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 #define dev_fmt pr_fmt
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/rwsem.h>
  14 #include <linux/list.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/kref.h>
  17 #include <linux/pci.h>
  18 #include <linux/wait.h>
  19 #include <linux/sched.h>
  20 #include <linux/atomic.h>
  21 #include <xen/events.h>
  22 #include <asm/xen/pci.h>
  23 #include <asm/xen/hypervisor.h>
  24 #include <xen/interface/physdev.h>
  25 #include "pciback.h"
  26 #include "conf_space.h"
  27 #include "conf_space_quirks.h"
  28
  29 #define PCISTUB_DRIVER_NAME "pciback"
  30
  31 static char *pci_devs_to_hide;
  32 wait_queue_head_t xen_pcibk_aer_wait_queue;
  33 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
  34 * We want to avoid in middle of AER ops, xen_pcibk devices is being removed
  35 */
  36 static DECLARE_RWSEM(pcistub_sem);
  37 module_param_named(hide, pci_devs_to_hide, charp, 0444);
  38
  39 struct pcistub_device_id {
  40         struct list_head slot_list;
  41         int domain;
  42         unsigned char bus;
  43         unsigned int devfn;
  44 };
  45 static LIST_HEAD(pcistub_device_ids);
  46 static DEFINE_SPINLOCK(device_ids_lock);
  47
  48 struct pcistub_device {
  49         struct kref kref;
  50         struct list_head dev_list;
  51         spinlock_t lock;
  52
  53         struct pci_dev *dev;
  54         struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */
  55 };
  56
  57 /* Access to pcistub_devices & seized_devices lists and the initialize_devices
  58  * flag must be locked with pcistub_devices_lock
  59  */
  60 static DEFINE_SPINLOCK(pcistub_devices_lock);
  61 static LIST_HEAD(pcistub_devices);
  62
  63 /* wait for device_initcall before initializing our devices
  64  * (see pcistub_init_devices_late)
  65  */
  66 static int initialize_devices;
  67 static LIST_HEAD(seized_devices);
  68
  69 static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
  70 {
  71         struct pcistub_device *psdev;
  72
  73         dev_dbg(&dev->dev, "pcistub_device_alloc\n");
  74
  75         psdev = kzalloc(sizeof(*psdev), GFP_KERNEL);
  76         if (!psdev)
  77                 return NULL;
  78
  79         psdev->dev = pci_dev_get(dev);
  80         if (!psdev->dev) {
  81                 kfree(psdev);
  82                 return NULL;
  83         }
  84
  85         kref_init(&psdev->kref);
  86         spin_lock_init(&psdev->lock);
  87
  88         return psdev;
  89 }
  90
  91 /* Don't call this directly as it's called by pcistub_device_put */
  92 static void pcistub_device_release(struct kref *kref)
  93 {
  94         struct pcistub_device *psdev;
  95         struct pci_dev *dev;
  96         struct xen_pcibk_dev_data *dev_data;
  97
  98         psdev = container_of(kref, struct pcistub_device, kref);
  99         dev = psdev->dev;
 100         dev_data = pci_get_drvdata(dev);
 101
 102         dev_dbg(&dev->dev, "pcistub_device_release\n");
 103
 104         xen_unregister_device_domain_owner(dev);
 105
 106         /* Call the reset function which does not take lock as this
 107          * is called from "unbind" which takes a device_lock mutex.
 108          */
 109         __pci_reset_function_locked(dev);
 110         if (dev_data &&
 111             pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state))
 112                 dev_info(&dev->dev, "Could not reload PCI state\n");
 113         else
 114                 pci_restore_state(dev);
 115
 116         if (dev->msix_cap) {
 117                 struct physdev_pci_device ppdev = {
 118                         .seg = pci_domain_nr(dev->bus),
 119                         .bus = dev->bus->number,
 120                         .devfn = dev->devfn
 121                 };
 122                 int err = HYPERVISOR_physdev_op(PHYSDEVOP_release_msix,
 123                                                 &ppdev);
 124
 125                 if (err && err != -ENOSYS)
 126                         dev_warn(&dev->dev, "MSI-X release failed (%d)\n",
 127                                  err);
 128         }
 129
 130         /* Disable the device */
 131         xen_pcibk_reset_device(dev);
 132
 133         kfree(dev_data);
 134         pci_set_drvdata(dev, NULL);
 135
 136         /* Clean-up the device */
 137         xen_pcibk_config_free_dyn_fields(dev);
 138         xen_pcibk_config_free_dev(dev);
 139
 140         pci_clear_dev_assigned(dev);
 141         pci_dev_put(dev);
 142
 143         kfree(psdev);
 144 }
 145
 146 static inline void pcistub_device_get(struct pcistub_device *psdev)
 147 {
 148         kref_get(&psdev->kref);
 149 }
 150
 151 static inline void pcistub_device_put(struct pcistub_device *psdev)
 152 {
 153         kref_put(&psdev->kref, pcistub_device_release);
 154 }
 155
 156 static struct pcistub_device *pcistub_device_find_locked(int domain, int bus,
 157                                                          int slot, int func)
 158 {
 159         struct pcistub_device *psdev;
 160
 161         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 162                 if (psdev->dev != NULL
 163                     && domain == pci_domain_nr(psdev->dev->bus)
 164                     && bus == psdev->dev->bus->number
 165                     && slot == PCI_SLOT(psdev->dev->devfn)
 166                     && func == PCI_FUNC(psdev->dev->devfn)) {
 167                         return psdev;
 168                 }
 169         }
 170
 171         return NULL;
 172 }
 173
 174 static struct pcistub_device *pcistub_device_find(int domain, int bus,
 175                                                   int slot, int func)
 176 {
 177         struct pcistub_device *psdev;
 178         unsigned long flags;
 179
 180         spin_lock_irqsave(&pcistub_devices_lock, flags);
 181
 182         psdev = pcistub_device_find_locked(domain, bus, slot, func);
 183         if (psdev)
 184                 pcistub_device_get(psdev);
 185
 186         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 187         return psdev;
 188 }
 189
 190 static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
 191                                                   struct pcistub_device *psdev)
 192 {
 193         struct pci_dev *pci_dev = NULL;
 194         unsigned long flags;
 195
 196         pcistub_device_get(psdev);
 197
 198         spin_lock_irqsave(&psdev->lock, flags);
 199         if (!psdev->pdev) {
 200                 psdev->pdev = pdev;
 201                 pci_dev = psdev->dev;
 202         }
 203         spin_unlock_irqrestore(&psdev->lock, flags);
 204
 205         if (!pci_dev)
 206                 pcistub_device_put(psdev);
 207
 208         return pci_dev;
 209 }
 210
 211 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 212                                             int domain, int bus,
 213                                             int slot, int func)
 214 {
 215         struct pcistub_device *psdev;
 216         struct pci_dev *found_dev = NULL;
 217         unsigned long flags;
 218
 219         spin_lock_irqsave(&pcistub_devices_lock, flags);
 220
 221         psdev = pcistub_device_find_locked(domain, bus, slot, func);
 222         if (psdev)
 223                 found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 224
 225         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 226         return found_dev;
 227 }
 228
 229 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 230                                     struct pci_dev *dev)
 231 {
 232         struct pcistub_device *psdev;
 233         struct pci_dev *found_dev = NULL;
 234         unsigned long flags;
 235
 236         spin_lock_irqsave(&pcistub_devices_lock, flags);
 237
 238         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 239                 if (psdev->dev == dev) {
 240                         found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 241                         break;
 242                 }
 243         }
 244
 245         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 246         return found_dev;
 247 }
 248
 249 /*
 250  * Called when:
 251  *  - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device
 252  *  - XenBus state has been disconnected (guest shutdown). See xen_pcibk_xenbus_remove
 253  *  - 'echo BDF > unbind' on pciback module with no guest attached. See pcistub_remove
 254  *  - 'echo BDF > unbind' with a guest still using it. See pcistub_remove
 255  *
 256  *  As such we have to be careful.
