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 #include <linux/ktime.h>
24 #include <xen/platform_pci.h>
25
26 #include <asm/xen/swiotlb-xen.h>
27 #define INVALID_GRANT_REF (0)
28 #define INVALID_EVTCHN (-1)
29
30 struct pci_bus_entry {
31 struct list_head list;
32 struct pci_bus *bus;
33 };
34
35 #define _PDEVB_op_active (0)
36 #define PDEVB_op_active (1 << (_PDEVB_op_active))
37
38 struct pcifront_device {
39 struct xenbus_device *xdev;
40 struct list_head root_buses;
41
42 int evtchn;
43 int gnt_ref;
44
45 int irq;
46
47 /* Lock this when doing any operations in sh_info */
48 spinlock_t sh_info_lock;
49 struct xen_pci_sharedinfo *sh_info;
50 struct work_struct op_work;
51 unsigned long flags;
52
53 };
54
55 struct pcifront_sd {
56 struct pci_sysdata sd;
57 struct pcifront_device *pdev;
58 };
59
60 static inline struct pcifront_device *
pcifront_get_pdev(struct pcifront_sd * sd)61 pcifront_get_pdev(struct pcifront_sd *sd)
62 {
63 return sd->pdev;
64 }
65
pcifront_init_sd(struct pcifront_sd * sd,unsigned int domain,unsigned int bus,struct pcifront_device * pdev)66 static inline void pcifront_init_sd(struct pcifront_sd *sd,
67 unsigned int domain, unsigned int bus,
68 struct pcifront_device *pdev)
69 {
70 /* Because we do not expose that information via XenBus. */
71 sd->sd.node = first_online_node;
72 sd->sd.domain = domain;
73 sd->pdev = pdev;
74 }
75
76 static DEFINE_SPINLOCK(pcifront_dev_lock);
77 static struct pcifront_device *pcifront_dev;
78
79 static int verbose_request;
80 module_param(verbose_request, int, 0644);
81
errno_to_pcibios_err(int errno)82 static int errno_to_pcibios_err(int errno)
83 {
84 switch (errno) {
85 case XEN_PCI_ERR_success:
86 return PCIBIOS_SUCCESSFUL;
87
88 case XEN_PCI_ERR_dev_not_found:
89 return PCIBIOS_DEVICE_NOT_FOUND;
90
91 case XEN_PCI_ERR_invalid_offset:
92 case XEN_PCI_ERR_op_failed:
93 return PCIBIOS_BAD_REGISTER_NUMBER;
94
95 case XEN_PCI_ERR_not_implemented:
96 return PCIBIOS_FUNC_NOT_SUPPORTED;
97
98 case XEN_PCI_ERR_access_denied:
99 return PCIBIOS_SET_FAILED;
100 }
101 return errno;
102 }
103
schedule_pcifront_aer_op(struct pcifront_device * pdev)104 static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
105 {
106 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
107 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
108 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
109 schedule_work(&pdev->op_work);
110 }
111 }
112
do_pci_op(struct pcifront_device * pdev,struct xen_pci_op * op)113 static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
114 {
115 int err = 0;
116 struct xen_pci_op *active_op = &pdev->sh_info->op;
117 unsigned long irq_flags;
118 evtchn_port_t port = pdev->evtchn;
119 unsigned irq = pdev->irq;
120 s64 ns, ns_timeout;
121
122 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
123
124 memcpy(active_op, op, sizeof(struct xen_pci_op));
125
126 /* Go */
127 wmb();
128 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
129 notify_remote_via_evtchn(port);
130
131 /*
132 * We set a poll timeout of 3 seconds but give up on return after
133 * 2 seconds. It is better to time out too late rather than too early
134 * (in the latter case we end up continually re-executing poll() with a
135 * timeout in the past). 1s difference gives plenty of slack for error.
136 */
137 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC;
138
139 xen_clear_irq_pending(irq);
140
141 while (test_bit(_XEN_PCIF_active,
142 (unsigned long *)&pdev->sh_info->flags)) {
143 xen_poll_irq_timeout(irq, jiffies + 3*HZ);
144 xen_clear_irq_pending(irq);
145 ns = ktime_get_ns();
146 if (ns > ns_timeout) {
147 dev_err(&pdev->xdev->dev,
148 "pciback not responding!!!\n");
149 clear_bit(_XEN_PCIF_active,
150 (unsigned long *)&pdev->sh_info->flags);
151 err = XEN_PCI_ERR_dev_not_found;
152 goto out;
153 }
154 }
155
156 /*
157 * We might lose backend service request since we
158 * reuse same evtchn with pci_conf backend response. So re-schedule
159 * aer pcifront service.
