1 /*
2  * PCI Stub Driver - Grabs devices in backend to be exported later
3  *
4  * Ryan Wilson <hap9@epoch.ncsc.mil>
5  * Chris Bookholt <hap10@epoch.ncsc.mil>
6  */
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/rwsem.h>
10 #include <linux/list.h>
11 #include <linux/spinlock.h>
12 #include <linux/kref.h>
13 #include <linux/pci.h>
14 #include <linux/wait.h>
15 #include <linux/sched.h>
16 #include <linux/atomic.h>
17 #include <xen/events.h>
18 #include <asm/xen/pci.h>
19 #include <asm/xen/hypervisor.h>
20 #include "pciback.h"
21 #include "conf_space.h"
22 #include "conf_space_quirks.h"
23 
24 static char *pci_devs_to_hide;
25 wait_queue_head_t xen_pcibk_aer_wait_queue;
26 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
27 * We want to avoid in middle of AER ops, xen_pcibk devices is being removed
28 */
29 static DECLARE_RWSEM(pcistub_sem);
30 module_param_named(hide, pci_devs_to_hide, charp, 0444);
31 
32 struct pcistub_device_id {
33 	struct list_head slot_list;
34 	int domain;
35 	unsigned char bus;
36 	unsigned int devfn;
37 };
38 static LIST_HEAD(pcistub_device_ids);
39 static DEFINE_SPINLOCK(device_ids_lock);
40 
41 struct pcistub_device {
42 	struct kref kref;
43 	struct list_head dev_list;
44 	spinlock_t lock;
45 
46 	struct pci_dev *dev;
47 	struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */
48 };
49 
50 /* Access to pcistub_devices & seized_devices lists and the initialize_devices
51  * flag must be locked with pcistub_devices_lock
52  */
53 static DEFINE_SPINLOCK(pcistub_devices_lock);
54 static LIST_HEAD(pcistub_devices);
55 
56 /* wait for device_initcall before initializing our devices
57  * (see pcistub_init_devices_late)
58  */
59 static int initialize_devices;
60 static LIST_HEAD(seized_devices);
61 
62 static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
63 {
64 	struct pcistub_device *psdev;
65 
66 	dev_dbg(&dev->dev, "pcistub_device_alloc\n");
67 
68 	psdev = kzalloc(sizeof(*psdev), GFP_ATOMIC);
69 	if (!psdev)
70 		return NULL;
71 
72 	psdev->dev = pci_dev_get(dev);
73 	if (!psdev->dev) {
74 		kfree(psdev);
75 		return NULL;
76 	}
77 
78 	kref_init(&psdev->kref);
79 	spin_lock_init(&psdev->lock);
80 
81 	return psdev;
82 }
83 
84 /* Don't call this directly as it's called by pcistub_device_put */
85 static void pcistub_device_release(struct kref *kref)
86 {
87 	struct pcistub_device *psdev;
88 	struct xen_pcibk_dev_data *dev_data;
89 
90 	psdev = container_of(kref, struct pcistub_device, kref);
91 	dev_data = pci_get_drvdata(psdev->dev);
92 
93 	dev_dbg(&psdev->dev->dev, "pcistub_device_release\n");
94 
95 	xen_unregister_device_domain_owner(psdev->dev);
96 
97 	/* Call the reset function which does not take lock as this
98 	 * is called from "unbind" which takes a device_lock mutex.
99 	 */
100 	__pci_reset_function_locked(psdev->dev);
101 	if (pci_load_and_free_saved_state(psdev->dev,
102 					  &dev_data->pci_saved_state)) {
103 		dev_dbg(&psdev->dev->dev, "Could not reload PCI state\n");
104 	} else
105 		pci_restore_state(psdev->dev);
106 
107 	/* Disable the device */
108 	xen_pcibk_reset_device(psdev->dev);
109 
110 	kfree(dev_data);
111 	pci_set_drvdata(psdev->dev, NULL);
112 
113 	/* Clean-up the device */
114 	xen_pcibk_config_free_dyn_fields(psdev->dev);
115 	xen_pcibk_config_free_dev(psdev->dev);
116 
117 	psdev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
118 	pci_dev_put(psdev->dev);
119 
120 	kfree(psdev);
121 }
122 
123 static inline void pcistub_device_get(struct pcistub_device *psdev)
124 {
125 	kref_get(&psdev->kref);
126 }
127 
128 static inline void pcistub_device_put(struct pcistub_device *psdev)
129 {
130 	kref_put(&psdev->kref, pcistub_device_release);
131 }
132 
133 static struct pcistub_device *pcistub_device_find(int domain, int bus,
134 						  int slot, int func)
135 {
136 	struct pcistub_device *psdev = NULL;
137 	unsigned long flags;
138 
139 	spin_lock_irqsave(&pcistub_devices_lock, flags);
140 
141 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
142 		if (psdev->dev != NULL
143 		    && domain == pci_domain_nr(psdev->dev->bus)
144 		    && bus == psdev->dev->bus->number
145 		    && PCI_DEVFN(slot, func) == psdev->dev->devfn) {
146 			pcistub_device_get(psdev);
147 			goto out;
148 		}
149 	}
150 
151 	/* didn't find it */
152 	psdev = NULL;
153 
154 out:
155 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
156 	return psdev;
157 }
158 
159 static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev,
160 						  struct pcistub_device *psdev)
161 {
162 	struct pci_dev *pci_dev = NULL;
163 	unsigned long flags;
164 
165 	pcistub_device_get(psdev);
166 
167 	spin_lock_irqsave(&psdev->lock, flags);
168 	if (!psdev->pdev) {
169 		psdev->pdev = pdev;
170 		pci_dev = psdev->dev;
171 	}
172 	spin_unlock_irqrestore(&psdev->lock, flags);
173 
174 	if (!pci_dev)
175 		pcistub_device_put(psdev);
176 
177 	return pci_dev;
178 }
179 
180 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
181 					    int domain, int bus,
