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Linux 3.18-rc1
[linux-block.git] / drivers / pci / xen-pcifront.c
CommitLineData
956a9202
RW		 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>
956a9202
RW		 16#include <xen/interface/io/pciif.h>
17#include <asm/xen/pci.h>
18#include <linux/interrupt.h>
60063497 19#include <linux/atomic.h>
956a9202
RW		 20#include <linux/workqueue.h>
21#include <linux/bitops.h>
22#include <linux/time.h>
51c71a3b 23#include <xen/platform_pci.h>
956a9202 24
3d925320 25#include <asm/xen/swiotlb-xen.h>
956a9202
RW		 26#define INVALID_GRANT_REF (0)
27#define INVALID_EVTCHN (-1)
28
29struct pci_bus_entry {
30 struct list_head list;
31 struct pci_bus *bus;
32};
33
34#define _PDEVB_op_active (0)
35#define PDEVB_op_active (1 << (_PDEVB_op_active))
36
37struct pcifront_device {
38 struct xenbus_device *xdev;
39 struct list_head root_buses;
40
41 int evtchn;
42 int gnt_ref;
43
44 int irq;
45
46 /* Lock this when doing any operations in sh_info */
47 spinlock_t sh_info_lock;
48 struct xen_pci_sharedinfo *sh_info;
49 struct work_struct op_work;
50 unsigned long flags;
51
52};
53
54struct pcifront_sd {
55 int domain;
56 struct pcifront_device *pdev;
57};
58
59static inline struct pcifront_device *
60pcifront_get_pdev(struct pcifront_sd *sd)
61{
62 return sd->pdev;
63}
64
65static inline void pcifront_init_sd(struct pcifront_sd *sd,
66 unsigned int domain, unsigned int bus,
67 struct pcifront_device *pdev)
68{
69 sd->domain = domain;
70 sd->pdev = pdev;
71}
72
73static DEFINE_SPINLOCK(pcifront_dev_lock);
74static struct pcifront_device *pcifront_dev;
75
76static int verbose_request;
77module_param(verbose_request, int, 0644);
78
79static int errno_to_pcibios_err(int errno)
80{
81 switch (errno) {
82 case XEN_PCI_ERR_success:
83 return PCIBIOS_SUCCESSFUL;
84
85 case XEN_PCI_ERR_dev_not_found:
86 return PCIBIOS_DEVICE_NOT_FOUND;
87
88 case XEN_PCI_ERR_invalid_offset:
89 case XEN_PCI_ERR_op_failed:
90 return PCIBIOS_BAD_REGISTER_NUMBER;
91
92 case XEN_PCI_ERR_not_implemented:
93 return PCIBIOS_FUNC_NOT_SUPPORTED;
94
95 case XEN_PCI_ERR_access_denied:
96 return PCIBIOS_SET_FAILED;
97 }
98 return errno;
99}
100
101static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
102{
103 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
104 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
105 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
106 schedule_work(&pdev->op_work);
107 }
108}
109
110static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
111{
112 int err = 0;
113 struct xen_pci_op *active_op = &pdev->sh_info->op;
114 unsigned long irq_flags;
115 evtchn_port_t port = pdev->evtchn;
116 unsigned irq = pdev->irq;
117 s64 ns, ns_timeout;
118 struct timeval tv;
119
120 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
121
122 memcpy(active_op, op, sizeof(struct xen_pci_op));
123
124 /* Go */
125 wmb();
126 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
127 notify_remote_via_evtchn(port);
128
129 /*
130 * We set a poll timeout of 3 seconds but give up on return after
131 * 2 seconds. It is better to time out too late rather than too early
132 * (in the latter case we end up continually re-executing poll() with a
133 * timeout in the past). 1s difference gives plenty of slack for error.