160 */
161 if (test_bit(_XEN_PCIB_active,
162 (unsigned long *)&pdev->sh_info->flags)) {
163 dev_err(&pdev->xdev->dev,
164 "schedule aer pcifront service\n");
165 schedule_pcifront_aer_op(pdev);
166 }
167
168 memcpy(op, active_op, sizeof(struct xen_pci_op));
169
170 err = op->err;
171 out:
172 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
173 return err;
174 }
175
176 /* Access to this function is spinlocked in drivers/pci/access.c */
pcifront_bus_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)177 static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
178 int where, int size, u32 *val)
179 {
180 int err = 0;
181 struct xen_pci_op op = {
182 .cmd = XEN_PCI_OP_conf_read,
183 .domain = pci_domain_nr(bus),
184 .bus = bus->number,
185 .devfn = devfn,
186 .offset = where,
187 .size = size,
188 };
189 struct pcifront_sd *sd = bus->sysdata;
190 struct pcifront_device *pdev = pcifront_get_pdev(sd);
191
192 if (verbose_request)
193 dev_info(&pdev->xdev->dev,
194 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
195 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
196 PCI_FUNC(devfn), where, size);
197
198 err = do_pci_op(pdev, &op);
199
200 if (likely(!err)) {
201 if (verbose_request)
202 dev_info(&pdev->xdev->dev, "read got back value %x\n",
203 op.value);
204
205 *val = op.value;
206 } else if (err == -ENODEV) {
207 /* No device here, pretend that it just returned 0 */
208 err = 0;
209 *val = 0;
210 }
211
212 return errno_to_pcibios_err(err);
213 }
214
215 /* Access to this function is spinlocked in drivers/pci/access.c */
pcifront_bus_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)216 static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
217 int where, int size, u32 val)
218 {
219 struct xen_pci_op op = {
220 .cmd = XEN_PCI_OP_conf_write,
221 .domain = pci_domain_nr(bus),
222 .bus = bus->number,
223 .devfn = devfn,
224 .offset = where,
225 .size = size,
226 .value = val,
227 };
228 struct pcifront_sd *sd = bus->sysdata;
229 struct pcifront_device *pdev = pcifront_get_pdev(sd);
230
231 if (verbose_request)
232 dev_info(&pdev->xdev->dev,
233 "write dev=%04x:%02x:%02x.%d - "
234 "offset %x size %d val %x\n",
235 pci_domain_nr(bus), bus->number,
236 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
237
238 return errno_to_pcibios_err(do_pci_op(pdev, &op));
239 }
240
241 static struct pci_ops pcifront_bus_ops = {
242 .read = pcifront_bus_read,
243 .write = pcifront_bus_write,
244 };
245
246 #ifdef CONFIG_PCI_MSI
pci_frontend_enable_msix(struct pci_dev * dev,int vector[],int nvec)247 static int pci_frontend_enable_msix(struct pci_dev *dev,
248 int vector[], int nvec)
249 {
250 int err;
251 int i;
252 struct xen_pci_op op = {
253 .cmd = XEN_PCI_OP_enable_msix,
254 .domain = pci_domain_nr(dev->bus),
255 .bus = dev->bus->number,
256 .devfn = dev->devfn,
257 .value = nvec,
258 };
259 struct pcifront_sd *sd = dev->bus->sysdata;
260 struct pcifront_device *pdev = pcifront_get_pdev(sd);
261 struct msi_desc *entry;
262
263 if (nvec > SH_INFO_MAX_VEC) {
264 dev_err(&dev->dev, "too much vector for pci frontend: %x."
