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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.%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 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.%d - "
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 err = op.value;
294 }
295 } else {
296 dev_err(&dev->dev, "enable msix get err %x\n", err);
297 }
298 return err;
299}
300
301static void pci_frontend_disable_msix(struct pci_dev *dev)
302{
303 int err;
304 struct xen_pci_op op = {
305 .cmd = XEN_PCI_OP_disable_msix,
306 .domain = pci_domain_nr(dev->bus),
307 .bus = dev->bus->number,
308 .devfn = dev->devfn,
309 };
310 struct pcifront_sd *sd = dev->bus->sysdata;
311 struct pcifront_device *pdev = pcifront_get_pdev(sd);
312
313 err = do_pci_op(pdev, &op);
314
315 /* What should do for error ? */
316 if (err)
317 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err);
318}
319
320static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
321{
322 int err;
323 struct xen_pci_op op = {
324 .cmd = XEN_PCI_OP_enable_msi,
325 .domain = pci_domain_nr(dev->bus),
326 .bus = dev->bus->number,
327 .devfn = dev->devfn,
328 };
329 struct pcifront_sd *sd = dev->bus->sysdata;
330 struct pcifront_device *pdev = pcifront_get_pdev(sd);
331
332 err = do_pci_op(pdev, &op);
333 if (likely(!err)) {
334 vector[0] = op.value;
335 if (op.value <= 0) {
336 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
337 op.value);
338 err = -EINVAL;
339 vector[0] = -1;
340 }
341 } else {
342 dev_err(&dev->dev, "pci frontend enable msi failed for dev "
343 "%x:%x\n", op.bus, op.devfn);
344 err = -EINVAL;
345 }
346 return err;
347}
348
349static void pci_frontend_disable_msi(struct pci_dev *dev)
350{
351 int err;
352 struct xen_pci_op op = {
353 .cmd = XEN_PCI_OP_disable_msi,
354 .domain = pci_domain_nr(dev->bus),
355 .bus = dev->bus->number,
356 .devfn = dev->devfn,
357 };
358 struct pcifront_sd *sd = dev->bus->sysdata;
359 struct pcifront_device *pdev = pcifront_get_pdev(sd);
360
361 err = do_pci_op(pdev, &op);
362 if (err == XEN_PCI_ERR_dev_not_found) {
363 /* XXX No response from backend, what shall we do? */
364 printk(KERN_DEBUG "get no response from backend for disable MSI\n");
365 return;
366 }
367 if (err)
368 /* how can pciback notify us fail? */
369 printk(KERN_DEBUG "get fake response frombackend\n");
370}
371
372static struct xen_pci_frontend_ops pci_frontend_ops = {
373 .enable_msi = pci_frontend_enable_msi,
374 .disable_msi = pci_frontend_disable_msi,
375 .enable_msix = pci_frontend_enable_msix,
376 .disable_msix = pci_frontend_disable_msix,
377};
378
379static void pci_frontend_registrar(int enable)
380{
381 if (enable)
382 xen_pci_frontend = &pci_frontend_ops;
383 else
384 xen_pci_frontend = NULL;
385};
386#else
387static inline void pci_frontend_registrar(int enable) { };
388#endif /* CONFIG_PCI_MSI */
389
390/* Claim resources for the PCI frontend as-is, backend won't allow changes */
391static int pcifront_claim_resource(struct pci_dev *dev, void *data)
392{
393 struct pcifront_device *pdev = data;
394 int i;
395 struct resource *r;
396
397 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
398 r = &dev->resource[i];
399
400 if (!r->parent && r->start && r->flags) {
401 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
402 pci_name(dev), i);
403 if (pci_claim_resource(dev, i)) {
404 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
405 "Device offline. Try using e820_host=1 in the guest config.\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.%d 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_stop_and_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 (pdrv) {
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 }
628 if (!flag)
629 result = PCI_ERS_RESULT_NONE;
630
631 return result;
632}
633
634
635static void pcifront_do_aer(struct work_struct *data)
636{
637 struct pcifront_device *pdev =
638 container_of(data, struct pcifront_device, op_work);
639 int cmd = pdev->sh_info->aer_op.cmd;
640 pci_channel_state_t state =
641 (pci_channel_state_t)pdev->sh_info->aer_op.err;
642
643 /*If a pci_conf op is in progress,
644 we have to wait until it is done before service aer op*/
645 dev_dbg(&pdev->xdev->dev,
646 "pcifront service aer bus %x devfn %x\n",
