xref: /linux/drivers/xen/xen-pciback/pci_stub.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 __devinit 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 __devinit 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 __devinit 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 __devinit 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 __devinit pcistub_probe(struct pci_dev *dev,
467 				   const struct pci_device_id *id)
468 {
469 	int err = 0;
470 
471 	dev_dbg(&dev->dev, "probing...\n");
472 
473 	if (pcistub_match(dev)) {
474 
475 		if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL
476 		    && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
477 			dev_err(&dev->dev, "can't export pci devices that "
478 				"don't have a normal (0) or bridge (1) "
479 				"header type!\n");
480 			err = -ENODEV;
481 			goto out;
482 		}
483 
484 		dev_info(&dev->dev, "seizing device\n");
485 		err = pcistub_seize(dev);
486 	} else
487 		/* Didn't find the device */
488 		err = -ENODEV;
489 
490 out:
491 	return err;
492 }
493 
494 static void pcistub_remove(struct pci_dev *dev)
495 {
496 	struct pcistub_device *psdev, *found_psdev = NULL;
497 	unsigned long flags;
498 
499 	dev_dbg(&dev->dev, "removing\n");
500 
501 	spin_lock_irqsave(&pcistub_devices_lock, flags);
502 
503 	xen_pcibk_config_quirk_release(dev);
504 
505 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
506 		if (psdev->dev == dev) {
507 			found_psdev = psdev;
508 			break;
509 		}
510 	}
511 
512 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
513 
514 	if (found_psdev) {
515 		dev_dbg(&dev->dev, "found device to remove - in use? %p\n",
516 			found_psdev->pdev);
517 
518 		if (found_psdev->pdev) {
519 			printk(KERN_WARNING DRV_NAME ": ****** removing device "
520 			       "%s while still in-use! ******\n",
521 			       pci_name(found_psdev->dev));
522 			printk(KERN_WARNING DRV_NAME ": ****** driver domain may"
523 			       " still access this device's i/o resources!\n");
524 			printk(KERN_WARNING DRV_NAME ": ****** shutdown driver "
525 			       "domain before binding device\n");
526 			printk(KERN_WARNING DRV_NAME ": ****** to other drivers "
527 			       "or domains\n");
528 
529 			xen_pcibk_release_pci_dev(found_psdev->pdev,
530 						found_psdev->dev);
531 		}
532 
533 		spin_lock_irqsave(&pcistub_devices_lock, flags);
534 		list_del(&found_psdev->dev_list);
535 		spin_unlock_irqrestore(&pcistub_devices_lock, flags);
536 
537 		/* the final put for releasing from the list */
538 		pcistub_device_put(found_psdev);
539 	}
540 }
541 
542 static DEFINE_PCI_DEVICE_TABLE(pcistub_ids) = {
543 	{
544 	 .vendor = PCI_ANY_ID,
545 	 .device = PCI_ANY_ID,
546 	 .subvendor = PCI_ANY_ID,
547 	 .subdevice = PCI_ANY_ID,
548 	 },
549 	{0,},
550 };
551 
552 #define PCI_NODENAME_MAX 40
553 static void kill_domain_by_device(struct pcistub_device *psdev)
554 {
555 	struct xenbus_transaction xbt;
556 	int err;
557 	char nodename[PCI_NODENAME_MAX];
558 
559 	BUG_ON(!psdev);
560 	snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
561 		psdev->pdev->xdev->otherend_id);
562 
563 again:
564 	err = xenbus_transaction_start(&xbt);
565 	if (err) {
566 		dev_err(&psdev->dev->dev,
567 			"error %d when start xenbus transaction\n", err);
568 		return;
569 	}
570 	/*PV AER handlers will set this flag*/
571 	xenbus_printf(xbt, nodename, "aerState" , "aerfail");
572 	err = xenbus_transaction_end(xbt, 0);
573 	if (err) {
574 		if (err == -EAGAIN)
575 			goto again;
576 		dev_err(&psdev->dev->dev,
577 			"error %d when end xenbus transaction\n", err);
578 		return;
579 	}
580 }
581 
582 /* For each aer recovery step error_detected, mmio_enabled, etc, front_end and
583  * backend need to have cooperation. In xen_pcibk, those steps will do similar
584  * jobs: send service request and waiting for front_end response.