265 " Increase SH_INFO_MAX_VEC.\n", nvec);
266 return -EINVAL;
267 }
268
269 i = 0;
270 for_each_pci_msi_entry(entry, dev) {
271 op.msix_entries[i].entry = entry->msi_attrib.entry_nr;
272 /* Vector is useless at this point. */
273 op.msix_entries[i].vector = -1;
274 i++;
275 }
276
277 err = do_pci_op(pdev, &op);
278
279 if (likely(!err)) {
280 if (likely(!op.value)) {
281 /* we get the result */
282 for (i = 0; i < nvec; i++) {
283 if (op.msix_entries[i].vector <= 0) {
284 dev_warn(&dev->dev, "MSI-X entry %d is invalid: %d!\n",
285 i, op.msix_entries[i].vector);
286 err = -EINVAL;
287 vector[i] = -1;
288 continue;
289 }
290 vector[i] = op.msix_entries[i].vector;
291 }
292 } else {
293 printk(KERN_DEBUG "enable msix get value %x\n",
294 op.value);
295 err = op.value;
296 }
297 } else {
298 dev_err(&dev->dev, "enable msix get err %x\n", err);
299 }
300 return err;
301 }
302
pci_frontend_disable_msix(struct pci_dev * dev)303 static void pci_frontend_disable_msix(struct pci_dev *dev)
304 {
305 int err;
306 struct xen_pci_op op = {
307 .cmd = XEN_PCI_OP_disable_msix,
308 .domain = pci_domain_nr(dev->bus),
309 .bus = dev->bus->number,
310 .devfn = dev->devfn,
311 };
312 struct pcifront_sd *sd = dev->bus->sysdata;
313 struct pcifront_device *pdev = pcifront_get_pdev(sd);
314
315 err = do_pci_op(pdev, &op);
316
317 /* What should do for error ? */
318 if (err)
319 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err);
320 }
321
pci_frontend_enable_msi(struct pci_dev * dev,int vector[])322 static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
323 {
324 int err;
325 struct xen_pci_op op = {
326 .cmd = XEN_PCI_OP_enable_msi,
327 .domain = pci_domain_nr(dev->bus),
328 .bus = dev->bus->number,
329 .devfn = dev->devfn,
330 };
331 struct pcifront_sd *sd = dev->bus->sysdata;
332 struct pcifront_device *pdev = pcifront_get_pdev(sd);
333
334 err = do_pci_op(pdev, &op);
335 if (likely(!err)) {
336 vector[0] = op.value;
337 if (op.value <= 0) {
338 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
339 op.value);
340 err = -EINVAL;
341 vector[0] = -1;
342 }
343 } else {
344 dev_err(&dev->dev, "pci frontend enable msi failed for dev "
345 "%x:%x\n", op.bus, op.devfn);
346 err = -EINVAL;
347 }
348 return err;
349 }
350
pci_frontend_disable_msi(struct pci_dev * dev)351 static void pci_frontend_disable_msi(struct pci_dev *dev)
352 {
353 int err;
354 struct xen_pci_op op = {
355 .cmd = XEN_PCI_OP_disable_msi,
356 .domain = pci_domain_nr(dev->bus),
357 .bus = dev->bus->number,
358 .devfn = dev->devfn,
359 };
360 struct pcifront_sd *sd = dev->bus->sysdata;
361 struct pcifront_device *pdev = pcifront_get_pdev(sd);
362
363 err = do_pci_op(pdev, &op);
364 if (err == XEN_PCI_ERR_dev_not_found) {
365 /* XXX No response from backend, what shall we do? */
366 printk(KERN_DEBUG "get no response from backend for disable MSI\n");
367 return;
368 }
369 if (err)
370 /* how can pciback notify us fail? */
371 printk(KERN_DEBUG "get fake response frombackend\n");
372 }
373
374 static struct xen_pci_frontend_ops pci_frontend_ops = {
375 .enable_msi = pci_frontend_enable_msi,
376 .disable_msi = pci_frontend_disable_msi,
377 .enable_msix = pci_frontend_enable_msix,
378 .disable_msix = pci_frontend_disable_msix,
379 };
380
pci_frontend_registrar(int enable)381 static void pci_frontend_registrar(int enable)
382 {
383 if (enable)
384 xen_pci_frontend = &pci_frontend_ops;
385 else
386 xen_pci_frontend = NULL;
387 };
388 #else
pci_frontend_registrar(int enable)389 static inline void pci_frontend_registrar(int enable) { };
390 #endif /* CONFIG_PCI_MSI */
391
392 /* Claim resources for the PCI frontend as-is, backend won't allow changes */
pcifront_claim_resource(struct pci_dev * dev,void * data)393 static int pcifront_claim_resource(struct pci_dev *dev, void *data)
394 {
395 struct pcifront_device *pdev = data;
396 int i;
397 struct resource *r;
398
399 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
400 r = &dev->resource[i];
401
402 if (!r->parent && r->start && r->flags) {
403 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
404 pci_name(dev), i);
405 if (pci_claim_resource(dev, i)) {
406 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
407 "Device offline. Try using e820_host=1 in the guest config.\n",
408 pci_name(dev), i);
409 }
410 }
411 }
412
413 return 0;
414 }
415
pcifront_scan_bus(struct pcifront_device * pdev,unsigned int domain,unsigned int bus,struct pci_bus * b)416 static int pcifront_scan_bus(struct pcifront_device *pdev,
417 unsigned int domain, unsigned int bus,
418 struct pci_bus *b)
419 {
420 struct pci_dev *d;
421 unsigned int devfn;
422
423 /* Scan the bus for functions and add.
424 * We omit handling of PCI bridge attachment because pciback prevents
425 * bridges from being exported.
