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PCI: Add SPDX GPL-2.0 when no license was specified
[linux-block.git] / drivers / pci / xen-pcifront.c
CommitLineData
7328c8f4 1// SPDX-License-Identifier: GPL-2.0
956a9202
RW		 2/*
3 * Xen PCI Frontend.
4 *
5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
6 */
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/mm.h>
10#include <xen/xenbus.h>
11#include <xen/events.h>
12#include <xen/grant_table.h>
13#include <xen/page.h>
14#include <linux/spinlock.h>
15#include <linux/pci.h>
16#include <linux/msi.h>
956a9202
RW		 17#include <xen/interface/io/pciif.h>
18#include <asm/xen/pci.h>
19#include <linux/interrupt.h>
60063497 20#include <linux/atomic.h>
956a9202
RW		 21#include <linux/workqueue.h>
22#include <linux/bitops.h>
23#include <linux/time.h>
e1d5bbcd 24#include <linux/ktime.h>
51c71a3b 25#include <xen/platform_pci.h>
956a9202 26
3d925320 27#include <asm/xen/swiotlb-xen.h>
956a9202
RW		 28#define INVALID_GRANT_REF (0)
29#define INVALID_EVTCHN (-1)
30
31struct pci_bus_entry {
32 struct list_head list;
33 struct pci_bus *bus;
34};
35
36#define _PDEVB_op_active (0)
37#define PDEVB_op_active (1 << (_PDEVB_op_active))
38
39struct pcifront_device {
40 struct xenbus_device *xdev;
41 struct list_head root_buses;
42
43 int evtchn;
44 int gnt_ref;
45
46 int irq;
47
48 /* Lock this when doing any operations in sh_info */
49 spinlock_t sh_info_lock;
50 struct xen_pci_sharedinfo *sh_info;
51 struct work_struct op_work;
52 unsigned long flags;
53
54};
55
56struct pcifront_sd {
4d8c8bd6 57 struct pci_sysdata sd;
956a9202
RW		 58 struct pcifront_device *pdev;
59};
60
61static inline struct pcifront_device *
62pcifront_get_pdev(struct pcifront_sd *sd)
63{
64 return sd->pdev;
65}
66
67static inline void pcifront_init_sd(struct pcifront_sd *sd,
68 unsigned int domain, unsigned int bus,
69 struct pcifront_device *pdev)
70{
4d8c8bd6
KRW		 71 /* Because we do not expose that information via XenBus. */
72 sd->sd.node = first_online_node;
73 sd->sd.domain = domain;
956a9202
RW		 74 sd->pdev = pdev;
75}
76
77static DEFINE_SPINLOCK(pcifront_dev_lock);
78static struct pcifront_device *pcifront_dev;
79
80static int verbose_request;
81module_param(verbose_request, int, 0644);
82
83static int errno_to_pcibios_err(int errno)
84{
85 switch (errno) {
86 case XEN_PCI_ERR_success:
87 return PCIBIOS_SUCCESSFUL;
88
89 case XEN_PCI_ERR_dev_not_found:
90 return PCIBIOS_DEVICE_NOT_FOUND;
91
92 case XEN_PCI_ERR_invalid_offset:
93 case XEN_PCI_ERR_op_failed:
94 return PCIBIOS_BAD_REGISTER_NUMBER;
95
96 case XEN_PCI_ERR_not_implemented:
97 return PCIBIOS_FUNC_NOT_SUPPORTED;
98
99 case XEN_PCI_ERR_access_denied:
100 return PCIBIOS_SET_FAILED;
101 }
102 return errno;
103}
104
105static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
106{
107 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
108 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
109 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
110 schedule_work(&pdev->op_work);
111 }
112}
113
114static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
115{
116 int err = 0;
117 struct xen_pci_op *active_op = &pdev->sh_info->op;
118 unsigned long irq_flags;
119 evtchn_port_t port = pdev->evtchn;
120 unsigned irq = pdev->irq;
121 s64 ns, ns_timeout;
956a9202
RW		 122
123 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
124
125 memcpy(active_op, op, sizeof(struct xen_pci_op));
126
127 /* Go */
128 wmb();
129 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
130 notify_remote_via_evtchn(port);
131
132 /*
133 * We set a poll timeout of 3 seconds but give up on return after
134 * 2 seconds. It is better to time out too late rather than too early
135 * (in the latter case we end up continually re-executing poll() with a
136 * timeout in the past). 1s difference gives plenty of slack for error.