585 */
586 static pci_ers_result_t common_process(struct pcistub_device *psdev,
587 				       pci_channel_state_t state, int aer_cmd,
588 				       pci_ers_result_t result)
589 {
590 	pci_ers_result_t res = result;
591 	struct xen_pcie_aer_op *aer_op;
592 	int ret;
593 
594 	/*with PV AER drivers*/
595 	aer_op = &(psdev->pdev->sh_info->aer_op);
596 	aer_op->cmd = aer_cmd ;
597 	/*useful for error_detected callback*/
598 	aer_op->err = state;
599 	/*pcifront_end BDF*/
600 	ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev,
601 		&aer_op->domain, &aer_op->bus, &aer_op->devfn);
602 	if (!ret) {
603 		dev_err(&psdev->dev->dev,
604 			DRV_NAME ": failed to get pcifront device\n");
605 		return PCI_ERS_RESULT_NONE;
606 	}
607 	wmb();
608 
609 	dev_dbg(&psdev->dev->dev,
610 			DRV_NAME ": aer_op %x dom %x bus %x devfn %x\n",
611 			aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn);
612 	/*local flag to mark there's aer request, xen_pcibk callback will use
613 	* this flag to judge whether we need to check pci-front give aer
614 	* service ack signal
615 	*/
616 	set_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
617 
618 	/*It is possible that a pcifront conf_read_write ops request invokes
619 	* the callback which cause the spurious execution of wake_up.
620 	* Yet it is harmless and better than a spinlock here
621 	*/
622 	set_bit(_XEN_PCIB_active,
623 		(unsigned long *)&psdev->pdev->sh_info->flags);
624 	wmb();
625 	notify_remote_via_irq(psdev->pdev->evtchn_irq);
626 
627 	ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
628 				 !(test_bit(_XEN_PCIB_active, (unsigned long *)
629 				 &psdev->pdev->sh_info->flags)), 300*HZ);
630 
631 	if (!ret) {
632 		if (test_bit(_XEN_PCIB_active,
633 			(unsigned long *)&psdev->pdev->sh_info->flags)) {
634 			dev_err(&psdev->dev->dev,
635 				"pcifront aer process not responding!\n");
636 			clear_bit(_XEN_PCIB_active,
637 			  (unsigned long *)&psdev->pdev->sh_info->flags);
638 			aer_op->err = PCI_ERS_RESULT_NONE;
639 			return res;
640 		}
641 	}
642 	clear_bit(_PCIB_op_pending, (unsigned long *)&psdev->pdev->flags);
643 
644 	if (test_bit(_XEN_PCIF_active,
645 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
646 		dev_dbg(&psdev->dev->dev,
647 			"schedule pci_conf service in " DRV_NAME "\n");
648 		xen_pcibk_test_and_schedule_op(psdev->pdev);
649 	}
650 
651 	res = (pci_ers_result_t)aer_op->err;
652 	return res;
653 }
654 
655 /*
656 * xen_pcibk_slot_reset: it will send the slot_reset request to  pcifront in case
657 * of the device driver could provide this service, and then wait for pcifront
658 * ack.
659 * @dev: pointer to PCI devices
660 * return value is used by aer_core do_recovery policy
661 */
662 static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
663 {
664 	struct pcistub_device *psdev;
665 	pci_ers_result_t result;
666 
667 	result = PCI_ERS_RESULT_RECOVERED;
668 	dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n",
669 		dev->bus->number, dev->devfn);
670 
671 	down_write(&pcistub_sem);
672 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
673 				dev->bus->number,
674 				PCI_SLOT(dev->devfn),
675 				PCI_FUNC(dev->devfn));
676 
677 	if (!psdev || !psdev->pdev) {
678 		dev_err(&dev->dev,
679 			DRV_NAME " device is not found/assigned\n");
680 		goto end;
681 	}
682 
683 	if (!psdev->pdev->sh_info) {
684 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
685 			" by HVM, kill it\n");
686 		kill_domain_by_device(psdev);
687 		goto end;
688 	}
689 
690 	if (!test_bit(_XEN_PCIB_AERHANDLER,
691 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
692 		dev_err(&dev->dev,
693 			"guest with no AER driver should have been killed\n");
694 		goto end;
695 	}
696 	result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
697 
698 	if (result == PCI_ERS_RESULT_NONE ||
699 		result == PCI_ERS_RESULT_DISCONNECT) {
700 		dev_dbg(&dev->dev,
701 			"No AER slot_reset service or disconnected!\n");
