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 <xen/pci.h>
  23#include <xen/xen.h>
  24#include <asm/xen/hypervisor.h>
  25#include <xen/interface/physdev.h>
  26#include "pciback.h"
  27#include "conf_space.h"
  28#include "conf_space_quirks.h"
  29
  30#define PCISTUB_DRIVER_NAME "pciback"
  31
  32static char *pci_devs_to_hide;
  33wait_queue_head_t xen_pcibk_aer_wait_queue;
  34/*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
  35* We want to avoid in middle of AER ops, xen_pcibk devices is being removed
  36*/
  37static DECLARE_RWSEM(pcistub_sem);
  38module_param_named(hide, pci_devs_to_hide, charp, 0444);
  39
  40struct pcistub_device_id {
  41	struct list_head slot_list;
  42	int domain;
  43	unsigned char bus;
  44	unsigned int devfn;
  45};
  46static LIST_HEAD(pcistub_device_ids);
  47static DEFINE_SPINLOCK(device_ids_lock);
  48
  49struct pcistub_device {
  50	struct kref kref;
  51	struct list_head dev_list;
  52	spinlock_t lock;
  53
  54	struct pci_dev *dev;
  55	struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */
  56};
  57
  58/* Access to pcistub_devices & seized_devices lists and the initialize_devices
  59 * flag must be locked with pcistub_devices_lock
  60 */
  61static DEFINE_SPINLOCK(pcistub_devices_lock);
  62static LIST_HEAD(pcistub_devices);
  63
  64/* wait for device_initcall before initializing our devices
  65 * (see pcistub_init_devices_late)
  66 */
  67static int initialize_devices;
  68static LIST_HEAD(seized_devices);
  69
  70static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
  71{
  72	struct pcistub_device *psdev;
  73
  74	dev_dbg(&dev->dev, "pcistub_device_alloc\n");
  75
  76	psdev = kzalloc(sizeof(*psdev), GFP_KERNEL);
  77	if (!psdev)
  78		return NULL;
  79
  80	psdev->dev = pci_dev_get(dev);
  81	if (!psdev->dev) {
  82		kfree(psdev);
  83		return NULL;
  84	}
  85
  86	kref_init(&psdev->kref);
  87	spin_lock_init(&psdev->lock);
  88
  89	return psdev;
  90}
  91
  92/* Don't call this directly as it's called by pcistub_device_put */
  93static void pcistub_device_release(struct kref *kref)
  94{
  95	struct pcistub_device *psdev;
  96	struct pci_dev *dev;
  97	struct xen_pcibk_dev_data *dev_data;
  98
  99	psdev = container_of(kref, struct pcistub_device, kref);
 100	dev = psdev->dev;
 101	dev_data = pci_get_drvdata(dev);
 102
 103	dev_dbg(&dev->dev, "pcistub_device_release\n");
 104
 105	xen_unregister_device_domain_owner(dev);
 106
 107	/* Call the reset function which does not take lock as this
 108	 * is called from "unbind" which takes a device_lock mutex.
 109	 */
 110	__pci_reset_function_locked(dev);
 111	if (dev_data &&
 112	    pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state))
 113		dev_info(&dev->dev, "Could not reload PCI state\n");
 114	else
 115		pci_restore_state(dev);
 116
 117	if (dev->msix_cap) {
 118		struct physdev_pci_device ppdev = {
 119			.seg = pci_domain_nr(dev->bus),
 120			.bus = dev->bus->number,
 121			.devfn = dev->devfn
 122		};
 123		int err = HYPERVISOR_physdev_op(PHYSDEVOP_release_msix,
 124						&ppdev);
 125
 126		if (err && err != -ENOSYS)
 127			dev_warn(&dev->dev, "MSI-X release failed (%d)\n",
 128				 err);
 129	}
 130
 131	/* Disable the device */
 132	xen_pcibk_reset_device(dev);
 133
 134	kfree(dev_data);
 135	pci_set_drvdata(dev, NULL);
 136
 137	/* Clean-up the device */
 138	xen_pcibk_config_free_dyn_fields(dev);
 139	xen_pcibk_config_free_dev(dev);
 140
 141	pci_clear_dev_assigned(dev);
 142	pci_dev_put(dev);
 143
 144	kfree(psdev);
 145}
 146
 147static inline void pcistub_device_get(struct pcistub_device *psdev)
 148{
 149	kref_get(&psdev->kref);
 150}
 151
 152static inline void pcistub_device_put(struct pcistub_device *psdev)
 153{
 154	kref_put(&psdev->kref, pcistub_device_release);
 155}
 156
 157static struct pcistub_device *pcistub_device_find_locked(int domain, int bus,
 158							 int slot, int func)
 159{
 160	struct pcistub_device *psdev;
 161
 162	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 163		if (psdev->dev != NULL
 164		    && domain == pci_domain_nr(psdev->dev->bus)
 165		    && bus == psdev->dev->bus->number
 166		    && slot == PCI_SLOT(psdev->dev->devfn)
 167		    && func == PCI_FUNC(psdev->dev->devfn)) {
 168			return psdev;
 169		}
 170	}
 171
 172	return NULL;
 173}
 174
 175static struct pcistub_device *pcistub_device_find(int domain, int bus,
 176						  int slot, int func)
 177{
 178	struct pcistub_device *psdev;
 179	unsigned long flags;
 180
 181	spin_lock_irqsave(&pcistub_devices_lock, flags);
 182
 183	psdev = pcistub_device_find_locked(domain, bus, slot, func);
 184	if (psdev)
 185		pcistub_device_get(psdev);
 186
 187	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 188	return psdev;
 189}
 190
 191static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
 192						  struct pcistub_device *psdev)
 193{
 194	struct pci_dev *pci_dev = NULL;
 195	unsigned long flags;
 196
 
 
 197	spin_lock_irqsave(&psdev->lock, flags);
 198	if (!psdev->pdev) {
 199		psdev->pdev = pdev;
 200		pci_dev = psdev->dev;
 201	}
 202	spin_unlock_irqrestore(&psdev->lock, flags);
 203
 204	if (pci_dev)
 205		pcistub_device_get(psdev);
 206
 207	return pci_dev;
 208}
 209
 210struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 211					    int domain, int bus,
 212					    int slot, int func)
 213{
 214	struct pcistub_device *psdev;
 215	struct pci_dev *found_dev = NULL;
 216	unsigned long flags;
 217
 218	spin_lock_irqsave(&pcistub_devices_lock, flags);
 219
 220	psdev = pcistub_device_find_locked(domain, bus, slot, func);
 221	if (psdev)
 222		found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 223
 224	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 225	return found_dev;
 226}
 227
 228struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 229				    struct pci_dev *dev)
 230{
 231	struct pcistub_device *psdev;
 232	struct pci_dev *found_dev = NULL;
 233	unsigned long flags;
 234
 235	spin_lock_irqsave(&pcistub_devices_lock, flags);
 236
 237	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 238		if (psdev->dev == dev) {
 239			found_dev = pcistub_device_get_pci_dev(pdev, psdev);
 240			break;
 241		}
 242	}
 243
 244	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 245	return found_dev;
 246}
 247
 248/*
 249 * Called when:
 250 *  - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device
 251 *  - XenBus state has been disconnected (guest shutdown). See xen_pcibk_xenbus_remove
 252 *  - 'echo BDF > unbind' on pciback module with no guest attached. See pcistub_remove
 253 *  - 'echo BDF > unbind' with a guest still using it. See pcistub_remove
 254 *
 255 *  As such we have to be careful.