647 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
648
649 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
650
651 /* Post the operation to the guest. */
652 wmb();
653 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
654 notify_remote_via_evtchn(pdev->evtchn);
655
656 /*in case of we lost an aer request in four lines time_window*/
657 smp_mb__before_clear_bit();
658 clear_bit(_PDEVB_op_active, &pdev->flags);
659 smp_mb__after_clear_bit();
660
661 schedule_pcifront_aer_op(pdev);
662
663}
664
665static irqreturn_t pcifront_handler_aer(int irq, void *dev)
666{
667 struct pcifront_device *pdev = dev;
668 schedule_pcifront_aer_op(pdev);
669 return IRQ_HANDLED;
670}
671static int pcifront_connect(struct pcifront_device *pdev)
672{
673 int err = 0;
674
675 spin_lock(&pcifront_dev_lock);
676
677 if (!pcifront_dev) {
678 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
679 pcifront_dev = pdev;
680 } else {
681 dev_err(&pdev->xdev->dev, "PCI frontend already installed!\n");
682 err = -EEXIST;
683 }
684
685 spin_unlock(&pcifront_dev_lock);
686
687 return err;
688}
689
690static void pcifront_disconnect(struct pcifront_device *pdev)
691{
692 spin_lock(&pcifront_dev_lock);
693
694 if (pdev == pcifront_dev) {
695 dev_info(&pdev->xdev->dev,
696 "Disconnecting PCI Frontend Buses\n");
697 pcifront_dev = NULL;
698 }
699
700 spin_unlock(&pcifront_dev_lock);
701}
702static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
703{
704 struct pcifront_device *pdev;
705
706 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
707 if (pdev == NULL)
708 goto out;
709
710 pdev->sh_info =
711 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
712 if (pdev->sh_info == NULL) {
713 kfree(pdev);
714 pdev = NULL;
715 goto out;
716 }
717 pdev->sh_info->flags = 0;
718
719 /*Flag for registering PV AER handler*/
720 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
721
722 dev_set_drvdata(&xdev->dev, pdev);
723 pdev->xdev = xdev;
724
725 INIT_LIST_HEAD(&pdev->root_buses);
726
727 spin_lock_init(&pdev->sh_info_lock);
728
729 pdev->evtchn = INVALID_EVTCHN;
730 pdev->gnt_ref = INVALID_GRANT_REF;
731 pdev->irq = -1;
732
733 INIT_WORK(&pdev->op_work, pcifront_do_aer);
734
735 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
736 pdev, pdev->sh_info);
737out:
738 return pdev;
739}
740
741static void free_pdev(struct pcifront_device *pdev)
742{
743 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
744
745 pcifront_free_roots(pdev);
746
747 cancel_work_sync(&pdev->op_work);
748
749 if (pdev->irq >= 0)
750 unbind_from_irqhandler(pdev->irq, pdev);
751
752 if (pdev->evtchn != INVALID_EVTCHN)
753 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
754
755 if (pdev->gnt_ref != INVALID_GRANT_REF)
756 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
757 (unsigned long)pdev->sh_info);
758 else
759 free_page((unsigned long)pdev->sh_info);
760
761 dev_set_drvdata(&pdev->xdev->dev, NULL);
762
763 kfree(pdev);
764}
765
766static int pcifront_publish_info(struct pcifront_device *pdev)
767{
768 int err = 0;
769 struct xenbus_transaction trans;
770
771 err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
772 if (err < 0)
773 goto out;
774
775 pdev->gnt_ref = err;
776
777 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
778 if (err)
779 goto out;
780
781 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
782 0, "pcifront", pdev);
783
784 if (err < 0)
785 return err;
786
787 pdev->irq = err;
788
789do_publish:
790 err = xenbus_transaction_start(&trans);
791 if (err) {
792 xenbus_dev_fatal(pdev->xdev, err,
793 "Error writing configuration for backend "
794 "(start transaction)");
795 goto out;
796 }
797
798 err = xenbus_printf(trans, pdev->xdev->nodename,
799 "pci-op-ref", "%u", pdev->gnt_ref);
800 if (!err)
801 err = xenbus_printf(trans, pdev->xdev->nodename,
802 "event-channel", "%u", pdev->evtchn);
803 if (!err)
804 err = xenbus_printf(trans, pdev->xdev->nodename,
805 "magic", XEN_PCI_MAGIC);
806
807 if (err) {
808 xenbus_transaction_end(trans, 1);
809 xenbus_dev_fatal(pdev->xdev, err,
810 "Error writing configuration for backend");
811 goto out;
812 } else {
813 err = xenbus_transaction_end(trans, 0);
814 if (err == -EAGAIN)
815 goto do_publish;
816 else if (err) {
817 xenbus_dev_fatal(pdev->xdev, err,
