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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 <xen/platform_pci.h>
26
27#include <asm/xen/swiotlb-xen.h>
28#define INVALID_GRANT_REF (0)
29#define INVALID_EVTCHN (-1)
30
31struct pci_bus_entry {
32 struct list_head list;
33 struct pci_bus *bus;
34};
35
36#define _PDEVB_op_active (0)
37#define PDEVB_op_active (1 << (_PDEVB_op_active))
38
39struct pcifront_device {
40 struct xenbus_device *xdev;
41 struct list_head root_buses;
42
43 int evtchn;
44 int gnt_ref;
45
46 int irq;
47
48 /* Lock this when doing any operations in sh_info */
49 spinlock_t sh_info_lock;
50 struct xen_pci_sharedinfo *sh_info;
51 struct work_struct op_work;
52 unsigned long flags;
53
54};
55
56struct pcifront_sd {
57 struct pci_sysdata sd;
58 struct pcifront_device *pdev;
59};
60
61static inline struct pcifront_device *
62pcifront_get_pdev(struct pcifront_sd *sd)
63{
64 return sd->pdev;
65}
66
67static inline void pcifront_init_sd(struct pcifront_sd *sd,
68 unsigned int domain, unsigned int bus,
69 struct pcifront_device *pdev)
70{
71 /* Because we do not expose that information via XenBus. */
72 sd->sd.node = first_online_node;
73 sd->sd.domain = domain;
74 sd->pdev = pdev;
75}
76
77static DEFINE_SPINLOCK(pcifront_dev_lock);
78static struct pcifront_device *pcifront_dev;
79
80static int verbose_request;
81module_param(verbose_request, int, 0644);
82
83static int errno_to_pcibios_err(int errno)
84{
85 switch (errno) {
86 case XEN_PCI_ERR_success:
87 return PCIBIOS_SUCCESSFUL;
88
89 case XEN_PCI_ERR_dev_not_found:
90 return PCIBIOS_DEVICE_NOT_FOUND;
91
92 case XEN_PCI_ERR_invalid_offset:
93 case XEN_PCI_ERR_op_failed:
94 return PCIBIOS_BAD_REGISTER_NUMBER;
95
96 case XEN_PCI_ERR_not_implemented:
97 return PCIBIOS_FUNC_NOT_SUPPORTED;
98
99 case XEN_PCI_ERR_access_denied:
100 return PCIBIOS_SET_FAILED;
101 }
102 return errno;
103}
104
105static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
106{
107 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
108 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
109 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
110 schedule_work(&pdev->op_work);
111 }
112}
113
114static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
115{
116 int err = 0;
117 struct xen_pci_op *active_op = &pdev->sh_info->op;
118 unsigned long irq_flags;
119 evtchn_port_t port = pdev->evtchn;
120 unsigned irq = pdev->irq;
121 s64 ns, ns_timeout;
122
123 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
124
125 memcpy(active_op, op, sizeof(struct xen_pci_op));
126
127 /* Go */
128 wmb();
129 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
130 notify_remote_via_evtchn(port);
131
132 /*
133 * We set a poll timeout of 3 seconds but give up on return after
134 * 2 seconds. It is better to time out too late rather than too early
135 * (in the latter case we end up continually re-executing poll() with a
136 * timeout in the past). 1s difference gives plenty of slack for error.
137 */
138 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC;
139
140 xen_clear_irq_pending(irq);
141
142 while (test_bit(_XEN_PCIF_active,
143 (unsigned long *)&pdev->sh_info->flags)) {
144 xen_poll_irq_timeout(irq, jiffies + 3*HZ);
145 xen_clear_irq_pending(irq);
146 ns = ktime_get_ns();
147 if (ns > ns_timeout) {
148 dev_err(&pdev->xdev->dev,
149 "pciback not responding!!!\n");
150 clear_bit(_XEN_PCIF_active,
151 (unsigned long *)&pdev->sh_info->flags);
152 err = XEN_PCI_ERR_dev_not_found;
153 goto out;
154 }
155 }
156
157 /*
158 * We might lose backend service request since we
159 * reuse same evtchn with pci_conf backend response. So re-schedule
160 * aer pcifront service.