 256 *
 257 *  To make this easier, the caller has to hold the device lock.
 258 */
 259void pcistub_put_pci_dev(struct pci_dev *dev)
 260{
 261	struct pcistub_device *psdev, *found_psdev = NULL;
 262	unsigned long flags;
 263	struct xen_pcibk_dev_data *dev_data;
 264	int ret;
 265
 266	spin_lock_irqsave(&pcistub_devices_lock, flags);
 267
 268	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 269		if (psdev->dev == dev) {
 270			found_psdev = psdev;
 271			break;
 272		}
 273	}
 274
 275	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 276	if (WARN_ON(!found_psdev))
 277		return;
 278
 279	/*hold this lock for avoiding breaking link between
 280	* pcistub and xen_pcibk when AER is in processing
 281	*/
 282	down_write(&pcistub_sem);
 283	/* Cleanup our device
 284	 * (so it's ready for the next domain)
 285	 */
 286	device_lock_assert(&dev->dev);
 287	__pci_reset_function_locked(dev);
 288
 289	dev_data = pci_get_drvdata(dev);
 290	ret = pci_load_saved_state(dev, dev_data->pci_saved_state);
 291	if (!ret) {
 292		/*
 293		 * The usual sequence is pci_save_state & pci_restore_state
 294		 * but the guest might have messed the configuration space up.
 295		 * Use the initial version (when device was bound to us).
 296		 */
 297		pci_restore_state(dev);
 298	} else
 299		dev_info(&dev->dev, "Could not reload PCI state\n");
 300	/* This disables the device. */
 301	xen_pcibk_reset_device(dev);
 302
 303	/* And cleanup up our emulated fields. */
 304	xen_pcibk_config_reset_dev(dev);
 305	xen_pcibk_config_free_dyn_fields(dev);
 306
 307	dev_data->allow_interrupt_control = 0;
 308
 309	xen_unregister_device_domain_owner(dev);
 310
 311	spin_lock_irqsave(&found_psdev->lock, flags);
 312	found_psdev->pdev = NULL;
 313	spin_unlock_irqrestore(&found_psdev->lock, flags);
 314
 315	pcistub_device_put(found_psdev);
 316	up_write(&pcistub_sem);
 317}
 318
 319static int pcistub_match_one(struct pci_dev *dev,
 320			     struct pcistub_device_id *pdev_id)
 321{
 322	/* Match the specified device by domain, bus, slot, func and also if
 323	 * any of the device's parent bridges match.
 324	 */
 325	for (; dev != NULL; dev = dev->bus->self) {
 326		if (pci_domain_nr(dev->bus) == pdev_id->domain
 327		    && dev->bus->number == pdev_id->bus
 328		    && dev->devfn == pdev_id->devfn)
 329			return 1;
 330
 331		/* Sometimes topmost bridge links to itself. */
 332		if (dev == dev->bus->self)
 333			break;
 334	}
 335
 336	return 0;
 337}
 338
 339static int pcistub_match(struct pci_dev *dev)
 340{
 341	struct pcistub_device_id *pdev_id;
 342	unsigned long flags;
 343	int found = 0;
 344
 345	spin_lock_irqsave(&device_ids_lock, flags);
 346	list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) {
 347		if (pcistub_match_one(dev, pdev_id)) {
 348			found = 1;
 349			break;
 350		}
 351	}
 352	spin_unlock_irqrestore(&device_ids_lock, flags);
 353
 354	return found;
 355}
 356
 357static int pcistub_init_device(struct pci_dev *dev)
 358{
 359	struct xen_pcibk_dev_data *dev_data;
 360	int err = 0;
 361
 362	dev_dbg(&dev->dev, "initializing...\n");
 363
 364	/* The PCI backend is not intended to be a module (or to work with
 365	 * removable PCI devices (yet). If it were, xen_pcibk_config_free()
 366	 * would need to be called somewhere to free the memory allocated
 367	 * here and then to call kfree(pci_get_drvdata(psdev->dev)).
 368	 */
 369	dev_data = kzalloc(sizeof(*dev_data) +  strlen(DRV_NAME "[]")
 370				+ strlen(pci_name(dev)) + 1, GFP_KERNEL);
 371	if (!dev_data) {
 372		err = -ENOMEM;
 373		goto out;
 374	}
 375	pci_set_drvdata(dev, dev_data);
 376
 377	/*
 378	 * Setup name for fake IRQ handler. It will only be enabled
 379	 * once the device is turned on by the guest.
 380	 */
 381	sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev));
 382
 383	dev_dbg(&dev->dev, "initializing config\n");
 384
 385	init_waitqueue_head(&xen_pcibk_aer_wait_queue);
 386	err = xen_pcibk_config_init_dev(dev);
 387	if (err)
 388		goto out;
 389
 390	/* HACK: Force device (& ACPI) to determine what IRQ it's on - we
 391	 * must do this here because pcibios_enable_device may specify
 392	 * the pci device's true irq (and possibly its other resources)
 393	 * if they differ from what's in the configuration space.
 394	 * This makes the assumption that the device's resources won't
 395	 * change after this point (otherwise this code may break!)
 396	 */
 397	dev_dbg(&dev->dev, "enabling device\n");
 398	err = pci_enable_device(dev);
 399	if (err)
 400		goto config_release;
 401
 402	if (dev->msix_cap) {
 403		struct physdev_pci_device ppdev = {
 404			.seg = pci_domain_nr(dev->bus),
 405			.bus = dev->bus->number,
 406			.devfn = dev->devfn
 407		};
 408
 409		err = HYPERVISOR_physdev_op(PHYSDEVOP_prepare_msix, &ppdev);
 410		if (err && err != -ENOSYS)
 411			dev_err(&dev->dev, "MSI-X preparation failed (%d)\n",
 412				err);
 413	}
 414
 415	/* We need the device active to save the state. */
 416	dev_dbg(&dev->dev, "save state of device\n");
 417	pci_save_state(dev);
 418	dev_data->pci_saved_state = pci_store_saved_state(dev);
 419	if (!dev_data->pci_saved_state)
 420		dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
 421	else {
 422		dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n");
 423		__pci_reset_function_locked(dev);
 424		pci_restore_state(dev);
 425	}
 426	/* Now disable the device (this also ensures some private device
 427	 * data is setup before we export)
 428	 */
 429	dev_dbg(&dev->dev, "reset device\n");
 430	xen_pcibk_reset_device(dev);
 431
 432	pci_set_dev_assigned(dev);
 433	return 0;
 434
 435config_release:
 436	xen_pcibk_config_free_dev(dev);
 437
 438out:
 439	pci_set_drvdata(dev, NULL);
 440	kfree(dev_data);
 441	return err;
 442}
 443
 444/*
 445 * Because some initialization still happens on
 446 * devices during fs_initcall, we need to defer
 447 * full initialization of our devices until
 448 * device_initcall.
