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