161 */
162 if (test_bit(_XEN_PCIB_active,
163 (unsigned long *)&pdev->sh_info->flags)) {
164 dev_err(&pdev->xdev->dev,
165 "schedule aer pcifront service\n");
166 schedule_pcifront_aer_op(pdev);
167 }
168
169 memcpy(op, active_op, sizeof(struct xen_pci_op));
170
171 err = op->err;
172out:
173 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
174 return err;
175}
176
177/* Access to this function is spinlocked in drivers/pci/access.c */
178static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
179 int where, int size, u32 *val)
180{
181 int err = 0;
182 struct xen_pci_op op = {
183 .cmd = XEN_PCI_OP_conf_read,
184 .domain = pci_domain_nr(bus),
185 .bus = bus->number,
186 .devfn = devfn,
187 .offset = where,
188 .size = size,
189 };
190 struct pcifront_sd *sd = bus->sysdata;
191 struct pcifront_device *pdev = pcifront_get_pdev(sd);
192
193 if (verbose_request)
194 dev_info(&pdev->xdev->dev,
195 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
196 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
197 PCI_FUNC(devfn), where, size);
198
199 err = do_pci_op(pdev, &op);
200
201 if (likely(!err)) {
202 if (verbose_request)
203 dev_info(&pdev->xdev->dev, "read got back value %x\n",
204 op.value);
205
206 *val = op.value;
207 } else if (err == -ENODEV) {
208 /* No device here, pretend that it just returned 0 */
209 err = 0;
210 *val = 0;
211 }
212
213 return errno_to_pcibios_err(err);
214}
215
216/* Access to this function is spinlocked in drivers/pci/access.c */
217static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
218 int where, int size, u32 val)
219{
220 struct xen_pci_op op = {
221 .cmd = XEN_PCI_OP_conf_write,
222 .domain = pci_domain_nr(bus),
223 .bus = bus->number,
224 .devfn = devfn,
225 .offset = where,
226 .size = size,
227 .value = val,
228 };
229 struct pcifront_sd *sd = bus->sysdata;
230 struct pcifront_device *pdev = pcifront_get_pdev(sd);
231
232 if (verbose_request)
233 dev_info(&pdev->xdev->dev,
234 "write dev=%04x:%02x:%02x.%d - "
235 "offset %x size %d val %x\n",
236 pci_domain_nr(bus), bus->number,
237 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
238
239 return errno_to_pcibios_err(do_pci_op(pdev, &op));
240}
241
242static struct pci_ops pcifront_bus_ops = {
243 .read = pcifront_bus_read,
244 .write = pcifront_bus_write,
245};
246
247#ifdef CONFIG_PCI_MSI
248static int pci_frontend_enable_msix(struct pci_dev *dev,
249 int vector[], int nvec)
250{
251 int err;
252 int i;
253 struct xen_pci_op op = {
254 .cmd = XEN_PCI_OP_enable_msix,
255 .domain = pci_domain_nr(dev->bus),
256 .bus = dev->bus->number,
257 .devfn = dev->devfn,
258 .value = nvec,
259 };
260 struct pcifront_sd *sd = dev->bus->sysdata;
261 struct pcifront_device *pdev = pcifront_get_pdev(sd);
262 struct msi_desc *entry;
263
264 if (nvec > SH_INFO_MAX_VEC) {
265 pci_err(dev, "too many vectors (0x%x) for PCI frontend:"
266 " Increase SH_INFO_MAX_VEC\n", nvec);
267 return -EINVAL;
268 }
269
270 i = 0;
271 for_each_pci_msi_entry(entry, dev) {
272 op.msix_entries[i].entry = entry->msi_attrib.entry_nr;
273 /* Vector is useless at this point. */
274 op.msix_entries[i].vector = -1;
275 i++;
276 }
277
278 err = do_pci_op(pdev, &op);
279
280 if (likely(!err)) {
281 if (likely(!op.value)) {
282 /* we get the result */
283 for (i = 0; i < nvec; i++) {
284 if (op.msix_entries[i].vector <= 0) {
285 pci_warn(dev, "MSI-X entry %d is invalid: %d!\n",
286 i, op.msix_entries[i].vector);
287 err = -EINVAL;
288 vector[i] = -1;
289 continue;
290 }
291 vector[i] = op.msix_entries[i].vector;
292 }
293 } else {
294 printk(KERN_DEBUG "enable msix get value %x\n",