134 */
135 do_gettimeofday(&tv);
136 ns_timeout = timeval_to_ns(&tv) + 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 do_gettimeofday(&tv);
145 ns = timeval_to_ns(&tv);
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;
171out:
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 */
177static 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,
e4de866a 194 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
956a9202
RW		 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 */
216static 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,
e4de866a 233 "write dev=%04x:%02x:%02x.%d - "
956a9202
RW		 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
b8b0f559 241static struct pci_ops pcifront_bus_ops = {
956a9202
RW		 242 .read = pcifront_bus_read,
243 .write = pcifront_bus_write,
244};
245
246#ifdef CONFIG_PCI_MSI
247static int pci_frontend_enable_msix(struct pci_dev *dev,
cc0f89c4 248 int vector[], int nvec)
956a9202
RW		 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 list_for_each_entry(entry, &dev->msi_list, list) {
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 */
1d461052
KRW		 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;
cc0f89c4 287 vector[i] = -1;
1d461052
KRW		 288 continue;
289 }
cc0f89c4 290 vector[i] = op.msix_entries[i].vector;
1d461052 291 }
956a9202
RW		 292 } else {
293 printk(KERN_DEBUG "enable msix get value %x\n",
294 op.value);
f09d8432 295 err = op.value;
956a9202
RW		 296 }
297 } else {
298 dev_err(&dev->dev, "enable msix get err %x\n", err);
956a9202 299 }
1d461052 300 return err;
956a9202
RW		 301}
302
303static 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
cc0f89c4 322static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
956a9202
RW		 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)) {
cc0f89c4 336 vector[0] = op.value;
1d461052
KRW		 337 if (op.value <= 0) {
338 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
339 op.value);
340 err = -EINVAL;
cc0f89c4 341 vector[0] = -1;
1d461052 342 }
956a9202
RW		 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
351static 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
374static 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
381static 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
389static 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 */
393static 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)) {
917e3e65
KRW		 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",
956a9202
RW		 408 pci_name(dev), i);
409 }
410 }
411 }
412
413 return 0;
414}
415
15856ad5 416static int pcifront_scan_bus(struct pcifront_device *pdev,
956a9202
RW		 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 "
e4de866a 438 "%04x:%02x:%02x.%d found.\n", domain, bus,
956a9202
RW		 439 PCI_SLOT(devfn), PCI_FUNC(devfn));
440 }
441
442 return 0;
443}
444
15856ad5 445static int pcifront_scan_root(struct pcifront_device *pdev,
956a9202
RW		 446 unsigned int domain, unsigned int bus)
447{
448 struct pci_bus *b;
449 struct pcifront_sd *sd = NULL;
450 struct pci_bus_entry *bus_entry = NULL;
451 int err = 0;
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 = kmalloc(sizeof(*bus_entry), GFP_KERNEL);
468 sd = kmalloc(sizeof(*sd), GFP_KERNEL);
469 if (!bus_entry || !sd) {
470 err = -ENOMEM;
471 goto err_out;
472 }
473 pcifront_init_sd(sd, domain, bus, pdev);
474
a83919e0
RW		 475 pci_lock_rescan_remove();
476
956a9202
RW		 477 b = pci_scan_bus_parented(&pdev->xdev->dev, bus,
478 &pcifront_bus_ops, sd);
479 if (!b) {
480 dev_err(&pdev->xdev->dev,
481 "Error creating PCI Frontend Bus!\n");
