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
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/rwsem.h>
  13 #include <linux/list.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/kref.h>
  16 #include <linux/pci.h>
  17 #include <linux/wait.h>
  18 #include <linux/sched.h>
  19 #include <linux/atomic.h>
  20 #include <xen/events.h>
  21 #include <asm/xen/pci.h>
  22 #include <asm/xen/hypervisor.h>
  23 #include <xen/interface/physdev.h>
  24 #include "pciback.h"
  25 #include "conf_space.h"
  26 #include "conf_space_quirks.h"
  27
  28 static char *pci_devs_to_hide;
  29 wait_queue_head_t xen_pcibk_aer_wait_queue;
  30 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
  31 * We want to avoid in middle of AER ops, xen_pcibk devices is being removed
  32 */
  33 static DECLARE_RWSEM(pcistub_sem);
  34 module_param_named(hide, pci_devs_to_hide, charp, 0444);
  35
  36 struct pcistub_device_id {
  37         struct list_head slot_list;
  38         int domain;
  39         unsigned char bus;
  40         unsigned int devfn;
  41 };
  42 static LIST_HEAD(pcistub_device_ids);
  43 static DEFINE_SPINLOCK(device_ids_lock);
  44
  45 struct pcistub_device {
  46         struct kref kref;
  47         struct list_head dev_list;
  48         spinlock_t lock;
  49
  50         struct pci_dev *dev;
  51         struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */
  52 };
  53
  54 /* Access to pcistub_devices & seized_devices lists and the initialize_devices
  55  * flag must be locked with pcistub_devices_lock
  56  */
  57 static DEFINE_SPINLOCK(pcistub_devices_lock);
  58 static LIST_HEAD(pcistub_devices);
  59
  60 /* wait for device_initcall before initializing our devices
  61  * (see pcistub_init_devices_late)
  62  */
  63 static int initialize_devices;
  64 static LIST_HEAD(seized_devices);
  65
  66 static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
  67 {
  68         struct pcistub_device *psdev;
  69
  70         dev_dbg(&dev->dev, "pcistub_device_alloc\n");
  71
  72         psdev = kzalloc(sizeof(*psdev), GFP_ATOMIC);
  73         if (!psdev)
  74                 return NULL;
  75
  76         psdev->dev = pci_dev_get(dev);
  77         if (!psdev->dev) {
  78                 kfree(psdev);
  79                 return NULL;
  80         }
  81
  82         kref_init(&psdev->kref);
  83         spin_lock_init(&psdev->lock);
  84
  85         return psdev;
  86 }
  87
  88 /* Don't call this directly as it's called by pcistub_device_put */
  89 static void pcistub_device_release(struct kref *kref)
  90 {
  91         struct pcistub_device *psdev;
  92         struct pci_dev *dev;
  93         struct xen_pcibk_dev_data *dev_data;
  94
  95         psdev = container_of(kref, struct pcistub_device, kref);
  96         dev = psdev->dev;
  97         dev_data = pci_get_drvdata(dev);
  98
  99         dev_dbg(&dev->dev, "pcistub_device_release\n");
 100
 101         xen_unregister_device_domain_owner(dev);
 102
 103         /* Call the reset function which does not take lock as this
 104          * is called from "unbind" which takes a device_lock mutex.
 105          */
 106         __pci_reset_function_locked(dev);
 107         if (pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state))
 108                 dev_dbg(&dev->dev, "Could not reload PCI state\n");
 109         else
 110                 pci_restore_state(dev);
 111
 112         if (dev->msix_cap) {
 113                 struct physdev_pci_device ppdev = {
 114                         .seg = pci_domain_nr(dev->bus),
 115                         .bus = dev->bus->number,
 116                         .devfn = dev->devfn
 117                 };
 118                 int err = HYPERVISOR_physdev_op(PHYSDEVOP_release_msix,
 119                                                 &ppdev);
 120
 121                 if (err)
 122                         dev_warn(&dev->dev, "MSI-X release failed (%d)\n",
 123                                  err);
 124         }
 125
 126         /* Disable the device */
 127         xen_pcibk_reset_device(dev);
 128
 129         kfree(dev_data);
 130         pci_set_drvdata(dev, NULL);
 131
 132         /* Clean-up the device */
 133         xen_pcibk_config_free_dyn_fields(dev);
 134         xen_pcibk_config_free_dev(dev);
 135
 136         dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
 137         pci_dev_put(dev);
 138
 139         kfree(psdev);
 140 }
 141
 142 static inline void pcistub_device_get(struct pcistub_device *psdev)
 143 {
 144         kref_get(&psdev->kref);
 145 }
 146
 147 static inline void pcistub_device_put(struct pcistub_device *psdev)
 148 {
 149         kref_put(&psdev->kref, pcistub_device_release);
 150 }
 151
 152 static struct pcistub_device *pcistub_device_find(int domain, int bus,
 153                                                   int slot, int func)
 154 {
 155         struct pcistub_device *psdev = NULL;
 156         unsigned long flags;
 157
 158         spin_lock_irqsave(&pcistub_devices_lock, flags);
 159
 160         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 161                 if (psdev->dev != NULL
 162                     && domain == pci_domain_nr(psdev->dev->bus)
 163                     && bus == psdev->dev->bus->number
 164                     && slot == PCI_SLOT(psdev->dev->devfn)
 165                     && func == PCI_FUNC(psdev->dev->devfn)) {
 166                         pcistub_device_get(psdev);
 167                         goto out;
 168                 }
 169         }
 170
 171         /* didn't find it */
 172         psdev = NULL;
 173
 174 out:
 175         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 176         return psdev;
 177 }
 178
 179 static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
 180                                                   struct pcistub_device *psdev)
 181 {
 182         struct pci_dev *pci_dev = NULL;
 183         unsigned long flags;
 184
 185         pcistub_device_get(psdev);
 186
 187         spin_lock_irqsave(&psdev->lock, flags);
 188         if (!psdev->pdev) {
 189                 psdev->pdev = pdev;
 190                 pci_dev = psdev->dev;
 191         }
 192         spin_unlock_irqrestore(&psdev->lock, flags);
 193
 194         if (!pci_dev)
 195                 pcistub_device_put(psdev);
 196
 197         return pci_dev;
 198 }
 199
 200 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 201                                             int domain, int bus,