295 op.value);
296 err = op.value;
297 }
298 } else {
299 pci_err(dev, "enable msix get err %x\n", err);
300 }
301 return err;
302}
303
304static void pci_frontend_disable_msix(struct pci_dev *dev)
305{
306 int err;
307 struct xen_pci_op op = {
308 .cmd = XEN_PCI_OP_disable_msix,
309 .domain = pci_domain_nr(dev->bus),
310 .bus = dev->bus->number,
311 .devfn = dev->devfn,
312 };
313 struct pcifront_sd *sd = dev->bus->sysdata;
314 struct pcifront_device *pdev = pcifront_get_pdev(sd);
315
316 err = do_pci_op(pdev, &op);
317
318 /* What should do for error ? */
319 if (err)
320 pci_err(dev, "pci_disable_msix get err %x\n", err);
321}
322
323static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
324{
325 int err;
326 struct xen_pci_op op = {
327 .cmd = XEN_PCI_OP_enable_msi,
328 .domain = pci_domain_nr(dev->bus),
329 .bus = dev->bus->number,
330 .devfn = dev->devfn,
331 };
332 struct pcifront_sd *sd = dev->bus->sysdata;
333 struct pcifront_device *pdev = pcifront_get_pdev(sd);
334
335 err = do_pci_op(pdev, &op);
336 if (likely(!err)) {
337 vector[0] = op.value;
338 if (op.value <= 0) {
339 pci_warn(dev, "MSI entry is invalid: %d!\n",
340 op.value);
341 err = -EINVAL;
342 vector[0] = -1;
343 }
344 } else {
345 pci_err(dev, "pci frontend enable msi failed for dev "
346 "%x:%x\n", op.bus, op.devfn);
347 err = -EINVAL;
348 }
349 return err;
350}
351
352static void pci_frontend_disable_msi(struct pci_dev *dev)
353{
354 int err;
355 struct xen_pci_op op = {
356 .cmd = XEN_PCI_OP_disable_msi,
357 .domain = pci_domain_nr(dev->bus),
358 .bus = dev->bus->number,
359 .devfn = dev->devfn,
360 };
361 struct pcifront_sd *sd = dev->bus->sysdata;
362 struct pcifront_device *pdev = pcifront_get_pdev(sd);
363
364 err = do_pci_op(pdev, &op);
365 if (err == XEN_PCI_ERR_dev_not_found) {
366 /* XXX No response from backend, what shall we do? */
367 printk(KERN_DEBUG "get no response from backend for disable MSI\n");
368 return;
369 }
370 if (err)
371 /* how can pciback notify us fail? */
372 printk(KERN_DEBUG "get fake response frombackend\n");
373}
374
375static struct xen_pci_frontend_ops pci_frontend_ops = {
376 .enable_msi = pci_frontend_enable_msi,
377 .disable_msi = pci_frontend_disable_msi,
378 .enable_msix = pci_frontend_enable_msix,
379 .disable_msix = pci_frontend_disable_msix,
380};
381
382static void pci_frontend_registrar(int enable)
383{
384 if (enable)
385 xen_pci_frontend = &pci_frontend_ops;
386 else
387 xen_pci_frontend = NULL;
388};
389#else
390static inline void pci_frontend_registrar(int enable) { };
391#endif /* CONFIG_PCI_MSI */
392
393/* Claim resources for the PCI frontend as-is, backend won't allow changes */
394static int pcifront_claim_resource(struct pci_dev *dev, void *data)
395{
396 struct pcifront_device *pdev = data;
397 int i;
398 struct resource *r;
399
400 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
401 r = &dev->resource[i];
402
403 if (!r->parent && r->start && r->flags) {
404 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
405 pci_name(dev), i);
406 if (pci_claim_resource(dev, i)) {
407 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
408 "Device offline. Try using e820_host=1 in the guest config.\n",
409 pci_name(dev), i);
410 }
411 }
412 }
413
414 return 0;
415}
416
417static int pcifront_scan_bus(struct pcifront_device *pdev,
418 unsigned int domain, unsigned int bus,
419 struct pci_bus *b)
420{
421 struct pci_dev *d;
422 unsigned int devfn;
423
424 /* Scan the bus for functions and add.
425 * We omit handling of PCI bridge attachment because pciback prevents
426 * bridges from being exported.