482 err = -ENOMEM;
a83919e0 483 pci_unlock_rescan_remove();
956a9202
RW		 484 goto err_out;
485 }
486
487 bus_entry->bus = b;
488
489 list_add(&bus_entry->list, &pdev->root_buses);
490
491 /* pci_scan_bus_parented skips devices which do not have a have
492 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
493 err = pcifront_scan_bus(pdev, domain, bus, b);
494
495 /* Claim resources before going "live" with our devices */
496 pci_walk_bus(b, pcifront_claim_resource, pdev);
497
498 /* Create SysFS and notify udev of the devices. Aka: "going live" */
499 pci_bus_add_devices(b);
500
a83919e0 501 pci_unlock_rescan_remove();
956a9202
RW		 502 return err;
503
504err_out:
505 kfree(bus_entry);
506 kfree(sd);
507
508 return err;
509}
510
15856ad5 511static int pcifront_rescan_root(struct pcifront_device *pdev,
956a9202
RW		 512 unsigned int domain, unsigned int bus)
513{
514 int err;
515 struct pci_bus *b;
516
517#ifndef CONFIG_PCI_DOMAINS
518 if (domain != 0) {
519 dev_err(&pdev->xdev->dev,
520 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
521 dev_err(&pdev->xdev->dev,
522 "Please compile with CONFIG_PCI_DOMAINS\n");
523 return -EINVAL;
524 }
525#endif
526
527 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
528 domain, bus);
529
530 b = pci_find_bus(domain, bus);
531 if (!b)
532 /* If the bus is unknown, create it. */
533 return pcifront_scan_root(pdev, domain, bus);
534
535 err = pcifront_scan_bus(pdev, domain, bus, b);
536
537 /* Claim resources before going "live" with our devices */
538 pci_walk_bus(b, pcifront_claim_resource, pdev);
539
540 /* Create SysFS and notify udev of the devices. Aka: "going live" */
541 pci_bus_add_devices(b);
542
543 return err;
544}
545
546static void free_root_bus_devs(struct pci_bus *bus)
547{
548 struct pci_dev *dev;
549
550 while (!list_empty(&bus->devices)) {
551 dev = container_of(bus->devices.next, struct pci_dev,
552 bus_list);
553 dev_dbg(&dev->dev, "removing device\n");
210647af 554 pci_stop_and_remove_bus_device(dev);
956a9202
RW		 555 }
556}
557
558static void pcifront_free_roots(struct pcifront_device *pdev)
559{
560 struct pci_bus_entry *bus_entry, *t;
561
562 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
563
a83919e0 564 pci_lock_rescan_remove();
956a9202
RW		 565 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
566 list_del(&bus_entry->list);
567
568 free_root_bus_devs(bus_entry->bus);
569
570 kfree(bus_entry->bus->sysdata);
571
572 device_unregister(bus_entry->bus->bridge);
573 pci_remove_bus(bus_entry->bus);
574
575 kfree(bus_entry);
576 }
a83919e0 577 pci_unlock_rescan_remove();
956a9202
RW		 578}
579
580static pci_ers_result_t pcifront_common_process(int cmd,
581 struct pcifront_device *pdev,
582 pci_channel_state_t state)
583{
584 pci_ers_result_t result;
585 struct pci_driver *pdrv;
586 int bus = pdev->sh_info->aer_op.bus;
587 int devfn = pdev->sh_info->aer_op.devfn;
588 struct pci_dev *pcidev;
589 int flag = 0;
590
591 dev_dbg(&pdev->xdev->dev,
592 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
593 cmd, bus, devfn);
594 result = PCI_ERS_RESULT_NONE;
595
596 pcidev = pci_get_bus_and_slot(bus, devfn);
597 if (!pcidev || !pcidev->driver) {
2a63dd72
JS		 598 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
599 if (pcidev)
600 pci_dev_put(pcidev);
956a9202
RW		 601 return result;
602 }
603 pdrv = pcidev->driver;
604
07d25146 605 if (pdrv) {
956a9202
RW		 606 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
607 dev_dbg(&pcidev->dev,
608 "trying to call AER service\n");
609 if (pcidev) {
610 flag = 1;
611 switch (cmd) {
