
 972                         pr_debug(DRV_NAME ": removed %04x:%02x:%02x.%d from "
 973                                  "seize list\n", domain, bus, slot, func);
 974                 }
 975         }
 976         spin_unlock_irqrestore(&device_ids_lock, flags);
 977
 978         return err;
 979 }
 980
 981 static int pcistub_reg_add(int domain, int bus, int slot, int func, int reg,
 982                            int size, int mask)
 983 {
 984         int err = 0;
 985         struct pcistub_device *psdev;
 986         struct pci_dev *dev;
 987         struct config_field *field;
 988
 989         psdev = pcistub_device_find(domain, bus, slot, func);
 990         if (!psdev || !psdev->dev) {
 991                 err = -ENODEV;
 992                 goto out;
 993         }
 994         dev = psdev->dev;
 995
 996         field = kzalloc(sizeof(*field), GFP_ATOMIC);
 997         if (!field) {
 998                 err = -ENOMEM;
 999                 goto out;
1000         }
1001
1002         field->offset = reg;
1003         field->size = size;
1004         field->mask = mask;
1005         field->init = NULL;
1006         field->reset = NULL;
1007         field->release = NULL;
1008         field->clean = xen_pcibk_config_field_free;
1009
1010         err = xen_pcibk_config_quirks_add_field(dev, field);
1011         if (err)
1012                 kfree(field);
1013 out:
1014         return err;
1015 }
1016
1017 static ssize_t pcistub_slot_add(struct device_driver *drv, const char *buf,
1018                                 size_t count)
1019 {
1020         int domain, bus, slot, func;
1021         int err;
1022
1023         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1024         if (err)
1025                 goto out;
1026
1027         err = pcistub_device_id_add(domain, bus, slot, func);
1028
1029 out:
1030         if (!err)
1031                 err = count;
1032         return err;
1033 }
1034 static DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
1035
1036 static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
1037                                    size_t count)
1038 {
1039         int domain, bus, slot, func;
1040         int err;
1041
1042         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1043         if (err)
1044                 goto out;
1045
1046         err = pcistub_device_id_remove(domain, bus, slot, func);
1047
1048 out:
1049         if (!err)
1050                 err = count;
1051         return err;
1052 }
1053 static DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
1054
1055 static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
1056 {
1057         struct pcistub_device_id *pci_dev_id;
1058         size_t count = 0;
1059         unsigned long flags;
1060
1061         spin_lock_irqsave(&device_ids_lock, flags);
1062         list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1063                 if (count >= PAGE_SIZE)
1064                         break;
1065
1066                 count += scnprintf(buf + count, PAGE_SIZE - count,
1067                                    "%04x:%02x:%02x.%d\n",
1068                                    pci_dev_id->domain, pci_dev_id->bus,
1069                                    PCI_SLOT(pci_dev_id->devfn),
1070                                    PCI_FUNC(pci_dev_id->devfn));
1071         }
1072         spin_unlock_irqrestore(&device_ids_lock, flags);
1073
1074         return count;
1075 }
1076 static DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
1077
1078 static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
1079 {
1080         struct pcistub_device *psdev;
1081         struct xen_pcibk_dev_data *dev_data;
1082         size_t count = 0;
1083         unsigned long flags;
1084
1085         spin_lock_irqsave(&pcistub_devices_lock, flags);
1086         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1087                 if (count >= PAGE_SIZE)
1088                         break;
1089                 if (!psdev->dev)
1090                         continue;
1091                 dev_data = pci_get_drvdata(psdev->dev);
1092                 if (!dev_data)
1093                         continue;
1094                 count +=
1095                     scnprintf(buf + count, PAGE_SIZE - count,
1096                               "%s:%s:%sing:%ld\n",
1097                               pci_name(psdev->dev),
1098                               dev_data->isr_on ? "on" : "off",
1099                               dev_data->ack_intr ? "ack" : "not ack",
1100                               dev_data->handled);
1101         }
1102         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1103         return count;
1104 }
1105 static DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
1106
1107 static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
1108                                           const char *buf,
1109                                           size_t count)
1110 {
1111         struct pcistub_device *psdev;
1112         struct xen_pcibk_dev_data *dev_data;
1113         int domain, bus, slot, func;
1114         int err = -ENOENT;
1115
1116         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1117         if (err)
1118                 goto out;
1119
1120         psdev = pcistub_device_find(domain, bus, slot, func);
1121
1122         if (!psdev)
1123                 goto out;
1124
1125         dev_data = pci_get_drvdata(psdev->dev);
1126         if (!dev_data)
1127                 goto out;
1128