427 */
428 for (devfn = 0; devfn < 0x100; devfn++) {
429 d = pci_get_slot(b, devfn);
430 if (d) {
431 /* Device is already known. */
432 pci_dev_put(d);
433 continue;
434 }
435
436 d = pci_scan_single_device(b, devfn);
437 if (d)
438 dev_info(&pdev->xdev->dev, "New device on "
439 "%04x:%02x:%02x.%d found.\n", domain, bus,
440 PCI_SLOT(devfn), PCI_FUNC(devfn));
441 }
442
443 return 0;
444}
445
446static int pcifront_scan_root(struct pcifront_device *pdev,
447 unsigned int domain, unsigned int bus)
448{
449 struct pci_bus *b;
450 LIST_HEAD(resources);
451 struct pcifront_sd *sd = NULL;
452 struct pci_bus_entry *bus_entry = NULL;
453 int err = 0;
454 static struct resource busn_res = {
455 .start = 0,
456 .end = 255,
457 .flags = IORESOURCE_BUS,
458 };
459
460#ifndef CONFIG_PCI_DOMAINS
461 if (domain != 0) {
462 dev_err(&pdev->xdev->dev,
463 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
464 dev_err(&pdev->xdev->dev,
465 "Please compile with CONFIG_PCI_DOMAINS\n");
466 err = -EINVAL;
467 goto err_out;
468 }
469#endif
470
471 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
472 domain, bus);
473
474 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
475 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
476 if (!bus_entry || !sd) {
477 err = -ENOMEM;
478 goto err_out;
479 }
480 pci_add_resource(&resources, &ioport_resource);
481 pci_add_resource(&resources, &iomem_resource);
482 pci_add_resource(&resources, &busn_res);
483 pcifront_init_sd(sd, domain, bus, pdev);
484
485 pci_lock_rescan_remove();
486
487 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
488 &pcifront_bus_ops, sd, &resources);
489 if (!b) {
490 dev_err(&pdev->xdev->dev,
491 "Error creating PCI Frontend Bus!\n");
492 err = -ENOMEM;
493 pci_unlock_rescan_remove();
494 pci_free_resource_list(&resources);
495 goto err_out;
496 }
497
498 bus_entry->bus = b;
499
500 list_add(&bus_entry->list, &pdev->root_buses);
501
502 /* pci_scan_root_bus skips devices which do not have a
503 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
504 err = pcifront_scan_bus(pdev, domain, bus, b);
505
506 /* Claim resources before going "live" with our devices */
507 pci_walk_bus(b, pcifront_claim_resource, pdev);
508
509 /* Create SysFS and notify udev of the devices. Aka: "going live" */
510 pci_bus_add_devices(b);
511
512 pci_unlock_rescan_remove();
513 return err;
514
515err_out:
516 kfree(bus_entry);
517 kfree(sd);
518
519 return err;
520}
521
522static int pcifront_rescan_root(struct pcifront_device *pdev,
523 unsigned int domain, unsigned int bus)
524{
525 int err;
526 struct pci_bus *b;
527
528#ifndef CONFIG_PCI_DOMAINS
529 if (domain != 0) {
530 dev_err(&pdev->xdev->dev,
531 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
532 dev_err(&pdev->xdev->dev,
533 "Please compile with CONFIG_PCI_DOMAINS\n");
534 return -EINVAL;
535 }
536#endif
537
538 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
539 domain, bus);
540
541 b = pci_find_bus(domain, bus);
542 if (!b)
543 /* If the bus is unknown, create it. */
544 return pcifront_scan_root(pdev, domain, bus);
545
546 err = pcifront_scan_bus(pdev, domain, bus, b);
547
548 /* Claim resources before going "live" with our devices */
549 pci_walk_bus(b, pcifront_claim_resource, pdev);
550
551 /* Create SysFS and notify udev of the devices. Aka: "going live" */
552 pci_bus_add_devices(b);
553
554 return err;
555}
556
557static void free_root_bus_devs(struct pci_bus *bus)
558{
559 struct pci_dev *dev;
560
561 while (!list_empty(&bus->devices)) {
562 dev = container_of(bus->devices.next, struct pci_dev,
563 bus_list);
564 pci_dbg(dev, "removing device\n");
565 pci_stop_and_remove_bus_device(dev);
566 }
567}
568
569static void pcifront_free_roots(struct pcifront_device *pdev)
570{
571 struct pci_bus_entry *bus_entry, *t;
572