612 case XEN_PCI_OP_aer_detected:
613 result = pdrv->err_handler->
614 error_detected(pcidev, state);
615 break;
616 case XEN_PCI_OP_aer_mmio:
617 result = pdrv->err_handler->
618 mmio_enabled(pcidev);
619 break;
620 case XEN_PCI_OP_aer_slotreset:
621 result = pdrv->err_handler->
622 slot_reset(pcidev);
623 break;
624 case XEN_PCI_OP_aer_resume:
625 pdrv->err_handler->resume(pcidev);
626 break;
627 default:
628 dev_err(&pdev->xdev->dev,
629 "bad request in aer recovery "
630 "operation!\n");
631
632 }
633 }
634 }
956a9202
RW		 635 }
636 if (!flag)
637 result = PCI_ERS_RESULT_NONE;
638
639 return result;
640}
641
642
643static void pcifront_do_aer(struct work_struct *data)
644{
645 struct pcifront_device *pdev =
646 container_of(data, struct pcifront_device, op_work);
647 int cmd = pdev->sh_info->aer_op.cmd;
648 pci_channel_state_t state =
649 (pci_channel_state_t)pdev->sh_info->aer_op.err;
650
651 /*If a pci_conf op is in progress,
652 we have to wait until it is done before service aer op*/
653 dev_dbg(&pdev->xdev->dev,
654 "pcifront service aer bus %x devfn %x\n",
655 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
656
657 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
658
659 /* Post the operation to the guest. */
660 wmb();
661 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
662 notify_remote_via_evtchn(pdev->evtchn);
663
664 /*in case of we lost an aer request in four lines time_window*/
4e857c58 665 smp_mb__before_atomic();
956a9202 666 clear_bit(_PDEVB_op_active, &pdev->flags);
4e857c58 667 smp_mb__after_atomic();
956a9202
RW		 668
669 schedule_pcifront_aer_op(pdev);
670
671}
672
673static irqreturn_t pcifront_handler_aer(int irq, void *dev)
674{
675 struct pcifront_device *pdev = dev;
676 schedule_pcifront_aer_op(pdev);
677 return IRQ_HANDLED;
678}
3d925320 679static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
956a9202
RW		 680{
681 int err = 0;
682
683 spin_lock(&pcifront_dev_lock);
684
685 if (!pcifront_dev) {
686 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
687 pcifront_dev = pdev;
098b1aea 688 } else
956a9202 689 err = -EEXIST;
098b1aea 690
956a9202
RW		 691 spin_unlock(&pcifront_dev_lock);
692
3d925320
KRW		 693 if (!err && !swiotlb_nr_tbl()) {
694 err = pci_xen_swiotlb_init_late();
695 if (err)
696 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
697 }
956a9202
RW		 698 return err;
699}
700
701static void pcifront_disconnect(struct pcifront_device *pdev)
702{
703 spin_lock(&pcifront_dev_lock);
704
705 if (pdev == pcifront_dev) {
706 dev_info(&pdev->xdev->dev,
707 "Disconnecting PCI Frontend Buses\n");
708 pcifront_dev = NULL;
709 }
710
711 spin_unlock(&pcifront_dev_lock);
712}
713static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
714{
715 struct pcifront_device *pdev;
716
717 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
718 if (pdev == NULL)
719 goto out;
720
721 pdev->sh_info =
722 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
723 if (pdev->sh_info == NULL) {
724 kfree(pdev);
725 pdev = NULL;
726 goto out;
727 }
728 pdev->sh_info->flags = 0;
729
730 /*Flag for registering PV AER handler*/
731 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
732
733 dev_set_drvdata(&xdev->dev, pdev);
734 pdev->xdev = xdev;
735
736 INIT_LIST_HEAD(&pdev->root_buses);
737
738 spin_lock_init(&pdev->sh_info_lock);
739
740 pdev->evtchn = INVALID_EVTCHN;
741 pdev->gnt_ref = INVALID_GRANT_REF;
742 pdev->irq = -1;
743
744 INIT_WORK(&pdev->op_work, pcifront_do_aer);
745
746 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
747 pdev, pdev->sh_info);
748out:
749 return pdev;