 202                                             int slot, int func)
 203 {
 204         struct pcistub_device *psdev;
 205         struct pci_dev *found_dev = NULL;
 206         unsigned long flags;
 207
 208         spin_lock_irqsave(&pcistub_devices_lock, flags);
 209
 210         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 211                 if (psdev->dev != NULL
 212                     && domain == pci_domain_nr(psdev->dev->bus)
 213                     && bus == psdev->dev->bus->number
 214                     && slot == PCI_SLOT(psdev->dev->devfn)
 215                     && func == PCI_FUNC(psdev->dev->devfn)) {
 216                         found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 217                         break;
 218                 }
 219         }
 220
 221         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 222         return found_dev;
 223 }
 224
 225 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 226                                     struct pci_dev *dev)
 227 {
 228         struct pcistub_device *psdev;
 229         struct pci_dev *found_dev = NULL;
 230         unsigned long flags;
 231
 232         spin_lock_irqsave(&pcistub_devices_lock, flags);
 233
 234         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 235                 if (psdev->dev == dev) {
 236                         found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 237                         break;
 238                 }
 239         }
 240
 241         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 242         return found_dev;
 243 }
 244
 245 void pcistub_put_pci_dev(struct pci_dev *dev)
 246 {
 247         struct pcistub_device *psdev, *found_psdev = NULL;
 248         unsigned long flags;
 249
 250         spin_lock_irqsave(&pcistub_devices_lock, flags);
 251
 252         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 253                 if (psdev->dev == dev) {
 254                         found_psdev = psdev;
 255                         break;
 256                 }
 257         }
 258
 259         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 260         if (WARN_ON(!found_psdev))
 261                 return;
 262
 263         /*hold this lock for avoiding breaking link between
 264         * pcistub and xen_pcibk when AER is in processing
 265         */
 266         down_write(&pcistub_sem);
 267         /* Cleanup our device
 268          * (so it's ready for the next domain)
 269          */
 270
 271         /* This is OK - we are running from workqueue context
 272          * and want to inhibit the user from fiddling with 'reset'
 273          */
 274         pci_reset_function(dev);
 275         pci_restore_state(dev);
 276
 277         /* This disables the device. */
 278         xen_pcibk_reset_device(dev);
 279
 280         /* And cleanup up our emulated fields. */
 281         xen_pcibk_config_reset_dev(dev);
 282         xen_pcibk_config_free_dyn_fields(dev);
 283
 284         xen_unregister_device_domain_owner(dev);
 285
 286         spin_lock_irqsave(&found_psdev->lock, flags);
 287         found_psdev->pdev = NULL;
 288         spin_unlock_irqrestore(&found_psdev->lock, flags);
 289
 290         pcistub_device_put(found_psdev);
 291         up_write(&pcistub_sem);
 292 }
 293
 294 static int pcistub_match_one(struct pci_dev *dev,
 295                              struct pcistub_device_id *pdev_id)
 296 {
 297         /* Match the specified device by domain, bus, slot, func and also if
 298          * any of the device's parent bridges match.
 299          */
 300         for (; dev != NULL; dev = dev->bus->self) {
 301                 if (pci_domain_nr(dev->bus) == pdev_id->domain
 302                     && dev->bus->number == pdev_id->bus
 303                     && dev->devfn == pdev_id->devfn)
 304                         return 1;
 305
 306                 /* Sometimes topmost bridge links to itself. */
 307                 if (dev == dev->bus->self)
 308                         break;
 309         }
 310
 311         return 0;
 312 }
 313
 314 static int pcistub_match(struct pci_dev *dev)
 315 {
 316         struct pcistub_device_id *pdev_id;
 317         unsigned long flags;
 318         int found = 0;
 319
 320         spin_lock_irqsave(&device_ids_lock, flags);
 321         list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) {
 322                 if (pcistub_match_one(dev, pdev_id)) {
 323                         found = 1;
 324                         break;
 325                 }
 326         }
 327         spin_unlock_irqrestore(&device_ids_lock, flags);
 328
 329         return found;
 330 }
 331
 332 static int pcistub_init_device(struct pci_dev *dev)
 333 {
 334         struct xen_pcibk_dev_data *dev_data;
 335         int err = 0;
 336
 337         dev_dbg(&dev->dev, "initializing...\n");
 338
 339         /* The PCI backend is not intended to be a module (or to work with
 340          * removable PCI devices (yet). If it were, xen_pcibk_config_free()
 341          * would need to be called somewhere to free the memory allocated
 342          * here and then to call kfree(pci_get_drvdata(psdev->dev)).
 343          */
 344         dev_data = kzalloc(sizeof(*dev_data) +  strlen(DRV_NAME "[]")
 345                                 + strlen(pci_name(dev)) + 1, GFP_ATOMIC);
 346         if (!dev_data) {
 347                 err = -ENOMEM;
 348                 goto out;
 349         }
 350         pci_set_drvdata(dev, dev_data);
 351
 352         /*
 353          * Setup name for fake IRQ handler. It will only be enabled
 354          * once the device is turned on by the guest.
 355          */
 356         sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev));
 357
 358         dev_dbg(&dev->dev, "initializing config\n");
 359
 360         init_waitqueue_head(&xen_pcibk_aer_wait_queue);
 361         err = xen_pcibk_config_init_dev(dev);
 362         if (err)
 363                 goto out;
 364
 365         /* HACK: Force device (& ACPI) to determine what IRQ it's on - we
 366          * must do this here because pcibios_enable_device may specify
 367          * the pci device's true irq (and possibly its other resources)
 368          * if they differ from what's in the configuration space.
 369          * This makes the assumption that the device's resources won't
 370          * change after this point (otherwise this code may break!)