 257  *
 258  *  To make this easier, the caller has to hold the device lock.
 259  */
 260 void pcistub_put_pci_dev(struct pci_dev *dev)
 261 {
 262         struct pcistub_device *psdev, *found_psdev = NULL;
 263         unsigned long flags;
 264         struct xen_pcibk_dev_data *dev_data;
 265         int ret;
 266
 267         spin_lock_irqsave(&pcistub_devices_lock, flags);
 268
 269         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 270                 if (psdev->dev == dev) {
 271                         found_psdev = psdev;
 272                         break;
 273                 }
 274         }
 275
 276         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 277         if (WARN_ON(!found_psdev))
 278                 return;
 279
 280         /*hold this lock for avoiding breaking link between
 281         * pcistub and xen_pcibk when AER is in processing
 282         */
 283         down_write(&pcistub_sem);
 284         /* Cleanup our device
 285          * (so it's ready for the next domain)
 286          */
 287         device_lock_assert(&dev->dev);
 288         __pci_reset_function_locked(dev);
 289
 290         dev_data = pci_get_drvdata(dev);
 291         ret = pci_load_saved_state(dev, dev_data->pci_saved_state);
 292         if (!ret) {
 293                 /*
 294                  * The usual sequence is pci_save_state & pci_restore_state
 295                  * but the guest might have messed the configuration space up.
 296                  * Use the initial version (when device was bound to us).
 297                  */
 298                 pci_restore_state(dev);
 299         } else
 300                 dev_info(&dev->dev, "Could not reload PCI state\n");
 301         /* This disables the device. */
 302         xen_pcibk_reset_device(dev);
 303
 304         /* And cleanup up our emulated fields. */
 305         xen_pcibk_config_reset_dev(dev);
 306         xen_pcibk_config_free_dyn_fields(dev);
 307
 308         dev_data->allow_interrupt_control = 0;
 309
 310         xen_unregister_device_domain_owner(dev);
 311
 312         spin_lock_irqsave(&found_psdev->lock, flags);
 313         found_psdev->pdev = NULL;
 314         spin_unlock_irqrestore(&found_psdev->lock, flags);
 315
 316         pcistub_device_put(found_psdev);
 317         up_write(&pcistub_sem);
 318 }
 319
 320 static int pcistub_match_one(struct pci_dev *dev,
 321                              struct pcistub_device_id *pdev_id)
 322 {
 323         /* Match the specified device by domain, bus, slot, func and also if
 324          * any of the device's parent bridges match.
 325          */
 326         for (; dev != NULL; dev = dev->bus->self) {
 327                 if (pci_domain_nr(dev->bus) == pdev_id->domain
 328                     && dev->bus->number == pdev_id->bus
 329                     && dev->devfn == pdev_id->devfn)
 330                         return 1;
 331
 332                 /* Sometimes topmost bridge links to itself. */
 333                 if (dev == dev->bus->self)
 334                         break;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static int pcistub_match(struct pci_dev *dev)
 341 {
 342         struct pcistub_device_id *pdev_id;
 343         unsigned long flags;
 344         int found = 0;
 345
 346         spin_lock_irqsave(&device_ids_lock, flags);
 347         list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) {
 348                 if (pcistub_match_one(dev, pdev_id)) {
 349                         found = 1;
 350                         break;
 351                 }
 352         }
 353         spin_unlock_irqrestore(&device_ids_lock, flags);
 354
 355         return found;
 356 }
 357
 358 static int pcistub_init_device(struct pci_dev *dev)
 359 {
 360         struct xen_pcibk_dev_data *dev_data;
 361         int err = 0;
 362
 363         dev_dbg(&dev->dev, "initializing...\n");
 364
 365         /* The PCI backend is not intended to be a module (or to work with
 366          * removable PCI devices (yet). If it were, xen_pcibk_config_free()
 367          * would need to be called somewhere to free the memory allocated
 368          * here and then to call kfree(pci_get_drvdata(psdev->dev)).
 369          */
 370         dev_data = kzalloc(sizeof(*dev_data) +  strlen(DRV_NAME "[]")
 371                                 + strlen(pci_name(dev)) + 1, GFP_KERNEL);
 372         if (!dev_data) {
 373                 err = -ENOMEM;
 374                 goto out;
 375         }
 376         pci_set_drvdata(dev, dev_data);
 377
 378         /*
 379          * Setup name for fake IRQ handler. It will only be enabled
 380          * once the device is turned on by the guest.
 381          */
 382         sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev));
 383
 384         dev_dbg(&dev->dev, "initializing config\n");
 385
 386         init_waitqueue_head(&xen_pcibk_aer_wait_queue);
 387         err = xen_pcibk_config_init_dev(dev);
 388         if (err)
 389                 goto out;
 390
 391         /* HACK: Force device (& ACPI) to determine what IRQ it's on - we
 392          * must do this here because pcibios_enable_device may specify
 393          * the pci device's true irq (and possibly its other resources)
 394          * if they differ from what's in the configuration space.
 395          * This makes the assumption that the device's resources won't
 396          * change after this point (otherwise this code may break!)
 397          */
 398         dev_dbg(&dev->dev, "enabling device\n");
 399         err = pci_enable_device(dev);
 400         if (err)
 401                 goto config_release;
 402
 403         if (dev->msix_cap) {
 404                 struct physdev_pci_device ppdev = {
 405                         .seg = pci_domain_nr(dev->bus),
 406                         .bus = dev->bus->number,
 407                         .devfn = dev->devfn
 408                 };
 409
 410                 err = HYPERVISOR_physdev_op(PHYSDEVOP_prepare_msix, &ppdev);
 411                 if (err && err != -ENOSYS)
 412                         dev_err(&dev->dev, "MSI-X preparation failed (%d)\n",
 413                                 err);
 414         }
 415
 416         /* We need the device active to save the state. */
 417         dev_dbg(&dev->dev, "save state of device\n");
 418         pci_save_state(dev);
 419         dev_data->pci_saved_state = pci_store_saved_state(dev);
 420         if (!dev_data->pci_saved_state)
 421                 dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
 422         else {
 423                 dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n");
 424                 __pci_reset_function_locked(dev);
 425                 pci_restore_state(dev);
 426         }
 427         /* Now disable the device (this also ensures some private device
 428          * data is setup before we export)
 429          */
 430         dev_dbg(&dev->dev, "reset device\n");
 431         xen_pcibk_reset_device(dev);
 432
 433         pci_set_dev_assigned(dev);
 434         return 0;
 435
 436 config_release:
 437         xen_pcibk_config_free_dev(dev);
 438
 439 out:
 440         pci_set_drvdata(dev, NULL);
 441         kfree(dev_data);
 442         return err;
 443 }
 444
 445 /*
 446  * Because some initialization still happens on
 447  * devices during fs_initcall, we need to defer
 448  * full initialization of our devices until
 449  * device_initcall.