818 "Error completing transaction "
819 "for backend");
820 goto out;
821 }
822 }
823
824 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
825
826 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
827
828out:
829 return err;
830}
831
832static int __devinit pcifront_try_connect(struct pcifront_device *pdev)
833{
834 int err = -EFAULT;
835 int i, num_roots, len;
836 char str[64];
837 unsigned int domain, bus;
838
839
840 /* Only connect once */
841 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
842 XenbusStateInitialised)
843 goto out;
844
845 err = pcifront_connect(pdev);
846 if (err) {
847 xenbus_dev_fatal(pdev->xdev, err,
848 "Error connecting PCI Frontend");
849 goto out;
850 }
851
852 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
853 "root_num", "%d", &num_roots);
854 if (err == -ENOENT) {
855 xenbus_dev_error(pdev->xdev, err,
856 "No PCI Roots found, trying 0000:00");
857 err = pcifront_scan_root(pdev, 0, 0);
858 num_roots = 0;
859 } else if (err != 1) {
860 if (err == 0)
861 err = -EINVAL;
862 xenbus_dev_fatal(pdev->xdev, err,
863 "Error reading number of PCI roots");
864 goto out;
865 }
866
867 for (i = 0; i < num_roots; i++) {
868 len = snprintf(str, sizeof(str), "root-%d", i);
869 if (unlikely(len >= (sizeof(str) - 1))) {
870 err = -ENOMEM;
871 goto out;
872 }
873
874 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
875 "%x:%x", &domain, &bus);
876 if (err != 2) {
877 if (err >= 0)
878 err = -EINVAL;
879 xenbus_dev_fatal(pdev->xdev, err,
880 "Error reading PCI root %d", i);
881 goto out;
882 }
883
884 err = pcifront_scan_root(pdev, domain, bus);
885 if (err) {
886 xenbus_dev_fatal(pdev->xdev, err,
887 "Error scanning PCI root %04x:%02x",
888 domain, bus);
889 goto out;
890 }
891 }
892
893 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
894
895out:
896 return err;
897}
898
899static int pcifront_try_disconnect(struct pcifront_device *pdev)
900{
901 int err = 0;
902 enum xenbus_state prev_state;
903
904
905 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
906
907 if (prev_state >= XenbusStateClosing)
908 goto out;
909
910 if (prev_state == XenbusStateConnected) {
911 pcifront_free_roots(pdev);
912 pcifront_disconnect(pdev);
913 }
914
915 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
916
917out:
918
919 return err;
920}
921
922static int __devinit pcifront_attach_devices(struct pcifront_device *pdev)
923{
924 int err = -EFAULT;
925 int i, num_roots, len;
926 unsigned int domain, bus;
927 char str[64];
928
929 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
930 XenbusStateReconfiguring)
931 goto out;
932
933 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
934 "root_num", "%d", &num_roots);
935 if (err == -ENOENT) {
936 xenbus_dev_error(pdev->xdev, err,
937 "No PCI Roots found, trying 0000:00");
938 err = pcifront_rescan_root(pdev, 0, 0);
939 num_roots = 0;
940 } else if (err != 1) {
941 if (err == 0)
942 err = -EINVAL;
943 xenbus_dev_fatal(pdev->xdev, err,
944 "Error reading number of PCI roots");
945 goto out;
946 }
947
948 for (i = 0; i < num_roots; i++) {
949 len = snprintf(str, sizeof(str), "root-%d", i);
950 if (unlikely(len >= (sizeof(str) - 1))) {
951 err = -ENOMEM;
952 goto out;
953 }
954
955 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
956 "%x:%x", &domain, &bus);
957 if (err != 2) {
958 if (err >= 0)
959 err = -EINVAL;
960 xenbus_dev_fatal(pdev->xdev, err,
961 "Error reading PCI root %d", i);
962 goto out;
963 }
964
965 err = pcifront_rescan_root(pdev, domain, bus);
966 if (err) {
967 xenbus_dev_fatal(pdev->xdev, err,
968 "Error scanning PCI root %04x:%02x",
969 domain, bus);
970 goto out;
971 }
972 }
973
974 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
975
976out:
977 return err;
978}
979
980static int pcifront_detach_devices(struct pcifront_device *pdev)
981{
982 int err = 0;
983 int i, num_devs;
984 unsigned int domain, bus, slot, func;
985 struct pci_bus *pci_bus;
986 struct pci_dev *pci_dev;
987 char str[64];
988
989 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
990 XenbusStateConnected)
991 goto out;
992
993 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
994 &num_devs);
995 if (err != 1) {
996 if (err >= 0)
997 err = -EINVAL;
998 xenbus_dev_fatal(pdev->xdev, err,
999 "Error reading number of PCI devices");