 371          */
 372         dev_dbg(&dev->dev, "enabling device\n");
 373         err = pci_enable_device(dev);
 374         if (err)
 375                 goto config_release;
 376
 377         if (dev->msix_cap) {
 378                 struct physdev_pci_device ppdev = {
 379                         .seg = pci_domain_nr(dev->bus),
 380                         .bus = dev->bus->number,
 381                         .devfn = dev->devfn
 382                 };
 383
 384                 err = HYPERVISOR_physdev_op(PHYSDEVOP_prepare_msix, &ppdev);
 385                 if (err)
 386                         dev_err(&dev->dev, "MSI-X preparation failed (%d)\n",
 387                                 err);
 388         }
 389
 390         /* We need the device active to save the state. */
 391         dev_dbg(&dev->dev, "save state of device\n");
 392         pci_save_state(dev);
 393         dev_data->pci_saved_state = pci_store_saved_state(dev);
 394         if (!dev_data->pci_saved_state)
 395                 dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
 396         else {
 397                 dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n");
 398                 __pci_reset_function_locked(dev);
 399                 pci_restore_state(dev);
 400         }
 401         /* Now disable the device (this also ensures some private device
 402          * data is setup before we export)
 403          */
 404         dev_dbg(&dev->dev, "reset device\n");
 405         xen_pcibk_reset_device(dev);
 406
 407         dev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
 408         return 0;
 409
 410 config_release:
 411         xen_pcibk_config_free_dev(dev);
 412
 413 out:
 414         pci_set_drvdata(dev, NULL);
 415         kfree(dev_data);
 416         return err;
 417 }
 418
 419 /*
 420  * Because some initialization still happens on
 421  * devices during fs_initcall, we need to defer
 422  * full initialization of our devices until
 423  * device_initcall.
 424  */
 425 static int __init pcistub_init_devices_late(void)
 426 {
 427         struct pcistub_device *psdev;
 428         unsigned long flags;
 429         int err = 0;
 430
 431         spin_lock_irqsave(&pcistub_devices_lock, flags);
 432
 433         while (!list_empty(&seized_devices)) {
 434                 psdev = container_of(seized_devices.next,
 435                                      struct pcistub_device, dev_list);
 436                 list_del(&psdev->dev_list);
 437
 438                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 439
 440                 err = pcistub_init_device(psdev->dev);
 441                 if (err) {
 442                         dev_err(&psdev->dev->dev,
 443                                 "error %d initializing device\n", err);
 444                         kfree(psdev);
 445                         psdev = NULL;
 446                 }
 447
 448                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 449
 450                 if (psdev)
 451                         list_add_tail(&psdev->dev_list, &pcistub_devices);
 452         }
 453
 454         initialize_devices = 1;
 455
 456         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 457
 458         return 0;
 459 }
 460
 461 static int pcistub_seize(struct pci_dev *dev)
 462 {
 463         struct pcistub_device *psdev;
 464         unsigned long flags;
 465         int err = 0;
 466
 467         psdev = pcistub_device_alloc(dev);
 468         if (!psdev)
 469                 return -ENOMEM;
 470
 471         spin_lock_irqsave(&pcistub_devices_lock, flags);
 472
 473         if (initialize_devices) {
 474                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 475
 476                 /* don't want irqs disabled when calling pcistub_init_device */
 477                 err = pcistub_init_device(psdev->dev);
 478
 479                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 480
 481                 if (!err)
 482                         list_add(&psdev->dev_list, &pcistub_devices);
 483         } else {
 484                 dev_dbg(&dev->dev, "deferring initialization\n");
 485                 list_add(&psdev->dev_list, &seized_devices);
 486         }
 487
 488         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 489
 490         if (err)
 491                 pcistub_device_put(psdev);
 492
 493         return err;
 494 }
 495
 496 /* Called when 'bind'. This means we must _NOT_ call pci_reset_function or
 497  * other functions that take the sysfs lock. */
 498 static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 499 {
 500         int err = 0;
 501
 502         dev_dbg(&dev->dev, "probing...\n");
 503
 504         if (pcistub_match(dev)) {
 505
 506                 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
 507                     && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 508                         dev_err(&dev->dev, "can't export pci devices that "
 509                                 "don't have a normal (0) or bridge (1) "
 510                                 "header type!\n");
 511                         err = -ENODEV;
 512                         goto out;
 513                 }
 514
 515                 dev_info(&dev->dev, "seizing device\n");
 516                 err = pcistub_seize(dev);
 517         } else
 518                 /* Didn't find the device */
 519                 err = -ENODEV;
 520
 521 out:
 522         return err;
 523 }
 524
 525 /* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or
 526  * other functions that take the sysfs lock. */
 527 static void pcistub_remove(struct pci_dev *dev)
 528 {
 529         struct pcistub_device *psdev, *found_psdev = NULL;
 530         unsigned long flags;
 531
 532         dev_dbg(&dev->dev, "removing\n");
 533
 534         spin_lock_irqsave(&pcistub_devices_lock, flags);
 535
 536         xen_pcibk_config_quirk_release(dev);
 537
 538         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 539                 if (psdev->dev == dev) {
 540                         found_psdev = psdev;
 541                         break;
 542                 }
 543         }
 544
 545         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 546
 547         if (found_psdev) {
 548                 dev_dbg(&dev->dev, "found device to remove - in use? %p\n",
 549                         found_psdev->pdev);
 550
 551                 if (found_psdev->pdev) {
 552                         pr_warn("****** removing device %s while still in-use! ******\n",
 553                                pci_name(found_psdev->dev));
 554                         pr_warn("****** driver domain may still access this device's i/o resources!\n");
 555                         pr_warn("****** shutdown driver domain before binding device\n");
 556                         pr_warn("****** to other drivers or domains\n");
 557
 558                         /* N.B. This ends up calling pcistub_put_pci_dev which ends up
 559                          * doing the FLR. */
 560                         xen_pcibk_release_pci_dev(found_psdev->pdev,
 561                                                 found_psdev->dev);
 562                 }
 563
 564                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 565                 list_del(&found_psdev->dev_list);
 566                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 567
 568                 /* the final put for releasing from the list */
 569                 pcistub_device_put(found_psdev);
 570         }
 571 }
 572
 573 static DEFINE_PCI_DEVICE_TABLE(pcistub_ids) = {
 574         {
 575          .vendor = PCI_ANY_ID,
 576          .device = PCI_ANY_ID,
 577          .subvendor = PCI_ANY_ID,
 578          .subdevice = PCI_ANY_ID,
 579          },
 580         {0,},
 581 };
 582
 583 #define PCI_NODENAME_MAX 40
 584 static void kill_domain_by_device(struct pcistub_device *psdev)
 585 {
 586         struct xenbus_transaction xbt;
 587         int err;
 588         char nodename[PCI_NODENAME_MAX];
 589
 590         BUG_ON(!psdev);
 591         snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
 592                 psdev->pdev->xdev->otherend_id);
 593
 594 again:
 595         err = xenbus_transaction_start(&xbt);
 596         if (err) {
 597                 dev_err(&psdev->dev->dev,
 598                         "error %d when start xenbus transaction\n", err);
 599                 return;
 600         }
 601         /*PV AER handlers will set this flag*/
 602         xenbus_printf(xbt, nodename, "aerState" , "aerfail");
 603         err = xenbus_transaction_end(xbt, 0);
 604         if (err) {
 605                 if (err == -EAGAIN)
 606                         goto again;
 607                 dev_err(&psdev->dev->dev,
 608                         "error %d when end xenbus transaction\n", err);
 609                 return;
 610         }
 611 }
 612
 613 /* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
 614  * backend need to have cooperation. In xen_pcibk, those steps will do similar
 615  * jobs: send service request and waiting for front_end response.