426 */
427 for (devfn = 0; devfn < 0x100; devfn++) {
428 d = pci_get_slot(b, devfn);
429 if (d) {
430 /* Device is already known. */
431 pci_dev_put(d);
432 continue;
433 }
434
435 d = pci_scan_single_device(b, devfn);
436 if (d)
437 dev_info(&pdev->xdev->dev, "New device on "
438 "%04x:%02x:%02x.%d found.\n", domain, bus,
439 PCI_SLOT(devfn), PCI_FUNC(devfn));
440 }
441
442 return 0;
443 }
444
pcifront_scan_root(struct pcifront_device * pdev,unsigned int domain,unsigned int bus)445 static int pcifront_scan_root(struct pcifront_device *pdev,
446 unsigned int domain, unsigned int bus)
447 {
448 struct pci_bus *b;
449 LIST_HEAD(resources);
450 struct pcifront_sd *sd = NULL;
451 struct pci_bus_entry *bus_entry = NULL;
452 int err = 0;
453 static struct resource busn_res = {
454 .start = 0,
455 .end = 255,
456 .flags = IORESOURCE_BUS,
457 };
458
459 #ifndef CONFIG_PCI_DOMAINS
460 if (domain != 0) {
461 dev_err(&pdev->xdev->dev,
462 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
463 dev_err(&pdev->xdev->dev,
464 "Please compile with CONFIG_PCI_DOMAINS\n");
465 err = -EINVAL;
466 goto err_out;
467 }
468 #endif
469
470 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
471 domain, bus);
472
473 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
474 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
475 if (!bus_entry || !sd) {
476 err = -ENOMEM;
477 goto err_out;
478 }
479 pci_add_resource(&resources, &ioport_resource);
480 pci_add_resource(&resources, &iomem_resource);
481 pci_add_resource(&resources, &busn_res);
482 pcifront_init_sd(sd, domain, bus, pdev);
483
484 pci_lock_rescan_remove();
485
486 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
487 &pcifront_bus_ops, sd, &resources);
488 if (!b) {
489 dev_err(&pdev->xdev->dev,
490 "Error creating PCI Frontend Bus!\n");
491 err = -ENOMEM;
492 pci_unlock_rescan_remove();
493 pci_free_resource_list(&resources);
494 goto err_out;
495 }
496
497 bus_entry->bus = b;
498
499 list_add(&bus_entry->list, &pdev->root_buses);
500
501 /* pci_scan_root_bus skips devices which do not have a
502 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
503 err = pcifront_scan_bus(pdev, domain, bus, b);
504
505 /* Claim resources before going "live" with our devices */
506 pci_walk_bus(b, pcifront_claim_resource, pdev);
507
508 /* Create SysFS and notify udev of the devices. Aka: "going live" */
509 pci_bus_add_devices(b);
510
511 pci_unlock_rescan_remove();
512 return err;
513
514 err_out:
515 kfree(bus_entry);
516 kfree(sd);
517
518 return err;
519 }
520
pcifront_rescan_root(struct pcifront_device * pdev,unsigned int domain,unsigned int bus)521 static int pcifront_rescan_root(struct pcifront_device *pdev,
522 unsigned int domain, unsigned int bus)
523 {
524 int err;
525 struct pci_bus *b;
526
527 #ifndef CONFIG_PCI_DOMAINS
528 if (domain != 0) {
529 dev_err(&pdev->xdev->dev,
530 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
531 dev_err(&pdev->xdev->dev,
532 "Please compile with CONFIG_PCI_DOMAINS\n");
533 return -EINVAL;
534 }
535 #endif
536
537 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
538 domain, bus);
539
540 b = pci_find_bus(domain, bus);
541 if (!b)
542 /* If the bus is unknown, create it. */
543 return pcifront_scan_root(pdev, domain, bus);
544
545 err = pcifront_scan_bus(pdev, domain, bus, b);
546
547 /* Claim resources before going "live" with our devices */
548 pci_walk_bus(b, pcifront_claim_resource, pdev);
549
550 /* Create SysFS and notify udev of the devices. Aka: "going live" */
551 pci_bus_add_devices(b);
552
553 return err;
554 }
555
free_root_bus_devs(struct pci_bus * bus)556 static void free_root_bus_devs(struct pci_bus *bus)
557 {
558 struct pci_dev *dev;
559
560 while (!list_empty(&bus->devices)) {
561 dev = container_of(bus->devices.next, struct pci_dev,
562 bus_list);
563 dev_dbg(&dev->dev, "removing device\n");
564 pci_stop_and_remove_bus_device(dev);
565 }
566 }
567
pcifront_free_roots(struct pcifront_device * pdev)568 static void pcifront_free_roots(struct pcifront_device *pdev)
569 {
570 struct pci_bus_entry *bus_entry, *t;