702 		kill_domain_by_device(psdev);
703 	}
704 end:
705 	if (psdev)
706 		pcistub_device_put(psdev);
707 	up_write(&pcistub_sem);
708 	return result;
709 
710 }
711 
712 
713 /*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to  pcifront
714 * in case of the device driver could provide this service, and then wait
715 * for pcifront ack
716 * @dev: pointer to PCI devices
717 * return value is used by aer_core do_recovery policy
718 */
719 
720 static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
721 {
722 	struct pcistub_device *psdev;
723 	pci_ers_result_t result;
724 
725 	result = PCI_ERS_RESULT_RECOVERED;
726 	dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n",
727 		dev->bus->number, dev->devfn);
728 
729 	down_write(&pcistub_sem);
730 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
731 				dev->bus->number,
732 				PCI_SLOT(dev->devfn),
733 				PCI_FUNC(dev->devfn));
734 
735 	if (!psdev || !psdev->pdev) {
736 		dev_err(&dev->dev,
737 			DRV_NAME " device is not found/assigned\n");
738 		goto end;
739 	}
740 
741 	if (!psdev->pdev->sh_info) {
742 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
743 			" by HVM, kill it\n");
744 		kill_domain_by_device(psdev);
745 		goto end;
746 	}
747 
748 	if (!test_bit(_XEN_PCIB_AERHANDLER,
749 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
750 		dev_err(&dev->dev,
751 			"guest with no AER driver should have been killed\n");
752 		goto end;
753 	}
754 	result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
755 
756 	if (result == PCI_ERS_RESULT_NONE ||
757 		result == PCI_ERS_RESULT_DISCONNECT) {
758 		dev_dbg(&dev->dev,
759 			"No AER mmio_enabled service or disconnected!\n");
760 		kill_domain_by_device(psdev);
761 	}
762 end:
763 	if (psdev)
764 		pcistub_device_put(psdev);
765 	up_write(&pcistub_sem);
766 	return result;
767 }
768 
769 /*xen_pcibk_error_detected: it will send the error_detected request to  pcifront
770 * in case of the device driver could provide this service, and then wait
771 * for pcifront ack.
772 * @dev: pointer to PCI devices
773 * @error: the current PCI connection state
774 * return value is used by aer_core do_recovery policy
775 */
776 
777 static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev,
778 	pci_channel_state_t error)
779 {
780 	struct pcistub_device *psdev;
781 	pci_ers_result_t result;
782 
783 	result = PCI_ERS_RESULT_CAN_RECOVER;
784 	dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n",
785 		dev->bus->number, dev->devfn);
786 
787 	down_write(&pcistub_sem);
788 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
789 				dev->bus->number,
790 				PCI_SLOT(dev->devfn),
791 				PCI_FUNC(dev->devfn));
792 
793 	if (!psdev || !psdev->pdev) {
794 		dev_err(&dev->dev,
795 			DRV_NAME " device is not found/assigned\n");
796 		goto end;
797 	}
798 
799 	if (!psdev->pdev->sh_info) {
800 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
801 			" by HVM, kill it\n");
802 		kill_domain_by_device(psdev);
803 		goto end;
804 	}
805 
806 	/*Guest owns the device yet no aer handler regiested, kill guest*/
807 	if (!test_bit(_XEN_PCIB_AERHANDLER,
808 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
809 		dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n");
810 		kill_domain_by_device(psdev);
811 		goto end;
812 	}
813 	result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result);
814 
815 	if (result == PCI_ERS_RESULT_NONE ||
816 		result == PCI_ERS_RESULT_DISCONNECT) {
817 		dev_dbg(&dev->dev,
818 			"No AER error_detected service or disconnected!\n");
819 		kill_domain_by_device(psdev);
820 	}
821 end:
822 	if (psdev)
823 		pcistub_device_put(psdev);
824 	up_write(&pcistub_sem);
825 	return result;
826 }
827 
828 /*xen_pcibk_error_resume: it will send the error_resume request to  pcifront
829 * in case of the device driver could provide this service, and then wait
830 * for pcifront ack.