573 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
574
575 pci_lock_rescan_remove();
576 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
577 list_del(&bus_entry->list);
578
579 free_root_bus_devs(bus_entry->bus);
580
581 kfree(bus_entry->bus->sysdata);
582
583 device_unregister(bus_entry->bus->bridge);
584 pci_remove_bus(bus_entry->bus);
585
586 kfree(bus_entry);
587 }
588 pci_unlock_rescan_remove();
589}
590
591static pci_ers_result_t pcifront_common_process(int cmd,
592 struct pcifront_device *pdev,
593 pci_channel_state_t state)
594{
595 pci_ers_result_t result;
596 struct pci_driver *pdrv;
597 int bus = pdev->sh_info->aer_op.bus;
598 int devfn = pdev->sh_info->aer_op.devfn;
599 int domain = pdev->sh_info->aer_op.domain;
600 struct pci_dev *pcidev;
601 int flag = 0;
602
603 dev_dbg(&pdev->xdev->dev,
604 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
605 cmd, bus, devfn);
606 result = PCI_ERS_RESULT_NONE;
607
608 pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
609 if (!pcidev || !pcidev->driver) {
610 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
611 pci_dev_put(pcidev);
612 return result;
613 }
614 pdrv = pcidev->driver;
615
616 if (pdrv) {
617 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
618 pci_dbg(pcidev, "trying to call AER service\n");
619 if (pcidev) {
620 flag = 1;
621 switch (cmd) {
622 case XEN_PCI_OP_aer_detected:
623 result = pdrv->err_handler->
624 error_detected(pcidev, state);
625 break;
626 case XEN_PCI_OP_aer_mmio:
627 result = pdrv->err_handler->
628 mmio_enabled(pcidev);
629 break;
630 case XEN_PCI_OP_aer_slotreset:
631 result = pdrv->err_handler->
632 slot_reset(pcidev);
633 break;
634 case XEN_PCI_OP_aer_resume:
635 pdrv->err_handler->resume(pcidev);
636 break;
637 default:
638 dev_err(&pdev->xdev->dev,
639 "bad request in aer recovery "
640 "operation!\n");
641
642 }
643 }
644 }
645 }
646 if (!flag)
647 result = PCI_ERS_RESULT_NONE;
648
649 return result;
650}
651
652
653static void pcifront_do_aer(struct work_struct *data)
654{
655 struct pcifront_device *pdev =
656 container_of(data, struct pcifront_device, op_work);
657 int cmd = pdev->sh_info->aer_op.cmd;
658 pci_channel_state_t state =
659 (pci_channel_state_t)pdev->sh_info->aer_op.err;
660
661 /*If a pci_conf op is in progress,
662 we have to wait until it is done before service aer op*/
663 dev_dbg(&pdev->xdev->dev,
664 "pcifront service aer bus %x devfn %x\n",
665 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
666
667 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
668
669 /* Post the operation to the guest. */
670 wmb();
671 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
672 notify_remote_via_evtchn(pdev->evtchn);
673
674 /*in case of we lost an aer request in four lines time_window*/
675 smp_mb__before_atomic();
676 clear_bit(_PDEVB_op_active, &pdev->flags);
677 smp_mb__after_atomic();
678
679 schedule_pcifront_aer_op(pdev);
680
681}
682
683static irqreturn_t pcifront_handler_aer(int irq, void *dev)
684{
685 struct pcifront_device *pdev = dev;
686 schedule_pcifront_aer_op(pdev);
687 return IRQ_HANDLED;
688}
689static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
690{
691 int err = 0;
692
693 spin_lock(&pcifront_dev_lock);
694
695 if (!pcifront_dev) {
696 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
697 pcifront_dev = pdev;
698 } else
699 err = -EEXIST;
700
701 spin_unlock(&pcifront_dev_lock);
702
703 if (!err && !swiotlb_nr_tbl()) {
704 err = pci_xen_swiotlb_init_late();
705 if (err)
706 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
707 }
708 return err;
709}
710
711static void pcifront_disconnect(struct pcifront_device *pdev)
712{
713 spin_lock(&pcifront_dev_lock);
714
715 if (pdev == pcifront_dev) {
716 dev_info(&pdev->xdev->dev,
717 "Disconnecting PCI Frontend Buses\n");
718 pcifront_dev = NULL;
719 }
720