 616 */
 617 static pci_ers_result_t common_process(struct pcistub_device *psdev,
 618                                        pci_channel_state_t state, int aer_cmd,
 619                                        pci_ers_result_t result)
 620 {
 621         pci_ers_result_t res = result;
 622         struct xen_pcie_aer_op *aer_op;
 623         int ret;
 624
 625         /*with PV AER drivers*/
 626         aer_op = &(psdev->pdev->sh_info->aer_op);
 627         aer_op->cmd = aer_cmd ;
 628         /*useful for error_detected callback*/
 629         aer_op->err = state;
 630         /*pcifront_end BDF*/
 631         ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
 632                 &aer_op->domain, &aer_op->bus, &aer_op->devfn);
 633         if (!ret) {
 634                 dev_err(&psdev->dev->dev,
 635                         DRV_NAME ": failed to get pcifront device\n");
 636                 return PCI_ERS_RESULT_NONE;
 637         }
 638         wmb();
 639
 640         dev_dbg(&psdev->dev->dev,
 641                         DRV_NAME ": aer_op %x dom %x bus %x devfn %x\n",
 642                         aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
 643         /*local flag to mark there's aer request, xen_pcibk callback will use
 644         * this flag to judge whether we need to check pci-front give aer
 645         * service ack signal
 646         */
 647         set_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
 648
 649         /*It is possible that a pcifront conf_read_write ops request invokes
 650         * the callback which cause the spurious execution of wake_up.
 651         * Yet it is harmless and better than a spinlock here
 652         */
 653         set_bit(_XEN_PCIB_active,
 654                 (unsigned long *)&psdev->pdev->sh_info->flags);
 655         wmb();
 656         notify_remote_via_irq(psdev->pdev->evtchn_irq);
 657
 658         ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
 659                                  !(test_bit(_XEN_PCIB_active, (unsigned long *)
 660                                  &psdev->pdev->sh_info->flags)), 300*HZ);
 661
 662         if (!ret) {
 663                 if (test_bit(_XEN_PCIB_active,
 664                         (unsigned long *)&psdev->pdev->sh_info->flags)) {
 665                         dev_err(&psdev->dev->dev,
 666                                 "pcifront aer process not responding!\n");
 667                         clear_bit(_XEN_PCIB_active,
 668                           (unsigned long *)&psdev->pdev->sh_info->flags);
 669                         aer_op->err = PCI_ERS_RESULT_NONE;
 670                         return res;
 671                 }
 672         }
 673         clear_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
 674
 675         if (test_bit(_XEN_PCIF_active,
 676                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 677                 dev_dbg(&psdev->dev->dev,
 678                         "schedule pci_conf service in " DRV_NAME "\n");
 679                 xen_pcibk_test_and_schedule_op(psdev->pdev);
 680         }
 681
 682         res = (pci_ers_result_t)aer_op->err;
 683         return res;
 684 }
 685
 686 /*
 687 * xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
 688 * of the device driver could provide this service, and then wait for pcifront
 689 * ack.
 690 * @dev: pointer to PCI devices
 691 * return value is used by aer_core do_recovery policy
 692 */
 693 static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
 694 {
 695         struct pcistub_device *psdev;
 696         pci_ers_result_t result;
 697
 698         result = PCI_ERS_RESULT_RECOVERED;
 699         dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
 700                 dev->bus->number, dev->devfn);
 701
 702         down_write(&pcistub_sem);
 703         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 704                                 dev->bus->number,
 705                                 PCI_SLOT(dev->devfn),
 706                                 PCI_FUNC(dev->devfn));
 707
 708         if (!psdev || !psdev->pdev) {
 709                 dev_err(&dev->dev,
 710                         DRV_NAME " device is not found/assigned\n");
 711                 goto end;
 712         }
 713
 714         if (!psdev->pdev->sh_info) {
 715                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 716                         " by HVM, kill it\n");
 717                 kill_domain_by_device(psdev);
 718                 goto end;
 719         }
 720
 721         if (!test_bit(_XEN_PCIB_AERHANDLER,
 722                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 723                 dev_err(&dev->dev,
 724                         "guest with no AER driver should have been killed\n");
 725                 goto end;
 726         }
 727         result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
 728
 729         if (result == PCI_ERS_RESULT_NONE ||
 730                 result == PCI_ERS_RESULT_DISCONNECT) {
 731                 dev_dbg(&dev->dev,
 732                         "No AER slot_reset service or disconnected!\n");
 733                 kill_domain_by_device(psdev);
 734         }
 735 end:
 736         if (psdev)
 737                 pcistub_device_put(psdev);
 738         up_write(&pcistub_sem);
 739         return result;
 740
 741 }
 742
 743
 744 /*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
 745 * in case of the device driver could provide this service, and then wait
 746 * for pcifront ack
 747 * @dev: pointer to PCI devices
 748 * return value is used by aer_core do_recovery policy
 749 */
 750
 751 static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
 752 {
 753         struct pcistub_device *psdev;
 754         pci_ers_result_t result;
 755
 756         result = PCI_ERS_RESULT_RECOVERED;
 757         dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n",
 758                 dev->bus->number, dev->devfn);
 759
 760         down_write(&pcistub_sem);
 761         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 762                                 dev->bus->number,
 763                                 PCI_SLOT(dev->devfn),
 764                                 PCI_FUNC(dev->devfn));
 765
 766         if (!psdev || !psdev->pdev) {
 767                 dev_err(&dev->dev,
 768                         DRV_NAME " device is not found/assigned\n");
 769                 goto end;
 770         }
 771
 772         if (!psdev->pdev->sh_info) {
 773                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 774                         " by HVM, kill it\n");
 775                 kill_domain_by_device(psdev);
 776                 goto end;
 777         }
 778
 779         if (!test_bit(_XEN_PCIB_AERHANDLER,
 780                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 781                 dev_err(&dev->dev,
 782                         "guest with no AER driver should have been killed\n");
 783                 goto end;
 784         }
 785         result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
 786
 787         if (result == PCI_ERS_RESULT_NONE ||
 788                 result == PCI_ERS_RESULT_DISCONNECT) {
 789                 dev_dbg(&dev->dev,
 790                         "No AER mmio_enabled service or disconnected!\n");
 791                 kill_domain_by_device(psdev);
 792         }
 793 end:
 794         if (psdev)
 795                 pcistub_device_put(psdev);
 796         up_write(&pcistub_sem);
 797         return result;
 798 }
 799
 800 /*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
 801 * in case of the device driver could provide this service, and then wait
 802 * for pcifront ack.