 450  */
 451 static int __init pcistub_init_devices_late(void)
 452 {
 453         struct pcistub_device *psdev;
 454         unsigned long flags;
 455         int err = 0;
 456
 457         spin_lock_irqsave(&pcistub_devices_lock, flags);
 458
 459         while (!list_empty(&seized_devices)) {
 460                 psdev = container_of(seized_devices.next,
 461                                      struct pcistub_device, dev_list);
 462                 list_del(&psdev->dev_list);
 463
 464                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 465
 466                 err = pcistub_init_device(psdev->dev);
 467                 if (err) {
 468                         dev_err(&psdev->dev->dev,
 469                                 "error %d initializing device\n", err);
 470                         kfree(psdev);
 471                         psdev = NULL;
 472                 }
 473
 474                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 475
 476                 if (psdev)
 477                         list_add_tail(&psdev->dev_list, &pcistub_devices);
 478         }
 479
 480         initialize_devices = 1;
 481
 482         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 483
 484         return 0;
 485 }
 486
 487 static void pcistub_device_id_add_list(struct pcistub_device_id *new,
 488                                        int domain, int bus, unsigned int devfn)
 489 {
 490         struct pcistub_device_id *pci_dev_id;
 491         unsigned long flags;
 492         int found = 0;
 493
 494         spin_lock_irqsave(&device_ids_lock, flags);
 495
 496         list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
 497                 if (pci_dev_id->domain == domain && pci_dev_id->bus == bus &&
 498                     pci_dev_id->devfn == devfn) {
 499                         found = 1;
 500                         break;
 501                 }
 502         }
 503
 504         if (!found) {
 505                 new->domain = domain;
 506                 new->bus = bus;
 507                 new->devfn = devfn;
 508                 list_add_tail(&new->slot_list, &pcistub_device_ids);
 509         }
 510
 511         spin_unlock_irqrestore(&device_ids_lock, flags);
 512
 513         if (found)
 514                 kfree(new);
 515 }
 516
 517 static int pcistub_seize(struct pci_dev *dev,
 518                          struct pcistub_device_id *pci_dev_id)
 519 {
 520         struct pcistub_device *psdev;
 521         unsigned long flags;
 522         int err = 0;
 523
 524         psdev = pcistub_device_alloc(dev);
 525         if (!psdev) {
 526                 kfree(pci_dev_id);
 527                 return -ENOMEM;
 528         }
 529
 530         spin_lock_irqsave(&pcistub_devices_lock, flags);
 531
 532         if (initialize_devices) {
 533                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 534
 535                 /* don't want irqs disabled when calling pcistub_init_device */
 536                 err = pcistub_init_device(psdev->dev);
 537
 538                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 539
 540                 if (!err)
 541                         list_add(&psdev->dev_list, &pcistub_devices);
 542         } else {
 543                 dev_dbg(&dev->dev, "deferring initialization\n");
 544                 list_add(&psdev->dev_list, &seized_devices);
 545         }
 546
 547         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 548
 549         if (err) {
 550                 kfree(pci_dev_id);
 551                 pcistub_device_put(psdev);
 552         } else if (pci_dev_id)
 553                 pcistub_device_id_add_list(pci_dev_id, pci_domain_nr(dev->bus),
 554                                            dev->bus->number, dev->devfn);
 555
 556         return err;
 557 }
 558
 559 /* Called when 'bind'. This means we must _NOT_ call pci_reset_function or
 560  * other functions that take the sysfs lock. */
 561 static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 562 {
 563         int err = 0, match;
 564         struct pcistub_device_id *pci_dev_id = NULL;
 565
 566         dev_dbg(&dev->dev, "probing...\n");
 567
 568         match = pcistub_match(dev);
 569
 570         if ((dev->driver_override &&
 571              !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) ||
 572             match) {
 573
 574                 if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
 575                     && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 576                         dev_err(&dev->dev, "can't export pci devices that "
 577                                 "don't have a normal (0) or bridge (1) "
 578                                 "header type!\n");
 579                         err = -ENODEV;
 580                         goto out;
 581                 }
 582
 583                 if (!match) {
 584                         pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
 585                         if (!pci_dev_id) {
 586                                 err = -ENOMEM;
 587                                 goto out;
 588                         }
 589                 }
 590
 591                 dev_info(&dev->dev, "seizing device\n");
 592                 err = pcistub_seize(dev, pci_dev_id);
 593         } else
 594                 /* Didn't find the device */
 595                 err = -ENODEV;
 596
 597 out:
 598         return err;
 599 }
 600
 601 /* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or
 602  * other functions that take the sysfs lock. */
 603 static void pcistub_remove(struct pci_dev *dev)
 604 {
 605         struct pcistub_device *psdev, *found_psdev = NULL;
 606         unsigned long flags;
 607
 608         dev_dbg(&dev->dev, "removing\n");
 609
 610         spin_lock_irqsave(&pcistub_devices_lock, flags);
 611
 612         xen_pcibk_config_quirk_release(dev);
 613
 614         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 615                 if (psdev->dev == dev) {
 616                         found_psdev = psdev;
 617                         break;
 618                 }
 619         }
 620
 621         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 622
 623         if (found_psdev) {
 624                 dev_dbg(&dev->dev, "found device to remove %s\n",
 625                         found_psdev->pdev ? "- in-use" : "");
 626
 627                 if (found_psdev->pdev) {
 628                         int domid = xen_find_device_domain_owner(dev);
 629
 630                         dev_warn(&dev->dev, "****** removing device %s while still in-use by domain %d! ******\n",
 631                                pci_name(found_psdev->dev), domid);
 632                         dev_warn(&dev->dev, "****** driver domain may still access this device's i/o resources!\n");
 633                         dev_warn(&dev->dev, "****** shutdown driver domain before binding device\n");
 634                         dev_warn(&dev->dev, "****** to other drivers or domains\n");
 635
 636                         /* N.B. This ends up calling pcistub_put_pci_dev which ends up
 637                          * doing the FLR. */
 638                         xen_pcibk_release_pci_dev(found_psdev->pdev,
 639                                                 found_psdev->dev,
 640                                                 false /* caller holds the lock. */);
 641                 }
 642
 643                 spin_lock_irqsave(&pcistub_devices_lock, flags);
 644                 list_del(&found_psdev->dev_list);
 645                 spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 646
 647                 /* the final put for releasing from the list */
 648                 pcistub_device_put(found_psdev);
 649         }
 650 }
 651
 652 static const struct pci_device_id pcistub_ids[] = {
 653         {
 654          .vendor = PCI_ANY_ID,
 655          .device = PCI_ANY_ID,
 656          .subvendor = PCI_ANY_ID,
 657          .subdevice = PCI_ANY_ID,
 658          },
 659         {0,},
 660 };
 661
 662 #define PCI_NODENAME_MAX 40
 663 static void kill_domain_by_device(struct pcistub_device *psdev)
 664 {
 665         struct xenbus_transaction xbt;
 666         int err;
 667         char nodename[PCI_NODENAME_MAX];
 668
 669         BUG_ON(!psdev);
 670         snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
 671                 psdev->pdev->xdev->otherend_id);
 672
 673 again:
 674         err = xenbus_transaction_start(&xbt);
 675         if (err) {
 676                 dev_err(&psdev->dev->dev,
 677                         "error %d when start xenbus transaction\n", err);
 678                 return;
 679         }
 680         /*PV AER handlers will set this flag*/
 681         xenbus_printf(xbt, nodename, "aerState" , "aerfail");
 682         err = xenbus_transaction_end(xbt, 0);
 683         if (err) {
 684                 if (err == -EAGAIN)
 685                         goto again;
 686                 dev_err(&psdev->dev->dev,
 687                         "error %d when end xenbus transaction\n", err);
 688                 return;
 689         }
 690 }
 691
 692 /* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
 693  * backend need to have cooperation. In xen_pcibk, those steps will do similar
 694  * jobs: send service request and waiting for front_end response.
