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1/*
2 * Xen PCI Frontend.
3 *
4 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
5 */
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/mm.h>
9#include <xen/xenbus.h>
10#include <xen/events.h>
11#include <xen/grant_table.h>
12#include <xen/page.h>
13#include <linux/spinlock.h>
14#include <linux/pci.h>
15#include <linux/msi.h>
16#include <xen/interface/io/pciif.h>
17#include <asm/xen/pci.h>
18#include <linux/interrupt.h>
19#include <linux/atomic.h>
20#include <linux/workqueue.h>
21#include <linux/bitops.h>
22#include <linux/time.h>
23
24#define INVALID_GRANT_REF (0)
25#define INVALID_EVTCHN (-1)
26
27struct pci_bus_entry {
28 struct list_head list;
29 struct pci_bus *bus;
30};
31
32#define _PDEVB_op_active (0)
33#define PDEVB_op_active (1 << (_PDEVB_op_active))
34
35struct pcifront_device {
36 struct xenbus_device *xdev;
37 struct list_head root_buses;
38
39 int evtchn;
40 int gnt_ref;
41
42 int irq;
43
44 /* Lock this when doing any operations in sh_info */
45 spinlock_t sh_info_lock;
46 struct xen_pci_sharedinfo *sh_info;
47 struct work_struct op_work;
48 unsigned long flags;
49
50};
51
52struct pcifront_sd {
53 int domain;
54 struct pcifront_device *pdev;
55};
56
57static inline struct pcifront_device *
58pcifront_get_pdev(struct pcifront_sd *sd)
59{
60 return sd->pdev;
61}
62
63static inline void pcifront_init_sd(struct pcifront_sd *sd,
64 unsigned int domain, unsigned int bus,
65 struct pcifront_device *pdev)
66{
67 sd->domain = domain;
68 sd->pdev = pdev;
69}
70
71static DEFINE_SPINLOCK(pcifront_dev_lock);
72static struct pcifront_device *pcifront_dev;
73
74static int verbose_request;
75module_param(verbose_request, int, 0644);
76
77static int errno_to_pcibios_err(int errno)
78{
79 switch (errno) {
80 case XEN_PCI_ERR_success:
81 return PCIBIOS_SUCCESSFUL;
82
83 case XEN_PCI_ERR_dev_not_found:
84 return PCIBIOS_DEVICE_NOT_FOUND;
85
86 case XEN_PCI_ERR_invalid_offset:
87 case XEN_PCI_ERR_op_failed:
88 return PCIBIOS_BAD_REGISTER_NUMBER;
89
90 case XEN_PCI_ERR_not_implemented:
91 return PCIBIOS_FUNC_NOT_SUPPORTED;
92
93 case XEN_PCI_ERR_access_denied:
94 return PCIBIOS_SET_FAILED;
95 }
96 return errno;
97}
98
99static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
100{
101 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
102 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
103 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
104 schedule_work(&pdev->op_work);
105 }
106}
107
108static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
109{
110 int err = 0;
111 struct xen_pci_op *active_op = &pdev->sh_info->op;
112 unsigned long irq_flags;
113 evtchn_port_t port = pdev->evtchn;
114 unsigned irq = pdev->irq;
115 s64 ns, ns_timeout;
116 struct timeval tv;
117
118 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
119
120 memcpy(active_op, op, sizeof(struct xen_pci_op));
121
122 /* Go */
123 wmb();
124 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
125 notify_remote_via_evtchn(port);
126
127 /*
128 * We set a poll timeout of 3 seconds but give up on return after
129 * 2 seconds. It is better to time out too late rather than too early
130 * (in the latter case we end up continually re-executing poll() with a
131 * timeout in the past). 1s difference gives plenty of slack for error.
132 */
133 do_gettimeofday(&tv);
134 ns_timeout = timeval_to_ns(&tv) + 2 * (s64)NSEC_PER_SEC;
135
136 xen_clear_irq_pending(irq);
137
138 while (test_bit(_XEN_PCIF_active,
139 (unsigned long *)&pdev->sh_info->flags)) {
140 xen_poll_irq_timeout(irq, jiffies + 3*HZ);
141 xen_clear_irq_pending(irq);
142 do_gettimeofday(&tv);
143 ns = timeval_to_ns(&tv);
144 if (ns > ns_timeout) {
145 dev_err(&pdev->xdev->dev,
146 "pciback not responding!!!\n");
147 clear_bit(_XEN_PCIF_active,
148 (unsigned long *)&pdev->sh_info->flags);
149 err = XEN_PCI_ERR_dev_not_found;
150 goto out;
151 }
152 }
153
154 /*
155 * We might lose backend service request since we
156 * reuse same evtchn with pci_conf backend response. So re-schedule
157 * aer pcifront service.
158 */
159 if (test_bit(_XEN_PCIB_active,
160 (unsigned long *)&pdev->sh_info->flags)) {
161 dev_err(&pdev->xdev->dev,
162 "schedule aer pcifront service\n");
163 schedule_pcifront_aer_op(pdev);
164 }
165
166 memcpy(op, active_op, sizeof(struct xen_pci_op));
167
168 err = op->err;
169out:
170 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
171 return err;
172}
173
174/* Access to this function is spinlocked in drivers/pci/access.c */
175static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
176 int where, int size, u32 *val)
177{
178 int err = 0;
179 struct xen_pci_op op = {
180 .cmd = XEN_PCI_OP_conf_read,
181 .domain = pci_domain_nr(bus),
182 .bus = bus->number,
183 .devfn = devfn,
184 .offset = where,
185 .size = size,
186 };
187 struct pcifront_sd *sd = bus->sysdata;
188 struct pcifront_device *pdev = pcifront_get_pdev(sd);
189
190 if (verbose_request)
191 dev_info(&pdev->xdev->dev,
192 "read dev=%04x:%02x:%02x.%01x - offset %x size %d\n",
193 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
194 PCI_FUNC(devfn), where, size);
195
196 err = do_pci_op(pdev, &op);
197
198 if (likely(!err)) {
199 if (verbose_request)
200 dev_info(&pdev->xdev->dev, "read got back value %x\n",
201 op.value);
202
203 *val = op.value;
204 } else if (err == -ENODEV) {
205 /* No device here, pretend that it just returned 0 */
206 err = 0;
207 *val = 0;
208 }
209
210 return errno_to_pcibios_err(err);
211}
212
213/* Access to this function is spinlocked in drivers/pci/access.c */
214static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
215 int where, int size, u32 val)
216{
217 struct xen_pci_op op = {
218 .cmd = XEN_PCI_OP_conf_write,
219 .domain = pci_domain_nr(bus),
220 .bus = bus->number,
221 .devfn = devfn,
222 .offset = where,
223 .size = size,
224 .value = val,
225 };
226 struct pcifront_sd *sd = bus->sysdata;
227 struct pcifront_device *pdev = pcifront_get_pdev(sd);
228
229 if (verbose_request)
230 dev_info(&pdev->xdev->dev,
231 "write dev=%04x:%02x:%02x.%01x - "
232 "offset %x size %d val %x\n",
233 pci_domain_nr(bus), bus->number,
234 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
235
236 return errno_to_pcibios_err(do_pci_op(pdev, &op));
237}
238
239struct pci_ops pcifront_bus_ops = {
240 .read = pcifront_bus_read,
241 .write = pcifront_bus_write,
242};
243
244#ifdef CONFIG_PCI_MSI
245static int pci_frontend_enable_msix(struct pci_dev *dev,
246 int vector[], int nvec)
247{
248 int err;
249 int i;
250 struct xen_pci_op op = {
251 .cmd = XEN_PCI_OP_enable_msix,
252 .domain = pci_domain_nr(dev->bus),
253 .bus = dev->bus->number,
254 .devfn = dev->devfn,
255 .value = nvec,
256 };
257 struct pcifront_sd *sd = dev->bus->sysdata;
258 struct pcifront_device *pdev = pcifront_get_pdev(sd);
259 struct msi_desc *entry;
260
261 if (nvec > SH_INFO_MAX_VEC) {
262 dev_err(&dev->dev, "too much vector for pci frontend: %x."