750}
751
752static void free_pdev(struct pcifront_device *pdev)
753{
754 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
755
756 pcifront_free_roots(pdev);
757
db2e2e6e 758 cancel_work_sync(&pdev->op_work);
956a9202
RW		 759
760 if (pdev->irq >= 0)
761 unbind_from_irqhandler(pdev->irq, pdev);
762
763 if (pdev->evtchn != INVALID_EVTCHN)
764 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
765
766 if (pdev->gnt_ref != INVALID_GRANT_REF)
767 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
768 (unsigned long)pdev->sh_info);
769 else
770 free_page((unsigned long)pdev->sh_info);
771
772 dev_set_drvdata(&pdev->xdev->dev, NULL);
773
774 kfree(pdev);
775}
776
777static int pcifront_publish_info(struct pcifront_device *pdev)
778{
779 int err = 0;
780 struct xenbus_transaction trans;
781
782 err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
783 if (err < 0)
784 goto out;
785
786 pdev->gnt_ref = err;
787
788 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
789 if (err)
790 goto out;
791
792 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
793 0, "pcifront", pdev);
794
795 if (err < 0)
796 return err;
797
798 pdev->irq = err;
799
800do_publish:
801 err = xenbus_transaction_start(&trans);
802 if (err) {
803 xenbus_dev_fatal(pdev->xdev, err,
804 "Error writing configuration for backend "
805 "(start transaction)");
806 goto out;
807 }
808
809 err = xenbus_printf(trans, pdev->xdev->nodename,
810 "pci-op-ref", "%u", pdev->gnt_ref);
811 if (!err)
812 err = xenbus_printf(trans, pdev->xdev->nodename,
813 "event-channel", "%u", pdev->evtchn);
814 if (!err)
815 err = xenbus_printf(trans, pdev->xdev->nodename,
816 "magic", XEN_PCI_MAGIC);
817
818 if (err) {
819 xenbus_transaction_end(trans, 1);
820 xenbus_dev_fatal(pdev->xdev, err,
821 "Error writing configuration for backend");
822 goto out;
823 } else {
824 err = xenbus_transaction_end(trans, 0);
825 if (err == -EAGAIN)
826 goto do_publish;
827 else if (err) {
828 xenbus_dev_fatal(pdev->xdev, err,
829 "Error completing transaction "
830 "for backend");
831 goto out;
832 }
833 }
834
835 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
836
837 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
838
839out:
840 return err;
841}
842
15856ad5 843static int pcifront_try_connect(struct pcifront_device *pdev)
956a9202
RW		 844{
845 int err = -EFAULT;
846 int i, num_roots, len;
847 char str[64];
848 unsigned int domain, bus;
849
850
851 /* Only connect once */
852 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
853 XenbusStateInitialised)
854 goto out;
855
3d925320 856 err = pcifront_connect_and_init_dma(pdev);
098b1aea 857 if (err && err != -EEXIST) {
956a9202 858 xenbus_dev_fatal(pdev->xdev, err,
3d925320 859 "Error setting up PCI Frontend");
956a9202
RW		 860 goto out;
861 }
862
863 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
864 "root_num", "%d", &num_roots);
865 if (err == -ENOENT) {
866 xenbus_dev_error(pdev->xdev, err,
867 "No PCI Roots found, trying 0000:00");
868 err = pcifront_scan_root(pdev, 0, 0);
869 num_roots = 0;
870 } else if (err != 1) {
871 if (err == 0)
872 err = -EINVAL;
873 xenbus_dev_fatal(pdev->xdev, err,
874 "Error reading number of PCI roots");
875 goto out;
876 }
877
878 for (i = 0; i < num_roots; i++) {
879 len = snprintf(str, sizeof(str), "root-%d", i);
880 if (unlikely(len >= (sizeof(str) - 1))) {
881 err = -ENOMEM;
882 goto out;
883 }
884
885 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
886 "%x:%x", &domain, &bus);
887 if (err != 2) {
888 if (err >= 0)
889 err = -EINVAL;
890 xenbus_dev_fatal(pdev->xdev, err,