 695 */
 696 static pci_ers_result_t common_process(struct pcistub_device *psdev,
 697                                        pci_channel_state_t state, int aer_cmd,
 698                                        pci_ers_result_t result)
 699 {
 700         pci_ers_result_t res = result;
 701         struct xen_pcie_aer_op *aer_op;
 702         struct xen_pcibk_device *pdev = psdev->pdev;
 703         struct xen_pci_sharedinfo *sh_info = pdev->sh_info;
 704         int ret;
 705
 706         /*with PV AER drivers*/
 707         aer_op = &(sh_info->aer_op);
 708         aer_op->cmd = aer_cmd ;
 709         /*useful for error_detected callback*/
 710         aer_op->err = state;
 711         /*pcifront_end BDF*/
 712         ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
 713                 &aer_op->domain, &aer_op->bus, &aer_op->devfn);
 714         if (!ret) {
 715                 dev_err(&psdev->dev->dev, "failed to get pcifront device\n");
 716                 return PCI_ERS_RESULT_NONE;
 717         }
 718         wmb();
 719
 720         dev_dbg(&psdev->dev->dev, "aer_op %x dom %x bus %x devfn %x\n",
 721                         aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
 722         /*local flag to mark there's aer request, xen_pcibk callback will use
 723         * this flag to judge whether we need to check pci-front give aer
 724         * service ack signal
 725         */
 726         set_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
 727
 728         /*It is possible that a pcifront conf_read_write ops request invokes
 729         * the callback which cause the spurious execution of wake_up.
 730         * Yet it is harmless and better than a spinlock here
 731         */
 732         set_bit(_XEN_PCIB_active,
 733                 (unsigned long *)&sh_info->flags);
 734         wmb();
 735         notify_remote_via_irq(pdev->evtchn_irq);
 736
 737         /* Enable IRQ to signal "request done". */
 738         xen_pcibk_lateeoi(pdev, 0);
 739
 740         ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
 741                                  !(test_bit(_XEN_PCIB_active, (unsigned long *)
 742                                  &sh_info->flags)), 300*HZ);
 743
 744         /* Enable IRQ for pcifront request if not already active. */
 745         if (!test_bit(_PDEVF_op_active, &pdev->flags))
 746                 xen_pcibk_lateeoi(pdev, 0);
 747
 748         if (!ret) {
 749                 if (test_bit(_XEN_PCIB_active,
 750                         (unsigned long *)&sh_info->flags)) {
 751                         dev_err(&psdev->dev->dev,
 752                                 "pcifront aer process not responding!\n");
 753                         clear_bit(_XEN_PCIB_active,
 754                           (unsigned long *)&sh_info->flags);
 755                         aer_op->err = PCI_ERS_RESULT_NONE;
 756                         return res;
 757                 }
 758         }
 759         clear_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
 760
 761         res = (pci_ers_result_t)aer_op->err;
 762         return res;
 763 }
 764
 765 /*
 766 * xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
 767 * of the device driver could provide this service, and then wait for pcifront
 768 * ack.
 769 * @dev: pointer to PCI devices
 770 * return value is used by aer_core do_recovery policy
 771 */
 772 static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
 773 {
 774         struct pcistub_device *psdev;
 775         pci_ers_result_t result;
 776
 777         result = PCI_ERS_RESULT_RECOVERED;
 778         dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
 779                 dev->bus->number, dev->devfn);
 780
 781         down_write(&pcistub_sem);
 782         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 783                                 dev->bus->number,
 784                                 PCI_SLOT(dev->devfn),
 785                                 PCI_FUNC(dev->devfn));
 786
 787         if (!psdev || !psdev->pdev) {
 788                 dev_err(&dev->dev, "device is not found/assigned\n");
 789                 goto end;
 790         }
 791
 792         if (!psdev->pdev->sh_info) {
 793                 dev_err(&dev->dev, "device is not connected or owned"
 794                         " by HVM, kill it\n");
 795                 kill_domain_by_device(psdev);
 796                 goto end;
 797         }
 798
 799         if (!test_bit(_XEN_PCIB_AERHANDLER,
 800                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 801                 dev_err(&dev->dev,
 802                         "guest with no AER driver should have been killed\n");
 803                 goto end;
 804         }
 805         result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
 806
 807         if (result == PCI_ERS_RESULT_NONE ||
 808                 result == PCI_ERS_RESULT_DISCONNECT) {
 809                 dev_dbg(&dev->dev,
 810                         "No AER slot_reset service or disconnected!\n");
 811                 kill_domain_by_device(psdev);
 812         }
 813 end:
 814         if (psdev)
 815                 pcistub_device_put(psdev);
 816         up_write(&pcistub_sem);
 817         return result;
 818
 819 }
 820
 821
 822 /*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
 823 * in case of the device driver could provide this service, and then wait
 824 * for pcifront ack
 825 * @dev: pointer to PCI devices
 826 * return value is used by aer_core do_recovery policy
 827 */
 828
 829 static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
 830 {
 831         struct pcistub_device *psdev;
 832         pci_ers_result_t result;
 833
 834         result = PCI_ERS_RESULT_RECOVERED;
 835         dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(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, "device is not found/assigned\n");
 846                 goto end;
 847         }
 848
 849         if (!psdev->pdev->sh_info) {
 850                 dev_err(&dev->dev, "device is not connected or owned"
 851                         " by HVM, kill it\n");
 852                 kill_domain_by_device(psdev);
 853                 goto end;
 854         }
 855
 856         if (!test_bit(_XEN_PCIB_AERHANDLER,
 857                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 858                 dev_err(&dev->dev,
 859                         "guest with no AER driver should have been killed\n");
 860                 goto end;
 861         }
 862         result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
 863
 864         if (result == PCI_ERS_RESULT_NONE ||
 865                 result == PCI_ERS_RESULT_DISCONNECT) {
 866                 dev_dbg(&dev->dev,
 867                         "No AER mmio_enabled service or disconnected!\n");
 868                 kill_domain_by_device(psdev);
 869         }
 870 end:
 871         if (psdev)
 872                 pcistub_device_put(psdev);
 873         up_write(&pcistub_sem);
 874         return result;
 875 }
 876
 877 /*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
 878 * in case of the device driver could provide this service, and then wait
 879 * for pcifront ack.