1000 goto out;
1001 }
1002
1003 /* Find devices being detached and remove them. */
1004 for (i = 0; i < num_devs; i++) {
1005 int l, state;
1006 l = snprintf(str, sizeof(str), "state-%d", i);
1007 if (unlikely(l >= (sizeof(str) - 1))) {
1008 err = -ENOMEM;
1009 goto out;
1010 }
1011 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d",
1012 &state);
1013 if (err != 1)
1014 state = XenbusStateUnknown;
1015
1016 if (state != XenbusStateClosing)
1017 continue;
1018
1019 /* Remove device. */
1020 l = snprintf(str, sizeof(str), "vdev-%d", i);
1021 if (unlikely(l >= (sizeof(str) - 1))) {
1022 err = -ENOMEM;
1023 goto out;
1024 }
1025 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1026 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1027 if (err != 4) {
1028 if (err >= 0)
1029 err = -EINVAL;
1030 xenbus_dev_fatal(pdev->xdev, err,
1031 "Error reading PCI device %d", i);
1032 goto out;
1033 }
1034
1035 pci_bus = pci_find_bus(domain, bus);
1036 if (!pci_bus) {
1037 dev_dbg(&pdev->xdev->dev, "Cannot get bus %04x:%02x\n",
1038 domain, bus);
1039 continue;
1040 }
1041 pci_dev = pci_get_slot(pci_bus, PCI_DEVFN(slot, func));
1042 if (!pci_dev) {
1043 dev_dbg(&pdev->xdev->dev,
1044 "Cannot get PCI device %04x:%02x:%02x.%d\n",
1045 domain, bus, slot, func);
1046 continue;
1047 }
1048 pci_stop_and_remove_bus_device(pci_dev);
1049 pci_dev_put(pci_dev);
1050
1051 dev_dbg(&pdev->xdev->dev,
1052 "PCI device %04x:%02x:%02x.%d removed.\n",
1053 domain, bus, slot, func);
1054 }
1055
1056 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1057
1058out:
1059 return err;
1060}
1061
1062static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev,
1063 enum xenbus_state be_state)
1064{
1065 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1066
1067 switch (be_state) {
1068 case XenbusStateUnknown:
1069 case XenbusStateInitialising:
1070 case XenbusStateInitWait:
1071 case XenbusStateInitialised:
1072 case XenbusStateClosed:
1073 break;
1074
1075 case XenbusStateConnected:
1076 pcifront_try_connect(pdev);
1077 break;
1078
1079 case XenbusStateClosing:
1080 dev_warn(&xdev->dev, "backend going away!\n");
1081 pcifront_try_disconnect(pdev);
1082 break;
1083
1084 case XenbusStateReconfiguring:
1085 pcifront_detach_devices(pdev);
1086 break;
1087
1088 case XenbusStateReconfigured:
1089 pcifront_attach_devices(pdev);
1090 break;
1091 }
1092}
1093
1094static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1095 const struct xenbus_device_id *id)
1096{
1097 int err = 0;
1098 struct pcifront_device *pdev = alloc_pdev(xdev);
1099
1100 if (pdev == NULL) {
1101 err = -ENOMEM;
1102 xenbus_dev_fatal(xdev, err,
1103 "Error allocating pcifront_device struct");
1104 goto out;
1105 }
1106
1107 err = pcifront_publish_info(pdev);
1108 if (err)
1109 free_pdev(pdev);
1110
1111out:
1112 return err;
1113}
1114
1115static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1116{
1117 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1118 if (pdev)
1119 free_pdev(pdev);
1120
1121 return 0;
1122}
1123
1124static const struct xenbus_device_id xenpci_ids[] = {
1125 {"pci"},
1126 {""},
1127};
1128
1129static DEFINE_XENBUS_DRIVER(xenpci, "pcifront",
1130 .probe = pcifront_xenbus_probe,
1131 .remove = pcifront_xenbus_remove,
1132 .otherend_changed = pcifront_backend_changed,
1133);
1134
1135static int __init pcifront_init(void)
1136{
1137 if (!xen_pv_domain() || xen_initial_domain())
1138 return -ENODEV;
1139
1140 pci_frontend_registrar(1 /* enable */);
1141
1142 return xenbus_register_frontend(&xenpci_driver);
1143}
1144
1145static void __exit pcifront_cleanup(void)
1146{
1147 xenbus_unregister_driver(&xenpci_driver);
1148 pci_frontend_registrar(0 /* disable */);
1149}
1150module_init(pcifront_init);
1151module_exit(pcifront_cleanup);
1152
1153MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1154MODULE_LICENSE("GPL");
1155MODULE_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 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 for_each_pci_msi_entry(entry, dev) {
266 op.msix_entries[i].entry = entry->msi_attrib.entry_nr;
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 /* Scan the bus for functions and add.
418 * We omit handling of PCI bridge attachment because pciback prevents
419 * bridges from being exported.