 449 */
 450static int __init pcistub_init_devices_late(void)
 451{
 452	struct pcistub_device *psdev;
 453	unsigned long flags;
 454	int err = 0;
 455
 456	spin_lock_irqsave(&pcistub_devices_lock, flags);
 457
 458	while (!list_empty(&seized_devices)) {
 459		psdev = container_of(seized_devices.next,
 460				     struct pcistub_device, dev_list);
 461		list_del(&psdev->dev_list);
 462
 463		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 464
 465		err = pcistub_init_device(psdev->dev);
 466		if (err) {
 467			dev_err(&psdev->dev->dev,
 468				"error %d initializing device\n", err);
 469			kfree(psdev);
 470			psdev = NULL;
 471		}
 472
 473		spin_lock_irqsave(&pcistub_devices_lock, flags);
 474
 475		if (psdev)
 476			list_add_tail(&psdev->dev_list, &pcistub_devices);
 477	}
 478
 479	initialize_devices = 1;
 480
 481	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 482
 483	return 0;
 484}
 485
 486static void pcistub_device_id_add_list(struct pcistub_device_id *new,
 487				       int domain, int bus, unsigned int devfn)
 488{
 489	struct pcistub_device_id *pci_dev_id;
 490	unsigned long flags;
 491	int found = 0;
 492
 493	spin_lock_irqsave(&device_ids_lock, flags);
 494
 495	list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
 496		if (pci_dev_id->domain == domain && pci_dev_id->bus == bus &&
 497		    pci_dev_id->devfn == devfn) {
 498			found = 1;
 499			break;
 500		}
 501	}
 502
 503	if (!found) {
 504		new->domain = domain;
 505		new->bus = bus;
 506		new->devfn = devfn;
 507		list_add_tail(&new->slot_list, &pcistub_device_ids);
 508	}
 509
 510	spin_unlock_irqrestore(&device_ids_lock, flags);
 511
 512	if (found)
 513		kfree(new);
 514}
 515
 516static int pcistub_seize(struct pci_dev *dev,
 517			 struct pcistub_device_id *pci_dev_id)
 518{
 519	struct pcistub_device *psdev;
 520	unsigned long flags;
 521	int err = 0;
 522
 523	psdev = pcistub_device_alloc(dev);
 524	if (!psdev) {
 525		kfree(pci_dev_id);
 526		return -ENOMEM;
 527	}
 528
 529	spin_lock_irqsave(&pcistub_devices_lock, flags);
 530
 531	if (initialize_devices) {
 532		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 533
 534		/* don't want irqs disabled when calling pcistub_init_device */
 535		err = pcistub_init_device(psdev->dev);
 536
 537		spin_lock_irqsave(&pcistub_devices_lock, flags);
 538
 539		if (!err)
 540			list_add(&psdev->dev_list, &pcistub_devices);
 541	} else {
 542		dev_dbg(&dev->dev, "deferring initialization\n");
 543		list_add(&psdev->dev_list, &seized_devices);
 544	}
 545
 546	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 547
 548	if (err) {
 549		kfree(pci_dev_id);
 550		pcistub_device_put(psdev);
 551	} else if (pci_dev_id)
 552		pcistub_device_id_add_list(pci_dev_id, pci_domain_nr(dev->bus),
 553					   dev->bus->number, dev->devfn);
 554
 555	return err;
 556}
 557
 558/* Called when 'bind'. This means we must _NOT_ call pci_reset_function or
 559 * other functions that take the sysfs lock. */
 560static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id)
 561{
 562	int err = 0, match;
 563	struct pcistub_device_id *pci_dev_id = NULL;
 564
 565	dev_dbg(&dev->dev, "probing...\n");
 566
 567	match = pcistub_match(dev);
 568
 569	if ((dev->driver_override &&
 570	     !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) ||
 571	    match) {
 572
 573		if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
 574		    && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
 575			dev_err(&dev->dev, "can't export pci devices that "
 576				"don't have a normal (0) or bridge (1) "
 577				"header type!\n");
 578			err = -ENODEV;
 579			goto out;
 580		}
 581
 582		if (!match) {
 583			pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
 584			if (!pci_dev_id) {
 585				err = -ENOMEM;
 586				goto out;
 587			}
 588		}
 589
 590		dev_info(&dev->dev, "seizing device\n");
 591		err = pcistub_seize(dev, pci_dev_id);
 592	} else
 593		/* Didn't find the device */
 594		err = -ENODEV;
 595
 596out:
 597	return err;
 598}
 599
 600/* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or
 601 * other functions that take the sysfs lock. */
 602static void pcistub_remove(struct pci_dev *dev)
 603{
 604	struct pcistub_device *psdev, *found_psdev = NULL;
 605	unsigned long flags;
 606
 607	dev_dbg(&dev->dev, "removing\n");
 608
 609	spin_lock_irqsave(&pcistub_devices_lock, flags);
 610
 611	xen_pcibk_config_quirk_release(dev);
 612
 613	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
 614		if (psdev->dev == dev) {
 615			found_psdev = psdev;
 616			break;
 617		}
 618	}
 619
 620	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 621
 622	if (found_psdev) {
 623		dev_dbg(&dev->dev, "found device to remove %s\n",
 624			found_psdev->pdev ? "- in-use" : "");
 625
 626		if (found_psdev->pdev) {
 627			int domid = xen_find_device_domain_owner(dev);
 628
 629			dev_warn(&dev->dev, "****** removing device %s while still in-use by domain %d! ******\n",
 630			       pci_name(found_psdev->dev), domid);
 631			dev_warn(&dev->dev, "****** driver domain may still access this device's i/o resources!\n");
 632			dev_warn(&dev->dev, "****** shutdown driver domain before binding device\n");
 633			dev_warn(&dev->dev, "****** to other drivers or domains\n");
 634
 635			/* N.B. This ends up calling pcistub_put_pci_dev which ends up
 636			 * doing the FLR. */
 637			xen_pcibk_release_pci_dev(found_psdev->pdev,
 638						found_psdev->dev,
 639						false /* caller holds the lock. */);
 640		}
 641
 642		spin_lock_irqsave(&pcistub_devices_lock, flags);
 643		list_del(&found_psdev->dev_list);
 644		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 645
 646		/* the final put for releasing from the list */
 647		pcistub_device_put(found_psdev);
 648	}
 649}
 650
 651static const struct pci_device_id pcistub_ids[] = {
 652	{
 653	 .vendor = PCI_ANY_ID,
 654	 .device = PCI_ANY_ID,
 655	 .subvendor = PCI_ANY_ID,
 656	 .subdevice = PCI_ANY_ID,
 657	 },
 658	{0,},
 659};
 660
 661#define PCI_NODENAME_MAX 40
 662static void kill_domain_by_device(struct pcistub_device *psdev)
 663{
 664	struct xenbus_transaction xbt;
 665	int err;
 666	char nodename[PCI_NODENAME_MAX];
 667
 668	BUG_ON(!psdev);
 669	snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
 670		psdev->pdev->xdev->otherend_id);
 671
 672again:
 673	err = xenbus_transaction_start(&xbt);
 674	if (err) {
 675		dev_err(&psdev->dev->dev,
 676			"error %d when start xenbus transaction\n", err);
 677		return;
 678	}
 679	/*PV AER handlers will set this flag*/
 680	xenbus_printf(xbt, nodename, "aerState" , "aerfail");
 681	err = xenbus_transaction_end(xbt, 0);
 682	if (err) {
 683		if (err == -EAGAIN)
 684			goto again;
 685		dev_err(&psdev->dev->dev,
 686			"error %d when end xenbus transaction\n", err);
 687		return;
 688	}
 689}
 690
 691/* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
 692 * backend need to have cooperation. In xen_pcibk, those steps will do similar
 693 * jobs: send service request and waiting for front_end response.