182 					    int slot, int func)
183 {
184 	struct pcistub_device *psdev;
185 	struct pci_dev *found_dev = NULL;
186 	unsigned long flags;
187 
188 	spin_lock_irqsave(&pcistub_devices_lock, flags);
189 
190 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
191 		if (psdev->dev != NULL
192 		    && domain == pci_domain_nr(psdev->dev->bus)
193 		    && bus == psdev->dev->bus->number
194 		    && PCI_DEVFN(slot, func) == psdev->dev->devfn) {
195 			found_dev = pcistub_device_get_pci_dev(pdev, psdev);
196 			break;
197 		}
198 	}
199 
200 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
201 	return found_dev;
202 }
203 
204 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
205 				    struct pci_dev *dev)
206 {
207 	struct pcistub_device *psdev;
208 	struct pci_dev *found_dev = NULL;
209 	unsigned long flags;
210 
211 	spin_lock_irqsave(&pcistub_devices_lock, flags);
212 
213 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
214 		if (psdev->dev == dev) {
215 			found_dev = pcistub_device_get_pci_dev(pdev, psdev);
216 			break;
217 		}
218 	}
219 
220 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
221 	return found_dev;
222 }
223 
224 void pcistub_put_pci_dev(struct pci_dev *dev)
225 {
226 	struct pcistub_device *psdev, *found_psdev = NULL;
227 	unsigned long flags;
228 
229 	spin_lock_irqsave(&pcistub_devices_lock, flags);
230 
231 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
232 		if (psdev->dev == dev) {
233 			found_psdev = psdev;
234 			break;
235 		}
236 	}
237 
238 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
239 	if (WARN_ON(!found_psdev))
240 		return;
241 
242 	/*hold this lock for avoiding breaking link between
243 	* pcistub and xen_pcibk when AER is in processing
244 	*/
245 	down_write(&pcistub_sem);
246 	/* Cleanup our device
247 	 * (so it's ready for the next domain)
248 	 */
249 
250 	/* This is OK - we are running from workqueue context
251 	 * and want to inhibit the user from fiddling with 'reset'
252 	 */
253 	pci_reset_function(dev);
254 	pci_restore_state(psdev->dev);
255 
256 	/* This disables the device. */
257 	xen_pcibk_reset_device(found_psdev->dev);
258 
259 	/* And cleanup up our emulated fields. */
260 	xen_pcibk_config_free_dyn_fields(found_psdev->dev);
261 	xen_pcibk_config_reset_dev(found_psdev->dev);
262 
263 	xen_unregister_device_domain_owner(found_psdev->dev);
264 
265 	spin_lock_irqsave(&found_psdev->lock, flags);
266 	found_psdev->pdev = NULL;
267 	spin_unlock_irqrestore(&found_psdev->lock, flags);
268 
269 	pcistub_device_put(found_psdev);
270 	up_write(&pcistub_sem);
271 }
272 
273 static int __devinit pcistub_match_one(struct pci_dev *dev,
274 				       struct pcistub_device_id *pdev_id)
275 {
276 	/* Match the specified device by domain, bus, slot, func and also if
277 	 * any of the device's parent bridges match.
278 	 */
279 	for (; dev != NULL; dev = dev->bus->self) {
280 		if (pci_domain_nr(dev->bus) == pdev_id->domain
281 		    && dev->bus->number == pdev_id->bus
282 		    && dev->devfn == pdev_id->devfn)
283 			return 1;
284 
285 		/* Sometimes topmost bridge links to itself. */
286 		if (dev == dev->bus->self)
287 			break;
288 	}
289 
290 	return 0;
291 }
292 
293 static int __devinit pcistub_match(struct pci_dev *dev)
294 {
295 	struct pcistub_device_id *pdev_id;
296 	unsigned long flags;
297 	int found = 0;
298 
299 	spin_lock_irqsave(&device_ids_lock, flags);
300 	list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) {
301 		if (pcistub_match_one(dev, pdev_id)) {
302 			found = 1;
303 			break;
304 		}
305 	}
306 	spin_unlock_irqrestore(&device_ids_lock, flags);
307 
308 	return found;
309 }
310 
311 static int __devinit pcistub_init_device(struct pci_dev *dev)
312 {
313 	struct xen_pcibk_dev_data *dev_data;
314 	int err = 0;
315 
316 	dev_dbg(&dev->dev, "initializing...\n");
317 
318 	/* The PCI backend is not intended to be a module (or to work with
319 	 * removable PCI devices (yet). If it were, xen_pcibk_config_free()
320 	 * would need to be called somewhere to free the memory allocated
321 	 * here and then to call kfree(pci_get_drvdata(psdev->dev)).
322 	 */
323 	dev_data = kzalloc(sizeof(*dev_data) +  strlen(DRV_NAME "[]")
324 				+ strlen(pci_name(dev)) + 1, GFP_ATOMIC);
325 	if (!dev_data) {
326 		err = -ENOMEM;
327 		goto out;
328 	}
329 	pci_set_drvdata(dev, dev_data);
330 
331 	/*
332 	 * Setup name for fake IRQ handler. It will only be enabled
333 	 * once the device is turned on by the guest.
334 	 */
335 	sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev));
336 
337 	dev_dbg(&dev->dev, "initializing config\n");
338 
339 	init_waitqueue_head(&xen_pcibk_aer_wait_queue);
340 	err = xen_pcibk_config_init_dev(dev);
341 	if (err)
342 		goto out;
343 
344 	/* HACK: Force device (& ACPI) to determine what IRQ it's on - we
345 	 * must do this here because pcibios_enable_device may specify
346 	 * the pci device's true irq (and possibly its other resources)
347 	 * if they differ from what's in the configuration space.