831 * @dev: pointer to PCI devices
832 */
833 
834 static void xen_pcibk_error_resume(struct pci_dev *dev)
835 {
836 	struct pcistub_device *psdev;
837 
838 	dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n",
839 		dev->bus->number, dev->devfn);
840 
841 	down_write(&pcistub_sem);
842 	psdev = pcistub_device_find(pci_domain_nr(dev->bus),
843 				dev->bus->number,
844 				PCI_SLOT(dev->devfn),
845 				PCI_FUNC(dev->devfn));
846 
847 	if (!psdev || !psdev->pdev) {
848 		dev_err(&dev->dev,
849 			DRV_NAME " device is not found/assigned\n");
850 		goto end;
851 	}
852 
853 	if (!psdev->pdev->sh_info) {
854 		dev_err(&dev->dev, DRV_NAME " device is not connected or owned"
855 			" by HVM, kill it\n");
856 		kill_domain_by_device(psdev);
857 		goto end;
858 	}
859 
860 	if (!test_bit(_XEN_PCIB_AERHANDLER,
861 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
862 		dev_err(&dev->dev,
863 			"guest with no AER driver should have been killed\n");
864 		kill_domain_by_device(psdev);
865 		goto end;
866 	}
867 	common_process(psdev, 1, XEN_PCI_OP_aer_resume,
868 		       PCI_ERS_RESULT_RECOVERED);
869 end:
870 	if (psdev)
871 		pcistub_device_put(psdev);
872 	up_write(&pcistub_sem);
873 	return;
874 }
875 
876 /*add xen_pcibk AER handling*/
877 static const struct pci_error_handlers xen_pcibk_error_handler = {
878 	.error_detected = xen_pcibk_error_detected,
879 	.mmio_enabled = xen_pcibk_mmio_enabled,
880 	.slot_reset = xen_pcibk_slot_reset,
881 	.resume = xen_pcibk_error_resume,
882 };
883 
884 /*
885  * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't
886  * for a normal device. I don't want it to be loaded automatically.
887  */
888 
889 static struct pci_driver xen_pcibk_pci_driver = {
890 	/* The name should be xen_pciback, but until the tools are updated
891 	 * we will keep it as pciback. */
892 	.name = "pciback",
893 	.id_table = pcistub_ids,
894 	.probe = pcistub_probe,
895 	.remove = pcistub_remove,
896 	.err_handler = &xen_pcibk_error_handler,
897 };
898 
899 static inline int str_to_slot(const char *buf, int *domain, int *bus,
900 			      int *slot, int *func)
901 {
902 	int parsed = 0;
903 
904 	switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func,
905 		       &parsed)) {
906 	case 3:
907 		*func = -1;
908 		sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed);
909 		break;
910 	case 2:
911 		*slot = *func = -1;
912 		sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed);
913 		break;
914 	}
915 	if (parsed && !buf[parsed])
916 		return 0;
917 
918 	/* try again without domain */
919 	*domain = 0;
920 	switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) {
921 	case 2:
922 		*func = -1;
923 		sscanf(buf, " %x:%x.* %n", bus, slot, &parsed);
924 		break;
925 	case 1:
926 		*slot = *func = -1;
927 		sscanf(buf, " %x:*.* %n", bus, &parsed);
928 		break;
929 	}
930 	if (parsed && !buf[parsed])
931 		return 0;
932 
933 	return -EINVAL;
934 }
935 
936 static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
937 			       *slot, int *func, int *reg, int *size, int *mask)
938 {
939 	int parsed = 0;
940 
941 	sscanf(buf, " %x:%x:%x.%x-%x:%x:%x %n", domain, bus, slot, func,
942 	       reg, size, mask, &parsed);
943 	if (parsed && !buf[parsed])
944 		return 0;
945 
946 	/* try again without domain */
947 	*domain = 0;
948 	sscanf(buf, " %x:%x.%x-%x:%x:%x %n", bus, slot, func, reg, size,
949 	       mask, &parsed);
950 	if (parsed && !buf[parsed])
951 		return 0;
952 
953 	return -EINVAL;
954 }
955 
956 static int pcistub_device_id_add(int domain, int bus, int slot, int func)
957 {
958 	struct pcistub_device_id *pci_dev_id;
959 	unsigned long flags;
960 	int rc = 0, devfn = PCI_DEVFN(slot, func);
961 
962 	if (slot < 0) {
963 		for (slot = 0; !rc && slot < 32; ++slot)
964 			rc = pcistub_device_id_add(domain, bus, slot, func);