891 "Error reading PCI root %d", i);
892 goto out;
893 }
894
895 err = pcifront_scan_root(pdev, domain, bus);
896 if (err) {
897 xenbus_dev_fatal(pdev->xdev, err,
898 "Error scanning PCI root %04x:%02x",
899 domain, bus);
900 goto out;
901 }
902 }
903
904 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
905
906out:
907 return err;
908}
909
910static int pcifront_try_disconnect(struct pcifront_device *pdev)
911{
912 int err = 0;
913 enum xenbus_state prev_state;
914
915
916 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
917
918 if (prev_state >= XenbusStateClosing)
919 goto out;
920
921 if (prev_state == XenbusStateConnected) {
922 pcifront_free_roots(pdev);
923 pcifront_disconnect(pdev);
924 }
925
926 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
927
928out:
929
930 return err;
931}
932
15856ad5 933static int pcifront_attach_devices(struct pcifront_device *pdev)
956a9202
RW		 934{
935 int err = -EFAULT;
936 int i, num_roots, len;
937 unsigned int domain, bus;
938 char str[64];
939
940 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
941 XenbusStateReconfiguring)
942 goto out;
943
944 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
945 "root_num", "%d", &num_roots);
946 if (err == -ENOENT) {
947 xenbus_dev_error(pdev->xdev, err,
948 "No PCI Roots found, trying 0000:00");
949 err = pcifront_rescan_root(pdev, 0, 0);
950 num_roots = 0;
951 } else if (err != 1) {
952 if (err == 0)
953 err = -EINVAL;
954 xenbus_dev_fatal(pdev->xdev, err,
955 "Error reading number of PCI roots");
956 goto out;
957 }
958
959 for (i = 0; i < num_roots; i++) {
960 len = snprintf(str, sizeof(str), "root-%d", i);
961 if (unlikely(len >= (sizeof(str) - 1))) {
962 err = -ENOMEM;
963 goto out;
964 }
965
966 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
967 "%x:%x", &domain, &bus);
968 if (err != 2) {
969 if (err >= 0)
970 err = -EINVAL;
971 xenbus_dev_fatal(pdev->xdev, err,
972 "Error reading PCI root %d", i);
973 goto out;
974 }
975
976 err = pcifront_rescan_root(pdev, domain, bus);
977 if (err) {
978 xenbus_dev_fatal(pdev->xdev, err,
979 "Error scanning PCI root %04x:%02x",
980 domain, bus);
981 goto out;
982 }
983 }
984
985 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
986
987out:
988 return err;
989}
990
991static int pcifront_detach_devices(struct pcifront_device *pdev)
992{
993 int err = 0;
994 int i, num_devs;
995 unsigned int domain, bus, slot, func;
956a9202
RW		 996 struct pci_dev *pci_dev;
997 char str[64];
998
999 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
1000 XenbusStateConnected)
1001 goto out;
1002
1003 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
1004 &num_devs);
1005 if (err != 1) {
1006 if (err >= 0)
1007 err = -EINVAL;
1008 xenbus_dev_fatal(pdev->xdev, err,
1009 "Error reading number of PCI devices");
1010 goto out;
1011 }
1012
1013 /* Find devices being detached and remove them. */
1014 for (i = 0; i < num_devs; i++) {
1015 int l, state;
1016 l = snprintf(str, sizeof(str), "state-%d", i);
1017 if (unlikely(l >= (sizeof(str) - 1))) {
1018 err = -ENOMEM;
1019 goto out;
1020 }
1021 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d",
1022 &state);
1023 if (err != 1)
1024 state = XenbusStateUnknown;
1025
1026 if (state != XenbusStateClosing)
1027 continue;
1028
1029 /* Remove device. */
1030 l = snprintf(str, sizeof(str), "vdev-%d", i);
1031 if (unlikely(l >= (sizeof(str) - 1))) {
1032 err = -ENOMEM;
1033 goto out;
1034 }
1035 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1036 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1037 if (err != 4) {
1038 if (err >= 0)