348 	 * This makes the assumption that the device's resources won't
349 	 * change after this point (otherwise this code may break!)
350 	 */
351 	dev_dbg(&dev->dev, "enabling device\n");
352 	err = pci_enable_device(dev);
353 	if (err)
354 		goto config_release;
355 
356 	dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
357 	__pci_reset_function_locked(dev);
358 
359 	/* We need the device active to save the state. */
360 	dev_dbg(&dev->dev, "save state of device\n");
361 	pci_save_state(dev);
362 	dev_data->pci_saved_state = pci_store_saved_state(dev);
363 	if (!dev_data->pci_saved_state)
364 		dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
365 
366 	/* Now disable the device (this also ensures some private device
367 	 * data is setup before we export)
368 	 */
369 	dev_dbg(&dev->dev, "reset device\n");
370 	xen_pcibk_reset_device(dev);
371 
372 	dev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
373 	return 0;
374 
375 config_release:
376 	xen_pcibk_config_free_dev(dev);
377 
378 out:
379 	pci_set_drvdata(dev, NULL);
380 	kfree(dev_data);
381 	return err;
382 }
383 
384 /*
385  * Because some initialization still happens on
386  * devices during fs_initcall, we need to defer
387  * full initialization of our devices until
388  * device_initcall.
389  */
390 static int __init pcistub_init_devices_late(void)
391 {
392 	struct pcistub_device *psdev;
393 	unsigned long flags;
394 	int err = 0;
395 
396 	pr_debug(DRV_NAME ": pcistub_init_devices_late\n");
397 
398 	spin_lock_irqsave(&pcistub_devices_lock, flags);
399 
400 	while (!list_empty(&seized_devices)) {
401 		psdev = container_of(seized_devices.next,
402 				     struct pcistub_device, dev_list);
403 		list_del(&psdev->dev_list);
404 
405 		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
406 
407 		err = pcistub_init_device(psdev->dev);
408 		if (err) {
409 			dev_err(&psdev->dev->dev,
410 				"error %d initializing device\n", err);
411 			kfree(psdev);
412 			psdev = NULL;
413 		}
414 
415 		spin_lock_irqsave(&pcistub_devices_lock, flags);
416 
417 		if (psdev)
418 			list_add_tail(&psdev->dev_list, &pcistub_devices);
419 	}
420 
421 	initialize_devices = 1;
422 
423 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
424 
425 	return 0;
426 }
427 
428 static int __devinit pcistub_seize(struct pci_dev *dev)
429 {
430 	struct pcistub_device *psdev;
431 	unsigned long flags;
432 	int err = 0;
433 
434 	psdev = pcistub_device_alloc(dev);
435 	if (!psdev)
436 		return -ENOMEM;
437 
438 	spin_lock_irqsave(&pcistub_devices_lock, flags);
439 
440 	if (initialize_devices) {
441 		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
442 
443 		/* don't want irqs disabled when calling pcistub_init_device */
444 		err = pcistub_init_device(psdev->dev);
445 
446 		spin_lock_irqsave(&pcistub_devices_lock, flags);
447 
448 		if (!err)
449 			list_add(&psdev->dev_list, &pcistub_devices);
450 	} else {
451 		dev_dbg(&dev->dev, "deferring initialization\n");
452 		list_add(&psdev->dev_list, &seized_devices);
453 	}
454 
455 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
456 
457 	if (err)
458 		pcistub_device_put(psdev);
459 
460 	return err;
461 }
462 
463 static int __devinit pcistub_probe(struct pci_dev *dev,
464 				   const struct pci_device_id *id)
465 {
466 	int err = 0;
467 
468 	dev_dbg(&dev->dev, "probing...\n");
469 
470 	if (pcistub_match(dev)) {
471 
472 		if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
473 		    && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
474 			dev_err(&dev->dev, "can't export pci devices that "
475 				"don't have a normal (0) or bridge (1) "
476 				"header type!\n");
477 			err = -ENODEV;
478 			goto out;
479 		}
480 
481 		dev_info(&dev->dev, "seizing device\n");
482 		err = pcistub_seize(dev);
483 	} else
484 		/* Didn't find the device */
485 		err = -ENODEV;
486 
487 out:
488 	return err;
489 }
490 
491 static void pcistub_remove(struct pci_dev *dev)
492 {
493 	struct pcistub_device *psdev, *found_psdev = NULL;
494 	unsigned long flags;
495 
496 	dev_dbg(&dev->dev, "removing\n");
497 
498 	spin_lock_irqsave(&pcistub_devices_lock, flags);
499 
500 	xen_pcibk_config_quirk_release(dev);
501 
502 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
503 		if (psdev->dev == dev) {
504 			found_psdev = psdev;
505 			break;
506 		}
507 	}
508 
509 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
510 
511 	if (found_psdev) {
512 		dev_dbg(&dev->dev, "found device to remove - in use? %p\n",
513 			found_psdev->pdev);
514 
515 		if (found_psdev->pdev) {
516 			printk(KERN_WARNING DRV_NAME ": ****** removing device "