 694*/
 695static pci_ers_result_t common_process(struct pcistub_device *psdev,
 696				       pci_channel_state_t state, int aer_cmd,
 697				       pci_ers_result_t result)
 698{
 699	pci_ers_result_t res = result;
 700	struct xen_pcie_aer_op *aer_op;
 701	struct xen_pcibk_device *pdev = psdev->pdev;
 702	struct xen_pci_sharedinfo *sh_info = pdev->sh_info;
 703	int ret;
 704
 705	/*with PV AER drivers*/
 706	aer_op = &(sh_info->aer_op);
 707	aer_op->cmd = aer_cmd ;
 708	/*useful for error_detected callback*/
 709	aer_op->err = state;
 710	/*pcifront_end BDF*/
 711	ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
 712		&aer_op->domain, &aer_op->bus, &aer_op->devfn);
 713	if (!ret) {
 714		dev_err(&psdev->dev->dev, "failed to get pcifront device\n");
 715		return PCI_ERS_RESULT_NONE;
 716	}
 717	wmb();
 718
 719	dev_dbg(&psdev->dev->dev, "aer_op %x dom %x bus %x devfn %x\n",
 720			aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
 721	/*local flag to mark there's aer request, xen_pcibk callback will use
 722	* this flag to judge whether we need to check pci-front give aer
 723	* service ack signal
 724	*/
 725	set_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
 726
 727	/*It is possible that a pcifront conf_read_write ops request invokes
 728	* the callback which cause the spurious execution of wake_up.
 729	* Yet it is harmless and better than a spinlock here
 730	*/
 731	set_bit(_XEN_PCIB_active,
 732		(unsigned long *)&sh_info->flags);
 733	wmb();
 734	notify_remote_via_irq(pdev->evtchn_irq);
 735
 736	/* Enable IRQ to signal "request done". */
 737	xen_pcibk_lateeoi(pdev, 0);
 738
 739	ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
 740				 !(test_bit(_XEN_PCIB_active, (unsigned long *)
 741				 &sh_info->flags)), 300*HZ);
 742
 743	/* Enable IRQ for pcifront request if not already active. */
 744	if (!test_bit(_PDEVF_op_active, &pdev->flags))
 745		xen_pcibk_lateeoi(pdev, 0);
 746
 747	if (!ret) {
 748		if (test_bit(_XEN_PCIB_active,
 749			(unsigned long *)&sh_info->flags)) {
 750			dev_err(&psdev->dev->dev,
 751				"pcifront aer process not responding!\n");
 752			clear_bit(_XEN_PCIB_active,
 753			  (unsigned long *)&sh_info->flags);
 754			aer_op->err = PCI_ERS_RESULT_NONE;
 755			return res;
 756		}
 757	}
 758	clear_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
 759
 
 
 
 
 
 
 760	res = (pci_ers_result_t)aer_op->err;
 761	return res;
 762}
 763
 764/*
 765* xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
 766* of the device driver could provide this service, and then wait for pcifront
 767* ack.
 768* @dev: pointer to PCI devices
 769* return value is used by aer_core do_recovery policy
 770*/
 771static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
 772{
 773	struct pcistub_device *psdev;
 774	pci_ers_result_t result;
 775
 776	result = PCI_ERS_RESULT_RECOVERED;
 777	dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
 778		dev->bus->number, dev->devfn);
 779
 780	down_write(&pcistub_sem);
 781	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 782				dev->bus->number,
 783				PCI_SLOT(dev->devfn),
 784				PCI_FUNC(dev->devfn));
 785
 786	if (!psdev || !psdev->pdev) {
 787		dev_err(&dev->dev, "device is not found/assigned\n");
 788		goto end;
 789	}
 790
 791	if (!psdev->pdev->sh_info) {
 792		dev_err(&dev->dev, "device is not connected or owned"
 793			" by HVM, kill it\n");
 794		kill_domain_by_device(psdev);
 795		goto end;
 796	}
 797
 798	if (!test_bit(_XEN_PCIB_AERHANDLER,
 799		(unsigned long *)&psdev->pdev->sh_info->flags)) {
 800		dev_err(&dev->dev,
 801			"guest with no AER driver should have been killed\n");
 802		goto end;
 803	}
 804	result = common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_slotreset, result);
 805
 806	if (result == PCI_ERS_RESULT_NONE ||
 807		result == PCI_ERS_RESULT_DISCONNECT) {
 808		dev_dbg(&dev->dev,
 809			"No AER slot_reset service or disconnected!\n");
 810		kill_domain_by_device(psdev);
 811	}
 812end:
 813	if (psdev)
 814		pcistub_device_put(psdev);
 815	up_write(&pcistub_sem);
 816	return result;
 817
 818}
 819
 820
 821/*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
 822* in case of the device driver could provide this service, and then wait
 823* for pcifront ack
 824* @dev: pointer to PCI devices
 825* return value is used by aer_core do_recovery policy
 826*/
 827
 828static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
 829{
 830	struct pcistub_device *psdev;
 831	pci_ers_result_t result;
 832
 833	result = PCI_ERS_RESULT_RECOVERED;
 834	dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n",
 835		dev->bus->number, dev->devfn);
 836
 837	down_write(&pcistub_sem);
 838	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 839				dev->bus->number,
 840				PCI_SLOT(dev->devfn),
 841				PCI_FUNC(dev->devfn));
 842
 843	if (!psdev || !psdev->pdev) {
 844		dev_err(&dev->dev, "device is not found/assigned\n");
 845		goto end;
 846	}
 847
 848	if (!psdev->pdev->sh_info) {
 849		dev_err(&dev->dev, "device is not connected or owned"
 850			" by HVM, kill it\n");
 851		kill_domain_by_device(psdev);
 852		goto end;
 853	}
 854
 855	if (!test_bit(_XEN_PCIB_AERHANDLER,
 856		(unsigned long *)&psdev->pdev->sh_info->flags)) {
 857		dev_err(&dev->dev,
 858			"guest with no AER driver should have been killed\n");
 859		goto end;
 860	}
 861	result = common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_mmio, result);
 862
 863	if (result == PCI_ERS_RESULT_NONE ||
 864		result == PCI_ERS_RESULT_DISCONNECT) {
 865		dev_dbg(&dev->dev,
 866			"No AER mmio_enabled service or disconnected!\n");
 867		kill_domain_by_device(psdev);
 868	}
 869end:
 870	if (psdev)
 871		pcistub_device_put(psdev);
 872	up_write(&pcistub_sem);
 873	return result;
 874}
 875
 876/*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
 877* in case of the device driver could provide this service, and then wait
 878* for pcifront ack.