 803 * @dev: pointer to PCI devices
 804 * @error: the current PCI connection state
 805 * return value is used by aer_core do_recovery policy
 806 */
 807
 808 static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
 809         pci_channel_state_t error)
 810 {
 811         struct pcistub_device *psdev;
 812         pci_ers_result_t result;
 813
 814         result = PCI_ERS_RESULT_CAN_RECOVER;
 815         dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
 816                 dev->bus->number, dev->devfn);
 817
 818         down_write(&pcistub_sem);
 819         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 820                                 dev->bus->number,
 821                                 PCI_SLOT(dev->devfn),
 822                                 PCI_FUNC(dev->devfn));
 823
 824         if (!psdev || !psdev->pdev) {
 825                 dev_err(&dev->dev,
 826                         DRV_NAME " device is not found/assigned\n");
 827                 goto end;
 828         }
 829
 830         if (!psdev->pdev->sh_info) {
 831                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 832                         " by HVM, kill it\n");
 833                 kill_domain_by_device(psdev);
 834                 goto end;
 835         }
 836
 837         /*Guest owns the device yet no aer handler regiested, kill guest*/
 838         if (!test_bit(_XEN_PCIB_AERHANDLER,
 839                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 840                 dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
 841                 kill_domain_by_device(psdev);
 842                 goto end;
 843         }
 844         result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
 845
 846         if (result == PCI_ERS_RESULT_NONE ||
 847                 result == PCI_ERS_RESULT_DISCONNECT) {
 848                 dev_dbg(&dev->dev,
 849                         "No AER error_detected service or disconnected!\n");
 850                 kill_domain_by_device(psdev);
 851         }
 852 end:
 853         if (psdev)
 854                 pcistub_device_put(psdev);
 855         up_write(&pcistub_sem);
 856         return result;
 857 }
 858
 859 /*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
 860 * in case of the device driver could provide this service, and then wait
 861 * for pcifront ack.
 862 * @dev: pointer to PCI devices
 863 */
 864
 865 static void xen_pcibk_error_resume(struct pci_dev *dev)
 866 {
 867         struct pcistub_device *psdev;
 868
 869         dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
 870                 dev->bus->number, dev->devfn);
 871
 872         down_write(&pcistub_sem);
 873         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 874                                 dev->bus->number,
 875                                 PCI_SLOT(dev->devfn),
 876                                 PCI_FUNC(dev->devfn));
 877
 878         if (!psdev || !psdev->pdev) {
 879                 dev_err(&dev->dev,
 880                         DRV_NAME " device is not found/assigned\n");
 881                 goto end;
 882         }
 883
 884         if (!psdev->pdev->sh_info) {
 885                 dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
 886                         " by HVM, kill it\n");
 887                 kill_domain_by_device(psdev);
 888                 goto end;
 889         }
 890
 891         if (!test_bit(_XEN_PCIB_AERHANDLER,
 892                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 893                 dev_err(&dev->dev,
 894                         "guest with no AER driver should have been killed\n");
 895                 kill_domain_by_device(psdev);
 896                 goto end;
 897         }
 898         common_process(psdev, 1, XEN_PCI_OP_aer_resume,
 899                        PCI_ERS_RESULT_RECOVERED);
 900 end:
 901         if (psdev)
 902                 pcistub_device_put(psdev);
 903         up_write(&pcistub_sem);
 904         return;
 905 }
 906
 907 /*add xen_pcibk AER handling*/
 908 static const struct pci_error_handlers xen_pcibk_error_handler = {
 909         .error_detected = xen_pcibk_error_detected,
 910         .mmio_enabled = xen_pcibk_mmio_enabled,
 911         .slot_reset = xen_pcibk_slot_reset,
 912         .resume = xen_pcibk_error_resume,
 913 };
 914
 915 /*
 916  * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
 917  * for a normal device. I don't want it to be loaded automatically.