517 			       "%s while still in-use! ******\n",
518 			       pci_name(found_psdev->dev));
519 			printk(KERN_WARNING DRV_NAME ": ****** driver domain may"
520 			       " still access this device's i/o resources!\n");
521 			printk(KERN_WARNING DRV_NAME ": ****** shutdown driver "
522 			       "domain before binding device\n");
523 			printk(KERN_WARNING DRV_NAME ": ****** to other drivers "
524 			       "or domains\n");
525 
526 			xen_pcibk_release_pci_dev(found_psdev->pdev,
527 						found_psdev->dev);
528 		}
529 
530 		spin_lock_irqsave(&pcistub_devices_lock, flags);
531 		list_del(&found_psdev->dev_list);
532 		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
533 
534 		/* the final put for releasing from the list */
535 		pcistub_device_put(found_psdev);
536 	}
537 }
538 
539 static DEFINE_PCI_DEVICE_TABLE(pcistub_ids) = {
540 	{
541 	 .vendor = PCI_ANY_ID,
542 	 .device = PCI_ANY_ID,
543 	 .subvendor = PCI_ANY_ID,
544 	 .subdevice = PCI_ANY_ID,
545 	 },
546 	{0,},
547 };
548 
549 #define PCI_NODENAME_MAX 40
550 static void kill_domain_by_device(struct pcistub_device *psdev)
551 {
552 	struct xenbus_transaction xbt;
553 	int err;
554 	char nodename[PCI_NODENAME_MAX];
555 
556 	BUG_ON(!psdev);
557 	snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
558 		psdev->pdev->xdev->otherend_id);
559 
560 again:
561 	err = xenbus_transaction_start(&xbt);
562 	if (err) {
563 		dev_err(&psdev->dev->dev,
564 			"error %d when start xenbus transaction\n", err);
565 		return;
566 	}
567 	/*PV AER handlers will set this flag*/
568 	xenbus_printf(xbt, nodename, "aerState" , "aerfail");
569 	err = xenbus_transaction_end(xbt, 0);
570 	if (err) {
571 		if (err == -EAGAIN)
572 			goto again;
573 		dev_err(&psdev->dev->dev,
574 			"error %d when end xenbus transaction\n", err);
575 		return;
576 	}
577 }
578 
579 /* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
580  * backend need to have cooperation. In xen_pcibk, those steps will do similar
581  * jobs: send service request and waiting for front_end response.
582 */
583 static pci_ers_result_t common_process(struct pcistub_device *psdev,
584 				       pci_channel_state_t state, int aer_cmd,
585 				       pci_ers_result_t result)
586 {
587 	pci_ers_result_t res = result;
588 	struct xen_pcie_aer_op *aer_op;
589 	int ret;
590 
591 	/*with PV AER drivers*/
592 	aer_op = &(psdev->pdev->sh_info->aer_op);
593 	aer_op->cmd = aer_cmd ;
594 	/*useful for error_detected callback*/
595 	aer_op->err = state;
596 	/*pcifront_end BDF*/
597 	ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
598 		&aer_op->domain, &aer_op->bus, &aer_op->devfn);
599 	if (!ret) {
600 		dev_err(&psdev->dev->dev,
601 			DRV_NAME ": failed to get pcifront device\n");
602 		return PCI_ERS_RESULT_NONE;
603 	}
604 	wmb();
605 
606 	dev_dbg(&psdev->dev->dev,
607 			DRV_NAME ": aer_op %x dom %x bus %x devfn %x\n",
608 			aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
609 	/*local flag to mark there's aer request, xen_pcibk callback will use
610 	* this flag to judge whether we need to check pci-front give aer
611 	* service ack signal
612 	*/
613 	set_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
614 
615 	/*It is possible that a pcifront conf_read_write ops request invokes
616 	* the callback which cause the spurious execution of wake_up.
617 	* Yet it is harmless and better than a spinlock here
618 	*/
619 	set_bit(_XEN_PCIB_active,
620 		(unsigned long *)&psdev->pdev->sh_info->flags);
621 	wmb();
622 	notify_remote_via_irq(psdev->pdev->evtchn_irq);
623 
624 	ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
625 				 !(test_bit(_XEN_PCIB_active, (unsigned long *)
626 				 &psdev->pdev->sh_info->flags)), 300*HZ);
627 
628 	if (!ret) {
629 		if (test_bit(_XEN_PCIB_active,
630 			(unsigned long *)&psdev->pdev->sh_info->flags)) {
631 			dev_err(&psdev->dev->dev,
632 				"pcifront aer process not responding!\n");
633 			clear_bit(_XEN_PCIB_active,
634 			  (unsigned long *)&psdev->pdev->sh_info->flags);
635 			aer_op->err = PCI_ERS_RESULT_NONE;
636 			return res;
637 		}
638 	}
639 	clear_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
640 
641 	if (test_bit(_XEN_PCIF_active,
642 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
643 		dev_dbg(&psdev->dev->dev,
644 			"schedule pci_conf service in " DRV_NAME "\n");
645 		xen_pcibk_test_and_schedule_op(psdev->pdev);
646 	}
647 
648 	res = (pci_ers_result_t)aer_op->err;
649 	return res;
650 }
651 
652 /*
653 * xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
654 * of the device driver could provide this service, and then wait for pcifront
655 * ack.