263 " Increase SH_INFO_MAX_VEC.\n", nvec);
264 return -EINVAL;
265 }
266
267 i = 0;
268 list_for_each_entry(entry, &dev->msi_list, list) {
269 op.msix_entries[i].entry = entry->msi_attrib.entry_nr;
270 /* Vector is useless at this point. */
271 op.msix_entries[i].vector = -1;
272 i++;
273 }
274
275 err = do_pci_op(pdev, &op);
276
277 if (likely(!err)) {
278 if (likely(!op.value)) {
279 /* we get the result */
280 for (i = 0; i < nvec; i++) {
281 if (op.msix_entries[i].vector <= 0) {
282 dev_warn(&dev->dev, "MSI-X entry %d is invalid: %d!\n",
283 i, op.msix_entries[i].vector);
284 err = -EINVAL;
285 vector[i] = -1;
286 continue;
287 }
288 vector[i] = op.msix_entries[i].vector;
289 }
290 } else {
291 printk(KERN_DEBUG "enable msix get value %x\n",
292 op.value);
293 }
294 } else {
295 dev_err(&dev->dev, "enable msix get err %x\n", err);
296 }
297 return err;
298}
299
300static void pci_frontend_disable_msix(struct pci_dev *dev)
301{
302 int err;
303 struct xen_pci_op op = {
304 .cmd = XEN_PCI_OP_disable_msix,
305 .domain = pci_domain_nr(dev->bus),
306 .bus = dev->bus->number,
307 .devfn = dev->devfn,
308 };
309 struct pcifront_sd *sd = dev->bus->sysdata;
310 struct pcifront_device *pdev = pcifront_get_pdev(sd);
311
312 err = do_pci_op(pdev, &op);
313
314 /* What should do for error ? */
315 if (err)
316 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err);
317}
318
319static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
320{
321 int err;
322 struct xen_pci_op op = {
323 .cmd = XEN_PCI_OP_enable_msi,
324 .domain = pci_domain_nr(dev->bus),
325 .bus = dev->bus->number,
326 .devfn = dev->devfn,
327 };
328 struct pcifront_sd *sd = dev->bus->sysdata;
329 struct pcifront_device *pdev = pcifront_get_pdev(sd);
330
331 err = do_pci_op(pdev, &op);
332 if (likely(!err)) {
333 vector[0] = op.value;
334 if (op.value <= 0) {
335 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
336 op.value);
337 err = -EINVAL;
338 vector[0] = -1;
339 }
340 } else {
341 dev_err(&dev->dev, "pci frontend enable msi failed for dev "
342 "%x:%x\n", op.bus, op.devfn);
343 err = -EINVAL;
344 }
345 return err;
346}
347
348static void pci_frontend_disable_msi(struct pci_dev *dev)
349{
350 int err;
351 struct xen_pci_op op = {
352 .cmd = XEN_PCI_OP_disable_msi,
353 .domain = pci_domain_nr(dev->bus),
354 .bus = dev->bus->number,
355 .devfn = dev->devfn,
356 };
357 struct pcifront_sd *sd = dev->bus->sysdata;
358 struct pcifront_device *pdev = pcifront_get_pdev(sd);
359
360 err = do_pci_op(pdev, &op);
361 if (err == XEN_PCI_ERR_dev_not_found) {
362 /* XXX No response from backend, what shall we do? */
363 printk(KERN_DEBUG "get no response from backend for disable MSI\n");
364 return;
365 }
366 if (err)
367 /* how can pciback notify us fail? */
368 printk(KERN_DEBUG "get fake response frombackend\n");
369}
370
371static struct xen_pci_frontend_ops pci_frontend_ops = {
372 .enable_msi = pci_frontend_enable_msi,
373 .disable_msi = pci_frontend_disable_msi,
374 .enable_msix = pci_frontend_enable_msix,
375 .disable_msix = pci_frontend_disable_msix,
376};
377
378static void pci_frontend_registrar(int enable)
379{
380 if (enable)
381 xen_pci_frontend = &pci_frontend_ops;
382 else
383 xen_pci_frontend = NULL;
384};
385#else
386static inline void pci_frontend_registrar(int enable) { };
387#endif /* CONFIG_PCI_MSI */
388
389/* Claim resources for the PCI frontend as-is, backend won't allow changes */
390static int pcifront_claim_resource(struct pci_dev *dev, void *data)
391{
392 struct pcifront_device *pdev = data;
393 int i;
394 struct resource *r;
395
396 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
397 r = &dev->resource[i];
398
399 if (!r->parent && r->start && r->flags) {
400 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
401 pci_name(dev), i);
402 if (pci_claim_resource(dev, i)) {
403 dev_err(&pdev->xdev->dev, "Could not claim "
404 "resource %s/%d! Device offline. Try "
405 "giving less than 4GB to domain.\n",
406 pci_name(dev), i);
407 }
408 }
409 }
410
411 return 0;
412}
413
414static int __devinit pcifront_scan_bus(struct pcifront_device *pdev,
415 unsigned int domain, unsigned int bus,
416 struct pci_bus *b)
417{
418 struct pci_dev *d;
419 unsigned int devfn;
420
421 /* Scan the bus for functions and add.
422 * We omit handling of PCI bridge attachment because pciback prevents
423 * bridges from being exported.
424 */
425 for (devfn = 0; devfn < 0x100; devfn++) {
426 d = pci_get_slot(b, devfn);
427 if (d) {
428 /* Device is already known. */
429 pci_dev_put(d);
430 continue;
431 }
432
433 d = pci_scan_single_device(b, devfn);
434 if (d)
435 dev_info(&pdev->xdev->dev, "New device on "
436 "%04x:%02x:%02x.%02x found.\n", domain, bus,
437 PCI_SLOT(devfn), PCI_FUNC(devfn));
438 }
439
440 return 0;
441}
442
443static int __devinit pcifront_scan_root(struct pcifront_device *pdev,
444 unsigned int domain, unsigned int bus)
445{
446 struct pci_bus *b;
447 struct pcifront_sd *sd = NULL;
448 struct pci_bus_entry *bus_entry = NULL;
449 int err = 0;
450
451#ifndef CONFIG_PCI_DOMAINS
452 if (domain != 0) {
453 dev_err(&pdev->xdev->dev,
454 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
455 dev_err(&pdev->xdev->dev,
456 "Please compile with CONFIG_PCI_DOMAINS\n");
457 err = -EINVAL;
458 goto err_out;
459 }
460#endif
461
462 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
463 domain, bus);
464
465 bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL);
466 sd = kmalloc(sizeof(*sd), GFP_KERNEL);
467 if (!bus_entry || !sd) {
468 err = -ENOMEM;
469 goto err_out;
470 }
471 pcifront_init_sd(sd, domain, bus, pdev);
472
473 b = pci_scan_bus_parented(&pdev->xdev->dev, bus,
474 &pcifront_bus_ops, sd);
475 if (!b) {
476 dev_err(&pdev->xdev->dev,
477 "Error creating PCI Frontend Bus!\n");
478 err = -ENOMEM;
479 goto err_out;
480 }
481
482 bus_entry->bus = b;
483
484 list_add(&bus_entry->list, &pdev->root_buses);
485
486 /* pci_scan_bus_parented skips devices which do not have a have
487 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
488 err = pcifront_scan_bus(pdev, domain, bus, b);
489
490 /* Claim resources before going "live" with our devices */
491 pci_walk_bus(b, pcifront_claim_resource, pdev);
492
493 /* Create SysFS and notify udev of the devices. Aka: "going live" */
494 pci_bus_add_devices(b);
495
496 return err;
497
498err_out:
499 kfree(bus_entry);
500 kfree(sd);
501
502 return err;
503}
504
505static int __devinit pcifront_rescan_root(struct pcifront_device *pdev,
506 unsigned int domain, unsigned int bus)
507{
508 int err;
509 struct pci_bus *b;
510
511#ifndef CONFIG_PCI_DOMAINS
512 if (domain != 0) {
513 dev_err(&pdev->xdev->dev,
514 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
515 dev_err(&pdev->xdev->dev,
516 "Please compile with CONFIG_PCI_DOMAINS\n");
517 return -EINVAL;
518 }
519#endif
520
521 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
522 domain, bus);
523
524 b = pci_find_bus(domain, bus);
525 if (!b)
526 /* If the bus is unknown, create it. */
527 return pcifront_scan_root(pdev, domain, bus);
528
529 err = pcifront_scan_bus(pdev, domain, bus, b);
530
531 /* Claim resources before going "live" with our devices */
532 pci_walk_bus(b, pcifront_claim_resource, pdev);