420 */
421 for (devfn = 0; devfn < 0x100; devfn++) {
422 d = pci_get_slot(b, devfn);
423 if (d) {
424 /* Device is already known. */
425 pci_dev_put(d);
426 continue;
427 }
428
429 d = pci_scan_single_device(b, devfn);
430 if (d)
431 dev_info(&pdev->xdev->dev, "New device on "
432 "%04x:%02x:%02x.%d found.\n", domain, bus,
433 PCI_SLOT(devfn), PCI_FUNC(devfn));
434 }
435
436 return 0;
437}
438
439static int pcifront_scan_root(struct pcifront_device *pdev,
440 unsigned int domain, unsigned int bus)
441{
442 struct pci_bus *b;
443 LIST_HEAD(resources);
444 struct pcifront_sd *sd = NULL;
445 struct pci_bus_entry *bus_entry = NULL;
446 int err = 0;
447 static struct resource busn_res = {
448 .start = 0,
449 .end = 255,
450 .flags = IORESOURCE_BUS,
451 };
452
453#ifndef CONFIG_PCI_DOMAINS
454 if (domain != 0) {
455 dev_err(&pdev->xdev->dev,
456 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
457 dev_err(&pdev->xdev->dev,
458 "Please compile with CONFIG_PCI_DOMAINS\n");
459 err = -EINVAL;
460 goto err_out;
461 }
462#endif
463
464 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
465 domain, bus);
466
467 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
468 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
469 if (!bus_entry || !sd) {
470 err = -ENOMEM;
471 goto err_out;
472 }
473 pci_add_resource(&resources, &ioport_resource);
474 pci_add_resource(&resources, &iomem_resource);
475 pci_add_resource(&resources, &busn_res);
476 pcifront_init_sd(sd, domain, bus, pdev);
477
478 pci_lock_rescan_remove();
479
480 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
481 &pcifront_bus_ops, sd, &resources);
482 if (!b) {
483 dev_err(&pdev->xdev->dev,
484 "Error creating PCI Frontend Bus!\n");
485 err = -ENOMEM;
486 pci_unlock_rescan_remove();
487 pci_free_resource_list(&resources);
488 goto err_out;
489 }
490
491 bus_entry->bus = b;
492
493 list_add(&bus_entry->list, &pdev->root_buses);
494
495 /* pci_scan_root_bus skips devices which do not have a
496 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
497 err = pcifront_scan_bus(pdev, domain, bus, b);
498
499 /* Claim resources before going "live" with our devices */
500 pci_walk_bus(b, pcifront_claim_resource, pdev);
501
502 /* Create SysFS and notify udev of the devices. Aka: "going live" */
503 pci_bus_add_devices(b);
504
505 pci_unlock_rescan_remove();
506 return err;
507
508err_out:
509 kfree(bus_entry);
510 kfree(sd);
511
512 return err;
513}
514
515static int pcifront_rescan_root(struct pcifront_device *pdev,
516 unsigned int domain, unsigned int bus)
517{
518 int err;
519 struct pci_bus *b;
520
521#ifndef CONFIG_PCI_DOMAINS
522 if (domain != 0) {
523 dev_err(&pdev->xdev->dev,
524 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
525 dev_err(&pdev->xdev->dev,
526 "Please compile with CONFIG_PCI_DOMAINS\n");
527 return -EINVAL;
528 }
529#endif
530
531 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
532 domain, bus);
533
534 b = pci_find_bus(domain, bus);
535 if (!b)
536 /* If the bus is unknown, create it. */
537 return pcifront_scan_root(pdev, domain, bus);
538
539 err = pcifront_scan_bus(pdev, domain, bus, b);
540
541 /* Claim resources before going "live" with our devices */
542 pci_walk_bus(b, pcifront_claim_resource, pdev);
543
544 /* Create SysFS and notify udev of the devices. Aka: "going live" */
545 pci_bus_add_devices(b);
546
547 return err;
548}
549
550static void free_root_bus_devs(struct pci_bus *bus)
551{
552 struct pci_dev *dev;
553
554 while (!list_empty(&bus->devices)) {
555 dev = container_of(bus->devices.next, struct pci_dev,
556 bus_list);
557 pci_dbg(dev, "removing device\n");
558 pci_stop_and_remove_bus_device(dev);
559 }
560}
561
562static void pcifront_free_roots(struct pcifront_device *pdev)
563{
564 struct pci_bus_entry *bus_entry, *t;
565
566 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
567
568 pci_lock_rescan_remove();
569 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
570 list_del(&bus_entry->list);
571
572 free_root_bus_devs(bus_entry->bus);
573
574 kfree(bus_entry->bus->sysdata);
575
576 device_unregister(bus_entry->bus->bridge);
577 pci_remove_bus(bus_entry->bus);
578
579 kfree(bus_entry);
580 }
581 pci_unlock_rescan_remove();
582}
583
584static pci_ers_result_t pcifront_common_process(int cmd,
585 struct pcifront_device *pdev,
586 pci_channel_state_t state)
587{
588 pci_ers_result_t result;
589 struct pci_driver *pdrv;
590 int bus = pdev->sh_info->aer_op.bus;
591 int devfn = pdev->sh_info->aer_op.devfn;
592 int domain = pdev->sh_info->aer_op.domain;
593 struct pci_dev *pcidev;
594 int flag = 0;
595
596 dev_dbg(&pdev->xdev->dev,
597 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
598 cmd, bus, devfn);
599 result = PCI_ERS_RESULT_NONE;
600
601 pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