721 spin_unlock(&pcifront_dev_lock);
722}
723static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
724{
725 struct pcifront_device *pdev;
726
727 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
728 if (pdev == NULL)
729 goto out;
730
731 pdev->sh_info =
732 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
733 if (pdev->sh_info == NULL) {
734 kfree(pdev);
735 pdev = NULL;
736 goto out;
737 }
738 pdev->sh_info->flags = 0;
739
740 /*Flag for registering PV AER handler*/
741 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
742
743 dev_set_drvdata(&xdev->dev, pdev);
744 pdev->xdev = xdev;
745
746 INIT_LIST_HEAD(&pdev->root_buses);
747
748 spin_lock_init(&pdev->sh_info_lock);
749
750 pdev->evtchn = INVALID_EVTCHN;
751 pdev->gnt_ref = INVALID_GRANT_REF;
752 pdev->irq = -1;
753
754 INIT_WORK(&pdev->op_work, pcifront_do_aer);
755
756 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
757 pdev, pdev->sh_info);
758out:
759 return pdev;
760}
761
762static void free_pdev(struct pcifront_device *pdev)
763{
764 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
765
766 pcifront_free_roots(pdev);
767
768 cancel_work_sync(&pdev->op_work);
769
770 if (pdev->irq >= 0)
771 unbind_from_irqhandler(pdev->irq, pdev);
772
773 if (pdev->evtchn != INVALID_EVTCHN)
774 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
775
776 if (pdev->gnt_ref != INVALID_GRANT_REF)
777 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
778 (unsigned long)pdev->sh_info);
779 else
780 free_page((unsigned long)pdev->sh_info);
781
782 dev_set_drvdata(&pdev->xdev->dev, NULL);
783
784 kfree(pdev);
785}
786
787static int pcifront_publish_info(struct pcifront_device *pdev)
788{
789 int err = 0;
790 struct xenbus_transaction trans;
791 grant_ref_t gref;
792
793 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
794 if (err < 0)
795 goto out;
796
797 pdev->gnt_ref = gref;
798
799 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
800 if (err)
801 goto out;
802
803 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
804 0, "pcifront", pdev);
805
806 if (err < 0)
807 return err;
808
809 pdev->irq = err;
810
811do_publish:
812 err = xenbus_transaction_start(&trans);
813 if (err) {
814 xenbus_dev_fatal(pdev->xdev, err,
815 "Error writing configuration for backend "
816 "(start transaction)");
817 goto out;
818 }
819
820 err = xenbus_printf(trans, pdev->xdev->nodename,
821 "pci-op-ref", "%u", pdev->gnt_ref);
822 if (!err)
823 err = xenbus_printf(trans, pdev->xdev->nodename,
824 "event-channel", "%u", pdev->evtchn);
825 if (!err)
826 err = xenbus_printf(trans, pdev->xdev->nodename,
827 "magic", XEN_PCI_MAGIC);
828
829 if (err) {
830 xenbus_transaction_end(trans, 1);
831 xenbus_dev_fatal(pdev->xdev, err,
832 "Error writing configuration for backend");
833 goto out;
834 } else {
835 err = xenbus_transaction_end(trans, 0);
836 if (err == -EAGAIN)
837 goto do_publish;
838 else if (err) {
839 xenbus_dev_fatal(pdev->xdev, err,
840 "Error completing transaction "
841 "for backend");
842 goto out;
843 }
844 }
845
846 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
847
848 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
849
850out:
851 return err;
852}
853
854static int pcifront_try_connect(struct pcifront_device *pdev)
855{
856 int err = -EFAULT;
857 int i, num_roots, len;
858 char str[64];
859 unsigned int domain, bus;
860
861
862 /* Only connect once */
863 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
864 XenbusStateInitialised)
865 goto out;
866
867 err = pcifront_connect_and_init_dma(pdev);
868 if (err && err != -EEXIST) {
869 xenbus_dev_fatal(pdev->xdev, err,
870 "Error setting up PCI Frontend");
871 goto out;
872 }
873
874 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
875 "root_num", "%d", &num_roots);
876 if (err == -ENOENT) {
877 xenbus_dev_error(pdev->xdev, err,