533
534 /* Create SysFS and notify udev of the devices. Aka: "going live" */
535 pci_bus_add_devices(b);
536
537 return err;
538}
539
540static void free_root_bus_devs(struct pci_bus *bus)
541{
542 struct pci_dev *dev;
543
544 while (!list_empty(&bus->devices)) {
545 dev = container_of(bus->devices.next, struct pci_dev,
546 bus_list);
547 dev_dbg(&dev->dev, "removing device\n");
548 pci_remove_bus_device(dev);
549 }
550}
551
552static void pcifront_free_roots(struct pcifront_device *pdev)
553{
554 struct pci_bus_entry *bus_entry, *t;
555
556 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
557
558 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
559 list_del(&bus_entry->list);
560
561 free_root_bus_devs(bus_entry->bus);
562
563 kfree(bus_entry->bus->sysdata);
564
565 device_unregister(bus_entry->bus->bridge);
566 pci_remove_bus(bus_entry->bus);
567
568 kfree(bus_entry);
569 }
570}
571
572static pci_ers_result_t pcifront_common_process(int cmd,
573 struct pcifront_device *pdev,
574 pci_channel_state_t state)
575{
576 pci_ers_result_t result;
577 struct pci_driver *pdrv;
578 int bus = pdev->sh_info->aer_op.bus;
579 int devfn = pdev->sh_info->aer_op.devfn;
580 struct pci_dev *pcidev;
581 int flag = 0;
582
583 dev_dbg(&pdev->xdev->dev,
584 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
585 cmd, bus, devfn);
586 result = PCI_ERS_RESULT_NONE;
587
588 pcidev = pci_get_bus_and_slot(bus, devfn);
589 if (!pcidev || !pcidev->driver) {
590 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
591 if (pcidev)
592 pci_dev_put(pcidev);
593 return result;
594 }
595 pdrv = pcidev->driver;
596
597 if (get_driver(&pdrv->driver)) {
598 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
599 dev_dbg(&pcidev->dev,
600 "trying to call AER service\n");
601 if (pcidev) {
602 flag = 1;
603 switch (cmd) {
604 case XEN_PCI_OP_aer_detected:
605 result = pdrv->err_handler->
606 error_detected(pcidev, state);
607 break;
608 case XEN_PCI_OP_aer_mmio:
609 result = pdrv->err_handler->
610 mmio_enabled(pcidev);
611 break;
612 case XEN_PCI_OP_aer_slotreset:
613 result = pdrv->err_handler->
614 slot_reset(pcidev);
615 break;
616 case XEN_PCI_OP_aer_resume:
617 pdrv->err_handler->resume(pcidev);
618 break;
619 default:
620 dev_err(&pdev->xdev->dev,
621 "bad request in aer recovery "
622 "operation!\n");
623
624 }
625 }
626 }
627 put_driver(&pdrv->driver);
628 }
629 if (!flag)
630 result = PCI_ERS_RESULT_NONE;
631
632 return result;
633}
634
635
636static void pcifront_do_aer(struct work_struct *data)
637{
638 struct pcifront_device *pdev =
639 container_of(data, struct pcifront_device, op_work);
640 int cmd = pdev->sh_info->aer_op.cmd;
641 pci_channel_state_t state =
642 (pci_channel_state_t)pdev->sh_info->aer_op.err;
643
644 /*If a pci_conf op is in progress,
645 we have to wait until it is done before service aer op*/
646 dev_dbg(&pdev->xdev->dev,
647 "pcifront service aer bus %x devfn %x\n",
648 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
649
650 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
651
652 /* Post the operation to the guest. */
653 wmb();
654 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
655 notify_remote_via_evtchn(pdev->evtchn);
656
657 /*in case of we lost an aer request in four lines time_window*/
658 smp_mb__before_clear_bit();
659 clear_bit(_PDEVB_op_active, &pdev->flags);
660 smp_mb__after_clear_bit();
661
662 schedule_pcifront_aer_op(pdev);
663
664}
665
666static irqreturn_t pcifront_handler_aer(int irq, void *dev)
667{
668 struct pcifront_device *pdev = dev;
669 schedule_pcifront_aer_op(pdev);
670 return IRQ_HANDLED;
671}
672static int pcifront_connect(struct pcifront_device *pdev)
673{
674 int err = 0;
675
676 spin_lock(&pcifront_dev_lock);
677
678 if (!pcifront_dev) {
679 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
680 pcifront_dev = pdev;
681 } else {
682 dev_err(&pdev->xdev->dev, "PCI frontend already installed!\n");
683 err = -EEXIST;
684 }
685
686 spin_unlock(&pcifront_dev_lock);
687
688 return err;
689}
690
691static void pcifront_disconnect(struct pcifront_device *pdev)
692{
693 spin_lock(&pcifront_dev_lock);
694
695 if (pdev == pcifront_dev) {
696 dev_info(&pdev->xdev->dev,
697 "Disconnecting PCI Frontend Buses\n");
698 pcifront_dev = NULL;
699 }
700
701 spin_unlock(&pcifront_dev_lock);
702}
703static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
704{
705 struct pcifront_device *pdev;
706
707 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
708 if (pdev == NULL)
709 goto out;
710
711 pdev->sh_info =
712 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
713 if (pdev->sh_info == NULL) {
714 kfree(pdev);
715 pdev = NULL;
716 goto out;
717 }
718 pdev->sh_info->flags = 0;
719
720 /*Flag for registering PV AER handler*/
721 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
722
723 dev_set_drvdata(&xdev->dev, pdev);
724 pdev->xdev = xdev;
725
726 INIT_LIST_HEAD(&pdev->root_buses);
727
728 spin_lock_init(&pdev->sh_info_lock);
729
730 pdev->evtchn = INVALID_EVTCHN;
731 pdev->gnt_ref = INVALID_GRANT_REF;
732 pdev->irq = -1;
733
734 INIT_WORK(&pdev->op_work, pcifront_do_aer);
735
736 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
737 pdev, pdev->sh_info);
738out:
739 return pdev;
740}
741
742static void free_pdev(struct pcifront_device *pdev)
743{
744 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
745
746 pcifront_free_roots(pdev);
747
748 cancel_work_sync(&pdev->op_work);
749
750 if (pdev->irq >= 0)
751 unbind_from_irqhandler(pdev->irq, pdev);
752
753 if (pdev->evtchn != INVALID_EVTCHN)
754 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
755
756 if (pdev->gnt_ref != INVALID_GRANT_REF)
757 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
758 (unsigned long)pdev->sh_info);
759 else
760 free_page((unsigned long)pdev->sh_info);
761
762 dev_set_drvdata(&pdev->xdev->dev, NULL);
763
764 kfree(pdev);
765}
766
767static int pcifront_publish_info(struct pcifront_device *pdev)
768{
769 int err = 0;
770 struct xenbus_transaction trans;
771
772 err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
773 if (err < 0)
774 goto out;
775
776 pdev->gnt_ref = err;
777
778 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
779 if (err)
780 goto out;
781
782 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
783 0, "pcifront", pdev);
784
785 if (err < 0)
786 return err;
787
788 pdev->irq = err;
789
790do_publish:
791 err = xenbus_transaction_start(&trans);
792 if (err) {
793 xenbus_dev_fatal(pdev->xdev, err,
794 "Error writing configuration for backend "
795 "(start transaction)");
796 goto out;
797 }
798
799 err = xenbus_printf(trans, pdev->xdev->nodename,
800 "pci-op-ref", "%u", pdev->gnt_ref);
801 if (!err)
802 err = xenbus_printf(trans, pdev->xdev->nodename,
803 "event-channel", "%u", pdev->evtchn);
804 if (!err)
805 err = xenbus_printf(trans, pdev->xdev->nodename,
806 "magic", XEN_PCI_MAGIC);
807
808 if (err) {
809 xenbus_transaction_end(trans, 1);
810 xenbus_dev_fatal(pdev->xdev, err,
811 "Error writing configuration for backend");
812 goto out;
813 } else {
814 err = xenbus_transaction_end(trans, 0);
815 if (err == -EAGAIN)
816 goto do_publish;
817 else if (err) {