602 if (!pcidev || !pcidev->driver) {
603 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
604 pci_dev_put(pcidev);
605 return result;
606 }
607 pdrv = pcidev->driver;
608
609 if (pdrv) {
610 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
611 pci_dbg(pcidev, "trying to call AER service\n");
612 if (pcidev) {
613 flag = 1;
614 switch (cmd) {
615 case XEN_PCI_OP_aer_detected:
616 result = pdrv->err_handler->
617 error_detected(pcidev, state);
618 break;
619 case XEN_PCI_OP_aer_mmio:
620 result = pdrv->err_handler->
621 mmio_enabled(pcidev);
622 break;
623 case XEN_PCI_OP_aer_slotreset:
624 result = pdrv->err_handler->
625 slot_reset(pcidev);
626 break;
627 case XEN_PCI_OP_aer_resume:
628 pdrv->err_handler->resume(pcidev);
629 break;
630 default:
631 dev_err(&pdev->xdev->dev,
632 "bad request in aer recovery "
633 "operation!\n");
634
635 }
636 }
637 }
638 }
639 if (!flag)
640 result = PCI_ERS_RESULT_NONE;
641
642 return result;
643}
644
645
646static void pcifront_do_aer(struct work_struct *data)
647{
648 struct pcifront_device *pdev =
649 container_of(data, struct pcifront_device, op_work);
650 int cmd = pdev->sh_info->aer_op.cmd;
651 pci_channel_state_t state =
652 (pci_channel_state_t)pdev->sh_info->aer_op.err;
653
654 /*If a pci_conf op is in progress,
655 we have to wait until it is done before service aer op*/
656 dev_dbg(&pdev->xdev->dev,
657 "pcifront service aer bus %x devfn %x\n",
658 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
659
660 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
661
662 /* Post the operation to the guest. */
663 wmb();
664 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
665 notify_remote_via_evtchn(pdev->evtchn);
666
667 /*in case of we lost an aer request in four lines time_window*/
668 smp_mb__before_atomic();
669 clear_bit(_PDEVB_op_active, &pdev->flags);
670 smp_mb__after_atomic();
671
672 schedule_pcifront_aer_op(pdev);
673
674}
675
676static irqreturn_t pcifront_handler_aer(int irq, void *dev)
677{
678 struct pcifront_device *pdev = dev;
679 schedule_pcifront_aer_op(pdev);
680 return IRQ_HANDLED;
681}
682static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
683{
684 int err = 0;
685
686 spin_lock(&pcifront_dev_lock);
687
688 if (!pcifront_dev) {
689 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
690 pcifront_dev = pdev;
691 } else
692 err = -EEXIST;
693
694 spin_unlock(&pcifront_dev_lock);
695
696 if (!err && !is_swiotlb_active()) {
697 err = pci_xen_swiotlb_init_late();
698 if (err)
699 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
700 }
701 return err;
702}
703
704static void pcifront_disconnect(struct pcifront_device *pdev)
705{
706 spin_lock(&pcifront_dev_lock);
707
708 if (pdev == pcifront_dev) {
709 dev_info(&pdev->xdev->dev,
710 "Disconnecting PCI Frontend Buses\n");
711 pcifront_dev = NULL;
712 }
713
714 spin_unlock(&pcifront_dev_lock);
715}
716static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
717{
718 struct pcifront_device *pdev;
719
720 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
721 if (pdev == NULL)
722 goto out;
723
724 pdev->sh_info =
725 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
726 if (pdev->sh_info == NULL) {
727 kfree(pdev);
728 pdev = NULL;
729 goto out;
730 }
731 pdev->sh_info->flags = 0;
732
733 /*Flag for registering PV AER handler*/
734 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
735
736 dev_set_drvdata(&xdev->dev, pdev);
737 pdev->xdev = xdev;
738
739 INIT_LIST_HEAD(&pdev->root_buses);
740
741 spin_lock_init(&pdev->sh_info_lock);
742
743 pdev->evtchn = INVALID_EVTCHN;
744 pdev->gnt_ref = INVALID_GRANT_REF;
745 pdev->irq = -1;
746
747 INIT_WORK(&pdev->op_work, pcifront_do_aer);
748
749 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
750 pdev, pdev->sh_info);
751out:
752 return pdev;
753}
754
755static void free_pdev(struct pcifront_device *pdev)
756{
757 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
758
759 pcifront_free_roots(pdev);
760
761 cancel_work_sync(&pdev->op_work);
762
763 if (pdev->irq >= 0)
764 unbind_from_irqhandler(pdev->irq, pdev);
765
766 if (pdev->evtchn != INVALID_EVTCHN)
767 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
768
769 if (pdev->gnt_ref != INVALID_GRANT_REF)
770 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
771 (unsigned long)pdev->sh_info);
772 else
773 free_page((unsigned long)pdev->sh_info);
774
775 dev_set_drvdata(&pdev->xdev->dev, NULL);
776
777 kfree(pdev);
778}
779
780static int pcifront_publish_info(struct pcifront_device *pdev)
781{
782 int err = 0;
783 struct xenbus_transaction trans;
784 grant_ref_t gref;
785
786 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
787 if (err < 0)
788 goto out;
789
790 pdev->gnt_ref = gref;
791