965 		return rc;
966 	}
967 
968 	if (func < 0) {
969 		for (func = 0; !rc && func < 8; ++func)
970 			rc = pcistub_device_id_add(domain, bus, slot, func);
971 		return rc;
972 	}
973 
974 	if ((
975 #if !defined(MODULE) /* pci_domains_supported is not being exported */ \
976     || !defined(CONFIG_PCI_DOMAINS)
977 	     !pci_domains_supported ? domain :
978 #endif
979 	     domain < 0 || domain > 0xffff)
980 	    || bus < 0 || bus > 0xff
981 	    || PCI_SLOT(devfn) != slot
982 	    || PCI_FUNC(devfn) != func)
983 		return -EINVAL;
984 
985 	pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL);
986 	if (!pci_dev_id)
987 		return -ENOMEM;
988 
989 	pci_dev_id->domain = domain;
990 	pci_dev_id->bus = bus;
991 	pci_dev_id->devfn = devfn;
992 
993 	pr_debug(DRV_NAME ": wants to seize %04x:%02x:%02x.%d\n",
994 		 domain, bus, slot, func);
995 
996 	spin_lock_irqsave(&device_ids_lock, flags);
997 	list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids);
998 	spin_unlock_irqrestore(&device_ids_lock, flags);
999 
1000 	return 0;
1001 }
1002 
1003 static int pcistub_device_id_remove(int domain, int bus, int slot, int func)
1004 {
1005 	struct pcistub_device_id *pci_dev_id, *t;
1006 	int err = -ENOENT;
1007 	unsigned long flags;
1008 
1009 	spin_lock_irqsave(&device_ids_lock, flags);
1010 	list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids,
1011 				 slot_list) {
1012 		if (pci_dev_id->domain == domain && pci_dev_id->bus == bus
1013 		    && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot)
1014 		    && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) {
1015 			/* Don't break; here because it's possible the same
1016 			 * slot could be in the list more than once
1017 			 */
1018 			list_del(&pci_dev_id->slot_list);
1019 			kfree(pci_dev_id);
1020 
1021 			err = 0;
1022 
1023 			pr_debug(DRV_NAME ": removed %04x:%02x:%02x.%d from "
1024 				 "seize list\n", domain, bus, slot, func);
1025 		}
1026 	}
1027 	spin_unlock_irqrestore(&device_ids_lock, flags);
1028 
1029 	return err;
1030 }
1031 
1032 static int pcistub_reg_add(int domain, int bus, int slot, int func,
1033 			   unsigned int reg, unsigned int size,
1034 			   unsigned int mask)
1035 {
1036 	int err = 0;
1037 	struct pcistub_device *psdev;
1038 	struct pci_dev *dev;
1039 	struct config_field *field;
1040 
1041 	if (reg > 0xfff || (size < 4 && (mask >> (size * 8))))
1042 		return -EINVAL;
1043 
1044 	psdev = pcistub_device_find(domain, bus, slot, func);
1045 	if (!psdev) {
1046 		err = -ENODEV;
1047 		goto out;
1048 	}
1049 	dev = psdev->dev;
1050 
1051 	field = kzalloc(sizeof(*field), GFP_ATOMIC);
1052 	if (!field) {
1053 		err = -ENOMEM;
1054 		goto out;
1055 	}
1056 
1057 	field->offset = reg;
1058 	field->size = size;
1059 	field->mask = mask;
1060 	field->init = NULL;
1061 	field->reset = NULL;
1062 	field->release = NULL;
1063 	field->clean = xen_pcibk_config_field_free;
1064 
1065 	err = xen_pcibk_config_quirks_add_field(dev, field);
1066 	if (err)
1067 		kfree(field);
1068 out:
1069 	if (psdev)
1070 		pcistub_device_put(psdev);
1071 	return err;
1072 }
1073 
1074 static ssize_t pcistub_slot_add(struct device_driver *drv, const char *buf,
1075 				size_t count)
1076 {
1077 	int domain, bus, slot, func;
1078 	int err;
1079 
1080 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1081 	if (err)
1082 		goto out;
1083 
1084 	err = pcistub_device_id_add(domain, bus, slot, func);
1085 
1086 out:
1087 	if (!err)
1088 		err = count;
1089 	return err;
1090 }
1091 static DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
1092 
1093 static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
1094 				   size_t count)
1095 {
1096 	int domain, bus, slot, func;
1097 	int err;
1098 
1099 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1100 	if (err)
1101 		goto out;
1102 