1129         dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1130                 dev_data->irq_name, dev_data->isr_on,
1131                 !dev_data->isr_on);
1132
1133         dev_data->isr_on = !(dev_data->isr_on);
1134         if (dev_data->isr_on)
1135                 dev_data->ack_intr = 1;
1136 out:
1137         if (!err)
1138                 err = count;
1139         return err;
1140 }
1141 static DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL,
1142                    pcistub_irq_handler_switch);
1143
1144 static ssize_t pcistub_quirk_add(struct device_driver *drv, const char *buf,
1145                                  size_t count)
1146 {
1147         int domain, bus, slot, func, reg, size, mask;
1148         int err;
1149
1150         err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1151                            &mask);
1152         if (err)
1153                 goto out;
1154
1155         err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1156
1157 out:
1158         if (!err)
1159                 err = count;
1160         return err;
1161 }
1162
1163 static ssize_t pcistub_quirk_show(struct device_driver *drv, char *buf)
1164 {
1165         int count = 0;
1166         unsigned long flags;
1167         struct xen_pcibk_config_quirk *quirk;
1168         struct xen_pcibk_dev_data *dev_data;
1169         const struct config_field *field;
1170         const struct config_field_entry *cfg_entry;
1171
1172         spin_lock_irqsave(&device_ids_lock, flags);
1173         list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1174                 if (count >= PAGE_SIZE)
1175                         goto out;
1176
1177                 count += scnprintf(buf + count, PAGE_SIZE - count,
1178                                    "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1179                                    quirk->pdev->bus->number,
1180                                    PCI_SLOT(quirk->pdev->devfn),
1181                                    PCI_FUNC(quirk->pdev->devfn),
1182                                    quirk->devid.vendor, quirk->devid.device,
1183                                    quirk->devid.subvendor,
1184                                    quirk->devid.subdevice);
1185
1186                 dev_data = pci_get_drvdata(quirk->pdev);
1187
1188                 list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1189                         field = cfg_entry->field;
1190                         if (count >= PAGE_SIZE)
1191                                 goto out;
1192
1193                         count += scnprintf(buf + count, PAGE_SIZE - count,
1194                                            "\t\t%08x:%01x:%08x\n",
1195                                            cfg_entry->base_offset +
1196                                            field->offset, field->size,
1197                                            field->mask);
1198                 }
1199         }
1200
1201 out:
1202         spin_unlock_irqrestore(&device_ids_lock, flags);
1203
1204         return count;
1205 }
1206 static DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show,
1207                    pcistub_quirk_add);
1208
1209 static ssize_t permissive_add(struct device_driver *drv, const char *buf,
1210                               size_t count)
1211 {
1212         int domain, bus, slot, func;
1213         int err;
1214         struct pcistub_device *psdev;
1215         struct xen_pcibk_dev_data *dev_data;
1216         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1217         if (err)
1218                 goto out;
1219         psdev = pcistub_device_find(domain, bus, slot, func);
1220         if (!psdev) {
1221                 err = -ENODEV;
1222                 goto out;
1223         }
1224         if (!psdev->dev) {
1225                 err = -ENODEV;
1226                 goto release;
1227         }
1228         dev_data = pci_get_drvdata(psdev->dev);
1229         /* the driver data for a device should never be null at this point */
1230         if (!dev_data) {
1231                 err = -ENXIO;
1232                 goto release;
1233         }
1234         if (!dev_data->permissive) {
1235                 dev_data->permissive = 1;
1236                 /* Let user know that what they're doing could be unsafe */
1237                 dev_warn(&psdev->dev->dev, "enabling permissive mode "
1238                          "configuration space accesses!\n");
1239                 dev_warn(&psdev->dev->dev,
1240                          "permissive mode is potentially unsafe!\n");
1241         }
1242 release:
1243         pcistub_device_put(psdev);
1244 out:
1245         if (!err)
1246                 err = count;
1247         return err;
1248 }
1249
1250 static ssize_t permissive_show(struct device_driver *drv, char *buf)
1251 {
1252         struct pcistub_device *psdev;
1253         struct xen_pcibk_dev_data *dev_data;
1254         size_t count = 0;
1255         unsigned long flags;
1256         spin_lock_irqsave(&pcistub_devices_lock, flags);
1257         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1258                 if (count >= PAGE_SIZE)
1259                         break;
1260                 if (!psdev->dev)
1261                         continue;
1262                 dev_data = pci_get_drvdata(psdev->dev);
1263                 if (!dev_data || !dev_data->permissive)
1264                         continue;
1265                 count +=