 879* @dev: pointer to PCI devices
 880* @error: the current PCI connection state
 881* return value is used by aer_core do_recovery policy
 882*/
 883
 884static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
 885	pci_channel_state_t error)
 886{
 887	struct pcistub_device *psdev;
 888	pci_ers_result_t result;
 889
 890	result = PCI_ERS_RESULT_CAN_RECOVER;
 891	dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
 892		dev->bus->number, dev->devfn);
 893
 894	down_write(&pcistub_sem);
 895	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 896				dev->bus->number,
 897				PCI_SLOT(dev->devfn),
 898				PCI_FUNC(dev->devfn));
 899
 900	if (!psdev || !psdev->pdev) {
 901		dev_err(&dev->dev, "device is not found/assigned\n");
 902		goto end;
 903	}
 904
 905	if (!psdev->pdev->sh_info) {
 906		dev_err(&dev->dev, "device is not connected or owned"
 907			" by HVM, kill it\n");
 908		kill_domain_by_device(psdev);
 909		goto end;
 910	}
 911
 912	/*Guest owns the device yet no aer handler regiested, kill guest*/
 913	if (!test_bit(_XEN_PCIB_AERHANDLER,
 914		(unsigned long *)&psdev->pdev->sh_info->flags)) {
 915		dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
 916		kill_domain_by_device(psdev);
 917		goto end;
 918	}
 919	result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
 920
 921	if (result == PCI_ERS_RESULT_NONE ||
 922		result == PCI_ERS_RESULT_DISCONNECT) {
 923		dev_dbg(&dev->dev,
 924			"No AER error_detected service or disconnected!\n");
 925		kill_domain_by_device(psdev);
 926	}
 927end:
 928	if (psdev)
 929		pcistub_device_put(psdev);
 930	up_write(&pcistub_sem);
 931	return result;
 932}
 933
 934/*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
 935* in case of the device driver could provide this service, and then wait
 936* for pcifront ack.
 937* @dev: pointer to PCI devices
 938*/
 939
 940static void xen_pcibk_error_resume(struct pci_dev *dev)
 941{
 942	struct pcistub_device *psdev;
 943
 944	dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
 945		dev->bus->number, dev->devfn);
 946
 947	down_write(&pcistub_sem);
 948	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
 949				dev->bus->number,
 950				PCI_SLOT(dev->devfn),
 951				PCI_FUNC(dev->devfn));
 952
 953	if (!psdev || !psdev->pdev) {
 954		dev_err(&dev->dev, "device is not found/assigned\n");
 955		goto end;
 956	}
 957
 958	if (!psdev->pdev->sh_info) {
 959		dev_err(&dev->dev, "device is not connected or owned"
 960			" by HVM, kill it\n");
 961		kill_domain_by_device(psdev);
 962		goto end;
 963	}
 964
 965	if (!test_bit(_XEN_PCIB_AERHANDLER,
 966		(unsigned long *)&psdev->pdev->sh_info->flags)) {
 967		dev_err(&dev->dev,
 968			"guest with no AER driver should have been killed\n");
 969		kill_domain_by_device(psdev);
 970		goto end;
 971	}
 972	common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_resume,
 973		       PCI_ERS_RESULT_RECOVERED);
 974end:
 975	if (psdev)
 976		pcistub_device_put(psdev);
 977	up_write(&pcistub_sem);
 978	return;
 979}
 980
 981/*add xen_pcibk AER handling*/
 982static const struct pci_error_handlers xen_pcibk_error_handler = {
 983	.error_detected = xen_pcibk_error_detected,
 984	.mmio_enabled = xen_pcibk_mmio_enabled,
 985	.slot_reset = xen_pcibk_slot_reset,
 986	.resume = xen_pcibk_error_resume,
 987};
 988
 989/*
 990 * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
 991 * for a normal device. I don't want it to be loaded automatically.