1103 	err = pcistub_device_id_remove(domain, bus, slot, func);
1104 
1105 out:
1106 	if (!err)
1107 		err = count;
1108 	return err;
1109 }
1110 static DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
1111 
1112 static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
1113 {
1114 	struct pcistub_device_id *pci_dev_id;
1115 	size_t count = 0;
1116 	unsigned long flags;
1117 
1118 	spin_lock_irqsave(&device_ids_lock, flags);
1119 	list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) {
1120 		if (count >= PAGE_SIZE)
1121 			break;
1122 
1123 		count += scnprintf(buf + count, PAGE_SIZE - count,
1124 				   "%04x:%02x:%02x.%d\n",
1125 				   pci_dev_id->domain, pci_dev_id->bus,
1126 				   PCI_SLOT(pci_dev_id->devfn),
1127 				   PCI_FUNC(pci_dev_id->devfn));
1128 	}
1129 	spin_unlock_irqrestore(&device_ids_lock, flags);
1130 
1131 	return count;
1132 }
1133 static DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
1134 
1135 static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
1136 {
1137 	struct pcistub_device *psdev;
1138 	struct xen_pcibk_dev_data *dev_data;
1139 	size_t count = 0;
1140 	unsigned long flags;
1141 
1142 	spin_lock_irqsave(&pcistub_devices_lock, flags);
1143 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1144 		if (count >= PAGE_SIZE)
1145 			break;
1146 		if (!psdev->dev)
1147 			continue;
1148 		dev_data = pci_get_drvdata(psdev->dev);
1149 		if (!dev_data)
1150 			continue;
1151 		count +=
1152 		    scnprintf(buf + count, PAGE_SIZE - count,
1153 			      "%s:%s:%sing:%ld\n",
1154 			      pci_name(psdev->dev),
1155 			      dev_data->isr_on ? "on" : "off",
1156 			      dev_data->ack_intr ? "ack" : "not ack",
1157 			      dev_data->handled);
1158 	}
1159 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1160 	return count;
1161 }
1162 static DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
1163 
1164 static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
1165 					  const char *buf,
1166 					  size_t count)
1167 {
1168 	struct pcistub_device *psdev;
1169 	struct xen_pcibk_dev_data *dev_data;
1170 	int domain, bus, slot, func;
1171 	int err = -ENOENT;
1172 
1173 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1174 	if (err)
1175 		return err;
1176 
1177 	psdev = pcistub_device_find(domain, bus, slot, func);
1178 	if (!psdev)
1179 		goto out;
1180 
1181 	dev_data = pci_get_drvdata(psdev->dev);
1182 	if (!dev_data)
1183 		goto out;
1184 
1185 	dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n",
1186 		dev_data->irq_name, dev_data->isr_on,
1187 		!dev_data->isr_on);
1188 
1189 	dev_data->isr_on = !(dev_data->isr_on);
1190 	if (dev_data->isr_on)
1191 		dev_data->ack_intr = 1;
1192 out:
1193 	if (psdev)
1194 		pcistub_device_put(psdev);
1195 	if (!err)
1196 		err = count;
1197 	return err;
1198 }
1199 static DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL,
1200 		   pcistub_irq_handler_switch);
1201 
1202 static ssize_t pcistub_quirk_add(struct device_driver *drv, const char *buf,
1203 				 size_t count)
1204 {
1205 	int domain, bus, slot, func, reg, size, mask;
1206 	int err;
1207 
1208 	err = str_to_quirk(buf, &domain, &bus, &slot, &func, &reg, &size,
1209 			   &mask);
1210 	if (err)
1211 		goto out;
1212 
1213 	err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask);
1214 
1215 out:
1216 	if (!err)
1217 		err = count;
1218 	return err;
1219 }
1220 
1221 static ssize_t pcistub_quirk_show(struct device_driver *drv, char *buf)
1222 {
1223 	int count = 0;
1224 	unsigned long flags;
1225 	struct xen_pcibk_config_quirk *quirk;
1226 	struct xen_pcibk_dev_data *dev_data;
1227 	const struct config_field *field;
1228 	const struct config_field_entry *cfg_entry;
1229 
1230 	spin_lock_irqsave(&device_ids_lock, flags);
1231 	list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) {
1232 		if (count >= PAGE_SIZE)