 880 * @dev: pointer to PCI devices
 881 * @error: the current PCI connection state
 882 * return value is used by aer_core do_recovery policy
 883 */
 884
 885 static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
 886         pci_channel_state_t error)
 887 {
 888         struct pcistub_device *psdev;
 889         pci_ers_result_t result;
 890
 891         result = PCI_ERS_RESULT_CAN_RECOVER;
 892         dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
 893                 dev->bus->number, dev->devfn);
 894
 895         down_write(&pcistub_sem);
 896         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 897                                 dev->bus->number,
 898                                 PCI_SLOT(dev->devfn),
 899                                 PCI_FUNC(dev->devfn));
 900
 901         if (!psdev || !psdev->pdev) {
 902                 dev_err(&dev->dev, "device is not found/assigned\n");
 903                 goto end;
 904         }
 905
 906         if (!psdev->pdev->sh_info) {
 907                 dev_err(&dev->dev, "device is not connected or owned"
 908                         " by HVM, kill it\n");
 909                 kill_domain_by_device(psdev);
 910                 goto end;
 911         }
 912
 913         /*Guest owns the device yet no aer handler regiested, kill guest*/
 914         if (!test_bit(_XEN_PCIB_AERHANDLER,
 915                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 916                 dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
 917                 kill_domain_by_device(psdev);
 918                 goto end;
 919         }
 920         result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
 921
 922         if (result == PCI_ERS_RESULT_NONE ||
 923                 result == PCI_ERS_RESULT_DISCONNECT) {
 924                 dev_dbg(&dev->dev,
 925                         "No AER error_detected service or disconnected!\n");
 926                 kill_domain_by_device(psdev);
 927         }
 928 end:
 929         if (psdev)
 930                 pcistub_device_put(psdev);
 931         up_write(&pcistub_sem);
 932         return result;
 933 }
 934
 935 /*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
 936 * in case of the device driver could provide this service, and then wait
 937 * for pcifront ack.
 938 * @dev: pointer to PCI devices
 939 */
 940
 941 static void xen_pcibk_error_resume(struct pci_dev *dev)
 942 {
 943         struct pcistub_device *psdev;
 944
 945         dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
 946                 dev->bus->number, dev->devfn);
 947
 948         down_write(&pcistub_sem);
 949         psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 950                                 dev->bus->number,
 951                                 PCI_SLOT(dev->devfn),
 952                                 PCI_FUNC(dev->devfn));
 953
 954         if (!psdev || !psdev->pdev) {
 955                 dev_err(&dev->dev, "device is not found/assigned\n");
 956                 goto end;
 957         }
 958
 959         if (!psdev->pdev->sh_info) {
 960                 dev_err(&dev->dev, "device is not connected or owned"
 961                         " by HVM, kill it\n");
 962                 kill_domain_by_device(psdev);
 963                 goto end;
 964         }
 965
 966         if (!test_bit(_XEN_PCIB_AERHANDLER,
 967                 (unsigned long *)&psdev->pdev->sh_info->flags)) {
 968                 dev_err(&dev->dev,
 969                         "guest with no AER driver should have been killed\n");
 970                 kill_domain_by_device(psdev);
 971                 goto end;
 972         }
 973         common_process(psdev, 1, XEN_PCI_OP_aer_resume,
 974                        PCI_ERS_RESULT_RECOVERED);
 975 end:
 976         if (psdev)
 977                 pcistub_device_put(psdev);
 978         up_write(&pcistub_sem);
 979         return;
 980 }
 981
 982 /*add xen_pcibk AER handling*/
 983 static const struct pci_error_handlers xen_pcibk_error_handler = {
 984         .error_detected = xen_pcibk_error_detected,
 985         .mmio_enabled = xen_pcibk_mmio_enabled,
 986         .slot_reset = xen_pcibk_slot_reset,
 987         .resume = xen_pcibk_error_resume,
 988 };
 989
 990 /*
 991  * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
 992  * for a normal device. I don't want it to be loaded automatically.
 993  */
 994
 995 static struct pci_driver xen_pcibk_pci_driver = {
 996         /* The name should be xen_pciback, but until the tools are updated
 997          * we will keep it as pciback. */
 998         .name = PCISTUB_DRIVER_NAME,
 999         .id_table = pcistub_ids,
1000         .probe = pcistub_probe,
1001         .remove = pcistub_remove,
1002         .err_handler = &xen_pcibk_error_handler,
1003 };
1004
1005 static inline int str_to_slot(const char *buf, int *domain, int *bus,
1006                               int *slot, int *func)
1007 {
1008         int parsed = 0;
1009
1010         switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func,
1011                        &parsed)) {
1012         case 3:
1013                 *func = -1;
1014                 sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed);
1015                 break;
1016         case 2:
1017                 *slot = *func = -1;
1018                 sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed);
1019                 break;
1020         }
1021         if (parsed && !buf[parsed])
1022                 return 0;
1023
1024         /* try again without domain */
1025         *domain = 0;
1026         switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) {
1027         case 2:
1028                 *func = -1;
1029                 sscanf(buf, " %x:%x.* %n", bus, slot, &parsed);
1030                 break;
1031         case 1:
1032                 *slot = *func = -1;
1033                 sscanf(buf, " %x:*.* %n", bus, &parsed);
1034                 break;
1035         }
1036         if (parsed && !buf[parsed])
1037                 return 0;
1038
1039         return -EINVAL;
1040 }
1041
1042 static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
1043                                *slot, int *func, int *reg, int *size, int *mask)
1044 {
1045         int parsed = 0;
1046
1047         sscanf(buf, " %x:%x:%x.%x-%x:%x:%x %n", domain, bus, slot, func,
1048                reg, size, mask, &parsed);
1049         if (parsed && !buf[parsed])
1050                 return 0;
1051
1052         /* try again without domain */
1053         *domain = 0;
1054         sscanf(buf, " %x:%x.%x-%x:%x:%x %n", bus, slot, func, reg, size,
1055                mask, &parsed);
1056         if (parsed && !buf[parsed])
1057                 return 0;
1058
1059         return -EINVAL;
1060 }
1061
1062 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
1063 {
1064         struct pcistub_device_id *pci_dev_id;
1065         int rc = 0, devfn = PCI_DEVFN(slot, func);
1066
1067         if (slot < 0) {
1068                 for (slot = 0; !rc && slot < 32; ++slot)
1069                         rc = pcistub_device_id_add(domain, bus, slot, func);
1070                 return rc;
1071         }
1072
1073         if (func < 0) {
1074                 for (func = 0; !rc && func < 8; ++func)
1075                         rc = pcistub_device_id_add(domain, bus, slot, func);
1076                 return rc;
1077         }
1078
1079         if ((
1080 #if !defined(MODULE) /* pci_domains_supported is not being exported */ \
1081     || !defined(CONFIG_PCI_DOMAINS)
1082              !pci_domains_supported ? domain :
1083 #endif
1084              domain < 0 || domain > 0xffff)
1085             || bus < 0 || bus > 0xff
1086             || PCI_SLOT(devfn) != slot
1087             || PCI_FUNC(devfn) != func)
1088                 return -EINVAL;