818 xenbus_dev_fatal(pdev->xdev, err,
819 "Error completing transaction "
820 "for backend");
821 goto out;
822 }
823 }
824
825 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
826
827 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
828
829out:
830 return err;
831}
832
833static int __devinit pcifront_try_connect(struct pcifront_device *pdev)
834{
835 int err = -EFAULT;
836 int i, num_roots, len;
837 char str[64];
838 unsigned int domain, bus;
839
840
841 /* Only connect once */
842 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
843 XenbusStateInitialised)
844 goto out;
845
846 err = pcifront_connect(pdev);
847 if (err) {
848 xenbus_dev_fatal(pdev->xdev, err,
849 "Error connecting PCI Frontend");
850 goto out;
851 }
852
853 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
854 "root_num", "%d", &num_roots);
855 if (err == -ENOENT) {
856 xenbus_dev_error(pdev->xdev, err,
857 "No PCI Roots found, trying 0000:00");
858 err = pcifront_scan_root(pdev, 0, 0);
859 num_roots = 0;
860 } else if (err != 1) {
861 if (err == 0)
862 err = -EINVAL;
863 xenbus_dev_fatal(pdev->xdev, err,
864 "Error reading number of PCI roots");
865 goto out;
866 }
867
868 for (i = 0; i < num_roots; i++) {
869 len = snprintf(str, sizeof(str), "root-%d", i);
870 if (unlikely(len >= (sizeof(str) - 1))) {
871 err = -ENOMEM;
872 goto out;
873 }
874
875 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
876 "%x:%x", &domain, &bus);
877 if (err != 2) {
878 if (err >= 0)
879 err = -EINVAL;
880 xenbus_dev_fatal(pdev->xdev, err,
881 "Error reading PCI root %d", i);
882 goto out;
883 }
884
885 err = pcifront_scan_root(pdev, domain, bus);
886 if (err) {
887 xenbus_dev_fatal(pdev->xdev, err,
888 "Error scanning PCI root %04x:%02x",
889 domain, bus);
890 goto out;
891 }
892 }
893
894 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
895
896out:
897 return err;
898}
899
900static int pcifront_try_disconnect(struct pcifront_device *pdev)
901{
902 int err = 0;
903 enum xenbus_state prev_state;
904
905
906 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
907
908 if (prev_state >= XenbusStateClosing)
909 goto out;
910
911 if (prev_state == XenbusStateConnected) {
912 pcifront_free_roots(pdev);
913 pcifront_disconnect(pdev);
914 }
915
916 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
917
918out:
919
920 return err;
921}
922
923static int __devinit pcifront_attach_devices(struct pcifront_device *pdev)
924{
925 int err = -EFAULT;
926 int i, num_roots, len;
927 unsigned int domain, bus;
928 char str[64];
929
930 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
931 XenbusStateReconfiguring)
932 goto out;
933
934 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
935 "root_num", "%d", &num_roots);
936 if (err == -ENOENT) {
937 xenbus_dev_error(pdev->xdev, err,
938 "No PCI Roots found, trying 0000:00");
939 err = pcifront_rescan_root(pdev, 0, 0);
940 num_roots = 0;
941 } else if (err != 1) {
942 if (err == 0)
943 err = -EINVAL;
944 xenbus_dev_fatal(pdev->xdev, err,
945 "Error reading number of PCI roots");
946 goto out;
947 }
948
949 for (i = 0; i < num_roots; i++) {
950 len = snprintf(str, sizeof(str), "root-%d", i);
951 if (unlikely(len >= (sizeof(str) - 1))) {
952 err = -ENOMEM;
953 goto out;
954 }
955
956 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
957 "%x:%x", &domain, &bus);
958 if (err != 2) {
959 if (err >= 0)
960 err = -EINVAL;
961 xenbus_dev_fatal(pdev->xdev, err,
962 "Error reading PCI root %d", i);
963 goto out;
964 }
965
966 err = pcifront_rescan_root(pdev, domain, bus);
967 if (err) {
968 xenbus_dev_fatal(pdev->xdev, err,
969 "Error scanning PCI root %04x:%02x",
970 domain, bus);
971 goto out;
972 }
973 }
974
975 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
976
977out:
978 return err;
979}
980
981static int pcifront_detach_devices(struct pcifront_device *pdev)
982{
983 int err = 0;
984 int i, num_devs;
985 unsigned int domain, bus, slot, func;
986 struct pci_bus *pci_bus;
987 struct pci_dev *pci_dev;
988 char str[64];
989
990 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
991 XenbusStateConnected)
992 goto out;
993
994 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
995 &num_devs);
996 if (err != 1) {
997 if (err >= 0)
998 err = -EINVAL;
999 xenbus_dev_fatal(pdev->xdev, err,
1000 "Error reading number of PCI devices");
1001 goto out;
1002 }
1003
1004 /* Find devices being detached and remove them. */
1005 for (i = 0; i < num_devs; i++) {
1006 int l, state;
1007 l = snprintf(str, sizeof(str), "state-%d", i);
1008 if (unlikely(l >= (sizeof(str) - 1))) {
1009 err = -ENOMEM;
1010 goto out;
1011 }
1012 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d",
1013 &state);
1014 if (err != 1)
1015 state = XenbusStateUnknown;
1016
1017 if (state != XenbusStateClosing)
1018 continue;
1019
1020 /* Remove device. */
1021 l = snprintf(str, sizeof(str), "vdev-%d", i);
1022 if (unlikely(l >= (sizeof(str) - 1))) {
1023 err = -ENOMEM;
1024 goto out;
1025 }
1026 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1027 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1028 if (err != 4) {
1029 if (err >= 0)
1030 err = -EINVAL;
1031 xenbus_dev_fatal(pdev->xdev, err,
1032 "Error reading PCI device %d", i);
1033 goto out;
1034 }
1035
1036 pci_bus = pci_find_bus(domain, bus);
1037 if (!pci_bus) {
1038 dev_dbg(&pdev->xdev->dev, "Cannot get bus %04x:%02x\n",
1039 domain, bus);
1040 continue;
1041 }
1042 pci_dev = pci_get_slot(pci_bus, PCI_DEVFN(slot, func));
1043 if (!pci_dev) {
1044 dev_dbg(&pdev->xdev->dev,
1045 "Cannot get PCI device %04x:%02x:%02x.%02x\n",
1046 domain, bus, slot, func);
1047 continue;
1048 }
1049 pci_remove_bus_device(pci_dev);
1050 pci_dev_put(pci_dev);
1051
1052 dev_dbg(&pdev->xdev->dev,
1053 "PCI device %04x:%02x:%02x.%02x removed.\n",
1054 domain, bus, slot, func);
1055 }
1056
1057 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1058
1059out:
1060 return err;
1061}
1062
1063static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev,
1064 enum xenbus_state be_state)
1065{
1066 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1067
1068 switch (be_state) {
1069 case XenbusStateUnknown:
1070 case XenbusStateInitialising:
1071 case XenbusStateInitWait:
1072 case XenbusStateInitialised:
1073 case XenbusStateClosed:
1074 break;
1075
1076 case XenbusStateConnected:
1077 pcifront_try_connect(pdev);
1078 break;
1079
1080 case XenbusStateClosing:
1081 dev_warn(&xdev->dev, "backend going away!\n");
1082 pcifront_try_disconnect(pdev);
1083 break;
1084
1085 case XenbusStateReconfiguring:
1086 pcifront_detach_devices(pdev);
1087 break;
1088
1089 case XenbusStateReconfigured:
1090 pcifront_attach_devices(pdev);
1091 break;
1092 }
1093}
1094
1095static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1096 const struct xenbus_device_id *id)
1097{
1098 int err = 0;
1099 struct pcifront_device *pdev = alloc_pdev(xdev);
1100
1101 if (pdev == NULL) {
1102 err = -ENOMEM;
1103 xenbus_dev_fatal(xdev, err,
1104 "Error allocating pcifront_device struct");
1105 goto out;
1106 }
1107
1108 err = pcifront_publish_info(pdev);
1109 if (err)
1110 free_pdev(pdev);
1111
1112out:
1113 return err;
1114}
1115
1116static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1117{