1039 err = -EINVAL;
1040 xenbus_dev_fatal(pdev->xdev, err,
1041 "Error reading PCI device %d", i);
1042 goto out;
1043 }
1044
2ccc246d
JL		 1045 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
1046 PCI_DEVFN(slot, func));
956a9202
RW		 1047 if (!pci_dev) {
1048 dev_dbg(&pdev->xdev->dev,
e4de866a 1049 "Cannot get PCI device %04x:%02x:%02x.%d\n",
956a9202
RW		 1050 domain, bus, slot, func);
1051 continue;
1052 }
a83919e0 1053 pci_lock_rescan_remove();
210647af 1054 pci_stop_and_remove_bus_device(pci_dev);
956a9202 1055 pci_dev_put(pci_dev);
a83919e0 1056 pci_unlock_rescan_remove();
956a9202
RW		 1057
1058 dev_dbg(&pdev->xdev->dev,
e4de866a 1059 "PCI device %04x:%02x:%02x.%d removed.\n",
956a9202
RW		 1060 domain, bus, slot, func);
1061 }
1062
1063 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1064
1065out:
1066 return err;
1067}
1068
1069static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev,
1070 enum xenbus_state be_state)
1071{
1072 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1073
1074 switch (be_state) {
1075 case XenbusStateUnknown:
1076 case XenbusStateInitialising:
1077 case XenbusStateInitWait:
1078 case XenbusStateInitialised:
956a9202
RW		 1079 break;
1080
1081 case XenbusStateConnected:
1082 pcifront_try_connect(pdev);
1083 break;
1084
d5af64de
DV		 1085 case XenbusStateClosed:
1086 if (xdev->state == XenbusStateClosed)
1087 break;
1088 /* Missed the backend's CLOSING state -- fallthrough */
956a9202
RW		 1089 case XenbusStateClosing:
1090 dev_warn(&xdev->dev, "backend going away!\n");
1091 pcifront_try_disconnect(pdev);
1092 break;
1093
1094 case XenbusStateReconfiguring:
1095 pcifront_detach_devices(pdev);
1096 break;
1097
1098 case XenbusStateReconfigured:
1099 pcifront_attach_devices(pdev);
1100 break;
1101 }
1102}
1103
1104static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1105 const struct xenbus_device_id *id)
1106{
1107 int err = 0;
1108 struct pcifront_device *pdev = alloc_pdev(xdev);
1109
1110 if (pdev == NULL) {
1111 err = -ENOMEM;
1112 xenbus_dev_fatal(xdev, err,
1113 "Error allocating pcifront_device struct");
1114 goto out;
1115 }
1116
1117 err = pcifront_publish_info(pdev);
1118 if (err)
1119 free_pdev(pdev);
1120
1121out:
1122 return err;
1123}
1124
1125static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1126{
1127 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1128 if (pdev)
1129 free_pdev(pdev);
1130
1131 return 0;
1132}
1133
1134static const struct xenbus_device_id xenpci_ids[] = {
1135 {"pci"},
1136 {""},
1137};
1138
95afae48
DV		 1139static struct xenbus_driver xenpci_driver = {
1140 .name = "pcifront",
1141 .ids = xenpci_ids,
956a9202
RW		 1142 .probe = pcifront_xenbus_probe,
1143 .remove = pcifront_xenbus_remove,
1144 .otherend_changed = pcifront_backend_changed,
95afae48 1145};
956a9202
RW		 1146
1147static int __init pcifront_init(void)
1148{
1149 if (!xen_pv_domain() || xen_initial_domain())
1150 return -ENODEV;
1151
51c71a3b
KRW		 1152 if (!xen_has_pv_devices())
1153 return -ENODEV;
1154
956a9202
RW		 1155 pci_frontend_registrar(1 /* enable */);
1156
73db144b 1157 return xenbus_register_frontend(&xenpci_driver);
956a9202
RW		 1158}
1159
1160static void __exit pcifront_cleanup(void)
1161{
73db144b 1162 xenbus_unregister_driver(&xenpci_driver);
956a9202
RW		 1163 pci_frontend_registrar(0 /* disable */);
1164}
1165module_init(pcifront_init);
1166module_exit(pcifront_cleanup);
1167
1168MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1169MODULE_LICENSE("GPL");
1170MODULE_ALIAS("xen:pci");
Linux 6.x block layer and io_uring tree(s)