1089
1090         pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
1091         if (!pci_dev_id)
1092                 return -ENOMEM;
1093
1094         pr_debug("wants to seize %04x:%02x:%02x.%d\n",
1095                  domain, bus, slot, func);
1096
1097         pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn);
1098
1099         return 0;
1100 }
1101
1102 static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
1103 {
1104         struct pcistub_device_id *pci_dev_id, *t;
1105         int err = -ENOENT;
1106         unsigned long flags;
1107
1108         spin_lock_irqsave(&device_ids_lock, flags);
1109         list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
1110                                  slot_list) {
1111                 if (pci_dev_id->domain == domain && pci_dev_id->bus == bus
1112                     && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot)
1113                     && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) {
1114                         /* Don't break; here because it's possible the same
1115                          * slot could be in the list more than once
1116                          */
1117                         list_del(&pci_dev_id->slot_list);
1118                         kfree(pci_dev_id);
1119
1120                         err = 0;
1121
1122                         pr_debug("removed %04x:%02x:%02x.%d from seize list\n",
1123                                  domain, bus, slot, func);
1124                 }
1125         }
1126         spin_unlock_irqrestore(&device_ids_lock, flags);
1127
1128         return err;
1129 }
1130
1131 static int pcistub_reg_add(int domain, int bus, int slot, int func,
1132                            unsigned int reg, unsigned int size,
1133                            unsigned int mask)
1134 {
1135         int err = 0;
1136         struct pcistub_device *psdev;
1137         struct pci_dev *dev;
1138         struct config_field *field;
1139
1140         if (reg > 0xfff || (size < 4 && (mask >> (size * 8))))
1141                 return -EINVAL;
1142
1143         psdev = pcistub_device_find(domain, bus, slot, func);
1144         if (!psdev) {
1145                 err = -ENODEV;
1146                 goto out;
1147         }
1148         dev = psdev->dev;
1149
1150         field = kzalloc(sizeof(*field), GFP_KERNEL);
1151         if (!field) {
1152                 err = -ENOMEM;
1153                 goto out;
1154         }
1155
1156         field->offset = reg;
1157         field->size = size;
1158         field->mask = mask;
1159         field->init = NULL;
1160         field->reset = NULL;
1161         field->release = NULL;
1162         field->clean = xen_pcibk_config_field_free;
1163
1164         err = xen_pcibk_config_quirks_add_field(dev, field);
1165         if (err)
1166                 kfree(field);
1167 out:
1168         if (psdev)
1169                 pcistub_device_put(psdev);
1170         return err;
1171 }
1172
1173 static ssize_t new_slot_store(struct device_driver *drv, const char *buf,
1174                               size_t count)
1175 {
1176         int domain, bus, slot, func;
1177         int err;
1178
1179         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1180         if (err)
1181                 goto out;
1182
1183         err = pcistub_device_id_add(domain, bus, slot, func);
1184
1185 out:
1186         if (!err)
1187                 err = count;
1188         return err;
1189 }
1190 static DRIVER_ATTR_WO(new_slot);
1191
1192 static ssize_t remove_slot_store(struct device_driver *drv, const char *buf,
1193                                  size_t count)
1194 {
1195         int domain, bus, slot, func;
1196         int err;
1197
1198         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1199         if (err)
1200                 goto out;
1201
1202         err = pcistub_device_id_remove(domain, bus, slot, func);
1203
1204 out:
1205         if (!err)
1206                 err = count;
1207         return err;
1208 }
1209 static DRIVER_ATTR_WO(remove_slot);
1210
1211 static ssize_t slots_show(struct device_driver *drv, char *buf)
1212 {
1213         struct pcistub_device_id *pci_dev_id;
1214         size_t count = 0;
1215         unsigned long flags;
1216
1217         spin_lock_irqsave(&device_ids_lock, flags);
1218         list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1219                 if (count >= PAGE_SIZE)
1220                         break;
1221
1222                 count += scnprintf(buf + count, PAGE_SIZE - count,
1223                                    "%04x:%02x:%02x.%d\n",
1224                                    pci_dev_id->domain, pci_dev_id->bus,
1225                                    PCI_SLOT(pci_dev_id->devfn),
1226                                    PCI_FUNC(pci_dev_id->devfn));
1227         }
1228         spin_unlock_irqrestore(&device_ids_lock, flags);
1229
1230         return count;
1231 }
1232 static DRIVER_ATTR_RO(slots);
1233
1234 static ssize_t irq_handlers_show(struct device_driver *drv, char *buf)
1235 {
1236         struct pcistub_device *psdev;
1237         struct xen_pcibk_dev_data *dev_data;
1238         size_t count = 0;
1239         unsigned long flags;
1240
1241         spin_lock_irqsave(&pcistub_devices_lock, flags);
1242         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1243                 if (count >= PAGE_SIZE)
1244                         break;
1245                 if (!psdev->dev)
1246                         continue;
1247                 dev_data = pci_get_drvdata(psdev->dev);
1248                 if (!dev_data)
1249                         continue;
1250                 count +=
1251                     scnprintf(buf + count, PAGE_SIZE - count,
1252                               "%s:%s:%sing:%ld\n",
1253                               pci_name(psdev->dev),
1254                               dev_data->isr_on ? "on" : "off",
1255                               dev_data->ack_intr ? "ack" : "not ack",
1256                               dev_data->handled);
1257         }
1258         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1259         return count;
1260 }
1261 static DRIVER_ATTR_RO(irq_handlers);
1262
1263 static ssize_t irq_handler_state_store(struct device_driver *drv,
1264                                        const char *buf, size_t count)
1265 {
1266         struct pcistub_device *psdev;
1267         struct xen_pcibk_dev_data *dev_data;
1268         int domain, bus, slot, func;
1269         int err;
1270
1271         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1272         if (err)
1273                 return err;
1274
1275         psdev = pcistub_device_find(domain, bus, slot, func);
1276         if (!psdev) {
1277                 err = -ENOENT;
1278                 goto out;
1279         }
1280
1281         dev_data = pci_get_drvdata(psdev->dev);
1282         if (!dev_data) {
1283                 err = -ENOENT;
1284                 goto out;
1285         }
1286
1287         dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1288                 dev_data->irq_name, dev_data->isr_on,
1289                 !dev_data->isr_on);
1290
1291         dev_data->isr_on = !(dev_data->isr_on);
1292         if (dev_data->isr_on)
1293                 dev_data->ack_intr = 1;
1294 out:
1295         if (psdev)
1296                 pcistub_device_put(psdev);
1297         if (!err)
1298                 err = count;
1299         return err;
1300 }
1301 static DRIVER_ATTR_WO(irq_handler_state);
1302
1303 static ssize_t quirks_store(struct device_driver *drv, const char *buf,
1304                             size_t count)
1305 {
1306         int domain, bus, slot, func, reg, size, mask;
1307         int err;
1308
1309         err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1310                            &mask);