571
572 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
573
574 pci_lock_rescan_remove();
575 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
576 list_del(&bus_entry->list);
577
578 free_root_bus_devs(bus_entry->bus);
579
580 kfree(bus_entry->bus->sysdata);
581
582 device_unregister(bus_entry->bus->bridge);
583 pci_remove_bus(bus_entry->bus);
584
585 kfree(bus_entry);
586 }
587 pci_unlock_rescan_remove();
588 }
589
pcifront_common_process(int cmd,struct pcifront_device * pdev,pci_channel_state_t state)590 static pci_ers_result_t pcifront_common_process(int cmd,
591 struct pcifront_device *pdev,
592 pci_channel_state_t state)
593 {
594 pci_ers_result_t result;
595 struct pci_driver *pdrv;
596 int bus = pdev->sh_info->aer_op.bus;
597 int devfn = pdev->sh_info->aer_op.devfn;
598 struct pci_dev *pcidev;
599 int flag = 0;
600
601 dev_dbg(&pdev->xdev->dev,
602 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
603 cmd, bus, devfn);
604 result = PCI_ERS_RESULT_NONE;
605
606 pcidev = pci_get_bus_and_slot(bus, devfn);
607 if (!pcidev || !pcidev->driver) {
608 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
609 pci_dev_put(pcidev);
610 return result;
611 }
612 pdrv = pcidev->driver;
613
614 if (pdrv) {
615 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
616 dev_dbg(&pcidev->dev,
617 "trying to call AER service\n");
618 if (pcidev) {
619 flag = 1;
620 switch (cmd) {
621 case XEN_PCI_OP_aer_detected:
622 result = pdrv->err_handler->
623 error_detected(pcidev, state);
624 break;
625 case XEN_PCI_OP_aer_mmio:
626 result = pdrv->err_handler->
627 mmio_enabled(pcidev);
628 break;
629 case XEN_PCI_OP_aer_slotreset:
630 result = pdrv->err_handler->
631 slot_reset(pcidev);
632 break;
633 case XEN_PCI_OP_aer_resume:
634 pdrv->err_handler->resume(pcidev);
635 break;
636 default:
637 dev_err(&pdev->xdev->dev,
638 "bad request in aer recovery "
639 "operation!\n");
640
641 }
642 }
643 }
644 }
645 if (!flag)
646 result = PCI_ERS_RESULT_NONE;
647
648 return result;
649 }
650
651
pcifront_do_aer(struct work_struct * data)652 static void pcifront_do_aer(struct work_struct *data)
653 {
654 struct pcifront_device *pdev =
655 container_of(data, struct pcifront_device, op_work);
656 int cmd = pdev->sh_info->aer_op.cmd;
657 pci_channel_state_t state =
658 (pci_channel_state_t)pdev->sh_info->aer_op.err;
659
660 /*If a pci_conf op is in progress,
661 we have to wait until it is done before service aer op*/
662 dev_dbg(&pdev->xdev->dev,
663 "pcifront service aer bus %x devfn %x\n",
664 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
665
666 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
667
668 /* Post the operation to the guest. */
669 wmb();
670 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
671 notify_remote_via_evtchn(pdev->evtchn);
672
673 /*in case of we lost an aer request in four lines time_window*/
674 smp_mb__before_atomic();
675 clear_bit(_PDEVB_op_active, &pdev->flags);
676 smp_mb__after_atomic();
677
678 schedule_pcifront_aer_op(pdev);
679
680 }
681
pcifront_handler_aer(int irq,void * dev)682 static irqreturn_t pcifront_handler_aer(int irq, void *dev)
683 {
684 struct pcifront_device *pdev = dev;
685 schedule_pcifront_aer_op(pdev);
686 return IRQ_HANDLED;
687 }
pcifront_connect_and_init_dma(struct pcifront_device * pdev)688 static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
689 {
690 int err = 0;
691
692 spin_lock(&pcifront_dev_lock);
693
694 if (!pcifront_dev) {
695 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
696 pcifront_dev = pdev;
697 } else
698 err = -EEXIST;
699
700 spin_unlock(&pcifront_dev_lock);
701
702 if (!err && !swiotlb_nr_tbl()) {
703 err = pci_xen_swiotlb_init_late();
704 if (err)
705 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
706 }
707 return err;
708 }
709
pcifront_disconnect(struct pcifront_device * pdev)710 static void pcifront_disconnect(struct pcifront_device *pdev)
711 {
712 spin_lock(&pcifront_dev_lock);
713
714 if (pdev == pcifront_dev) {
715 dev_info(&pdev->xdev->dev,
716 "Disconnecting PCI Frontend Buses\n");