656 * @dev: pointer to PCI devices
657 * return value is used by aer_core do_recovery policy
658 */
659 static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
660 {
661 	struct pcistub_device *psdev;
662 	pci_ers_result_t result;
663 
664 	result = PCI_ERS_RESULT_RECOVERED;
665 	dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
666 		dev->bus->number, dev->devfn);
667 
668 	down_write(&pcistub_sem);
669 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
670 				dev->bus->number,
671 				PCI_SLOT(dev->devfn),
672 				PCI_FUNC(dev->devfn));
673 
674 	if (!psdev || !psdev->pdev) {
675 		dev_err(&dev->dev,
676 			DRV_NAME " device is not found/assigned\n");
677 		goto end;
678 	}
679 
680 	if (!psdev->pdev->sh_info) {
681 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
682 			" by HVM, kill it\n");
683 		kill_domain_by_device(psdev);
684 		goto release;
685 	}
686 
687 	if (!test_bit(_XEN_PCIB_AERHANDLER,
688 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
689 		dev_err(&dev->dev,
690 			"guest with no AER driver should have been killed\n");
691 		goto release;
692 	}
693 	result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
694 
695 	if (result == PCI_ERS_RESULT_NONE ||
696 		result == PCI_ERS_RESULT_DISCONNECT) {
697 		dev_dbg(&dev->dev,
698 			"No AER slot_reset service or disconnected!\n");
699 		kill_domain_by_device(psdev);
700 	}
701 release:
702 	pcistub_device_put(psdev);
703 end:
704 	up_write(&pcistub_sem);
705 	return result;
706 
707 }
708 
709 
710 /*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
711 * in case of the device driver could provide this service, and then wait
712 * for pcifront ack
713 * @dev: pointer to PCI devices
714 * return value is used by aer_core do_recovery policy
715 */
716 
717 static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
718 {
719 	struct pcistub_device *psdev;
720 	pci_ers_result_t result;
721 
722 	result = PCI_ERS_RESULT_RECOVERED;
723 	dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n",
724 		dev->bus->number, dev->devfn);
725 
726 	down_write(&pcistub_sem);
727 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
728 				dev->bus->number,
729 				PCI_SLOT(dev->devfn),
730 				PCI_FUNC(dev->devfn));
731 
732 	if (!psdev || !psdev->pdev) {
733 		dev_err(&dev->dev,
734 			DRV_NAME " device is not found/assigned\n");
735 		goto end;
736 	}
737 
738 	if (!psdev->pdev->sh_info) {
739 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
740 			" by HVM, kill it\n");
741 		kill_domain_by_device(psdev);
742 		goto release;
743 	}
744 
745 	if (!test_bit(_XEN_PCIB_AERHANDLER,
746 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
747 		dev_err(&dev->dev,
748 			"guest with no AER driver should have been killed\n");
749 		goto release;
750 	}
751 	result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
752 
753 	if (result == PCI_ERS_RESULT_NONE ||
754 		result == PCI_ERS_RESULT_DISCONNECT) {
755 		dev_dbg(&dev->dev,
756 			"No AER mmio_enabled service or disconnected!\n");
757 		kill_domain_by_device(psdev);
758 	}
759 release:
760 	pcistub_device_put(psdev);
761 end:
762 	up_write(&pcistub_sem);
763 	return result;
764 }
765 
766 /*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
767 * in case of the device driver could provide this service, and then wait
768 * for pcifront ack.
769 * @dev: pointer to PCI devices
770 * @error: the current PCI connection state
771 * return value is used by aer_core do_recovery policy
772 */
773 
774 static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
775 	pci_channel_state_t error)
776 {
777 	struct pcistub_device *psdev;
778 	pci_ers_result_t result;
779 
780 	result = PCI_ERS_RESULT_CAN_RECOVER;
781 	dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
782 		dev->bus->number, dev->devfn);
783 
784 	down_write(&pcistub_sem);
785 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
786 				dev->bus->number,
787 				PCI_SLOT(dev->devfn),
788 				PCI_FUNC(dev->devfn));
789 
790 	if (!psdev || !psdev->pdev) {
791 		dev_err(&dev->dev,
792 			DRV_NAME " device is not found/assigned\n");
793 		goto end;
794 	}
795 
796 	if (!psdev->pdev->sh_info) {
797 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
798 			" by HVM, kill it\n");
799 		kill_domain_by_device(psdev);
800 		goto release;
801 	}
802 
803 	/*Guest owns the device yet no aer handler regiested, kill guest*/
804 	if (!test_bit(_XEN_PCIB_AERHANDLER,
805 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
806 		dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
807 		kill_domain_by_device(psdev);
808 		goto release;
809 	}
810 	result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
811 
812 	if (result == PCI_ERS_RESULT_NONE ||
813 		result == PCI_ERS_RESULT_DISCONNECT) {
814 		dev_dbg(&dev->dev,
815 			"No AER error_detected service or disconnected!\n");
816 		kill_domain_by_device(psdev);
817 	}
818 release:
819 	pcistub_device_put(psdev);
820 end:
821 	up_write(&pcistub_sem);
822 	return result;
823 }
824 
825 /*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
826 * in case of the device driver could provide this service, and then wait
827 * for pcifront ack.
828 * @dev: pointer to PCI devices
829 */
830 
831 static void xen_pcibk_error_resume(struct pci_dev *dev)
832 {
833 	struct pcistub_device *psdev;
834 
835 	dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
836 		dev->bus->number, dev->devfn);
837 
838 	down_write(&pcistub_sem);
839 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
840 				dev->bus->number,
841 				PCI_SLOT(dev->devfn),
842 				PCI_FUNC(dev->devfn));
843 
844 	if (!psdev || !psdev->pdev) {
845 		dev_err(&dev->dev,
846 			DRV_NAME " device is not found/assigned\n");
847 		goto end;
848 	}
849 
850 	if (!psdev->pdev->sh_info) {
851 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
852 			" by HVM, kill it\n");
853 		kill_domain_by_device(psdev);
854 		goto release;
855 	}
856 
857 	if (!test_bit(_XEN_PCIB_AERHANDLER,
858 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
859 		dev_err(&dev->dev,
860 			"guest with no AER driver should have been killed\n");
861 		kill_domain_by_device(psdev);
862 		goto release;
863 	}
864 	common_process(psdev, 1, XEN_PCI_OP_aer_resume,
865 		       PCI_ERS_RESULT_RECOVERED);
866 release:
867 	pcistub_device_put(psdev);
868 end:
869 	up_write(&pcistub_sem);
870 	return;
871 }
872 
873 /*add xen_pcibk AER handling*/
874 static struct pci_error_handlers xen_pcibk_error_handler = {
875 	.error_detected = xen_pcibk_error_detected,
876 	.mmio_enabled = xen_pcibk_mmio_enabled,
877 	.slot_reset = xen_pcibk_slot_reset,
878 	.resume = xen_pcibk_error_resume,
879 };
880 
881 /*
882  * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
883  * for a normal device. I don't want it to be loaded automatically.