1311         if (err)
1312                 goto out;
1313
1314         err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1315
1316 out:
1317         if (!err)
1318                 err = count;
1319         return err;
1320 }
1321
1322 static ssize_t quirks_show(struct device_driver *drv, char *buf)
1323 {
1324         int count = 0;
1325         unsigned long flags;
1326         struct xen_pcibk_config_quirk *quirk;
1327         struct xen_pcibk_dev_data *dev_data;
1328         const struct config_field *field;
1329         const struct config_field_entry *cfg_entry;
1330
1331         spin_lock_irqsave(&device_ids_lock, flags);
1332         list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1333                 if (count >= PAGE_SIZE)
1334                         goto out;
1335
1336                 count += scnprintf(buf + count, PAGE_SIZE - count,
1337                                    "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1338                                    quirk->pdev->bus->number,
1339                                    PCI_SLOT(quirk->pdev->devfn),
1340                                    PCI_FUNC(quirk->pdev->devfn),
1341                                    quirk->devid.vendor, quirk->devid.device,
1342                                    quirk->devid.subvendor,
1343                                    quirk->devid.subdevice);
1344
1345                 dev_data = pci_get_drvdata(quirk->pdev);
1346
1347                 list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1348                         field = cfg_entry->field;
1349                         if (count >= PAGE_SIZE)
1350                                 goto out;
1351
1352                         count += scnprintf(buf + count, PAGE_SIZE - count,
1353                                            "\t\t%08x:%01x:%08x\n",
1354                                            cfg_entry->base_offset +
1355                                            field->offset, field->size,
1356                                            field->mask);
1357                 }
1358         }
1359
1360 out:
1361         spin_unlock_irqrestore(&device_ids_lock, flags);
1362
1363         return count;
1364 }
1365 static DRIVER_ATTR_RW(quirks);
1366
1367 static ssize_t permissive_store(struct device_driver *drv, const char *buf,
1368                                 size_t count)
1369 {
1370         int domain, bus, slot, func;
1371         int err;
1372         struct pcistub_device *psdev;
1373         struct xen_pcibk_dev_data *dev_data;
1374
1375         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1376         if (err)
1377                 goto out;
1378
1379         psdev = pcistub_device_find(domain, bus, slot, func);
1380         if (!psdev) {
1381                 err = -ENODEV;
1382                 goto out;
1383         }
1384
1385         dev_data = pci_get_drvdata(psdev->dev);
1386         /* the driver data for a device should never be null at this point */
1387         if (!dev_data) {
1388                 err = -ENXIO;
1389                 goto release;
1390         }
1391         if (!dev_data->permissive) {
1392                 dev_data->permissive = 1;
1393                 /* Let user know that what they're doing could be unsafe */
1394                 dev_warn(&psdev->dev->dev, "enabling permissive mode "
1395                          "configuration space accesses!\n");
1396                 dev_warn(&psdev->dev->dev,
1397                          "permissive mode is potentially unsafe!\n");
1398         }
1399 release:
1400         pcistub_device_put(psdev);
1401 out:
1402         if (!err)
1403                 err = count;
1404         return err;
1405 }
1406
1407 static ssize_t permissive_show(struct device_driver *drv, char *buf)
1408 {
1409         struct pcistub_device *psdev;
1410         struct xen_pcibk_dev_data *dev_data;
1411         size_t count = 0;
1412         unsigned long flags;
1413         spin_lock_irqsave(&pcistub_devices_lock, flags);
1414         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1415                 if (count >= PAGE_SIZE)
1416                         break;
1417                 if (!psdev->dev)
1418                         continue;
1419                 dev_data = pci_get_drvdata(psdev->dev);
1420                 if (!dev_data || !dev_data->permissive)
1421                         continue;
1422                 count +=
1423                     scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1424                               pci_name(psdev->dev));
1425         }
1426         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1427         return count;
1428 }
1429 static DRIVER_ATTR_RW(permissive);
1430
1431 static ssize_t allow_interrupt_control_store(struct device_driver *drv,
1432                                              const char *buf, size_t count)
1433 {
1434         int domain, bus, slot, func;
1435         int err;
1436         struct pcistub_device *psdev;
1437         struct xen_pcibk_dev_data *dev_data;
1438
1439         err = str_to_slot(buf, &domain, &bus, &slot, &func);
1440         if (err)
1441                 goto out;
1442
1443         psdev = pcistub_device_find(domain, bus, slot, func);
1444         if (!psdev) {
1445                 err = -ENODEV;
1446                 goto out;
1447         }
1448
1449         dev_data = pci_get_drvdata(psdev->dev);
1450         /* the driver data for a device should never be null at this point */
1451         if (!dev_data) {
1452                 err = -ENXIO;
1453                 goto release;
1454         }
1455         dev_data->allow_interrupt_control = 1;
1456 release:
1457         pcistub_device_put(psdev);
1458 out:
1459         if (!err)
1460                 err = count;
1461         return err;
1462 }
1463
1464 static ssize_t allow_interrupt_control_show(struct device_driver *drv,
1465                                             char *buf)
1466 {
1467         struct pcistub_device *psdev;
1468         struct xen_pcibk_dev_data *dev_data;
1469         size_t count = 0;
1470         unsigned long flags;
1471
1472         spin_lock_irqsave(&pcistub_devices_lock, flags);
1473         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1474                 if (count >= PAGE_SIZE)
1475                         break;
1476                 if (!psdev->dev)
1477                         continue;
1478                 dev_data = pci_get_drvdata(psdev->dev);
1479                 if (!dev_data || !dev_data->allow_interrupt_control)
1480                         continue;
1481                 count +=
1482                     scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1483                               pci_name(psdev->dev));
1484         }
1485         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1486         return count;
1487 }
1488 static DRIVER_ATTR_RW(allow_interrupt_control);
1489
1490 static void pcistub_exit(void)
1491 {
1492         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1493         driver_remove_file(&xen_pcibk_pci_driver.driver,
1494                            &driver_attr_remove_slot);
1495         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1496         driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1497         driver_remove_file(&xen_pcibk_pci_driver.driver,
1498                            &driver_attr_permissive);
1499         driver_remove_file(&xen_pcibk_pci_driver.driver,
1500                            &driver_attr_allow_interrupt_control);
1501         driver_remove_file(&xen_pcibk_pci_driver.driver,
1502                            &driver_attr_irq_handlers);
1503         driver_remove_file(&xen_pcibk_pci_driver.driver,
1504                            &driver_attr_irq_handler_state);
1505         pci_unregister_driver(&xen_pcibk_pci_driver);