137 */
e1d5bbcd 138 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC;
956a9202
RW		 139
140 xen_clear_irq_pending(irq);
141
142 while (test_bit(_XEN_PCIF_active,
143 (unsigned long *)&pdev->sh_info->flags)) {
144 xen_poll_irq_timeout(irq, jiffies + 3*HZ);
145 xen_clear_irq_pending(irq);
e1d5bbcd 146 ns = ktime_get_ns();
956a9202
RW		 147 if (ns > ns_timeout) {
148 dev_err(&pdev->xdev->dev,
149 "pciback not responding!!!\n");
150 clear_bit(_XEN_PCIF_active,
151 (unsigned long *)&pdev->sh_info->flags);
152 err = XEN_PCI_ERR_dev_not_found;
153 goto out;
154 }
155 }
156
157 /*
158 * We might lose backend service request since we
159 * reuse same evtchn with pci_conf backend response. So re-schedule
160 * aer pcifront service.
161 */
162 if (test_bit(_XEN_PCIB_active,
163 (unsigned long *)&pdev->sh_info->flags)) {
164 dev_err(&pdev->xdev->dev,
165 "schedule aer pcifront service\n");
166 schedule_pcifront_aer_op(pdev);
167 }
168
169 memcpy(op, active_op, sizeof(struct xen_pci_op));
170
171 err = op->err;
172out:
173 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
174 return err;
175}
176
177/* Access to this function is spinlocked in drivers/pci/access.c */
178static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
179 int where, int size, u32 *val)
180{
181 int err = 0;
182 struct xen_pci_op op = {
183 .cmd = XEN_PCI_OP_conf_read,
184 .domain = pci_domain_nr(bus),
185 .bus = bus->number,
186 .devfn = devfn,
187 .offset = where,
188 .size = size,
189 };
190 struct pcifront_sd *sd = bus->sysdata;
191 struct pcifront_device *pdev = pcifront_get_pdev(sd);
192
193 if (verbose_request)
194 dev_info(&pdev->xdev->dev,
e4de866a 195 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
956a9202
RW		 196 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
197 PCI_FUNC(devfn), where, size);
198
199 err = do_pci_op(pdev, &op);
200
201 if (likely(!err)) {
202 if (verbose_request)
203 dev_info(&pdev->xdev->dev, "read got back value %x\n",
204 op.value);
205
206 *val = op.value;
207 } else if (err == -ENODEV) {
208 /* No device here, pretend that it just returned 0 */
209 err = 0;
210 *val = 0;
211 }
212
213 return errno_to_pcibios_err(err);
214}
215
216/* Access to this function is spinlocked in drivers/pci/access.c */
217static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
218 int where, int size, u32 val)
219{
220 struct xen_pci_op op = {
221 .cmd = XEN_PCI_OP_conf_write,
222 .domain = pci_domain_nr(bus),
223 .bus = bus->number,
224 .devfn = devfn,
225 .offset = where,
226 .size = size,
227 .value = val,
228 };
229 struct pcifront_sd *sd = bus->sysdata;
230 struct pcifront_device *pdev = pcifront_get_pdev(sd);
231
232 if (verbose_request)
233 dev_info(&pdev->xdev->dev,
e4de866a 234 "write dev=%04x:%02x:%02x.%d - "
956a9202
RW		 235 "offset %x size %d val %x\n",
236 pci_domain_nr(bus), bus->number,
237 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
238
239 return errno_to_pcibios_err(do_pci_op(pdev, &op));
240}
241