1118 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1119 if (pdev)
1120 free_pdev(pdev);
1121
1122 return 0;
1123}
1124
1125static const struct xenbus_device_id xenpci_ids[] = {
1126 {"pci"},
1127 {""},
1128};
1129
1130static struct xenbus_driver xenbus_pcifront_driver = {
1131 .name = "pcifront",
1132 .owner = THIS_MODULE,
1133 .ids = xenpci_ids,
1134 .probe = pcifront_xenbus_probe,
1135 .remove = pcifront_xenbus_remove,
1136 .otherend_changed = pcifront_backend_changed,
1137};
1138
1139static int __init pcifront_init(void)
1140{
1141 if (!xen_pv_domain() || xen_initial_domain())
1142 return -ENODEV;
1143
1144 pci_frontend_registrar(1 /* enable */);
1145
1146 return xenbus_register_frontend(&xenbus_pcifront_driver);
1147}
1148
1149static void __exit pcifront_cleanup(void)
1150{
1151 xenbus_unregister_driver(&xenbus_pcifront_driver);
1152 pci_frontend_registrar(0 /* disable */);
1153}
1154module_init(pcifront_init);
1155module_exit(pcifront_cleanup);
1156
1157MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1158MODULE_LICENSE("GPL");
1159MODULE_ALIAS("xen:pci");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Xen PCI Frontend
4 *
5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
6 */
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/mm.h>
10#include <xen/xenbus.h>
11#include <xen/events.h>
12#include <xen/grant_table.h>
13#include <xen/page.h>
14#include <linux/spinlock.h>
15#include <linux/pci.h>
16#include <linux/msi.h>
17#include <xen/interface/io/pciif.h>
18#include <asm/xen/pci.h>
19#include <linux/interrupt.h>
20#include <linux/atomic.h>
21#include <linux/workqueue.h>
22#include <linux/bitops.h>
23#include <linux/time.h>
24#include <linux/ktime.h>
25#include <linux/swiotlb.h>
26#include <xen/platform_pci.h>
27
28#include <asm/xen/swiotlb-xen.h>
29
30#define INVALID_EVTCHN (-1)
31
32struct pci_bus_entry {
33 struct list_head list;
34 struct pci_bus *bus;
35};
36
37#define _PDEVB_op_active (0)
38#define PDEVB_op_active (1 << (_PDEVB_op_active))
39
40struct pcifront_device {
41 struct xenbus_device *xdev;
42 struct list_head root_buses;
43
44 int evtchn;
45 grant_ref_t gnt_ref;
46
47 int irq;
48
49 /* Lock this when doing any operations in sh_info */
50 spinlock_t sh_info_lock;
51 struct xen_pci_sharedinfo *sh_info;
52 struct work_struct op_work;
53 unsigned long flags;
54
55};
56
57struct pcifront_sd {
58 struct pci_sysdata sd;
59 struct pcifront_device *pdev;
60};
61
62static inline struct pcifront_device *
63pcifront_get_pdev(struct pcifront_sd *sd)
64{
65 return sd->pdev;
66}
67
68static inline void pcifront_init_sd(struct pcifront_sd *sd,
69 unsigned int domain, unsigned int bus,
70 struct pcifront_device *pdev)
71{
72 /* Because we do not expose that information via XenBus. */
73 sd->sd.node = first_online_node;
74 sd->sd.domain = domain;
75 sd->pdev = pdev;
76}
77
78static DEFINE_SPINLOCK(pcifront_dev_lock);
79static struct pcifront_device *pcifront_dev;
80
81static int errno_to_pcibios_err(int errno)
82{
83 switch (errno) {
84 case XEN_PCI_ERR_success:
85 return PCIBIOS_SUCCESSFUL;
86
87 case XEN_PCI_ERR_dev_not_found:
88 return PCIBIOS_DEVICE_NOT_FOUND;
89
90 case XEN_PCI_ERR_invalid_offset:
91 case XEN_PCI_ERR_op_failed:
92 return PCIBIOS_BAD_REGISTER_NUMBER;
93
94 case XEN_PCI_ERR_not_implemented:
95 return PCIBIOS_FUNC_NOT_SUPPORTED;
96
97 case XEN_PCI_ERR_access_denied:
98 return PCIBIOS_SET_FAILED;
99 }
100 return errno;
101}
102
103static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
104{
105 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
106 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
107 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
108 schedule_work(&pdev->op_work);
109 }
110}
111
112static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
113{
114 int err = 0;
115 struct xen_pci_op *active_op = &pdev->sh_info->op;
116 unsigned long irq_flags;
117 evtchn_port_t port = pdev->evtchn;
118 unsigned int irq = pdev->irq;
119 s64 ns, ns_timeout;
120
121 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
122
123 memcpy(active_op, op, sizeof(struct xen_pci_op));
124
125 /* Go */
126 wmb();
127 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
128 notify_remote_via_evtchn(port);
129
130 /*
131 * We set a poll timeout of 3 seconds but give up on return after
132 * 2 seconds. It is better to time out too late rather than too early
133 * (in the latter case we end up continually re-executing poll() with a
134 * timeout in the past). 1s difference gives plenty of slack for error.
135 */
136 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC;
137
138 xen_clear_irq_pending(irq);
139
140 while (test_bit(_XEN_PCIF_active,
141 (unsigned long *)&pdev->sh_info->flags)) {
142 xen_poll_irq_timeout(irq, jiffies + 3*HZ);
143 xen_clear_irq_pending(irq);
144 ns = ktime_get_ns();
145 if (ns > ns_timeout) {
146 dev_err(&pdev->xdev->dev,
147 "pciback not responding!!!\n");
148 clear_bit(_XEN_PCIF_active,
149 (unsigned long *)&pdev->sh_info->flags);
150 err = XEN_PCI_ERR_dev_not_found;
151 goto out;
152 }
153 }
154
155 /*
156 * We might lose backend service request since we
157 * reuse same evtchn with pci_conf backend response. So re-schedule
158 * aer pcifront service.
159 */
160 if (test_bit(_XEN_PCIB_active,
161 (unsigned long *)&pdev->sh_info->flags)) {
162 dev_err(&pdev->xdev->dev,
163 "schedule aer pcifront service\n");
164 schedule_pcifront_aer_op(pdev);
165 }
166
167 memcpy(op, active_op, sizeof(struct xen_pci_op));
168
169 err = op->err;
170out:
171 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
172 return err;
173}
174
175/* Access to this function is spinlocked in drivers/pci/access.c */
176static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
177 int where, int size, u32 *val)
178{
179 int err = 0;
180 struct xen_pci_op op = {
181 .cmd = XEN_PCI_OP_conf_read,
182 .domain = pci_domain_nr(bus),
183 .bus = bus->number,
184 .devfn = devfn,
185 .offset = where,
186 .size = size,
187 };
188 struct pcifront_sd *sd = bus->sysdata;
189 struct pcifront_device *pdev = pcifront_get_pdev(sd);
190
191 dev_dbg(&pdev->xdev->dev,
192 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
193 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
194 PCI_FUNC(devfn), where, size);
195
196 err = do_pci_op(pdev, &op);
197
198 if (likely(!err)) {
199 dev_dbg(&pdev->xdev->dev, "read got back value %x\n",
200 op.value);
201
202 *val = op.value;
203 } else if (err == -ENODEV) {
204 /* No device here, pretend that it just returned 0 */
205 err = 0;
206 *val = 0;
207 }
208
209 return errno_to_pcibios_err(err);
210}
211
212/* Access to this function is spinlocked in drivers/pci/access.c */
213static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
214 int where, int size, u32 val)
215{
216 struct xen_pci_op op = {
217 .cmd = XEN_PCI_OP_conf_write,
218 .domain = pci_domain_nr(bus),
219 .bus = bus->number,
220 .devfn = devfn,
221 .offset = where,
222 .size = size,
223 .value = val,
224 };
225 struct pcifront_sd *sd = bus->sysdata;
226 struct pcifront_device *pdev = pcifront_get_pdev(sd);
227
228 dev_dbg(&pdev->xdev->dev,
229 "write dev=%04x:%02x:%02x.%d - offset %x size %d val %x\n",