 918  */
 919
 920 static struct pci_driver xen_pcibk_pci_driver = {
 921         /* The name should be xen_pciback, but until the tools are updated
 922          * we will keep it as pciback. */
 923         .name = "pciback",
 924         .id_table = pcistub_ids,
 925         .probe = pcistub_probe,
 926         .remove = pcistub_remove,
 927         .err_handler = &xen_pcibk_error_handler,
 928 };
 929
 930 static inline int str_to_slot(const char *buf, int *domain, int *bus,
 931                               int *slot, int *func)
 932 {
 933         int parsed = 0;
 934
 935         switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func,
 936                        &parsed)) {
 937         case 3:
 938                 *func = -1;
 939                 sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed);
 940                 break;
 941         case 2:
 942                 *slot = *func = -1;
 943                 sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed);
 944                 break;
 945         }
 946         if (parsed && !buf[parsed])
 947                 return 0;
 948
 949         /* try again without domain */
 950         *domain = 0;
 951         switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) {
 952         case 2:
 953                 *func = -1;
 954                 sscanf(buf, " %x:%x.* %n", bus, slot, &parsed);
 955                 break;
 956         case 1:
 957                 *slot = *func = -1;
 958                 sscanf(buf, " %x:*.* %n", bus, &parsed);
 959                 break;
 960         }
 961         if (parsed && !buf[parsed])
 962                 return 0;
 963
 964         return -EINVAL;
 965 }
 966
 967 static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
 968                                *slot, int *func, int *reg, int *size, int *mask)
 969 {
 970         int parsed = 0;
 971
 972         sscanf(buf, " %x:%x:%x.%x-%x:%x:%x %n", domain, bus, slot, func,
 973                reg, size, mask, &parsed);
 974         if (parsed && !buf[parsed])
 975                 return 0;
 976
 977         /* try again without domain */
 978         *domain = 0;
 979         sscanf(buf, " %x:%x.%x-%x:%x:%x %n", bus, slot, func, reg, size,
 980                mask, &parsed);
 981         if (parsed && !buf[parsed])
 982                 return 0;
 983
 984         return -EINVAL;
 985 }
 986
 987 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
 988 {
 989         struct pcistub_device_id *pci_dev_id;
 990         unsigned long flags;
 991         int rc = 0, devfn = PCI_DEVFN(slot, func);
 992
 993         if (slot < 0) {
 994                 for (slot = 0; !rc && slot < 32; ++slot)
 995                         rc = pcistub_device_id_add(domain, bus, slot, func);
 996                 return rc;
 997         }
 998
 999         if (func < 0) {
1000                 for (func = 0; !rc && func < 8; ++func)
1001                         rc = pcistub_device_id_add(domain, bus, slot, func);
1002                 return rc;
1003         }
1004
1005         if ((
1006 #if !defined(MODULE) /* pci_domains_supported is not being exported */ \
1007     || !defined(CONFIG_PCI_DOMAINS)
1008              !pci_domains_supported ? domain :
1009 #endif
1010              domain < 0 || domain > 0xffff)
1011             || bus < 0 || bus > 0xff
1012             || PCI_SLOT(devfn) != slot
1013             || PCI_FUNC(devfn) != func)
1014                 return -EINVAL;
1015
1016         pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
1017         if (!pci_dev_id)
1018                 return -ENOMEM;
1019
1020         pci_dev_id->domain = domain;
1021         pci_dev_id->bus = bus;
1022         pci_dev_id->devfn = devfn;
1023
1024         pr_debug("wants to seize %04x:%02x:%02x.%d\n",
1025                  domain, bus, slot, func);
1026
1027         spin_lock_irqsave(&device_ids_lock, flags);
1028         list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
1029         spin_unlock_irqrestore(&device_ids_lock, flags);
1030
1031         return 0;
1032 }
1033
1034 static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
1035 {
1036         struct pcistub_device_id *pci_dev_id, *t;
1037         int err = -ENOENT;
1038         unsigned long flags;
1039
1040         spin_lock_irqsave(&device_ids_lock, flags);
1041         list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
1042                                  slot_list) {
1043                 if (pci_dev_id->domain == domain && pci_dev_id->bus == bus
1044                     && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot)
1045                     && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) {
1046                         /* Don't break; here because it's possible the same
1047                          * slot could be in the list more than once
1048                          */
1049                         list_del(&pci_dev_id->slot_list);
1050                         kfree(pci_dev_id);
1051
1052                         err = 0;
1053
1054                         pr_debug("removed %04x:%02x:%02x.%d from seize list\n",
1055                                  domain, bus, slot, func);
1056                 }
1057         }
1058         spin_unlock_irqrestore(&device_ids_lock, flags);
1059
1060         return err;
1061 }
1062
1063 static int pcistub_reg_add(int domain, int bus, int slot, int func,
1064                            unsigned int reg, unsigned int size,
1065                            unsigned int mask)
1066 {
1067         int err = 0;
1068         struct pcistub_device *psdev;
1069         struct pci_dev *dev;
1070         struct config_field *field;
1071
1072         if (reg > 0xfff || (size < 4 && (mask >> (size * 8))))
1073                 return -EINVAL;
1074
1075         psdev = pcistub_device_find(domain, bus, slot, func);
1076         if (!psdev) {
1077                 err = -ENODEV;
1078                 goto out;
1079         }
1080         dev = psdev->dev;
1081
1082         field = kzalloc(sizeof(*field), GFP_ATOMIC);
1083         if (!field) {
1084                 err = -ENOMEM;
1085                 goto out;
1086         }
1087
1088         field->offset = reg;
1089         field->size = size;
1090         field->mask = mask;
1091         field->init = NULL;
1092         field->reset = NULL;
1093         field->release = NULL;
1094         field->clean = xen_pcibk_config_field_free;
1095
1096         err = xen_pcibk_config_quirks_add_field(dev, field);
1097         if (err)
1098                 kfree(field);
1099 out:
1100         if (psdev)
1101                 pcistub_device_put(psdev);
1102         return err;
1103 }
1104
1105 static ssize_t pcistub_slot_add(struct device_driver *drv, const char *buf,
1106                                 size_t count)
1107 {
1108         int domain, bus, slot, func;
1109         int err;
1110
1111         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1112         if (err)
1113                 goto out;
1114
1115         err = pcistub_device_id_add(domain, bus, slot, func);
1116
1117 out:
1118         if (!err)
1119                 err = count;
1120         return err;
1121 }
1122 static DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
1123
1124 static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
1125                                    size_t count)
1126 {
1127         int domain, bus, slot, func;
1128         int err;
1129
1130         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1131         if (err)
1132                 goto out;
1133
1134         err = pcistub_device_id_remove(domain, bus, slot, func);
1135
1136 out:
1137         if (!err)
1138                 err = count;
1139         return err;
1140 }