717 pcifront_dev = NULL;
718 }
719
720 spin_unlock(&pcifront_dev_lock);
721 }
alloc_pdev(struct xenbus_device * xdev)722 static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
723 {
724 struct pcifront_device *pdev;
725
726 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
727 if (pdev == NULL)
728 goto out;
729
730 pdev->sh_info =
731 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
732 if (pdev->sh_info == NULL) {
733 kfree(pdev);
734 pdev = NULL;
735 goto out;
736 }
737 pdev->sh_info->flags = 0;
738
739 /*Flag for registering PV AER handler*/
740 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
741
742 dev_set_drvdata(&xdev->dev, pdev);
743 pdev->xdev = xdev;
744
745 INIT_LIST_HEAD(&pdev->root_buses);
746
747 spin_lock_init(&pdev->sh_info_lock);
748
749 pdev->evtchn = INVALID_EVTCHN;
750 pdev->gnt_ref = INVALID_GRANT_REF;
751 pdev->irq = -1;
752
753 INIT_WORK(&pdev->op_work, pcifront_do_aer);
754
755 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
756 pdev, pdev->sh_info);
757 out:
758 return pdev;
759 }
760
free_pdev(struct pcifront_device * pdev)761 static void free_pdev(struct pcifront_device *pdev)
762 {
763 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
764
765 pcifront_free_roots(pdev);
766
767 cancel_work_sync(&pdev->op_work);
768
769 if (pdev->irq >= 0)
770 unbind_from_irqhandler(pdev->irq, pdev);
771
772 if (pdev->evtchn != INVALID_EVTCHN)
773 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
774
775 if (pdev->gnt_ref != INVALID_GRANT_REF)
776 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
777 (unsigned long)pdev->sh_info);
778 else
779 free_page((unsigned long)pdev->sh_info);
780
781 dev_set_drvdata(&pdev->xdev->dev, NULL);
782
783 kfree(pdev);
784 }
785
pcifront_publish_info(struct pcifront_device * pdev)786 static int pcifront_publish_info(struct pcifront_device *pdev)
787 {
788 int err = 0;
789 struct xenbus_transaction trans;
790 grant_ref_t gref;
791
792 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
793 if (err < 0)
794 goto out;
795
796 pdev->gnt_ref = gref;
797
798 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
799 if (err)
800 goto out;
801
802 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
803 0, "pcifront", pdev);
804
805 if (err < 0)
806 return err;
807
808 pdev->irq = err;
809
810 do_publish:
811 err = xenbus_transaction_start(&trans);
812 if (err) {
813 xenbus_dev_fatal(pdev->xdev, err,
814 "Error writing configuration for backend "
815 "(start transaction)");
816 goto out;
817 }
818
819 err = xenbus_printf(trans, pdev->xdev->nodename,
820 "pci-op-ref", "%u", pdev->gnt_ref);
821 if (!err)
822 err = xenbus_printf(trans, pdev->xdev->nodename,
823 "event-channel", "%u", pdev->evtchn);
824 if (!err)
825 err = xenbus_printf(trans, pdev->xdev->nodename,
826 "magic", XEN_PCI_MAGIC);
827
828 if (err) {
829 xenbus_transaction_end(trans, 1);
830 xenbus_dev_fatal(pdev->xdev, err,
831 "Error writing configuration for backend");
832 goto out;
833 } else {
834 err = xenbus_transaction_end(trans, 0);
835 if (err == -EAGAIN)
836 goto do_publish;
837 else if (err) {
838 xenbus_dev_fatal(pdev->xdev, err,
839 "Error completing transaction "
840 "for backend");
841 goto out;
842 }
843 }
844
845 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
846
847 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
848
849 out:
850 return err;
851 }
852
pcifront_try_connect(struct pcifront_device * pdev)853 static int pcifront_try_connect(struct pcifront_device *pdev)
854 {
855 int err = -EFAULT;
856 int i, num_roots, len;
857 char str[64];
858 unsigned int domain, bus;
859
860
861 /* Only connect once */
862 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
863 XenbusStateInitialised)
864 goto out;
865
866 err = pcifront_connect_and_init_dma(pdev);
867 if (err && err != -EEXIST) {
868 xenbus_dev_fatal(pdev->xdev, err,
869 "Error setting up PCI Frontend");
870 goto out;
871 }
872
873 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
874 "root_num", "%d", &num_roots);
875 if (err == -ENOENT) {
876 xenbus_dev_error(pdev->xdev, err,