230 pci_domain_nr(bus), bus->number,
231 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
232
233 return errno_to_pcibios_err(do_pci_op(pdev, &op));
234}
235
236static struct pci_ops pcifront_bus_ops = {
237 .read = pcifront_bus_read,
238 .write = pcifront_bus_write,
239};
240
241#ifdef CONFIG_PCI_MSI
242static int pci_frontend_enable_msix(struct pci_dev *dev,
243 int vector[], int nvec)
244{
245 int err;
246 int i;
247 struct xen_pci_op op = {
248 .cmd = XEN_PCI_OP_enable_msix,
249 .domain = pci_domain_nr(dev->bus),
250 .bus = dev->bus->number,
251 .devfn = dev->devfn,
252 .value = nvec,
253 };
254 struct pcifront_sd *sd = dev->bus->sysdata;
255 struct pcifront_device *pdev = pcifront_get_pdev(sd);
256 struct msi_desc *entry;
257
258 if (nvec > SH_INFO_MAX_VEC) {
259 pci_err(dev, "too many vectors (0x%x) for PCI frontend:"
260 " Increase SH_INFO_MAX_VEC\n", nvec);
261 return -EINVAL;
262 }
263
264 i = 0;
265 msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) {
266 op.msix_entries[i].entry = entry->msi_index;
267 /* Vector is useless at this point. */
268 op.msix_entries[i].vector = -1;
269 i++;
270 }
271
272 err = do_pci_op(pdev, &op);
273
274 if (likely(!err)) {
275 if (likely(!op.value)) {
276 /* we get the result */
277 for (i = 0; i < nvec; i++) {
278 if (op.msix_entries[i].vector <= 0) {
279 pci_warn(dev, "MSI-X entry %d is invalid: %d!\n",
280 i, op.msix_entries[i].vector);
281 err = -EINVAL;
282 vector[i] = -1;
283 continue;
284 }
285 vector[i] = op.msix_entries[i].vector;
286 }
287 } else {
288 pr_info("enable msix get value %x\n", op.value);
289 err = op.value;
290 }
291 } else {
292 pci_err(dev, "enable msix get err %x\n", err);
293 }
294 return err;
295}
296
297static void pci_frontend_disable_msix(struct pci_dev *dev)
298{
299 int err;
300 struct xen_pci_op op = {
301 .cmd = XEN_PCI_OP_disable_msix,
302 .domain = pci_domain_nr(dev->bus),
303 .bus = dev->bus->number,
304 .devfn = dev->devfn,
305 };
306 struct pcifront_sd *sd = dev->bus->sysdata;
307 struct pcifront_device *pdev = pcifront_get_pdev(sd);
308
309 err = do_pci_op(pdev, &op);
310
311 /* What should do for error ? */
312 if (err)
313 pci_err(dev, "pci_disable_msix get err %x\n", err);
314}
315
316static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
317{
318 int err;
319 struct xen_pci_op op = {
320 .cmd = XEN_PCI_OP_enable_msi,
321 .domain = pci_domain_nr(dev->bus),
322 .bus = dev->bus->number,
323 .devfn = dev->devfn,
324 };
325 struct pcifront_sd *sd = dev->bus->sysdata;
326 struct pcifront_device *pdev = pcifront_get_pdev(sd);
327
328 err = do_pci_op(pdev, &op);
329 if (likely(!err)) {
330 vector[0] = op.value;
331 if (op.value <= 0) {
332 pci_warn(dev, "MSI entry is invalid: %d!\n",
333 op.value);
334 err = -EINVAL;
335 vector[0] = -1;
336 }
337 } else {
338 pci_err(dev, "pci frontend enable msi failed for dev "
339 "%x:%x\n", op.bus, op.devfn);
340 err = -EINVAL;
341 }
342 return err;
343}
344
345static void pci_frontend_disable_msi(struct pci_dev *dev)
346{
347 int err;
348 struct xen_pci_op op = {
349 .cmd = XEN_PCI_OP_disable_msi,
350 .domain = pci_domain_nr(dev->bus),
351 .bus = dev->bus->number,
352 .devfn = dev->devfn,
353 };
354 struct pcifront_sd *sd = dev->bus->sysdata;
355 struct pcifront_device *pdev = pcifront_get_pdev(sd);
356
357 err = do_pci_op(pdev, &op);
358 if (err == XEN_PCI_ERR_dev_not_found) {
359 /* XXX No response from backend, what shall we do? */
360 pr_info("get no response from backend for disable MSI\n");
361 return;
362 }
363 if (err)
364 /* how can pciback notify us fail? */
365 pr_info("get fake response from backend\n");
366}
367
368static struct xen_pci_frontend_ops pci_frontend_ops = {
369 .enable_msi = pci_frontend_enable_msi,
370 .disable_msi = pci_frontend_disable_msi,
371 .enable_msix = pci_frontend_enable_msix,
372 .disable_msix = pci_frontend_disable_msix,
373};
374
375static void pci_frontend_registrar(int enable)
376{
377 if (enable)
378 xen_pci_frontend = &pci_frontend_ops;
379 else
380 xen_pci_frontend = NULL;
381};
382#else
383static inline void pci_frontend_registrar(int enable) { };
384#endif /* CONFIG_PCI_MSI */
385
386/* Claim resources for the PCI frontend as-is, backend won't allow changes */
387static int pcifront_claim_resource(struct pci_dev *dev, void *data)
388{
389 struct pcifront_device *pdev = data;
390 int i;
391 struct resource *r;
392
393 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
394 r = &dev->resource[i];
395
396 if (!r->parent && r->start && r->flags) {
397 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
398 pci_name(dev), i);
399 if (pci_claim_resource(dev, i)) {
400 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
401 "Device offline. Try using e820_host=1 in the guest config.\n",
402 pci_name(dev), i);
403 }
404 }
405 }
406
407 return 0;
408}
409
410static int pcifront_scan_bus(struct pcifront_device *pdev,
411 unsigned int domain, unsigned int bus,
412 struct pci_bus *b)
413{
414 struct pci_dev *d;
415 unsigned int devfn;
416
417 /*
418 * Scan the bus for functions and add.
419 * We omit handling of PCI bridge attachment because pciback prevents
420 * bridges from being exported.
421 */
422 for (devfn = 0; devfn < 0x100; devfn++) {
423 d = pci_get_slot(b, devfn);
424 if (d) {
425 /* Device is already known. */
426 pci_dev_put(d);
427 continue;
428 }
429
430 d = pci_scan_single_device(b, devfn);
431 if (d)
432 dev_info(&pdev->xdev->dev, "New device on "
433 "%04x:%02x:%02x.%d found.\n", domain, bus,
434 PCI_SLOT(devfn), PCI_FUNC(devfn));
435 }
436
437 return 0;
438}
439
440static int pcifront_scan_root(struct pcifront_device *pdev,
441 unsigned int domain, unsigned int bus)
442{
443 struct pci_bus *b;
444 LIST_HEAD(resources);
445 struct pcifront_sd *sd = NULL;
446 struct pci_bus_entry *bus_entry = NULL;
447 int err = 0;
448 static struct resource busn_res = {
449 .start = 0,
450 .end = 255,
451 .flags = IORESOURCE_BUS,
452 };
453
454#ifndef CONFIG_PCI_DOMAINS
455 if (domain != 0) {
456 dev_err(&pdev->xdev->dev,
457 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
458 dev_err(&pdev->xdev->dev,
459 "Please compile with CONFIG_PCI_DOMAINS\n");
460 err = -EINVAL;
461 goto err_out;
462 }
463#endif
464
465 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
466 domain, bus);
467
468 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
469 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
470 if (!bus_entry || !sd) {
471 err = -ENOMEM;
472 goto err_out;
473 }
474 pci_add_resource(&resources, &ioport_resource);
475 pci_add_resource(&resources, &iomem_resource);
476 pci_add_resource(&resources, &busn_res);
477 pcifront_init_sd(sd, domain, bus, pdev);
478
479 pci_lock_rescan_remove();
480
481 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
482 &pcifront_bus_ops, sd, &resources);
483 if (!b) {
484 dev_err(&pdev->xdev->dev,
485 "Error creating PCI Frontend Bus!\n");
486 err = -ENOMEM;
487 pci_unlock_rescan_remove();
488 pci_free_resource_list(&resources);
489 goto err_out;
490 }
491
492 bus_entry->bus = b;
493
494 list_add(&bus_entry->list, &pdev->root_buses);
495
496 /*
497 * pci_scan_root_bus skips devices which do not have a
498 * devfn==0. The pcifront_scan_bus enumerates all devfn.