884  */
885 
886 static struct pci_driver xen_pcibk_pci_driver = {
887 	/* The name should be xen_pciback, but until the tools are updated
888 	 * we will keep it as pciback. */
889 	.name = "pciback",
890 	.id_table = pcistub_ids,
891 	.probe = pcistub_probe,
892 	.remove = pcistub_remove,
893 	.err_handler = &xen_pcibk_error_handler,
894 };
895 
896 static inline int str_to_slot(const char *buf, int *domain, int *bus,
897 			      int *slot, int *func)
898 {
899 	int err;
900 
901 	err = sscanf(buf, " %x:%x:%x.%x", domain, bus, slot, func);
902 	if (err == 4)
903 		return 0;
904 	else if (err < 0)
905 		return -EINVAL;
906 
907 	/* try again without domain */
908 	*domain = 0;
909 	err = sscanf(buf, " %x:%x.%x", bus, slot, func);
910 	if (err == 3)
911 		return 0;
912 
913 	return -EINVAL;
914 }
915 
916 static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
917 			       *slot, int *func, int *reg, int *size, int *mask)
918 {
919 	int err;
920 
921 	err =
922 	    sscanf(buf, " %04x:%02x:%02x.%d-%08x:%1x:%08x", domain, bus, slot,
923 		   func, reg, size, mask);
924 	if (err == 7)
925 		return 0;
926 	return -EINVAL;
927 }
928 
929 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
930 {
931 	struct pcistub_device_id *pci_dev_id;
932 	unsigned long flags;
933 
934 	pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
935 	if (!pci_dev_id)
936 		return -ENOMEM;
937 
938 	pci_dev_id->domain = domain;
939 	pci_dev_id->bus = bus;
940 	pci_dev_id->devfn = PCI_DEVFN(slot, func);
941 
942 	pr_debug(DRV_NAME ": wants to seize %04x:%02x:%02x.%d\n",
943 		 domain, bus, slot, func);
944 
945 	spin_lock_irqsave(&device_ids_lock, flags);
946 	list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
947 	spin_unlock_irqrestore(&device_ids_lock, flags);
948 
949 	return 0;
950 }
951 
952 static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
953 {
954 	struct pcistub_device_id *pci_dev_id, *t;
955 	int devfn = PCI_DEVFN(slot, func);
956 	int err = -ENOENT;
957 	unsigned long flags;
958 
959 	spin_lock_irqsave(&device_ids_lock, flags);
960 	list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
961 				 slot_list) {
962 		if (pci_dev_id->domain == domain
963 		    && pci_dev_id->bus == bus && pci_dev_id->devfn == devfn) {
964 			/* Don't break; here because it's possible the same
965 			 * slot could be in the list more than once
966 			 */
967 			list_del(&pci_dev_id->slot_list);
968 			kfree(pci_dev_id);
969 
970 			err = 0;
971 
972 			pr_debug(DRV_NAME ": removed %04x:%02x:%02x.%d from "
973 				 "seize list\n", domain, bus, slot, func);
974 		}
975 	}
976 	spin_unlock_irqrestore(&device_ids_lock, flags);
977 
978 	return err;
979 }
980 
981 static int pcistub_reg_add(int domain, int bus, int slot, int func, int reg,
982 			   int size, int mask)
983 {
984 	int err = 0;
985 	struct pcistub_device *psdev;
986 	struct pci_dev *dev;
987 	struct config_field *field;
988 
989 	psdev = pcistub_device_find(domain, bus, slot, func);
990 	if (!psdev || !psdev->dev) {
991 		err = -ENODEV;
992 		goto out;
993 	}
994 	dev = psdev->dev;
995 
996 	field = kzalloc(sizeof(*field), GFP_ATOMIC);
997 	if (!field) {
998 		err = -ENOMEM;
999 		goto out;
1000 	}
1001 
1002 	field->offset = reg;
1003 	field->size = size;
1004 	field->mask = mask;
1005 	field->init = NULL;
1006 	field->reset = NULL;
1007 	field->release = NULL;
1008 	field->clean = xen_pcibk_config_field_free;
1009 
1010 	err = xen_pcibk_config_quirks_add_field(dev, field);
1011 	if (err)
1012 		kfree(field);
1013 out:
1014 	return err;
1015 }
1016 
1017 static ssize_t pcistub_slot_add(struct device_driver *drv, const char *buf,
1018 				size_t count)
1019 {
1020 	int domain, bus, slot, func;
1021 	int err;
1022 
1023 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1024 	if (err)
1025 		goto out;
1026 
1027 	err = pcistub_device_id_add(domain, bus, slot, func);
1028 
1029 out:
1030 	if (!err)
1031 		err = count;
1032 	return err;
1033 }
1034 static DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
1035 
1036 static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
1037 				   size_t count)
1038 {
1039 	int domain, bus, slot, func;
1040 	int err;
1041 
1042 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1043 	if (err)
1044 		goto out;
1045 
1046 	err = pcistub_device_id_remove(domain, bus, slot, func);
1047 
1048 out:
1049 	if (!err)
1050 		err = count;
1051 	return err;
1052 }
1053 static DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
1054 
1055 static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
1056 {
1057 	struct pcistub_device_id *pci_dev_id;
1058 	size_t count = 0;
1059 	unsigned long flags;
1060 
1061 	spin_lock_irqsave(&device_ids_lock, flags);
1062 	list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1063 		if (count >= PAGE_SIZE)
1064 			break;
1065 
1066 		count += scnprintf(buf + count, PAGE_SIZE - count,
1067 				   "%04x:%02x:%02x.%d\n",
1068 				   pci_dev_id->domain, pci_dev_id->bus,
1069 				   PCI_SLOT(pci_dev_id->devfn),