1233 			goto out;
1234 
1235 		count += scnprintf(buf + count, PAGE_SIZE - count,
1236 				   "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n",
1237 				   quirk->pdev->bus->number,
1238 				   PCI_SLOT(quirk->pdev->devfn),
1239 				   PCI_FUNC(quirk->pdev->devfn),
1240 				   quirk->devid.vendor, quirk->devid.device,
1241 				   quirk->devid.subvendor,
1242 				   quirk->devid.subdevice);
1243 
1244 		dev_data = pci_get_drvdata(quirk->pdev);
1245 
1246 		list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
1247 			field = cfg_entry->field;
1248 			if (count >= PAGE_SIZE)
1249 				goto out;
1250 
1251 			count += scnprintf(buf + count, PAGE_SIZE - count,
1252 					   "\t\t%08x:%01x:%08x\n",
1253 					   cfg_entry->base_offset +
1254 					   field->offset, field->size,
1255 					   field->mask);
1256 		}
1257 	}
1258 
1259 out:
1260 	spin_unlock_irqrestore(&device_ids_lock, flags);
1261 
1262 	return count;
1263 }
1264 static DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show,
1265 		   pcistub_quirk_add);
1266 
1267 static ssize_t permissive_add(struct device_driver *drv, const char *buf,
1268 			      size_t count)
1269 {
1270 	int domain, bus, slot, func;
1271 	int err;
1272 	struct pcistub_device *psdev;
1273 	struct xen_pcibk_dev_data *dev_data;
1274 
1275 	err = str_to_slot(buf, &domain, &bus, &slot, &func);
1276 	if (err)
1277 		goto out;
1278 
1279 	psdev = pcistub_device_find(domain, bus, slot, func);
1280 	if (!psdev) {
1281 		err = -ENODEV;
1282 		goto out;
1283 	}
1284 
1285 	dev_data = pci_get_drvdata(psdev->dev);
1286 	/* the driver data for a device should never be null at this point */
1287 	if (!dev_data) {
1288 		err = -ENXIO;
1289 		goto release;
1290 	}
1291 	if (!dev_data->permissive) {
1292 		dev_data->permissive = 1;
1293 		/* Let user know that what they're doing could be unsafe */
1294 		dev_warn(&psdev->dev->dev, "enabling permissive mode "
1295 			 "configuration space accesses!\n");
1296 		dev_warn(&psdev->dev->dev,
1297 			 "permissive mode is potentially unsafe!\n");
1298 	}
1299 release:
1300 	pcistub_device_put(psdev);
1301 out:
1302 	if (!err)
1303 		err = count;
1304 	return err;
1305 }
1306 
1307 static ssize_t permissive_show(struct device_driver *drv, char *buf)
1308 {
1309 	struct pcistub_device *psdev;
1310 	struct xen_pcibk_dev_data *dev_data;
1311 	size_t count = 0;
1312 	unsigned long flags;
1313 	spin_lock_irqsave(&pcistub_devices_lock, flags);
1314 	list_for_each_entry(psdev, &pcistub_devices, dev_list) {
1315 		if (count >= PAGE_SIZE)
1316 			break;
1317 		if (!psdev->dev)
1318 			continue;
1319 		dev_data = pci_get_drvdata(psdev->dev);
1320 		if (!dev_data || !dev_data->permissive)
1321 			continue;
1322 		count +=
1323 		    scnprintf(buf + count, PAGE_SIZE - count, "%s\n",
1324 			      pci_name(psdev->dev));
1325 	}
1326 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
1327 	return count;
1328 }
1329 static DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show,
1330 		   permissive_add);
1331 
1332 static void pcistub_exit(void)
1333 {
1334 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot);
1335 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1336 			   &driver_attr_remove_slot);
1337 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots);
1338 	driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks);
1339 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1340 			   &driver_attr_permissive);
1341 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1342 			   &driver_attr_irq_handlers);
1343 	driver_remove_file(&xen_pcibk_pci_driver.driver,
1344 			   &driver_attr_irq_handler_state);
1345 	pci_unregister_driver(&xen_pcibk_pci_driver);
1346 }
1347 
1348 static int __init pcistub_init(void)
1349 {
1350 	int pos = 0;
1351 	int err = 0;
1352 	int domain, bus, slot, func;