792 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
793 if (err)
794 goto out;
795
796 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
797 0, "pcifront", pdev);
798
799 if (err < 0)
800 return err;
801
802 pdev->irq = err;
803
804do_publish:
805 err = xenbus_transaction_start(&trans);
806 if (err) {
807 xenbus_dev_fatal(pdev->xdev, err,
808 "Error writing configuration for backend "
809 "(start transaction)");
810 goto out;
811 }
812
813 err = xenbus_printf(trans, pdev->xdev->nodename,
814 "pci-op-ref", "%u", pdev->gnt_ref);
815 if (!err)
816 err = xenbus_printf(trans, pdev->xdev->nodename,
817 "event-channel", "%u", pdev->evtchn);
818 if (!err)
819 err = xenbus_printf(trans, pdev->xdev->nodename,
820 "magic", XEN_PCI_MAGIC);
821
822 if (err) {
823 xenbus_transaction_end(trans, 1);
824 xenbus_dev_fatal(pdev->xdev, err,
825 "Error writing configuration for backend");
826 goto out;
827 } else {
828 err = xenbus_transaction_end(trans, 0);
829 if (err == -EAGAIN)
830 goto do_publish;
831 else if (err) {
832 xenbus_dev_fatal(pdev->xdev, err,
833 "Error completing transaction "
834 "for backend");
835 goto out;
836 }
837 }
838
839 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
840
841 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
842
843out:
844 return err;
845}
846
847static int pcifront_try_connect(struct pcifront_device *pdev)
848{
849 int err = -EFAULT;
850 int i, num_roots, len;
851 char str[64];
852 unsigned int domain, bus;
853
854
855 /* Only connect once */
856 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
857 XenbusStateInitialised)
858 goto out;
859
860 err = pcifront_connect_and_init_dma(pdev);
861 if (err && err != -EEXIST) {
862 xenbus_dev_fatal(pdev->xdev, err,
863 "Error setting up PCI Frontend");
864 goto out;
865 }
866
867 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
868 "root_num", "%d", &num_roots);
869 if (err == -ENOENT) {
870 xenbus_dev_error(pdev->xdev, err,
871 "No PCI Roots found, trying 0000:00");
872 err = pcifront_scan_root(pdev, 0, 0);
873 if (err) {
874 xenbus_dev_fatal(pdev->xdev, err,
875 "Error scanning PCI root 0000:00");
876 goto out;
877 }
878 num_roots = 0;
879 } else if (err != 1) {
880 if (err == 0)
881 err = -EINVAL;
882 xenbus_dev_fatal(pdev->xdev, err,
883 "Error reading number of PCI roots");
884 goto out;
885 }
886
887 for (i = 0; i < num_roots; i++) {
888 len = snprintf(str, sizeof(str), "root-%d", i);
889 if (unlikely(len >= (sizeof(str) - 1))) {
890 err = -ENOMEM;
891 goto out;
892 }
893
894 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
895 "%x:%x", &domain, &bus);
896 if (err != 2) {
897 if (err >= 0)
898 err = -EINVAL;
899 xenbus_dev_fatal(pdev->xdev, err,
900 "Error reading PCI root %d", i);
901 goto out;
902 }
903
904 err = pcifront_scan_root(pdev, domain, bus);
905 if (err) {
906 xenbus_dev_fatal(pdev->xdev, err,
907 "Error scanning PCI root %04x:%02x",
908 domain, bus);
909 goto out;
910 }
911 }
912
913 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
914
915out:
916 return err;
917}
918
919static int pcifront_try_disconnect(struct pcifront_device *pdev)
920{
921 int err = 0;
922 enum xenbus_state prev_state;
923
924
925 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
926
927 if (prev_state >= XenbusStateClosing)
928 goto out;
929
930 if (prev_state == XenbusStateConnected) {
931 pcifront_free_roots(pdev);
932 pcifront_disconnect(pdev);
933 }
934
935 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
936
937out:
938
939 return err;
940}
941
942static int pcifront_attach_devices(struct pcifront_device *pdev)
943{
944 int err = -EFAULT;
945 int i, num_roots, len;
946 unsigned int domain, bus;
947 char str[64];
948
949 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
950 XenbusStateReconfiguring)
951 goto out;
952
953 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
954 "root_num", "%d", &num_roots);
955 if (err == -ENOENT) {
956 xenbus_dev_error(pdev->xdev, err,
957 "No PCI Roots found, trying 0000:00");
958 err = pcifront_rescan_root(pdev, 0, 0);
959 if (err) {
960 xenbus_dev_fatal(pdev->xdev, err,
961 "Error scanning PCI root 0000:00");
962 goto out;
963 }
964 num_roots = 0;
965 } else if (err != 1) {
966 if (err == 0)
967 err = -EINVAL;
968 xenbus_dev_fatal(pdev->xdev, err,
969 "Error reading number of PCI roots");
970 goto out;
971 }
972
973 for (i = 0; i < num_roots; i++) {
974 len = snprintf(str, sizeof(str), "root-%d", i);
975 if (unlikely(len >= (sizeof(str) - 1))) {
976 err = -ENOMEM;
977 goto out;
978 }
979
980 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
981 "%x:%x", &domain, &bus);
982 if (err != 2) {
983 if (err >= 0)
984 err = -EINVAL;
985 xenbus_dev_fatal(pdev->xdev, err,
986 "Error reading PCI root %d", i);
987 goto out;
988 }
989
990 err = pcifront_rescan_root(pdev, domain, bus);