 992 */
 993
 994static struct pci_driver xen_pcibk_pci_driver = {
 995	/* The name should be xen_pciback, but until the tools are updated
 996	 * we will keep it as pciback. */
 997	.name = PCISTUB_DRIVER_NAME,
 998	.id_table = pcistub_ids,
 999	.probe = pcistub_probe,
1000	.remove = pcistub_remove,
1001	.err_handler = &xen_pcibk_error_handler,
1002};
1003
1004static inline int str_to_slot(const char *buf, int *domain, int *bus,
1005			      int *slot, int *func)
1006{
1007	int parsed = 0;
1008
1009	switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func,
1010		       &parsed)) {
1011	case 3:
1012		*func = -1;
1013		sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed);
1014		break;
1015	case 2:
1016		*slot = *func = -1;
1017		sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed);
1018		break;
1019	}
1020	if (parsed && !buf[parsed])
1021		return 0;
1022
1023	/* try again without domain */
1024	*domain = 0;
1025	switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) {
1026	case 2:
1027		*func = -1;
1028		sscanf(buf, " %x:%x.* %n", bus, slot, &parsed);
1029		break;
1030	case 1:
1031		*slot = *func = -1;
1032		sscanf(buf, " %x:*.* %n", bus, &parsed);
1033		break;
1034	}
1035	if (parsed && !buf[parsed])
1036		return 0;
1037
1038	return -EINVAL;
1039}
1040
1041static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
1042			       *slot, int *func, int *reg, int *size, int *mask)
1043{
1044	int parsed = 0;
1045
1046	sscanf(buf, " %x:%x:%x.%x-%x:%x:%x %n", domain, bus, slot, func,
1047	       reg, size, mask, &parsed);
1048	if (parsed && !buf[parsed])
1049		return 0;
1050
1051	/* try again without domain */
1052	*domain = 0;
1053	sscanf(buf, " %x:%x.%x-%x:%x:%x %n", bus, slot, func, reg, size,
1054	       mask, &parsed);
1055	if (parsed && !buf[parsed])
1056		return 0;
1057
1058	return -EINVAL;
1059}
1060
1061static int pcistub_device_id_add(int domain, int bus, int slot, int func)
1062{
1063	struct pcistub_device_id *pci_dev_id;
1064	int rc = 0, devfn = PCI_DEVFN(slot, func);
1065
1066	if (slot < 0) {
1067		for (slot = 0; !rc && slot < 32; ++slot)
1068			rc = pcistub_device_id_add(domain, bus, slot, func);
1069		return rc;
1070	}
1071
1072	if (func < 0) {
1073		for (func = 0; !rc && func < 8; ++func)
1074			rc = pcistub_device_id_add(domain, bus, slot, func);
1075		return rc;
1076	}
1077
1078	if ((
1079#if !defined(MODULE) /* pci_domains_supported is not being exported */ \
1080    || !defined(CONFIG_PCI_DOMAINS)
1081	     !pci_domains_supported ? domain :
1082#endif
1083	     domain < 0 || domain > 0xffff)
1084	    || bus < 0 || bus > 0xff
1085	    || PCI_SLOT(devfn) != slot
1086	    || PCI_FUNC(devfn) != func)
1087		return -EINVAL;
1088
1089	pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
1090	if (!pci_dev_id)
1091		return -ENOMEM;
1092
1093	pr_debug("wants to seize %04x:%02x:%02x.%d\n",
1094		 domain, bus, slot, func);
1095
1096	pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn);
1097
1098	return 0;
1099}
1100
1101static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
1102{
1103	struct pcistub_device_id *pci_dev_id, *t;
1104	int err = -ENOENT;
1105	unsigned long flags;
1106
1107	spin_lock_irqsave(&device_ids_lock, flags);
1108	list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
1109				 slot_list) {
1110		if (pci_dev_id->domain == domain && pci_dev_id->bus == bus
1111		    && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot)
1112		    && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) {
1113			/* Don't break; here because it's possible the same
1114			 * slot could be in the list more than once
1115			 */
1116			list_del(&pci_dev_id->slot_list);
1117			kfree(pci_dev_id);
1118
1119			err = 0;
1120
1121			pr_debug("removed %04x:%02x:%02x.%d from seize list\n",
1122				 domain, bus, slot, func);
1123		}
1124	}
1125	spin_unlock_irqrestore(&device_ids_lock, flags);
1126
1127	return err;
1128}
1129
1130static int pcistub_reg_add(int domain, int bus, int slot, int func,
1131			   unsigned int reg, unsigned int size,
1132			   unsigned int mask)
1133{
1134	int err = 0;
1135	struct pcistub_device *psdev;
1136	struct pci_dev *dev;
1137	struct config_field *field;
1138
1139	if (reg > 0xfff || (size < 4 && (mask >> (size * 8))))
1140		return -EINVAL;
1141
1142	psdev = pcistub_device_find(domain, bus, slot, func);
1143	if (!psdev) {
1144		err = -ENODEV;
1145		goto out;
1146	}
1147	dev = psdev->dev;
1148
1149	field = kzalloc(sizeof(*field), GFP_KERNEL);
1150	if (!field) {
1151		err = -ENOMEM;
1152		goto out;
1153	}
1154
1155	field->offset = reg;
1156	field->size = size;
1157	field->mask = mask;
1158	field->init = NULL;
1159	field->reset = NULL;
1160	field->release = NULL;
1161	field->clean = xen_pcibk_config_field_free;
1162
1163	err = xen_pcibk_config_quirks_add_field(dev, field);
1164	if (err)
1165		kfree(field);
1166out:
1167	if (psdev)
1168		pcistub_device_put(psdev);
1169	return err;
1170}
1171
1172static ssize_t new_slot_store(struct device_driver *drv, const char *buf,
1173			      size_t count)
1174{
1175	int domain, bus, slot, func;
1176	int err;
1177
1178	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1179	if (err)
1180		goto out;
1181
1182	err = pcistub_device_id_add(domain, bus, slot, func);
1183
1184out:
1185	if (!err)
1186		err = count;
1187	return err;
1188}
1189static DRIVER_ATTR_WO(new_slot);
1190
1191static ssize_t remove_slot_store(struct device_driver *drv, const char *buf,
1192				 size_t count)
1193{
1194	int domain, bus, slot, func;
1195	int err;
1196
1197	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1198	if (err)
1199		goto out;
1200
1201	err = pcistub_device_id_remove(domain, bus, slot, func);
1202
1203out:
1204	if (!err)
1205		err = count;
1206	return err;
1207}
1208static DRIVER_ATTR_WO(remove_slot);
1209
1210static ssize_t slots_show(struct device_driver *drv, char *buf)
1211{
1212	struct pcistub_device_id *pci_dev_id;
1213	size_t count = 0;
1214	unsigned long flags;
1215
1216	spin_lock_irqsave(&device_ids_lock, flags);
1217	list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1218		if (count >= PAGE_SIZE)
1219			break;
1220
1221		count += scnprintf(buf + count, PAGE_SIZE - count,
1222				   "%04x:%02x:%02x.%d\n",
1223				   pci_dev_id->domain, pci_dev_id->bus,
1224				   PCI_SLOT(pci_dev_id->devfn),
1225				   PCI_FUNC(pci_dev_id->devfn));
1226	}
1227	spin_unlock_irqrestore(&device_ids_lock, flags);
1228
1229	return count;
1230}
1231static DRIVER_ATTR_RO(slots);
1232
1233static ssize_t irq_handlers_show(struct device_driver *drv, char *buf)
1234{
1235	struct pcistub_device *psdev;