878 "No PCI Roots found, trying 0000:00");
879 err = pcifront_scan_root(pdev, 0, 0);
880 if (err) {
881 xenbus_dev_fatal(pdev->xdev, err,
882 "Error scanning PCI root 0000:00");
883 goto out;
884 }
885 num_roots = 0;
886 } else if (err != 1) {
887 if (err == 0)
888 err = -EINVAL;
889 xenbus_dev_fatal(pdev->xdev, err,
890 "Error reading number of PCI roots");
891 goto out;
892 }
893
894 for (i = 0; i < num_roots; i++) {
895 len = snprintf(str, sizeof(str), "root-%d", i);
896 if (unlikely(len >= (sizeof(str) - 1))) {
897 err = -ENOMEM;
898 goto out;
899 }
900
901 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
902 "%x:%x", &domain, &bus);
903 if (err != 2) {
904 if (err >= 0)
905 err = -EINVAL;
906 xenbus_dev_fatal(pdev->xdev, err,
907 "Error reading PCI root %d", i);
908 goto out;
909 }
910
911 err = pcifront_scan_root(pdev, domain, bus);
912 if (err) {
913 xenbus_dev_fatal(pdev->xdev, err,
914 "Error scanning PCI root %04x:%02x",
915 domain, bus);
916 goto out;
917 }
918 }
919
920 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
921
922out:
923 return err;
924}
925
926static int pcifront_try_disconnect(struct pcifront_device *pdev)
927{
928 int err = 0;
929 enum xenbus_state prev_state;
930
931
932 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
933
934 if (prev_state >= XenbusStateClosing)
935 goto out;
936
937 if (prev_state == XenbusStateConnected) {
938 pcifront_free_roots(pdev);
939 pcifront_disconnect(pdev);
940 }
941
942 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
943
944out:
945
946 return err;
947}
948
949static int pcifront_attach_devices(struct pcifront_device *pdev)
950{
951 int err = -EFAULT;
952 int i, num_roots, len;
953 unsigned int domain, bus;
954 char str[64];
955
956 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
957 XenbusStateReconfiguring)
958 goto out;
959
960 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
961 "root_num", "%d", &num_roots);
962 if (err == -ENOENT) {
963 xenbus_dev_error(pdev->xdev, err,
964 "No PCI Roots found, trying 0000:00");
965 err = pcifront_rescan_root(pdev, 0, 0);
966 if (err) {
967 xenbus_dev_fatal(pdev->xdev, err,
968 "Error scanning PCI root 0000:00");
969 goto out;
970 }
971 num_roots = 0;
972 } else if (err != 1) {
973 if (err == 0)
974 err = -EINVAL;
975 xenbus_dev_fatal(pdev->xdev, err,
976 "Error reading number of PCI roots");
977 goto out;
978 }
979
980 for (i = 0; i < num_roots; i++) {
981 len = snprintf(str, sizeof(str), "root-%d", i);
982 if (unlikely(len >= (sizeof(str) - 1))) {
983 err = -ENOMEM;
984 goto out;
985 }
986
987 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
988 "%x:%x", &domain, &bus);
989 if (err != 2) {
990 if (err >= 0)
991 err = -EINVAL;
992 xenbus_dev_fatal(pdev->xdev, err,
993 "Error reading PCI root %d", i);
994 goto out;
995 }
996
997 err = pcifront_rescan_root(pdev, domain, bus);
998 if (err) {
999 xenbus_dev_fatal(pdev->xdev, err,
1000 "Error scanning PCI root %04x:%02x",
1001 domain, bus);
1002 goto out;
1003 }
1004 }
1005
1006 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
1007
1008out:
1009 return err;
1010}
1011
1012static int pcifront_detach_devices(struct pcifront_device *pdev)
1013{
1014 int err = 0;
1015 int i, num_devs;
1016 unsigned int domain, bus, slot, func;
1017 struct pci_dev *pci_dev;
1018 char str[64];
1019
1020 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
1021 XenbusStateConnected)
1022 goto out;
1023
1024 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
1025 &num_devs);
1026 if (err != 1) {
1027 if (err >= 0)
1028 err = -EINVAL;
1029 xenbus_dev_fatal(pdev->xdev, err,
1030 "Error reading number of PCI devices");
1031 goto out;
1032 }
1033
1034 /* Find devices being detached and remove them. */
1035 for (i = 0; i < num_devs; i++) {
1036 int l, state;
1037 l = snprintf(str, sizeof(str), "state-%d", i);