1266                     scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1267                               pci_name(psdev->dev));
1268         }
1269         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1270         return count;
1271 }
1272 static DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show,
1273                    permissive_add);
1274
1275 static void pcistub_exit(void)
1276 {
1277         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1278         driver_remove_file(&xen_pcibk_pci_driver.driver,
1279                            &driver_attr_remove_slot);
1280         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1281         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1282         driver_remove_file(&xen_pcibk_pci_driver.driver,
1283                            &driver_attr_permissive);
1284         driver_remove_file(&xen_pcibk_pci_driver.driver,
1285                            &driver_attr_irq_handlers);
1286         driver_remove_file(&xen_pcibk_pci_driver.driver,
1287                            &driver_attr_irq_handler_state);
1288         pci_unregister_driver(&xen_pcibk_pci_driver);
1289 }
1290
1291 static int __init pcistub_init(void)
1292 {
1293         int pos = 0;
1294         int err = 0;
1295         int domain, bus, slot, func;
1296         int parsed;
1297
1298         if (pci_devs_to_hide && *pci_devs_to_hide) {
1299                 do {
1300                         parsed = 0;
1301
1302                         err = sscanf(pci_devs_to_hide + pos,
1303                                      " (%x:%x:%x.%x) %n",
1304                                      &domain, &bus, &slot, &func, &parsed);
1305                         if (err != 4) {
1306                                 domain = 0;
1307                                 err = sscanf(pci_devs_to_hide + pos,
1308                                              " (%x:%x.%x) %n",
1309                                              &bus, &slot, &func, &parsed);
1310                                 if (err != 3)
1311                                         goto parse_error;
1312                         }
1313
1314                         err = pcistub_device_id_add(domain, bus, slot, func);
1315                         if (err)
1316                                 goto out;
1317
1318                         /* if parsed<=0, we've reached the end of the string */
1319                         pos += parsed;
1320                 } while (parsed > 0 && pci_devs_to_hide[pos]);
1321         }
1322
1323         /* If we're the first PCI Device Driver to register, we're the
1324          * first one to get offered PCI devices as they become
1325          * available (and thus we can be the first to grab them)
1326          */
1327         err = pci_register_driver(&xen_pcibk_pci_driver);
1328         if (err < 0)
1329                 goto out;
1330
1331         err = driver_create_file(&xen_pcibk_pci_driver.driver,
1332                                  &driver_attr_new_slot);
1333         if (!err)
1334                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1335                                          &driver_attr_remove_slot);
1336         if (!err)
1337                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1338                                          &driver_attr_slots);
1339         if (!err)
1340                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1341                                          &driver_attr_quirks);
1342         if (!err)
1343                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1344                                          &driver_attr_permissive);
1345
1346         if (!err)
1347                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1348                                          &driver_attr_irq_handlers);
1349         if (!err)
1350                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1351                                         &driver_attr_irq_handler_state);
1352         if (err)
1353                 pcistub_exit();
1354
1355 out:
1356         return err;
1357
1358 parse_error:
1359         printk(KERN_ERR DRV_NAME ": Error parsing pci_devs_to_hide at \"%s\"\n",
1360                pci_devs_to_hide + pos);
1361         return -EINVAL;
1362 }
1363
1364 #ifndef MODULE
1365 /*
1366  * fs_initcall happens before device_initcall
1367  * so xen_pcibk *should* get called first (b/c we
1368  * want to suck up any device before other drivers
1369  * get a chance by being the first pci device
1370  * driver to register)
1371  */
1372 fs_initcall(pcistub_init);
1373 #endif
1374
1375 static int __init xen_pcibk_init(void)
1376 {
1377         int err;
1378
1379         if (!xen_initial_domain())
1380                 return -ENODEV;
1381
1382         err = xen_pcibk_config_init();
1383         if (err)
1384                 return err;
1385
1386 #ifdef MODULE
1387         err = pcistub_init();
1388         if (err < 0)
1389                 return err;
1390 #endif
1391
1392         pcistub_init_devices_late();
1393         err = xen_pcibk_xenbus_register();
1394         if (err)
1395                 pcistub_exit();
1396
1397         return err;
1398 }
1399
1400 static void __exit xen_pcibk_cleanup(void)
1401 {
1402         xen_pcibk_xenbus_unregister();
1403         pcistub_exit();
1404 }
1405
1406 module_init(xen_pcibk_init);
1407 module_exit(xen_pcibk_cleanup);
1408
1409 MODULE_LICENSE("Dual BSD/GPL");
1410 MODULE_ALIAS("xen-backend:pci");