1236	struct xen_pcibk_dev_data *dev_data;
1237	size_t count = 0;
1238	unsigned long flags;
1239
1240	spin_lock_irqsave(&pcistub_devices_lock, flags);
1241	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1242		if (count >= PAGE_SIZE)
1243			break;
1244		if (!psdev->dev)
1245			continue;
1246		dev_data = pci_get_drvdata(psdev->dev);
1247		if (!dev_data)
1248			continue;
1249		count +=
1250		    scnprintf(buf + count, PAGE_SIZE - count,
1251			      "%s:%s:%sing:%ld\n",
1252			      pci_name(psdev->dev),
1253			      dev_data->isr_on ? "on" : "off",
1254			      dev_data->ack_intr ? "ack" : "not ack",
1255			      dev_data->handled);
1256	}
1257	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1258	return count;
1259}
1260static DRIVER_ATTR_RO(irq_handlers);
1261
1262static ssize_t irq_handler_state_store(struct device_driver *drv,
1263				       const char *buf, size_t count)
1264{
1265	struct pcistub_device *psdev;
1266	struct xen_pcibk_dev_data *dev_data;
1267	int domain, bus, slot, func;
1268	int err;
1269
1270	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1271	if (err)
1272		return err;
1273
1274	psdev = pcistub_device_find(domain, bus, slot, func);
1275	if (!psdev) {
1276		err = -ENOENT;
1277		goto out;
1278	}
1279
1280	dev_data = pci_get_drvdata(psdev->dev);
1281	if (!dev_data) {
1282		err = -ENOENT;
1283		goto out;
1284	}
1285
1286	dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1287		dev_data->irq_name, dev_data->isr_on,
1288		!dev_data->isr_on);
1289
1290	dev_data->isr_on = !(dev_data->isr_on);
1291	if (dev_data->isr_on)
1292		dev_data->ack_intr = 1;
1293out:
1294	if (psdev)
1295		pcistub_device_put(psdev);
1296	if (!err)
1297		err = count;
1298	return err;
1299}
1300static DRIVER_ATTR_WO(irq_handler_state);
1301
1302static ssize_t quirks_store(struct device_driver *drv, const char *buf,
1303			    size_t count)
1304{
1305	int domain, bus, slot, func, reg, size, mask;
1306	int err;
1307
1308	err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1309			   &mask);
1310	if (err)
1311		goto out;
1312
1313	err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1314
1315out:
1316	if (!err)
1317		err = count;
1318	return err;
1319}
1320
1321static ssize_t quirks_show(struct device_driver *drv, char *buf)
1322{
1323	int count = 0;
1324	unsigned long flags;
1325	struct xen_pcibk_config_quirk *quirk;
1326	struct xen_pcibk_dev_data *dev_data;
1327	const struct config_field *field;
1328	const struct config_field_entry *cfg_entry;
1329
1330	spin_lock_irqsave(&device_ids_lock, flags);
1331	list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1332		if (count >= PAGE_SIZE)
1333			goto out;
1334
1335		count += scnprintf(buf + count, PAGE_SIZE - count,
1336				   "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1337				   quirk->pdev->bus->number,
1338				   PCI_SLOT(quirk->pdev->devfn),
1339				   PCI_FUNC(quirk->pdev->devfn),
1340				   quirk->devid.vendor, quirk->devid.device,
1341				   quirk->devid.subvendor,
1342				   quirk->devid.subdevice);
1343
1344		dev_data = pci_get_drvdata(quirk->pdev);
1345
1346		list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1347			field = cfg_entry->field;
1348			if (count >= PAGE_SIZE)
1349				goto out;
1350
1351			count += scnprintf(buf + count, PAGE_SIZE - count,
1352					   "\t\t%08x:%01x:%08x\n",
1353					   cfg_entry->base_offset +
1354					   field->offset, field->size,
1355					   field->mask);
1356		}
1357	}
1358
1359out:
1360	spin_unlock_irqrestore(&device_ids_lock, flags);
1361
1362	return count;
1363}
1364static DRIVER_ATTR_RW(quirks);
1365
1366static ssize_t permissive_store(struct device_driver *drv, const char *buf,
1367				size_t count)
1368{
1369	int domain, bus, slot, func;
1370	int err;
1371	struct pcistub_device *psdev;
1372	struct xen_pcibk_dev_data *dev_data;
1373
1374	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1375	if (err)
1376		goto out;
1377
1378	psdev = pcistub_device_find(domain, bus, slot, func);
1379	if (!psdev) {
1380		err = -ENODEV;
1381		goto out;
1382	}
1383
1384	dev_data = pci_get_drvdata(psdev->dev);
1385	/* the driver data for a device should never be null at this point */
1386	if (!dev_data) {
1387		err = -ENXIO;
1388		goto release;
1389	}
1390	if (!dev_data->permissive) {
1391		dev_data->permissive = 1;
1392		/* Let user know that what they're doing could be unsafe */
1393		dev_warn(&psdev->dev->dev, "enabling permissive mode "
1394			 "configuration space accesses!\n");
1395		dev_warn(&psdev->dev->dev,
1396			 "permissive mode is potentially unsafe!\n");
1397	}
1398release:
1399	pcistub_device_put(psdev);
1400out:
1401	if (!err)
1402		err = count;
1403	return err;
1404}
1405
1406static ssize_t permissive_show(struct device_driver *drv, char *buf)
1407{
1408	struct pcistub_device *psdev;
1409	struct xen_pcibk_dev_data *dev_data;
1410	size_t count = 0;
1411	unsigned long flags;
1412	spin_lock_irqsave(&pcistub_devices_lock, flags);
1413	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1414		if (count >= PAGE_SIZE)
1415			break;
1416		if (!psdev->dev)
1417			continue;
1418		dev_data = pci_get_drvdata(psdev->dev);
1419		if (!dev_data || !dev_data->permissive)
1420			continue;
1421		count +=
1422		    scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1423			      pci_name(psdev->dev));
1424	}
1425	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1426	return count;
1427}
1428static DRIVER_ATTR_RW(permissive);
1429
1430static ssize_t allow_interrupt_control_store(struct device_driver *drv,
1431					     const char *buf, size_t count)
1432{
1433	int domain, bus, slot, func;
1434	int err;
1435	struct pcistub_device *psdev;
1436	struct xen_pcibk_dev_data *dev_data;
1437
1438	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1439	if (err)
1440		goto out;
1441
1442	psdev = pcistub_device_find(domain, bus, slot, func);
1443	if (!psdev) {
1444		err = -ENODEV;
1445		goto out;
1446	}
1447
1448	dev_data = pci_get_drvdata(psdev->dev);
1449	/* the driver data for a device should never be null at this point */
1450	if (!dev_data) {
1451		err = -ENXIO;
1452		goto release;
1453	}
1454	dev_data->allow_interrupt_control = 1;
1455release:
1456	pcistub_device_put(psdev);
1457out:
1458	if (!err)
1459		err = count;
1460	return err;
1461}
1462
1463static ssize_t allow_interrupt_control_show(struct device_driver *drv,
1464					    char *buf)
1465{
1466	struct pcistub_device *psdev;
1467	struct xen_pcibk_dev_data *dev_data;
1468	size_t count = 0;
1469	unsigned long flags;
1470
1471	spin_lock_irqsave(&pcistub_devices_lock, flags);