499 */
500 err = pcifront_scan_bus(pdev, domain, bus, b);
501
502 /* Claim resources before going "live" with our devices */
503 pci_walk_bus(b, pcifront_claim_resource, pdev);
504
505 /* Create SysFS and notify udev of the devices. Aka: "going live" */
506 pci_bus_add_devices(b);
507
508 pci_unlock_rescan_remove();
509 return err;
510
511err_out:
512 kfree(bus_entry);
513 kfree(sd);
514
515 return err;
516}
517
518static int pcifront_rescan_root(struct pcifront_device *pdev,
519 unsigned int domain, unsigned int bus)
520{
521 int err;
522 struct pci_bus *b;
523
524 b = pci_find_bus(domain, bus);
525 if (!b)
526 /* If the bus is unknown, create it. */
527 return pcifront_scan_root(pdev, domain, bus);
528
529 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
530 domain, bus);
531
532 err = pcifront_scan_bus(pdev, domain, bus, b);
533
534 /* Claim resources before going "live" with our devices */
535 pci_walk_bus(b, pcifront_claim_resource, pdev);
536
537 /* Create SysFS and notify udev of the devices. Aka: "going live" */
538 pci_bus_add_devices(b);
539
540 return err;
541}
542
543static void free_root_bus_devs(struct pci_bus *bus)
544{
545 struct pci_dev *dev;
546
547 while (!list_empty(&bus->devices)) {
548 dev = container_of(bus->devices.next, struct pci_dev,
549 bus_list);
550 pci_dbg(dev, "removing device\n");
551 pci_stop_and_remove_bus_device(dev);
552 }
553}
554
555static void pcifront_free_roots(struct pcifront_device *pdev)
556{
557 struct pci_bus_entry *bus_entry, *t;
558
559 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
560
561 pci_lock_rescan_remove();
562 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
563 list_del(&bus_entry->list);
564
565 free_root_bus_devs(bus_entry->bus);
566
567 kfree(bus_entry->bus->sysdata);
568
569 device_unregister(bus_entry->bus->bridge);
570 pci_remove_bus(bus_entry->bus);
571
572 kfree(bus_entry);
573 }
574 pci_unlock_rescan_remove();
575}
576
577static pci_ers_result_t pcifront_common_process(int cmd,
578 struct pcifront_device *pdev,
579 pci_channel_state_t state)
580{
581 struct pci_driver *pdrv;
582 int bus = pdev->sh_info->aer_op.bus;
583 int devfn = pdev->sh_info->aer_op.devfn;
584 int domain = pdev->sh_info->aer_op.domain;
585 struct pci_dev *pcidev;
586
587 dev_dbg(&pdev->xdev->dev,
588 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
589 cmd, bus, devfn);
590
591 pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
592 if (!pcidev || !pcidev->dev.driver) {
593 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
594 pci_dev_put(pcidev);
595 return PCI_ERS_RESULT_NONE;
596 }
597 pdrv = to_pci_driver(pcidev->dev.driver);
598
599 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
600 pci_dbg(pcidev, "trying to call AER service\n");
601 switch (cmd) {
602 case XEN_PCI_OP_aer_detected:
603 return pdrv->err_handler->error_detected(pcidev, state);
604 case XEN_PCI_OP_aer_mmio:
605 return pdrv->err_handler->mmio_enabled(pcidev);
606 case XEN_PCI_OP_aer_slotreset:
607 return pdrv->err_handler->slot_reset(pcidev);
608 case XEN_PCI_OP_aer_resume:
609 pdrv->err_handler->resume(pcidev);
610 return PCI_ERS_RESULT_NONE;
611 default:
612 dev_err(&pdev->xdev->dev,
613 "bad request in aer recovery operation!\n");
614 }
615 }
616
617 return PCI_ERS_RESULT_NONE;
618}
619
620
621static void pcifront_do_aer(struct work_struct *data)
622{
623 struct pcifront_device *pdev =
624 container_of(data, struct pcifront_device, op_work);
625 int cmd = pdev->sh_info->aer_op.cmd;
626 pci_channel_state_t state =
627 (pci_channel_state_t)pdev->sh_info->aer_op.err;
628
629 /*
630 * If a pci_conf op is in progress, we have to wait until it is done
631 * before service aer op
632 */
633 dev_dbg(&pdev->xdev->dev,
634 "pcifront service aer bus %x devfn %x\n",
635 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
636
637 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
638
639 /* Post the operation to the guest. */
640 wmb();
641 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
642 notify_remote_via_evtchn(pdev->evtchn);
643
644 /*in case of we lost an aer request in four lines time_window*/
645 smp_mb__before_atomic();
646 clear_bit(_PDEVB_op_active, &pdev->flags);
647 smp_mb__after_atomic();
648
649 schedule_pcifront_aer_op(pdev);
650
651}
652
653static irqreturn_t pcifront_handler_aer(int irq, void *dev)
654{
655 struct pcifront_device *pdev = dev;
656
657 schedule_pcifront_aer_op(pdev);
658 return IRQ_HANDLED;
659}
660static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
661{
662 int err = 0;
663
664 spin_lock(&pcifront_dev_lock);
665
666 if (!pcifront_dev) {
667 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
668 pcifront_dev = pdev;
669 } else
670 err = -EEXIST;
671
672 spin_unlock(&pcifront_dev_lock);
673
674 if (!err && !is_swiotlb_active(&pdev->xdev->dev)) {
675 err = pci_xen_swiotlb_init_late();
676 if (err)
677 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
678 }
679 return err;
680}
681
682static void pcifront_disconnect(struct pcifront_device *pdev)
683{
684 spin_lock(&pcifront_dev_lock);
685
686 if (pdev == pcifront_dev) {
687 dev_info(&pdev->xdev->dev,
688 "Disconnecting PCI Frontend Buses\n");
689 pcifront_dev = NULL;
690 }
691
692 spin_unlock(&pcifront_dev_lock);
693}
694static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
695{
696 struct pcifront_device *pdev;
697
698 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
699 if (pdev == NULL)
700 goto out;
701
702 if (xenbus_setup_ring(xdev, GFP_KERNEL, (void **)&pdev->sh_info, 1,
703 &pdev->gnt_ref)) {
704 kfree(pdev);
705 pdev = NULL;
706 goto out;
707 }
708 pdev->sh_info->flags = 0;
709
710 /*Flag for registering PV AER handler*/
711 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
712
713 dev_set_drvdata(&xdev->dev, pdev);
714 pdev->xdev = xdev;
715
716 INIT_LIST_HEAD(&pdev->root_buses);
717
718 spin_lock_init(&pdev->sh_info_lock);
719
720 pdev->evtchn = INVALID_EVTCHN;
721 pdev->irq = -1;
722
723 INIT_WORK(&pdev->op_work, pcifront_do_aer);
724
725 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
726 pdev, pdev->sh_info);
727out:
728 return pdev;
729}
730
731static void free_pdev(struct pcifront_device *pdev)
732{
733 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
734
735 pcifront_free_roots(pdev);
736
737 cancel_work_sync(&pdev->op_work);
738
739 if (pdev->irq >= 0)
740 unbind_from_irqhandler(pdev->irq, pdev);
741
742 if (pdev->evtchn != INVALID_EVTCHN)
743 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
744
745 xenbus_teardown_ring((void **)&pdev->sh_info, 1, &pdev->gnt_ref);
746
747 dev_set_drvdata(&pdev->xdev->dev, NULL);
748
749 kfree(pdev);
750}
751
752static int pcifront_publish_info(struct pcifront_device *pdev)
753{
754 int err = 0;
755 struct xenbus_transaction trans;
756
757 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
758 if (err)
759 goto out;
760
761 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
762 0, "pcifront", pdev);
763
764 if (err < 0)
765 return err;
766
767 pdev->irq = err;
768
769do_publish:
770 err = xenbus_transaction_start(&trans);
771 if (err) {
772 xenbus_dev_fatal(pdev->xdev, err,
773 "Error writing configuration for backend "
774 "(start transaction)");
775 goto out;
776 }
777
778 err = xenbus_printf(trans, pdev->xdev->nodename,
779 "pci-op-ref", "%u", pdev->gnt_ref);
780 if (!err)
781 err = xenbus_printf(trans, pdev->xdev->nodename,
782 "event-channel", "%u", pdev->evtchn);
783 if (!err)
784 err = xenbus_printf(trans, pdev->xdev->nodename,
785 "magic", XEN_PCI_MAGIC);
786
787 if (err) {
788 xenbus_transaction_end(trans, 1);
789 xenbus_dev_fatal(pdev->xdev, err,
790 "Error writing configuration for backend");
791 goto out;
792 } else {