1141 static DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
1142
1143 static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
1144 {
1145         struct pcistub_device_id *pci_dev_id;
1146         size_t count = 0;
1147         unsigned long flags;
1148
1149         spin_lock_irqsave(&device_ids_lock, flags);
1150         list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1151                 if (count >= PAGE_SIZE)
1152                         break;
1153
1154                 count += scnprintf(buf + count, PAGE_SIZE - count,
1155                                    "%04x:%02x:%02x.%d\n",
1156                                    pci_dev_id->domain, pci_dev_id->bus,
1157                                    PCI_SLOT(pci_dev_id->devfn),
1158                                    PCI_FUNC(pci_dev_id->devfn));
1159         }
1160         spin_unlock_irqrestore(&device_ids_lock, flags);
1161
1162         return count;
1163 }
1164 static DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
1165
1166 static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
1167 {
1168         struct pcistub_device *psdev;
1169         struct xen_pcibk_dev_data *dev_data;
1170         size_t count = 0;
1171         unsigned long flags;
1172
1173         spin_lock_irqsave(&pcistub_devices_lock, flags);
1174         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1175                 if (count >= PAGE_SIZE)
1176                         break;
1177                 if (!psdev->dev)
1178                         continue;
1179                 dev_data = pci_get_drvdata(psdev->dev);
1180                 if (!dev_data)
1181                         continue;
1182                 count +=
1183                     scnprintf(buf + count, PAGE_SIZE - count,
1184                               "%s:%s:%sing:%ld\n",
1185                               pci_name(psdev->dev),
1186                               dev_data->isr_on ? "on" : "off",
1187                               dev_data->ack_intr ? "ack" : "not ack",
1188                               dev_data->handled);
1189         }
1190         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1191         return count;
1192 }
1193 static DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
1194
1195 static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
1196                                           const char *buf,
1197                                           size_t count)
1198 {
1199         struct pcistub_device *psdev;
1200         struct xen_pcibk_dev_data *dev_data;
1201         int domain, bus, slot, func;
1202         int err;
1203
1204         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1205         if (err)
1206                 return err;
1207
1208         psdev = pcistub_device_find(domain, bus, slot, func);
1209         if (!psdev) {
1210                 err = -ENOENT;
1211                 goto out;
1212         }
1213
1214         dev_data = pci_get_drvdata(psdev->dev);
1215         if (!dev_data) {
1216                 err = -ENOENT;
1217                 goto out;
1218         }
1219
1220         dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1221                 dev_data->irq_name, dev_data->isr_on,
1222                 !dev_data->isr_on);
1223
1224         dev_data->isr_on = !(dev_data->isr_on);
1225         if (dev_data->isr_on)
1226                 dev_data->ack_intr = 1;
1227 out:
1228         if (psdev)
1229                 pcistub_device_put(psdev);
1230         if (!err)
1231                 err = count;
1232         return err;
1233 }
1234 static DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL,
1235                    pcistub_irq_handler_switch);
1236
1237 static ssize_t pcistub_quirk_add(struct device_driver *drv, const char *buf,
1238                                  size_t count)
1239 {
1240         int domain, bus, slot, func, reg, size, mask;
1241         int err;
1242
1243         err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1244                            &mask);
1245         if (err)
1246                 goto out;
1247
1248         err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1249
1250 out:
1251         if (!err)
1252                 err = count;
1253         return err;
1254 }
1255
1256 static ssize_t pcistub_quirk_show(struct device_driver *drv, char *buf)
1257 {
1258         int count = 0;
1259         unsigned long flags;
1260         struct xen_pcibk_config_quirk *quirk;
1261         struct xen_pcibk_dev_data *dev_data;
1262         const struct config_field *field;
1263         const struct config_field_entry *cfg_entry;
1264
1265         spin_lock_irqsave(&device_ids_lock, flags);
1266         list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1267                 if (count >= PAGE_SIZE)
1268                         goto out;
1269
1270                 count += scnprintf(buf + count, PAGE_SIZE - count,
1271                                    "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1272                                    quirk->pdev->bus->number,
1273                                    PCI_SLOT(quirk->pdev->devfn),
1274                                    PCI_FUNC(quirk->pdev->devfn),
1275                                    quirk->devid.vendor, quirk->devid.device,
1276                                    quirk->devid.subvendor,
1277                                    quirk->devid.subdevice);
1278
1279                 dev_data = pci_get_drvdata(quirk->pdev);
1280
1281                 list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1282                         field = cfg_entry->field;
1283                         if (count >= PAGE_SIZE)
1284                                 goto out;
1285
1286                         count += scnprintf(buf + count, PAGE_SIZE - count,
1287                                            "\t\t%08x:%01x:%08x\n",
1288                                            cfg_entry->base_offset +
1289                                            field->offset, field->size,
1290                                            field->mask);
1291                 }
1292         }
1293
1294 out:
1295         spin_unlock_irqrestore(&device_ids_lock, flags);
1296
1297         return count;
1298 }
1299 static DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show,
1300                    pcistub_quirk_add);
1301
1302 static ssize_t permissive_add(struct device_driver *drv, const char *buf,
1303                               size_t count)
1304 {
1305         int domain, bus, slot, func;
1306         int err;
1307         struct pcistub_device *psdev;
1308         struct xen_pcibk_dev_data *dev_data;
1309
1310         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1311         if (err)
1312                 goto out;
1313
1314         psdev = pcistub_device_find(domain, bus, slot, func);
1315         if (!psdev) {
1316                 err = -ENODEV;
1317                 goto out;
1318         }
1319
1320         dev_data = pci_get_drvdata(psdev->dev);
1321         /* the driver data for a device should never be null at this point */
1322         if (!dev_data) {
1323                 err = -ENXIO;
1324                 goto release;
1325         }
1326         if (!dev_data->permissive) {
1327                 dev_data->permissive = 1;
1328                 /* Let user know that what they're doing could be unsafe */
1329                 dev_warn(&psdev->dev->dev, "enabling permissive mode "
1330                          "configuration space accesses!\n");
1331                 dev_warn(&psdev->dev->dev,
1332                          "permissive mode is potentially unsafe!\n");
1333         }
1334 release:
1335         pcistub_device_put(psdev);
1336 out:
1337         if (!err)