1070 				   PCI_FUNC(pci_dev_id->devfn));
1071 	}
1072 	spin_unlock_irqrestore(&device_ids_lock, flags);
1073 
1074 	return count;
1075 }
1076 static DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
1077 
1078 static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
1079 {
1080 	struct pcistub_device *psdev;
1081 	struct xen_pcibk_dev_data *dev_data;
1082 	size_t count = 0;
1083 	unsigned long flags;
1084 
1085 	spin_lock_irqsave(&pcistub_devices_lock, flags);
1086 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1087 		if (count >= PAGE_SIZE)
1088 			break;
1089 		if (!psdev->dev)
1090 			continue;
1091 		dev_data = pci_get_drvdata(psdev->dev);
1092 		if (!dev_data)
1093 			continue;
1094 		count +=
1095 		    scnprintf(buf + count, PAGE_SIZE - count,
1096 			      "%s:%s:%sing:%ld\n",
1097 			      pci_name(psdev->dev),
1098 			      dev_data->isr_on ? "on" : "off",
1099 			      dev_data->ack_intr ? "ack" : "not ack",
1100 			      dev_data->handled);
1101 	}
1102 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1103 	return count;
1104 }
1105 static DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
1106 
1107 static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
1108 					  const char *buf,
1109 					  size_t count)
1110 {
1111 	struct pcistub_device *psdev;
1112 	struct xen_pcibk_dev_data *dev_data;
1113 	int domain, bus, slot, func;
1114 	int err = -ENOENT;
1115 
1116 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1117 	if (err)
1118 		goto out;
1119 
1120 	psdev = pcistub_device_find(domain, bus, slot, func);
1121 
1122 	if (!psdev)
1123 		goto out;
1124 
1125 	dev_data = pci_get_drvdata(psdev->dev);
1126 	if (!dev_data)
1127 		goto out;
1128 
1129 	dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1130 		dev_data->irq_name, dev_data->isr_on,
1131 		!dev_data->isr_on);
1132 
1133 	dev_data->isr_on = !(dev_data->isr_on);
1134 	if (dev_data->isr_on)
1135 		dev_data->ack_intr = 1;
1136 out:
1137 	if (!err)
1138 		err = count;
1139 	return err;
1140 }
1141 static DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL,
1142 		   pcistub_irq_handler_switch);
1143 
1144 static ssize_t pcistub_quirk_add(struct device_driver *drv, const char *buf,
1145 				 size_t count)
1146 {
1147 	int domain, bus, slot, func, reg, size, mask;
1148 	int err;
1149 
1150 	err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1151 			   &mask);
1152 	if (err)
1153 		goto out;
1154 
1155 	err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1156 
1157 out:
1158 	if (!err)
1159 		err = count;
1160 	return err;
1161 }
1162 
1163 static ssize_t pcistub_quirk_show(struct device_driver *drv, char *buf)
1164 {
1165 	int count = 0;
1166 	unsigned long flags;
1167 	struct xen_pcibk_config_quirk *quirk;
1168 	struct xen_pcibk_dev_data *dev_data;
1169 	const struct config_field *field;
1170 	const struct config_field_entry *cfg_entry;
1171 
1172 	spin_lock_irqsave(&device_ids_lock, flags);
1173 	list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1174 		if (count >= PAGE_SIZE)
1175 			goto out;
1176 
1177 		count += scnprintf(buf + count, PAGE_SIZE - count,
1178 				   "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1179 				   quirk->pdev->bus->number,
1180 				   PCI_SLOT(quirk->pdev->devfn),
1181 				   PCI_FUNC(quirk->pdev->devfn),
1182 				   quirk->devid.vendor, quirk->devid.device,
1183 				   quirk->devid.subvendor,
1184 				   quirk->devid.subdevice);
1185 
1186 		dev_data = pci_get_drvdata(quirk->pdev);
1187 
1188 		list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1189 			field = cfg_entry->field;
1190 			if (count >= PAGE_SIZE)
1191 				goto out;
1192 
1193 			count += scnprintf(buf + count, PAGE_SIZE - count,
1194 					   "\t\t%08x:%01x:%08x\n",
1195 					   cfg_entry->base_offset +
1196 					   field->offset, field->size,
1197 					   field->mask);
1198 		}
1199 	}
1200 
1201 out:
1202 	spin_unlock_irqrestore(&device_ids_lock, flags);
1203 
1204 	return count;
1205 }
1206 static DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show,
1207 		   pcistub_quirk_add);
1208 
1209 static ssize_t permissive_add(struct device_driver *drv, const char *buf,
1210 			      size_t count)
1211 {
1212 	int domain, bus, slot, func;
1213 	int err;
1214 	struct pcistub_device *psdev;
1215 	struct xen_pcibk_dev_data *dev_data;
1216 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1217 	if (err)
1218 		goto out;
1219 	psdev = pcistub_device_find(domain, bus, slot, func);
1220 	if (!psdev) {
1221 		err = -ENODEV;
1222 		goto out;
1223 	}
1224 	if (!psdev->dev) {
1225 		err = -ENODEV;
1226 		goto release;
1227 	}
1228 	dev_data = pci_get_drvdata(psdev->dev);
1229 	/* the driver data for a device should never be null at this point */
1230 	if (!dev_data) {
1231 		err = -ENXIO;
1232 		goto release;
1233 	}
1234 	if (!dev_data->permissive) {
1235 		dev_data->permissive = 1;
1236 		/* Let user know that what they're doing could be unsafe */
1237 		dev_warn(&psdev->dev->dev, "enabling permissive mode "