b8b0f559 242static struct pci_ops pcifront_bus_ops = {
956a9202
RW		 243 .read = pcifront_bus_read,
244 .write = pcifront_bus_write,
245};
246
247#ifdef CONFIG_PCI_MSI
248static int pci_frontend_enable_msix(struct pci_dev *dev,
cc0f89c4 249 int vector[], int nvec)
956a9202
RW		 250{
251 int err;
252 int i;
253 struct xen_pci_op op = {
254 .cmd = XEN_PCI_OP_enable_msix,
255 .domain = pci_domain_nr(dev->bus),
256 .bus = dev->bus->number,
257 .devfn = dev->devfn,
258 .value = nvec,
259 };
260 struct pcifront_sd *sd = dev->bus->sysdata;
261 struct pcifront_device *pdev = pcifront_get_pdev(sd);
262 struct msi_desc *entry;
263
264 if (nvec > SH_INFO_MAX_VEC) {
265 dev_err(&dev->dev, "too much vector for pci frontend: %x."
266 " Increase SH_INFO_MAX_VEC.\n", nvec);
267 return -EINVAL;
268 }
269
270 i = 0;
5004e98a 271 for_each_pci_msi_entry(entry, dev) {
956a9202
RW		 272 op.msix_entries[i].entry = entry->msi_attrib.entry_nr;
273 /* Vector is useless at this point. */
274 op.msix_entries[i].vector = -1;
275 i++;
276 }
277
278 err = do_pci_op(pdev, &op);
279
280 if (likely(!err)) {
281 if (likely(!op.value)) {
282 /* we get the result */
1d461052
KRW		 283 for (i = 0; i < nvec; i++) {
284 if (op.msix_entries[i].vector <= 0) {
285 dev_warn(&dev->dev, "MSI-X entry %d is invalid: %d!\n",
286 i, op.msix_entries[i].vector);
287 err = -EINVAL;
cc0f89c4 288 vector[i] = -1;
1d461052
KRW		 289 continue;
290 }
cc0f89c4 291 vector[i] = op.msix_entries[i].vector;
1d461052 292 }
956a9202
RW		 293 } else {
294 printk(KERN_DEBUG "enable msix get value %x\n",
295 op.value);
f09d8432 296 err = op.value;
956a9202
RW		 297 }
298 } else {
299 dev_err(&dev->dev, "enable msix get err %x\n", err);
956a9202 300 }
1d461052 301 return err;
956a9202
RW		 302}
303
304static void pci_frontend_disable_msix(struct pci_dev *dev)
305{
306 int err;
307 struct xen_pci_op op = {
308 .cmd = XEN_PCI_OP_disable_msix,
309 .domain = pci_domain_nr(dev->bus),
310 .bus = dev->bus->number,
311 .devfn = dev->devfn,
312 };
313 struct pcifront_sd *sd = dev->bus->sysdata;
314 struct pcifront_device *pdev = pcifront_get_pdev(sd);
315
316 err = do_pci_op(pdev, &op);
317
318 /* What should do for error ? */
319 if (err)
320 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err);
321}
322
cc0f89c4 323static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
956a9202
RW		 324{
325 int err;
326 struct xen_pci_op op = {
327 .cmd = XEN_PCI_OP_enable_msi,
328 .domain = pci_domain_nr(dev->bus),
329 .bus = dev->bus->number,
330 .devfn = dev->devfn,
331 };
332 struct pcifront_sd *sd = dev->bus->sysdata;
333 struct pcifront_device *pdev = pcifront_get_pdev(sd);
334
335 err = do_pci_op(pdev, &op);
336 if (likely(!err)) {
cc0f89c4 337 vector[0] = op.value;
1d461052
KRW		 338 if (op.value <= 0) {
339 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
340 op.value);
341 err = -EINVAL;
cc0f89c4 342 vector[0] = -1;
1d461052 343 }
956a9202
RW		 344 } else {
345 dev_err(&dev->dev, "pci frontend enable msi failed for dev "
