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