991 if (err) {
992 xenbus_dev_fatal(pdev->xdev, err,
993 "Error scanning PCI root %04x:%02x",
994 domain, bus);
995 goto out;
996 }
997 }
998
999 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
1000
1001out:
1002 return err;
1003}
1004
1005static int pcifront_detach_devices(struct pcifront_device *pdev)
1006{
1007 int err = 0;
1008 int i, num_devs;
1009 unsigned int domain, bus, slot, func;
1010 struct pci_dev *pci_dev;
1011 char str[64];
1012
1013 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
1014 XenbusStateConnected)
1015 goto out;
1016
1017 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
1018 &num_devs);
1019 if (err != 1) {
1020 if (err >= 0)
1021 err = -EINVAL;
1022 xenbus_dev_fatal(pdev->xdev, err,
1023 "Error reading number of PCI devices");
1024 goto out;
1025 }
1026
1027 /* Find devices being detached and remove them. */
1028 for (i = 0; i < num_devs; i++) {
1029 int l, state;
1030 l = snprintf(str, sizeof(str), "state-%d", i);
1031 if (unlikely(l >= (sizeof(str) - 1))) {
1032 err = -ENOMEM;
1033 goto out;
1034 }
1035 state = xenbus_read_unsigned(pdev->xdev->otherend, str,
1036 XenbusStateUnknown);
1037
1038 if (state != XenbusStateClosing)
1039 continue;
1040
1041 /* Remove device. */
1042 l = snprintf(str, sizeof(str), "vdev-%d", i);
1043 if (unlikely(l >= (sizeof(str) - 1))) {
1044 err = -ENOMEM;
1045 goto out;
1046 }
1047 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1048 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1049 if (err != 4) {
1050 if (err >= 0)
1051 err = -EINVAL;
1052 xenbus_dev_fatal(pdev->xdev, err,
1053 "Error reading PCI device %d", i);
1054 goto out;
1055 }
1056
1057 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
1058 PCI_DEVFN(slot, func));
1059 if (!pci_dev) {
1060 dev_dbg(&pdev->xdev->dev,
1061 "Cannot get PCI device %04x:%02x:%02x.%d\n",
1062 domain, bus, slot, func);
1063 continue;
1064 }
1065 pci_lock_rescan_remove();
1066 pci_stop_and_remove_bus_device(pci_dev);
1067 pci_dev_put(pci_dev);
1068 pci_unlock_rescan_remove();
1069
1070 dev_dbg(&pdev->xdev->dev,
1071 "PCI device %04x:%02x:%02x.%d removed.\n",
1072 domain, bus, slot, func);
1073 }
1074
1075 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1076
1077out:
1078 return err;
1079}
1080
1081static void __ref pcifront_backend_changed(struct xenbus_device *xdev,
1082 enum xenbus_state be_state)
1083{
1084 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1085
1086 switch (be_state) {
1087 case XenbusStateUnknown:
1088 case XenbusStateInitialising:
1089 case XenbusStateInitWait:
1090 case XenbusStateInitialised:
1091 break;
1092
1093 case XenbusStateConnected:
1094 pcifront_try_connect(pdev);
1095 break;
1096
1097 case XenbusStateClosed:
1098 if (xdev->state == XenbusStateClosed)
1099 break;
1100 fallthrough; /* Missed the backend's CLOSING state */
1101 case XenbusStateClosing:
1102 dev_warn(&xdev->dev, "backend going away!\n");
1103 pcifront_try_disconnect(pdev);
1104 break;
1105
1106 case XenbusStateReconfiguring:
1107 pcifront_detach_devices(pdev);
1108 break;
1109
1110 case XenbusStateReconfigured:
1111 pcifront_attach_devices(pdev);
1112 break;
1113 }
1114}
1115
1116static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1117 const struct xenbus_device_id *id)
1118{
1119 int err = 0;
1120 struct pcifront_device *pdev = alloc_pdev(xdev);
1121
1122 if (pdev == NULL) {
1123 err = -ENOMEM;
1124 xenbus_dev_fatal(xdev, err,
1125 "Error allocating pcifront_device struct");
1126 goto out;
1127 }
1128
1129 err = pcifront_publish_info(pdev);
1130 if (err)
1131 free_pdev(pdev);
1132
1133out:
1134 return err;
1135}
1136
1137static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1138{
1139 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1140 if (pdev)
1141 free_pdev(pdev);
1142
1143 return 0;
1144}
1145
1146static const struct xenbus_device_id xenpci_ids[] = {
1147 {"pci"},
1148 {""},
1149};
1150
1151static struct xenbus_driver xenpci_driver = {
1152 .name = "pcifront",
1153 .ids = xenpci_ids,
1154 .probe = pcifront_xenbus_probe,
1155 .remove = pcifront_xenbus_remove,
1156 .otherend_changed = pcifront_backend_changed,
1157};
1158
1159static int __init pcifront_init(void)
1160{
1161 if (!xen_pv_domain() || xen_initial_domain())
1162 return -ENODEV;
1163
1164 if (!xen_has_pv_devices())
1165 return -ENODEV;
1166
1167 pci_frontend_registrar(1 /* enable */);
1168
1169 return xenbus_register_frontend(&xenpci_driver);
1170}
1171
1172static void __exit pcifront_cleanup(void)
1173{
1174 xenbus_unregister_driver(&xenpci_driver);
1175 pci_frontend_registrar(0 /* disable */);
1176}
1177module_init(pcifront_init);
1178module_exit(pcifront_cleanup);
1179
1180MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1181MODULE_LICENSE("GPL");
1182MODULE_ALIAS("xen:pci");