793 err = xenbus_transaction_end(trans, 0);
794 if (err == -EAGAIN)
795 goto do_publish;
796 else if (err) {
797 xenbus_dev_fatal(pdev->xdev, err,
798 "Error completing transaction "
799 "for backend");
800 goto out;
801 }
802 }
803
804 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
805
806 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
807
808out:
809 return err;
810}
811
812static void pcifront_connect(struct pcifront_device *pdev)
813{
814 int err;
815 int i, num_roots, len;
816 char str[64];
817 unsigned int domain, bus;
818
819 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
820 "root_num", "%d", &num_roots);
821 if (err == -ENOENT) {
822 xenbus_dev_error(pdev->xdev, err,
823 "No PCI Roots found, trying 0000:00");
824 err = pcifront_rescan_root(pdev, 0, 0);
825 if (err) {
826 xenbus_dev_fatal(pdev->xdev, err,
827 "Error scanning PCI root 0000:00");
828 return;
829 }
830 num_roots = 0;
831 } else if (err != 1) {
832 xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err,
833 "Error reading number of PCI roots");
834 return;
835 }
836
837 for (i = 0; i < num_roots; i++) {
838 len = snprintf(str, sizeof(str), "root-%d", i);
839 if (unlikely(len >= (sizeof(str) - 1)))
840 return;
841
842 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
843 "%x:%x", &domain, &bus);
844 if (err != 2) {
845 xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err,
846 "Error reading PCI root %d", i);
847 return;
848 }
849
850 err = pcifront_rescan_root(pdev, domain, bus);
851 if (err) {
852 xenbus_dev_fatal(pdev->xdev, err,
853 "Error scanning PCI root %04x:%02x",
854 domain, bus);
855 return;
856 }
857 }
858
859 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
860}
861
862static void pcifront_try_connect(struct pcifront_device *pdev)
863{
864 int err;
865
866 /* Only connect once */
867 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
868 XenbusStateInitialised)
869 return;
870
871 err = pcifront_connect_and_init_dma(pdev);
872 if (err && err != -EEXIST) {
873 xenbus_dev_fatal(pdev->xdev, err,
874 "Error setting up PCI Frontend");
875 return;
876 }
877
878 pcifront_connect(pdev);
879}
880
881static int pcifront_try_disconnect(struct pcifront_device *pdev)
882{
883 int err = 0;
884 enum xenbus_state prev_state;
885
886
887 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
888
889 if (prev_state >= XenbusStateClosing)
890 goto out;
891
892 if (prev_state == XenbusStateConnected) {
893 pcifront_free_roots(pdev);
894 pcifront_disconnect(pdev);
895 }
896
897 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
898
899out:
900
901 return err;
902}
903
904static void pcifront_attach_devices(struct pcifront_device *pdev)
905{
906 if (xenbus_read_driver_state(pdev->xdev->nodename) ==
907 XenbusStateReconfiguring)
908 pcifront_connect(pdev);
909}
910
911static int pcifront_detach_devices(struct pcifront_device *pdev)
912{
913 int err = 0;
914 int i, num_devs;
915 enum xenbus_state state;
916 unsigned int domain, bus, slot, func;
917 struct pci_dev *pci_dev;
918 char str[64];
919
920 state = xenbus_read_driver_state(pdev->xdev->nodename);
921 if (state == XenbusStateInitialised) {
922 dev_dbg(&pdev->xdev->dev, "Handle skipped connect.\n");
923 /* We missed Connected and need to initialize. */
924 err = pcifront_connect_and_init_dma(pdev);
925 if (err && err != -EEXIST) {
926 xenbus_dev_fatal(pdev->xdev, err,
927 "Error setting up PCI Frontend");
928 goto out;
929 }
930
931 goto out_switch_state;
932 } else if (state != XenbusStateConnected) {
933 goto out;
934 }
935
936 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
937 &num_devs);
938 if (err != 1) {
939 if (err >= 0)
940 err = -EINVAL;
941 xenbus_dev_fatal(pdev->xdev, err,
942 "Error reading number of PCI devices");
943 goto out;
944 }
945
946 /* Find devices being detached and remove them. */
947 for (i = 0; i < num_devs; i++) {
948 int l, state;
949
950 l = snprintf(str, sizeof(str), "state-%d", i);
951 if (unlikely(l >= (sizeof(str) - 1))) {
952 err = -ENOMEM;
953 goto out;
954 }
955 state = xenbus_read_unsigned(pdev->xdev->otherend, str,
956 XenbusStateUnknown);
957
958 if (state != XenbusStateClosing)
959 continue;
960
961 /* Remove device. */
962 l = snprintf(str, sizeof(str), "vdev-%d", i);
963 if (unlikely(l >= (sizeof(str) - 1))) {
964 err = -ENOMEM;
965 goto out;
966 }
967 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
968 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
969 if (err != 4) {
970 if (err >= 0)
971 err = -EINVAL;
972 xenbus_dev_fatal(pdev->xdev, err,
973 "Error reading PCI device %d", i);
974 goto out;
975 }
976
977 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
978 PCI_DEVFN(slot, func));
979 if (!pci_dev) {
980 dev_dbg(&pdev->xdev->dev,
981 "Cannot get PCI device %04x:%02x:%02x.%d\n",
982 domain, bus, slot, func);
983 continue;
984 }
985 pci_lock_rescan_remove();
986 pci_stop_and_remove_bus_device(pci_dev);
987 pci_dev_put(pci_dev);
988 pci_unlock_rescan_remove();
989
990 dev_dbg(&pdev->xdev->dev,
991 "PCI device %04x:%02x:%02x.%d removed.\n",
992 domain, bus, slot, func);
993 }
994
995 out_switch_state:
996 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
997
998out:
999 return err;
1000}
1001
1002static void pcifront_backend_changed(struct xenbus_device *xdev,
1003 enum xenbus_state be_state)
1004{
1005 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1006
1007 switch (be_state) {
1008 case XenbusStateUnknown:
1009 case XenbusStateInitialising:
1010 case XenbusStateInitWait:
1011 case XenbusStateInitialised:
1012 break;
1013
1014 case XenbusStateConnected:
1015 pcifront_try_connect(pdev);
1016 break;
1017
1018 case XenbusStateClosed:
1019 if (xdev->state == XenbusStateClosed)
1020 break;
1021 fallthrough; /* Missed the backend's CLOSING state */
1022 case XenbusStateClosing:
1023 dev_warn(&xdev->dev, "backend going away!\n");
1024 pcifront_try_disconnect(pdev);
1025 break;
1026
1027 case XenbusStateReconfiguring:
1028 pcifront_detach_devices(pdev);
1029 break;
1030
1031 case XenbusStateReconfigured:
1032 pcifront_attach_devices(pdev);
1033 break;
1034 }
1035}
1036
1037static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1038 const struct xenbus_device_id *id)
1039{
1040 int err = 0;
1041 struct pcifront_device *pdev = alloc_pdev(xdev);
1042
1043 if (pdev == NULL) {
1044 err = -ENOMEM;
1045 xenbus_dev_fatal(xdev, err,
1046 "Error allocating pcifront_device struct");
1047 goto out;
1048 }
1049
1050 err = pcifront_publish_info(pdev);
1051 if (err)
1052 free_pdev(pdev);
1053
1054out:
1055 return err;
1056}
1057
1058static void pcifront_xenbus_remove(struct xenbus_device *xdev)
1059{
1060 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1061
1062 if (pdev)
1063 free_pdev(pdev);
1064}
1065
1066static const struct xenbus_device_id xenpci_ids[] = {
1067 {"pci"},
1068 {""},
1069};
1070
1071static struct xenbus_driver xenpci_driver = {
1072 .name = "pcifront",
1073 .ids = xenpci_ids,
1074 .probe = pcifront_xenbus_probe,
1075 .remove = pcifront_xenbus_remove,
1076 .otherend_changed = pcifront_backend_changed,
1077};
1078
1079static int __init pcifront_init(void)
1080{
1081 if (!xen_pv_domain() || xen_initial_domain())
1082 return -ENODEV;
1083
1084 if (!xen_has_pv_devices())
1085 return -ENODEV;
1086
1087 pci_frontend_registrar(1 /* enable */);
1088
1089 return xenbus_register_frontend(&xenpci_driver);
1090}
1091
1092static void __exit pcifront_cleanup(void)
1093{
1094 xenbus_unregister_driver(&xenpci_driver);
1095 pci_frontend_registrar(0 /* disable */);
1096}
1097module_init(pcifront_init);
1098module_exit(pcifront_cleanup);
1099
1100MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1101MODULE_LICENSE("GPL");
1102MODULE_ALIAS("xen:pci");