1238 			 "configuration space accesses!\n");
1239 		dev_warn(&psdev->dev->dev,
1240 			 "permissive mode is potentially unsafe!\n");
1241 	}
1242 release:
1243 	pcistub_device_put(psdev);
1244 out:
1245 	if (!err)
1246 		err = count;
1247 	return err;
1248 }
1249 
1250 static ssize_t permissive_show(struct device_driver *drv, char *buf)
1251 {
1252 	struct pcistub_device *psdev;
1253 	struct xen_pcibk_dev_data *dev_data;
1254 	size_t count = 0;
1255 	unsigned long flags;
1256 	spin_lock_irqsave(&pcistub_devices_lock, flags);
1257 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1258 		if (count >= PAGE_SIZE)
1259 			break;
1260 		if (!psdev->dev)
1261 			continue;
1262 		dev_data = pci_get_drvdata(psdev->dev);
1263 		if (!dev_data || !dev_data->permissive)
1264 			continue;
1265 		count +=
1266 		    scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1267 			      pci_name(psdev->dev));
1268 	}
1269 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1270 	return count;
1271 }
1272 static DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show,
1273 		   permissive_add);
1274 
1275 static void pcistub_exit(void)
1276 {
1277 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1278 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1279 			   &driver_attr_remove_slot);
1280 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1281 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1282 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1283 			   &driver_attr_permissive);
1284 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1285 			   &driver_attr_irq_handlers);
1286 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1287 			   &driver_attr_irq_handler_state);
1288 	pci_unregister_driver(&xen_pcibk_pci_driver);
1289 }
1290 
1291 static int __init pcistub_init(void)
1292 {
1293 	int pos = 0;
1294 	int err = 0;
1295 	int domain, bus, slot, func;
1296 	int parsed;
1297 
1298 	if (pci_devs_to_hide && *pci_devs_to_hide) {
1299 		do {
1300 			parsed = 0;
1301 
1302 			err = sscanf(pci_devs_to_hide + pos,
1303 				     " (%x:%x:%x.%x) %n",
1304 				     &domain, &bus, &slot, &func, &parsed);
1305 			if (err != 4) {
1306 				domain = 0;
1307 				err = sscanf(pci_devs_to_hide + pos,
1308 					     " (%x:%x.%x) %n",
1309 					     &bus, &slot, &func, &parsed);
1310 				if (err != 3)
1311 					goto parse_error;
1312 			}
1313 
1314 			err = pcistub_device_id_add(domain, bus, slot, func);
1315 			if (err)
1316 				goto out;
1317 
1318 			/* if parsed<=0, we've reached the end of the string */
1319 			pos += parsed;
1320 		} while (parsed > 0 && pci_devs_to_hide[pos]);
1321 	}
1322 
1323 	/* If we're the first PCI Device Driver to register, we're the
1324 	 * first one to get offered PCI devices as they become
1325 	 * available (and thus we can be the first to grab them)
1326 	 */
1327 	err = pci_register_driver(&xen_pcibk_pci_driver);
1328 	if (err < 0)
1329 		goto out;
1330 
1331 	err = driver_create_file(&xen_pcibk_pci_driver.driver,
1332 				 &driver_attr_new_slot);
1333 	if (!err)
1334 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1335 					 &driver_attr_remove_slot);
1336 	if (!err)
1337 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1338 					 &driver_attr_slots);
1339 	if (!err)
1340 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1341 					 &driver_attr_quirks);
1342 	if (!err)
1343 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1344 					 &driver_attr_permissive);
1345 
1346 	if (!err)
1347 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1348 					 &driver_attr_irq_handlers);
1349 	if (!err)
1350 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1351 					&driver_attr_irq_handler_state);
1352 	if (err)
1353 		pcistub_exit();
1354 
1355 out:
1356 	return err;
1357 
1358 parse_error:
1359 	printk(KERN_ERR DRV_NAME ": Error parsing pci_devs_to_hide at \"%s\"\n",
1360 	       pci_devs_to_hide + pos);
1361 	return -EINVAL;
1362 }
1363 
1364 #ifndef MODULE
1365 /*
1366  * fs_initcall happens before device_initcall
1367  * so xen_pcibk *should* get called first (b/c we
1368  * want to suck up any device before other drivers
1369  * get a chance by being the first pci device
1370  * driver to register)
1371  */
1372 fs_initcall(pcistub_init);
1373 #endif
1374 
1375 static int __init xen_pcibk_init(void)
1376 {
1377 	int err;
1378 
1379 	if (!xen_initial_domain())
1380 		return -ENODEV;
1381 
1382 	err = xen_pcibk_config_init();
1383 	if (err)
1384 		return err;
1385 
1386 #ifdef MODULE
1387 	err = pcistub_init();
1388 	if (err < 0)
1389 		return err;
1390 #endif
1391 
1392 	pcistub_init_devices_late();
1393 	err = xen_pcibk_xenbus_register();
1394 	if (err)
1395 		pcistub_exit();
1396 
1397 	return err;
1398 }
1399 
1400 static void __exit xen_pcibk_cleanup(void)
1401 {
1402 	xen_pcibk_xenbus_unregister();
1403 	pcistub_exit();
1404 }
1405 
1406 module_init(xen_pcibk_init);
1407 module_exit(xen_pcibk_cleanup);
1408 
1409 MODULE_LICENSE("Dual BSD/GPL");
1410 MODULE_ALIAS("xen-backend:pci");
1411