1353 	int parsed;
1354 
1355 	if (pci_devs_to_hide && *pci_devs_to_hide) {
1356 		do {
1357 			parsed = 0;
1358 
1359 			err = sscanf(pci_devs_to_hide + pos,
1360 				     " (%x:%x:%x.%x) %n",
1361 				     &domain, &bus, &slot, &func, &parsed);
1362 			switch (err) {
1363 			case 3:
1364 				func = -1;
1365 				sscanf(pci_devs_to_hide + pos,
1366 				       " (%x:%x:%x.*) %n",
1367 				       &domain, &bus, &slot, &parsed);
1368 				break;
1369 			case 2:
1370 				slot = func = -1;
1371 				sscanf(pci_devs_to_hide + pos,
1372 				       " (%x:%x:*.*) %n",
1373 				       &domain, &bus, &parsed);
1374 				break;
1375 			}
1376 
1377 			if (!parsed) {
1378 				domain = 0;
1379 				err = sscanf(pci_devs_to_hide + pos,
1380 					     " (%x:%x.%x) %n",
1381 					     &bus, &slot, &func, &parsed);
1382 				switch (err) {
1383 				case 2:
1384 					func = -1;
1385 					sscanf(pci_devs_to_hide + pos,
1386 					       " (%x:%x.*) %n",
1387 					       &bus, &slot, &parsed);
1388 					break;
1389 				case 1:
1390 					slot = func = -1;
1391 					sscanf(pci_devs_to_hide + pos,
1392 					       " (%x:*.*) %n",
1393 					       &bus, &parsed);
1394 					break;
1395 				}
1396 			}
1397 
1398 			if (parsed <= 0)
1399 				goto parse_error;
1400 
1401 			err = pcistub_device_id_add(domain, bus, slot, func);
1402 			if (err)
1403 				goto out;
1404 
1405 			pos += parsed;
1406 		} while (pci_devs_to_hide[pos]);
1407 	}
1408 
1409 	/* If we're the first PCI Device Driver to register, we're the
1410 	 * first one to get offered PCI devices as they become
1411 	 * available (and thus we can be the first to grab them)
1412 	 */
1413 	err = pci_register_driver(&xen_pcibk_pci_driver);
1414 	if (err < 0)
1415 		goto out;
1416 
1417 	err = driver_create_file(&xen_pcibk_pci_driver.driver,
1418 				 &driver_attr_new_slot);
1419 	if (!err)
1420 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1421 					 &driver_attr_remove_slot);
1422 	if (!err)
1423 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1424 					 &driver_attr_slots);
1425 	if (!err)
1426 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1427 					 &driver_attr_quirks);
1428 	if (!err)
1429 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1430 					 &driver_attr_permissive);
1431 
1432 	if (!err)
1433 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1434 					 &driver_attr_irq_handlers);
1435 	if (!err)
1436 		err = driver_create_file(&xen_pcibk_pci_driver.driver,
1437 					&driver_attr_irq_handler_state);
1438 	if (err)
1439 		pcistub_exit();
1440 
1441 out:
1442 	return err;
1443 
1444 parse_error:
1445 	printk(KERN_ERR DRV_NAME ": Error parsing pci_devs_to_hide at \"%s\"\n",
1446 	       pci_devs_to_hide + pos);
1447 	return -EINVAL;
1448 }
1449 
1450 #ifndef MODULE
1451 /*
1452  * fs_initcall happens before device_initcall
1453  * so xen_pcibk *should* get called first (b/c we
1454  * want to suck up any device before other drivers
1455  * get a chance by being the first pci device
1456  * driver to register)
1457  */
1458 fs_initcall(pcistub_init);
1459 #endif
1460 
1461 static int __init xen_pcibk_init(void)
1462 {
1463 	int err;
1464 
1465 	if (!xen_initial_domain())
1466 		return -ENODEV;
1467 
1468 	err = xen_pcibk_config_init();
1469 	if (err)
1470 		return err;
1471 
1472 #ifdef MODULE
1473 	err = pcistub_init();
1474 	if (err < 0)
1475 		return err;
1476 #endif
1477 
1478 	pcistub_init_devices_late();
1479 	err = xen_pcibk_xenbus_register();
1480 	if (err)
1481 		pcistub_exit();
1482 
1483 	return err;
1484 }
1485 
1486 static void __exit xen_pcibk_cleanup(void)
1487 {
1488 	xen_pcibk_xenbus_unregister();
1489 	pcistub_exit();
1490 }
1491 
1492 module_init(xen_pcibk_init);
1493 module_exit(xen_pcibk_cleanup);
1494 
1495 MODULE_LICENSE("Dual BSD/GPL");
1496 MODULE_ALIAS("xen-backend:pci");
1497