1038 if (unlikely(l >= (sizeof(str) - 1))) {
1039 err = -ENOMEM;
1040 goto out;
1041 }
1042 state = xenbus_read_unsigned(pdev->xdev->otherend, str,
1043 XenbusStateUnknown);
1044
1045 if (state != XenbusStateClosing)
1046 continue;
1047
1048 /* Remove device. */
1049 l = snprintf(str, sizeof(str), "vdev-%d", i);
1050 if (unlikely(l >= (sizeof(str) - 1))) {
1051 err = -ENOMEM;
1052 goto out;
1053 }
1054 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1055 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1056 if (err != 4) {
1057 if (err >= 0)
1058 err = -EINVAL;
1059 xenbus_dev_fatal(pdev->xdev, err,
1060 "Error reading PCI device %d", i);
1061 goto out;
1062 }
1063
1064 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
1065 PCI_DEVFN(slot, func));
1066 if (!pci_dev) {
1067 dev_dbg(&pdev->xdev->dev,
1068 "Cannot get PCI device %04x:%02x:%02x.%d\n",
1069 domain, bus, slot, func);
1070 continue;
1071 }
1072 pci_lock_rescan_remove();
1073 pci_stop_and_remove_bus_device(pci_dev);
1074 pci_dev_put(pci_dev);
1075 pci_unlock_rescan_remove();
1076
1077 dev_dbg(&pdev->xdev->dev,
1078 "PCI device %04x:%02x:%02x.%d removed.\n",
1079 domain, bus, slot, func);
1080 }
1081
1082 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1083
1084out:
1085 return err;
1086}
1087
1088static void __ref pcifront_backend_changed(struct xenbus_device *xdev,
1089 enum xenbus_state be_state)
1090{
1091 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1092
1093 switch (be_state) {
1094 case XenbusStateUnknown:
1095 case XenbusStateInitialising:
1096 case XenbusStateInitWait:
1097 case XenbusStateInitialised:
1098 break;
1099
1100 case XenbusStateConnected:
1101 pcifront_try_connect(pdev);
1102 break;
1103
1104 case XenbusStateClosed:
1105 if (xdev->state == XenbusStateClosed)
1106 break;
1107 /* Missed the backend's CLOSING state -- fallthrough */
1108 case XenbusStateClosing:
1109 dev_warn(&xdev->dev, "backend going away!\n");
1110 pcifront_try_disconnect(pdev);
1111 break;
1112
1113 case XenbusStateReconfiguring:
1114 pcifront_detach_devices(pdev);
1115 break;
1116
1117 case XenbusStateReconfigured:
1118 pcifront_attach_devices(pdev);
1119 break;
1120 }
1121}
1122
1123static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1124 const struct xenbus_device_id *id)
1125{
1126 int err = 0;
1127 struct pcifront_device *pdev = alloc_pdev(xdev);
1128
1129 if (pdev == NULL) {
1130 err = -ENOMEM;
1131 xenbus_dev_fatal(xdev, err,
1132 "Error allocating pcifront_device struct");
1133 goto out;
1134 }
1135
1136 err = pcifront_publish_info(pdev);
1137 if (err)
1138 free_pdev(pdev);
1139
1140out:
1141 return err;
1142}
1143
1144static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1145{
1146 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1147 if (pdev)
1148 free_pdev(pdev);
1149
1150 return 0;
1151}
1152
1153static const struct xenbus_device_id xenpci_ids[] = {
1154 {"pci"},
1155 {""},
1156};
1157
1158static struct xenbus_driver xenpci_driver = {
1159 .name = "pcifront",
1160 .ids = xenpci_ids,
1161 .probe = pcifront_xenbus_probe,
1162 .remove = pcifront_xenbus_remove,
1163 .otherend_changed = pcifront_backend_changed,
1164};
1165
1166static int __init pcifront_init(void)
1167{
1168 if (!xen_pv_domain() || xen_initial_domain())
1169 return -ENODEV;
1170
1171 if (!xen_has_pv_devices())
1172 return -ENODEV;
1173
1174 pci_frontend_registrar(1 /* enable */);
1175
1176 return xenbus_register_frontend(&xenpci_driver);
1177}
1178
1179static void __exit pcifront_cleanup(void)
1180{
1181 xenbus_unregister_driver(&xenpci_driver);
1182 pci_frontend_registrar(0 /* disable */);
1183}
1184module_init(pcifront_init);
1185module_exit(pcifront_cleanup);
1186
1187MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1188MODULE_LICENSE("GPL");
1189MODULE_ALIAS("xen:pci");