1472	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1473		if (count >= PAGE_SIZE)
1474			break;
1475		if (!psdev->dev)
1476			continue;
1477		dev_data = pci_get_drvdata(psdev->dev);
1478		if (!dev_data || !dev_data->allow_interrupt_control)
1479			continue;
1480		count +=
1481		    scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1482			      pci_name(psdev->dev));
1483	}
1484	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1485	return count;
1486}
1487static DRIVER_ATTR_RW(allow_interrupt_control);
1488
1489static void pcistub_exit(void)
1490{
1491	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1492	driver_remove_file(&xen_pcibk_pci_driver.driver,
1493			   &driver_attr_remove_slot);
1494	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1495	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1496	driver_remove_file(&xen_pcibk_pci_driver.driver,
1497			   &driver_attr_permissive);
1498	driver_remove_file(&xen_pcibk_pci_driver.driver,
1499			   &driver_attr_allow_interrupt_control);
1500	driver_remove_file(&xen_pcibk_pci_driver.driver,
1501			   &driver_attr_irq_handlers);
1502	driver_remove_file(&xen_pcibk_pci_driver.driver,
1503			   &driver_attr_irq_handler_state);
1504	pci_unregister_driver(&xen_pcibk_pci_driver);
1505}
1506
1507static int __init pcistub_init(void)
1508{
1509	int pos = 0;
1510	int err = 0;
1511	int domain, bus, slot, func;
1512	int parsed;
1513
1514	if (pci_devs_to_hide && *pci_devs_to_hide) {
1515		do {
1516			parsed = 0;
1517
1518			err = sscanf(pci_devs_to_hide + pos,
1519				     " (%x:%x:%x.%x) %n",
1520				     &domain, &bus, &slot, &func, &parsed);
1521			switch (err) {
1522			case 3:
1523				func = -1;
1524				sscanf(pci_devs_to_hide + pos,
1525				       " (%x:%x:%x.*) %n",
1526				       &domain, &bus, &slot, &parsed);
1527				break;
1528			case 2:
1529				slot = func = -1;
1530				sscanf(pci_devs_to_hide + pos,
1531				       " (%x:%x:*.*) %n",
1532				       &domain, &bus, &parsed);
1533				break;
1534			}
1535
1536			if (!parsed) {
1537				domain = 0;
1538				err = sscanf(pci_devs_to_hide + pos,
1539					     " (%x:%x.%x) %n",
1540					     &bus, &slot, &func, &parsed);
1541				switch (err) {
1542				case 2:
1543					func = -1;
1544					sscanf(pci_devs_to_hide + pos,
1545					       " (%x:%x.*) %n",
1546					       &bus, &slot, &parsed);
1547					break;
1548				case 1:
1549					slot = func = -1;
1550					sscanf(pci_devs_to_hide + pos,
1551					       " (%x:*.*) %n",
1552					       &bus, &parsed);
1553					break;
1554				}
1555			}
1556
1557			if (parsed <= 0)
1558				goto parse_error;
1559
1560			err = pcistub_device_id_add(domain, bus, slot, func);
1561			if (err)
1562				goto out;
1563
1564			pos += parsed;
1565		} while (pci_devs_to_hide[pos]);
1566	}
1567
1568	/* If we're the first PCI Device Driver to register, we're the
1569	 * first one to get offered PCI devices as they become
1570	 * available (and thus we can be the first to grab them)
1571	 */
1572	err = pci_register_driver(&xen_pcibk_pci_driver);
1573	if (err < 0)
1574		goto out;
1575
1576	err = driver_create_file(&xen_pcibk_pci_driver.driver,
1577				 &driver_attr_new_slot);
1578	if (!err)
1579		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1580					 &driver_attr_remove_slot);
1581	if (!err)
1582		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1583					 &driver_attr_slots);
1584	if (!err)
1585		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1586					 &driver_attr_quirks);
1587	if (!err)
1588		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1589					 &driver_attr_permissive);
1590	if (!err)
1591		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1592					 &driver_attr_allow_interrupt_control);
1593
1594	if (!err)
1595		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1596					 &driver_attr_irq_handlers);
1597	if (!err)
1598		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1599					&driver_attr_irq_handler_state);
1600	if (err)
1601		pcistub_exit();
1602
1603out:
1604	return err;
1605
1606parse_error:
1607	pr_err("Error parsing pci_devs_to_hide at \"%s\"\n",
1608	       pci_devs_to_hide + pos);
1609	return -EINVAL;
1610}
1611
1612#ifndef MODULE
1613/*
1614 * fs_initcall happens before device_initcall
1615 * so xen_pcibk *should* get called first (b/c we
1616 * want to suck up any device before other drivers
1617 * get a chance by being the first pci device
1618 * driver to register)
1619 */
1620fs_initcall(pcistub_init);
1621#endif
1622
1623#ifdef CONFIG_PCI_IOV
1624static struct pcistub_device *find_vfs(const struct pci_dev *pdev)
1625{
1626	struct pcistub_device *psdev = NULL;
1627	unsigned long flags;
1628	bool found = false;
1629
1630	spin_lock_irqsave(&pcistub_devices_lock, flags);
1631	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1632		if (!psdev->pdev && psdev->dev != pdev
1633		    && pci_physfn(psdev->dev) == pdev) {
1634			found = true;
1635			break;
1636		}
1637	}
1638	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1639	if (found)
1640		return psdev;
1641	return NULL;
1642}
1643
1644static int pci_stub_notifier(struct notifier_block *nb,
1645			     unsigned long action, void *data)
1646{
1647	struct device *dev = data;
1648	const struct pci_dev *pdev = to_pci_dev(dev);
1649
1650	if (action != BUS_NOTIFY_UNBIND_DRIVER)
1651		return NOTIFY_DONE;
1652
1653	if (!pdev->is_physfn)
1654		return NOTIFY_DONE;
1655
1656	for (;;) {
1657		struct pcistub_device *psdev = find_vfs(pdev);
1658		if (!psdev)
1659			break;
1660		device_release_driver(&psdev->dev->dev);
1661	}
1662	return NOTIFY_DONE;
1663}
1664
1665static struct notifier_block pci_stub_nb = {
1666	.notifier_call = pci_stub_notifier,
1667};
1668#endif
1669
1670static int __init xen_pcibk_init(void)
1671{
1672	int err;
1673
1674	if (!xen_initial_domain())
1675		return -ENODEV;
1676
1677	err = xen_pcibk_config_init();
1678	if (err)
1679		return err;
1680
1681#ifdef MODULE
1682	err = pcistub_init();
1683	if (err < 0)
1684		return err;
1685#endif
1686
1687	pcistub_init_devices_late();
1688	err = xen_pcibk_xenbus_register();
1689	if (err)
1690		pcistub_exit();
1691#ifdef CONFIG_PCI_IOV
1692	else
1693		bus_register_notifier(&pci_bus_type, &pci_stub_nb);
1694#endif
1695
1696	return err;
1697}
1698
1699static void __exit xen_pcibk_cleanup(void)
1700{
1701#ifdef CONFIG_PCI_IOV
1702	bus_unregister_notifier(&pci_bus_type, &pci_stub_nb);
1703#endif
1704	xen_pcibk_xenbus_unregister();
1705	pcistub_exit();
1706}
1707
1708module_init(xen_pcibk_init);
1709module_exit(xen_pcibk_cleanup);
1710
1711MODULE_LICENSE("Dual BSD/GPL");
1712MODULE_ALIAS("xen-backend:pci");