877 "No PCI Roots found, trying 0000:00");
878 err = pcifront_scan_root(pdev, 0, 0);
879 if (err) {
880 xenbus_dev_fatal(pdev->xdev, err,
881 "Error scanning PCI root 0000:00");
882 goto out;
883 }
884 num_roots = 0;
885 } else if (err != 1) {
886 if (err == 0)
887 err = -EINVAL;
888 xenbus_dev_fatal(pdev->xdev, err,
889 "Error reading number of PCI roots");
890 goto out;
891 }
892
893 for (i = 0; i < num_roots; i++) {
894 len = snprintf(str, sizeof(str), "root-%d", i);
895 if (unlikely(len >= (sizeof(str) - 1))) {
896 err = -ENOMEM;
897 goto out;
898 }
899
900 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
901 "%x:%x", &domain, &bus);
902 if (err != 2) {
903 if (err >= 0)
904 err = -EINVAL;
905 xenbus_dev_fatal(pdev->xdev, err,
906 "Error reading PCI root %d", i);
907 goto out;
908 }
909
910 err = pcifront_scan_root(pdev, domain, bus);
911 if (err) {
912 xenbus_dev_fatal(pdev->xdev, err,
913 "Error scanning PCI root %04x:%02x",
914 domain, bus);
915 goto out;
916 }
917 }
918
919 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
920
921 out:
922 return err;
923 }
924
pcifront_try_disconnect(struct pcifront_device * pdev)925 static int pcifront_try_disconnect(struct pcifront_device *pdev)
926 {
927 int err = 0;
928 enum xenbus_state prev_state;
929
930
931 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
932
933 if (prev_state >= XenbusStateClosing)
934 goto out;
935
936 if (prev_state == XenbusStateConnected) {
937 pcifront_free_roots(pdev);
938 pcifront_disconnect(pdev);
939 }
940
941 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
942
943 out:
944
945 return err;
946 }
947
pcifront_attach_devices(struct pcifront_device * pdev)948 static int pcifront_attach_devices(struct pcifront_device *pdev)
949 {
950 int err = -EFAULT;
951 int i, num_roots, len;
952 unsigned int domain, bus;
953 char str[64];
954
955 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
956 XenbusStateReconfiguring)
957 goto out;
958
959 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
960 "root_num", "%d", &num_roots);
961 if (err == -ENOENT) {
962 xenbus_dev_error(pdev->xdev, err,
963 "No PCI Roots found, trying 0000:00");
964 err = pcifront_rescan_root(pdev, 0, 0);
965 if (err) {
966 xenbus_dev_fatal(pdev->xdev, err,
967 "Error scanning PCI root 0000:00");
968 goto out;
969 }
970 num_roots = 0;
971 } else if (err != 1) {
972 if (err == 0)
973 err = -EINVAL;
974 xenbus_dev_fatal(pdev->xdev, err,
975 "Error reading number of PCI roots");
976 goto out;
977 }
978
979 for (i = 0; i < num_roots; i++) {
980 len = snprintf(str, sizeof(str), "root-%d", i);
981 if (unlikely(len >= (sizeof(str) - 1))) {
982 err = -ENOMEM;
983 goto out;
984 }
985
986 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
987 "%x:%x", &domain, &bus);
988 if (err != 2) {
989 if (err >= 0)
990 err = -EINVAL;
991 xenbus_dev_fatal(pdev->xdev, err,
992 "Error reading PCI root %d", i);
993 goto out;
994 }
995
996 err = pcifront_rescan_root(pdev, domain, bus);
997 if (err) {
998 xenbus_dev_fatal(pdev->xdev, err,
999 "Error scanning PCI root %04x:%02x",
1000 domain, bus);
1001 goto out;
1002 }
1003 }
1004
1005 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
1006
1007 out:
1008 return err;
1009 }
1010
pcifront_detach_devices(struct pcifront_device * pdev)1011 static int pcifront_detach_devices(struct pcifront_device *pdev)
1012 {
1013 int err = 0;
1014 int i, num_devs;
1015 unsigned int domain, bus, slot, func;
1016 struct pci_dev *pci_dev;
1017 char str[64];
1018
1019 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
1020 XenbusStateConnected)
1021 goto out;
1022
1023 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
1024 &num_devs);
1025 if (err != 1) {
1026 if (err >= 0)
1027 err = -EINVAL;
1028 xenbus_dev_fatal(pdev->xdev, err,
1029 "Error reading number of PCI devices");
1030 goto out;
1031 }
1032
1033 /* Find devices being detached and remove them. */
1034 for (i = 0; i < num_devs; i++) {
1035 int l, state;
1036 l = snprintf(str, sizeof(str), "state-%d", i);
1037 if (unlikely(l >= (sizeof(str) - 1))) {
1038 err = -ENOMEM;