1338                 err = count;
1339         return err;
1340 }
1341
1342 static ssize_t permissive_show(struct device_driver *drv, char *buf)
1343 {
1344         struct pcistub_device *psdev;
1345         struct xen_pcibk_dev_data *dev_data;
1346         size_t count = 0;
1347         unsigned long flags;
1348         spin_lock_irqsave(&pcistub_devices_lock, flags);
1349         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1350                 if (count >= PAGE_SIZE)
1351                         break;
1352                 if (!psdev->dev)
1353                         continue;
1354                 dev_data = pci_get_drvdata(psdev->dev);
1355                 if (!dev_data || !dev_data->permissive)
1356                         continue;
1357                 count +=
1358                     scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1359                               pci_name(psdev->dev));
1360         }
1361         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1362         return count;
1363 }
1364 static DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show,
1365                    permissive_add);
1366
1367 static void pcistub_exit(void)
1368 {
1369         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1370         driver_remove_file(&xen_pcibk_pci_driver.driver,
1371                            &driver_attr_remove_slot);
1372         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1373         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1374         driver_remove_file(&xen_pcibk_pci_driver.driver,
1375                            &driver_attr_permissive);
1376         driver_remove_file(&xen_pcibk_pci_driver.driver,
1377                            &driver_attr_irq_handlers);
1378         driver_remove_file(&xen_pcibk_pci_driver.driver,
1379                            &driver_attr_irq_handler_state);
1380         pci_unregister_driver(&xen_pcibk_pci_driver);
1381 }
1382
1383 static int __init pcistub_init(void)
1384 {
1385         int pos = 0;
1386         int err = 0;
1387         int domain, bus, slot, func;
1388         int parsed;
1389
1390         if (pci_devs_to_hide && *pci_devs_to_hide) {
1391                 do {
1392                         parsed = 0;
1393
1394                         err = sscanf(pci_devs_to_hide + pos,
1395                                      " (%x:%x:%x.%x) %n",
1396                                      &domain, &bus, &slot, &func, &parsed);
1397                         switch (err) {
1398                         case 3:
1399                                 func = -1;
1400                                 sscanf(pci_devs_to_hide + pos,
1401                                        " (%x:%x:%x.*) %n",
1402                                        &domain, &bus, &slot, &parsed);
1403                                 break;
1404                         case 2:
1405                                 slot = func = -1;
1406                                 sscanf(pci_devs_to_hide + pos,
1407                                        " (%x:%x:*.*) %n",
1408                                        &domain, &bus, &parsed);
1409                                 break;
1410                         }
1411
1412                         if (!parsed) {
1413                                 domain = 0;
1414                                 err = sscanf(pci_devs_to_hide + pos,
1415                                              " (%x:%x.%x) %n",
1416                                              &bus, &slot, &func, &parsed);
1417                                 switch (err) {
1418                                 case 2:
1419                                         func = -1;
1420                                         sscanf(pci_devs_to_hide + pos,
1421                                                " (%x:%x.*) %n",
1422                                                &bus, &slot, &parsed);
1423                                         break;
1424                                 case 1:
1425                                         slot = func = -1;
1426                                         sscanf(pci_devs_to_hide + pos,
1427                                                " (%x:*.*) %n",
1428                                                &bus, &parsed);
1429                                         break;
1430                                 }
1431                         }
1432
1433                         if (parsed <= 0)
1434                                 goto parse_error;
1435
1436                         err = pcistub_device_id_add(domain, bus, slot, func);
1437                         if (err)
1438                                 goto out;
1439
1440                         pos += parsed;
1441                 } while (pci_devs_to_hide[pos]);
1442         }
1443
1444         /* If we're the first PCI Device Driver to register, we're the
1445          * first one to get offered PCI devices as they become
1446          * available (and thus we can be the first to grab them)
1447          */
1448         err = pci_register_driver(&xen_pcibk_pci_driver);
1449         if (err < 0)
1450                 goto out;
1451
1452         err = driver_create_file(&xen_pcibk_pci_driver.driver,
1453                                  &driver_attr_new_slot);
1454         if (!err)
1455                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1456                                          &driver_attr_remove_slot);
1457         if (!err)
1458                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1459                                          &driver_attr_slots);
1460         if (!err)
1461                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1462                                          &driver_attr_quirks);
1463         if (!err)
1464                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1465                                          &driver_attr_permissive);
1466
1467         if (!err)
1468                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1469                                          &driver_attr_irq_handlers);
1470         if (!err)
1471                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1472                                         &driver_attr_irq_handler_state);
1473         if (err)
1474                 pcistub_exit();
1475
1476 out:
1477         return err;
1478
1479 parse_error:
1480         pr_err("Error parsing pci_devs_to_hide at \"%s\"\n",
1481                pci_devs_to_hide + pos);
1482         return -EINVAL;
1483 }
1484
1485 #ifndef MODULE
1486 /*
1487  * fs_initcall happens before device_initcall
1488  * so xen_pcibk *should* get called first (b/c we
1489  * want to suck up any device before other drivers
1490  * get a chance by being the first pci device
1491  * driver to register)
1492  */
1493 fs_initcall(pcistub_init);
1494 #endif
1495
1496 static int __init xen_pcibk_init(void)
1497 {
1498         int err;
1499
1500         if (!xen_initial_domain())
1501                 return -ENODEV;
1502
1503         err = xen_pcibk_config_init();
1504         if (err)
1505                 return err;
1506
1507 #ifdef MODULE
1508         err = pcistub_init();
1509         if (err < 0)
1510                 return err;
1511 #endif
1512
1513         pcistub_init_devices_late();
1514         err = xen_pcibk_xenbus_register();
1515         if (err)
1516                 pcistub_exit();
1517
1518         return err;
1519 }
1520
1521 static void __exit xen_pcibk_cleanup(void)
1522 {
1523         xen_pcibk_xenbus_unregister();
1524         pcistub_exit();
1525 }
1526
1527 module_init(xen_pcibk_init);
1528 module_exit(xen_pcibk_cleanup);
1529
1530 MODULE_LICENSE("Dual BSD/GPL");
1531 MODULE_ALIAS("xen-backend:pci");