PCI/e1000e: Add and use pci_disable_link_state_locked()
[linux-2.6.git] / drivers / pci / xen-pcifront.c
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 <asm/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
27 struct 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
35 struct 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
52 struct pcifront_sd {
53         int domain;
54         struct pcifront_device *pdev;
55 };
56
57 static inline struct pcifront_device *
58 pcifront_get_pdev(struct pcifront_sd *sd)
59 {
60         return sd->pdev;
61 }
62
63 static 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
71 static DEFINE_SPINLOCK(pcifront_dev_lock);
72 static struct pcifront_device *pcifront_dev;
73
74 static int verbose_request;
75 module_param(verbose_request, int, 0644);
76
77 static 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
99 static 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
108 static 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;
169 out:
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 */
175 static 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 */
214 static 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
239 struct pci_ops pcifront_bus_ops = {
240         .read = pcifront_bus_read,
241         .write = pcifront_bus_write,
242 };
243
244 #ifdef CONFIG_PCI_MSI
245 static 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
300 static 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
319 static 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
348 static 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
371 static 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
378 static 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
386 static 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 */
390 static 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
414 static 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
443 static 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
498 err_out:
499         kfree(bus_entry);
500         kfree(sd);
501
502         return err;
503 }
504
505 static 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
540 static 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
552 static 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
572 static 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
636 static 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
666 static 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 }
672 static 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
691 static 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 }
703 static 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);
738 out:
739         return pdev;
740 }
741
742 static 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
767 static 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
790 do_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
829 out:
830         return err;
831 }
832
833 static 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
896 out:
897         return err;
898 }
899
900 static 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
918 out:
919
920         return err;
921 }
922
923 static 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
977 out:
978         return err;
979 }
980
981 static 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
1059 out:
1060         return err;
1061 }
1062
1063 static 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
1095 static 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
1112 out:
1113         return err;
1114 }
1115
1116 static 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
1125 static const struct xenbus_device_id xenpci_ids[] = {
1126         {"pci"},
1127         {""},
1128 };
1129
1130 static 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
1139 static 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
1149 static void __exit pcifront_cleanup(void)
1150 {
1151         xenbus_unregister_driver(&xenbus_pcifront_driver);
1152         pci_frontend_registrar(0 /* disable */);
1153 }
1154 module_init(pcifront_init);
1155 module_exit(pcifront_cleanup);
1156
1157 MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1158 MODULE_LICENSE("GPL");
1159 MODULE_ALIAS("xen:pci");