1039 goto out;
1040 }
1041 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d",
1042 &state);
1043 if (err != 1)
1044 state = XenbusStateUnknown;
1045
1046 if (state != XenbusStateClosing)
1047 continue;
1048
1049 /* Remove device. */
1050 l = snprintf(str, sizeof(str), "vdev-%d", i);
1051 if (unlikely(l >= (sizeof(str) - 1))) {
1052 err = -ENOMEM;
1053 goto out;
1054 }
1055 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1056 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1057 if (err != 4) {
1058 if (err >= 0)
1059 err = -EINVAL;
1060 xenbus_dev_fatal(pdev->xdev, err,
1061 "Error reading PCI device %d", i);
1062 goto out;
1063 }
1064
1065 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
1066 PCI_DEVFN(slot, func));
1067 if (!pci_dev) {
1068 dev_dbg(&pdev->xdev->dev,
1069 "Cannot get PCI device %04x:%02x:%02x.%d\n",
1070 domain, bus, slot, func);
1071 continue;
1072 }
1073 pci_lock_rescan_remove();
1074 pci_stop_and_remove_bus_device(pci_dev);
1075 pci_dev_put(pci_dev);
1076 pci_unlock_rescan_remove();
1077
1078 dev_dbg(&pdev->xdev->dev,
1079 "PCI device %04x:%02x:%02x.%d removed.\n",
1080 domain, bus, slot, func);
1081 }
1082
1083 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1084
1085 out:
1086 return err;
1087 }
1088
pcifront_backend_changed(struct xenbus_device * xdev,enum xenbus_state be_state)1089 static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev,
1090 enum xenbus_state be_state)
1091 {
1092 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1093
1094 switch (be_state) {
1095 case XenbusStateUnknown:
1096 case XenbusStateInitialising:
1097 case XenbusStateInitWait:
1098 case XenbusStateInitialised:
1099 break;
1100
1101 case XenbusStateConnected:
1102 pcifront_try_connect(pdev);
1103 break;
1104
1105 case XenbusStateClosed:
1106 if (xdev->state == XenbusStateClosed)
1107 break;
1108 /* Missed the backend's CLOSING state -- fallthrough */
1109 case XenbusStateClosing:
1110 dev_warn(&xdev->dev, "backend going away!\n");
1111 pcifront_try_disconnect(pdev);
1112 break;
1113
1114 case XenbusStateReconfiguring:
1115 pcifront_detach_devices(pdev);
1116 break;
1117
1118 case XenbusStateReconfigured:
1119 pcifront_attach_devices(pdev);
1120 break;
1121 }
1122 }
1123
pcifront_xenbus_probe(struct xenbus_device * xdev,const struct xenbus_device_id * id)1124 static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1125 const struct xenbus_device_id *id)
1126 {
1127 int err = 0;
1128 struct pcifront_device *pdev = alloc_pdev(xdev);
1129
1130 if (pdev == NULL) {
1131 err = -ENOMEM;
1132 xenbus_dev_fatal(xdev, err,
1133 "Error allocating pcifront_device struct");
1134 goto out;
1135 }
1136
1137 err = pcifront_publish_info(pdev);
1138 if (err)
1139 free_pdev(pdev);
1140
1141 out:
1142 return err;
1143 }
1144
pcifront_xenbus_remove(struct xenbus_device * xdev)1145 static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1146 {
1147 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1148 if (pdev)
1149 free_pdev(pdev);
1150
1151 return 0;
1152 }
1153
1154 static const struct xenbus_device_id xenpci_ids[] = {
1155 {"pci"},
1156 {""},
1157 };
1158
1159 static struct xenbus_driver xenpci_driver = {
1160 .name = "pcifront",
1161 .ids = xenpci_ids,
1162 .probe = pcifront_xenbus_probe,
1163 .remove = pcifront_xenbus_remove,
1164 .otherend_changed = pcifront_backend_changed,
1165 };
1166
pcifront_init(void)1167 static int __init pcifront_init(void)
1168 {
1169 if (!xen_pv_domain() || xen_initial_domain())
1170 return -ENODEV;
1171
1172 if (!xen_has_pv_devices())
1173 return -ENODEV;
1174
1175 pci_frontend_registrar(1 /* enable */);
1176
1177 return xenbus_register_frontend(&xenpci_driver);
1178 }
1179
pcifront_cleanup(void)1180 static void __exit pcifront_cleanup(void)
1181 {
1182 xenbus_unregister_driver(&xenpci_driver);
1183 pci_frontend_registrar(0 /* disable */);
1184 }
1185 module_init(pcifront_init);
1186 module_exit(pcifront_cleanup);
1187
1188 MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1189 MODULE_LICENSE("GPL");
1190 MODULE_ALIAS("xen:pci");
1191