1506 }
1507
1508 static int __init pcistub_init(void)
1509 {
1510         int pos = 0;
1511         int err = 0;
1512         int domain, bus, slot, func;
1513         int parsed;
1514
1515         if (pci_devs_to_hide && *pci_devs_to_hide) {
1516                 do {
1517                         parsed = 0;
1518
1519                         err = sscanf(pci_devs_to_hide + pos,
1520                                      " (%x:%x:%x.%x) %n",
1521                                      &domain, &bus, &slot, &func, &parsed);
1522                         switch (err) {
1523                         case 3:
1524                                 func = -1;
1525                                 sscanf(pci_devs_to_hide + pos,
1526                                        " (%x:%x:%x.*) %n",
1527                                        &domain, &bus, &slot, &parsed);
1528                                 break;
1529                         case 2:
1530                                 slot = func = -1;
1531                                 sscanf(pci_devs_to_hide + pos,
1532                                        " (%x:%x:*.*) %n",
1533                                        &domain, &bus, &parsed);
1534                                 break;
1535                         }
1536
1537                         if (!parsed) {
1538                                 domain = 0;
1539                                 err = sscanf(pci_devs_to_hide + pos,
1540                                              " (%x:%x.%x) %n",
1541                                              &bus, &slot, &func, &parsed);
1542                                 switch (err) {
1543                                 case 2:
1544                                         func = -1;
1545                                         sscanf(pci_devs_to_hide + pos,
1546                                                " (%x:%x.*) %n",
1547                                                &bus, &slot, &parsed);
1548                                         break;
1549                                 case 1:
1550                                         slot = func = -1;
1551                                         sscanf(pci_devs_to_hide + pos,
1552                                                " (%x:*.*) %n",
1553                                                &bus, &parsed);
1554                                         break;
1555                                 }
1556                         }
1557
1558                         if (parsed <= 0)
1559                                 goto parse_error;
1560
1561                         err = pcistub_device_id_add(domain, bus, slot, func);
1562                         if (err)
1563                                 goto out;
1564
1565                         pos += parsed;
1566                 } while (pci_devs_to_hide[pos]);
1567         }
1568
1569         /* If we're the first PCI Device Driver to register, we're the
1570          * first one to get offered PCI devices as they become
1571          * available (and thus we can be the first to grab them)
1572          */
1573         err = pci_register_driver(&xen_pcibk_pci_driver);
1574         if (err < 0)
1575                 goto out;
1576
1577         err = driver_create_file(&xen_pcibk_pci_driver.driver,
1578                                  &driver_attr_new_slot);
1579         if (!err)
1580                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1581                                          &driver_attr_remove_slot);
1582         if (!err)
1583                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1584                                          &driver_attr_slots);
1585         if (!err)
1586                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1587                                          &driver_attr_quirks);
1588         if (!err)
1589                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1590                                          &driver_attr_permissive);
1591         if (!err)
1592                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1593                                          &driver_attr_allow_interrupt_control);
1594
1595         if (!err)
1596                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1597                                          &driver_attr_irq_handlers);
1598         if (!err)
1599                 err = driver_create_file(&xen_pcibk_pci_driver.driver,
1600                                         &driver_attr_irq_handler_state);
1601         if (err)
1602                 pcistub_exit();
1603
1604 out:
1605         return err;
1606
1607 parse_error:
1608         pr_err("Error parsing pci_devs_to_hide at \"%s\"\n",
1609                pci_devs_to_hide + pos);
1610         return -EINVAL;
1611 }
1612
1613 #ifndef MODULE
1614 /*
1615  * fs_initcall happens before device_initcall
1616  * so xen_pcibk *should* get called first (b/c we
1617  * want to suck up any device before other drivers
1618  * get a chance by being the first pci device
1619  * driver to register)
1620  */
1621 fs_initcall(pcistub_init);
1622 #endif
1623
1624 #ifdef CONFIG_PCI_IOV
1625 static struct pcistub_device *find_vfs(const struct pci_dev *pdev)
1626 {
1627         struct pcistub_device *psdev = NULL;
1628         unsigned long flags;
1629         bool found = false;
1630
1631         spin_lock_irqsave(&pcistub_devices_lock, flags);
1632         list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1633                 if (!psdev->pdev && psdev->dev != pdev
1634                     && pci_physfn(psdev->dev) == pdev) {
1635                         found = true;
1636                         break;
1637                 }
1638         }
1639         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1640         if (found)
1641                 return psdev;
1642         return NULL;
1643 }
1644
1645 static int pci_stub_notifier(struct notifier_block *nb,
1646                              unsigned long action, void *data)
1647 {
1648         struct device *dev = data;
1649         const struct pci_dev *pdev = to_pci_dev(dev);
1650
1651         if (action != BUS_NOTIFY_UNBIND_DRIVER)
1652                 return NOTIFY_DONE;
1653
1654         if (!pdev->is_physfn)
1655                 return NOTIFY_DONE;
1656
1657         for (;;) {
1658                 struct pcistub_device *psdev = find_vfs(pdev);
1659                 if (!psdev)
1660                         break;
1661                 device_release_driver(&psdev->dev->dev);
1662         }
1663         return NOTIFY_DONE;
1664 }
1665
1666 static struct notifier_block pci_stub_nb = {
1667         .notifier_call = pci_stub_notifier,
1668 };
1669 #endif
1670
1671 static int __init xen_pcibk_init(void)
1672 {
1673         int err;
1674
1675         if (!xen_initial_domain())
1676                 return -ENODEV;
1677
1678         err = xen_pcibk_config_init();
1679         if (err)
1680                 return err;
1681
1682 #ifdef MODULE
1683         err = pcistub_init();
1684         if (err < 0)
1685                 return err;
1686 #endif
1687
1688         pcistub_init_devices_late();
1689         err = xen_pcibk_xenbus_register();
1690         if (err)
1691                 pcistub_exit();
1692 #ifdef CONFIG_PCI_IOV
1693         else
1694                 bus_register_notifier(&pci_bus_type, &pci_stub_nb);
1695 #endif
1696
1697         return err;
1698 }
1699
1700 static void __exit xen_pcibk_cleanup(void)
1701 {
1702 #ifdef CONFIG_PCI_IOV
1703         bus_unregister_notifier(&pci_bus_type, &pci_stub_nb);
1704 #endif
1705         xen_pcibk_xenbus_unregister();
1706         pcistub_exit();
1707 }
1708
1709 module_init(xen_pcibk_init);
1710 module_exit(xen_pcibk_cleanup);
1711
1712 MODULE_LICENSE("Dual BSD/GPL");
1713 MODULE_ALIAS("xen-backend:pci");