346 "%x:%x\n", op.bus, op.devfn);
347 err = -EINVAL;
348 }
349 return err;
350}
351
352static void pci_frontend_disable_msi(struct pci_dev *dev)
353{
354 int err;
355 struct xen_pci_op op = {
356 .cmd = XEN_PCI_OP_disable_msi,
357 .domain = pci_domain_nr(dev->bus),
358 .bus = dev->bus->number,
359 .devfn = dev->devfn,
360 };
361 struct pcifront_sd *sd = dev->bus->sysdata;
362 struct pcifront_device *pdev = pcifront_get_pdev(sd);
363
364 err = do_pci_op(pdev, &op);
365 if (err == XEN_PCI_ERR_dev_not_found) {
366 /* XXX No response from backend, what shall we do? */
367 printk(KERN_DEBUG "get no response from backend for disable MSI\n");
368 return;
369 }
370 if (err)
371 /* how can pciback notify us fail? */
372 printk(KERN_DEBUG "get fake response frombackend\n");
373}
374
375static struct xen_pci_frontend_ops pci_frontend_ops = {
376 .enable_msi = pci_frontend_enable_msi,
377 .disable_msi = pci_frontend_disable_msi,
378 .enable_msix = pci_frontend_enable_msix,
379 .disable_msix = pci_frontend_disable_msix,
380};
381
382static void pci_frontend_registrar(int enable)
383{
384 if (enable)
385 xen_pci_frontend = &pci_frontend_ops;
386 else
387 xen_pci_frontend = NULL;
388};
389#else
390static inline void pci_frontend_registrar(int enable) { };
391#endif /* CONFIG_PCI_MSI */
392
393/* Claim resources for the PCI frontend as-is, backend won't allow changes */
394static int pcifront_claim_resource(struct pci_dev *dev, void *data)
395{
396 struct pcifront_device *pdev = data;
397 int i;
398 struct resource *r;
399
400 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
401 r = &dev->resource[i];
402
403 if (!r->parent && r->start && r->flags) {
404 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
405 pci_name(dev), i);
406 if (pci_claim_resource(dev, i)) {
917e3e65
KRW		 407 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
408 "Device offline. Try using e820_host=1 in the guest config.\n",
956a9202
RW		 409 pci_name(dev), i);
410 }
411 }
412 }
413
414 return 0;
415}
416
15856ad5 417static int pcifront_scan_bus(struct pcifront_device *pdev,
956a9202
RW		 418 unsigned int domain, unsigned int bus,
419 struct pci_bus *b)
420{
421 struct pci_dev *d;
422 unsigned int devfn;
423
424 /* Scan the bus for functions and add.
425 * We omit handling of PCI bridge attachment because pciback prevents
426 * bridges from being exported.
427 */
428 for (devfn = 0; devfn < 0x100; devfn++) {
429 d = pci_get_slot(b, devfn);
430 if (d) {
431 /* Device is already known. */
432 pci_dev_put(d);
433 continue;
434 }
435
436 d = pci_scan_single_device(b, devfn);
437 if (d)
438 dev_info(&pdev->xdev->dev, "New device on "
e4de866a 439 "%04x:%02x:%02x.%d found.\n", domain, bus,
956a9202
RW		 440 PCI_SLOT(devfn), PCI_FUNC(devfn));
441 }
442
443 return 0;
444}
445
15856ad5 446static int pcifront_scan_root(struct pcifront_device *pdev,
956a9202
RW		 447 unsigned int domain, unsigned int bus)
448{
449 struct pci_bus *b;
515d425b 450 LIST_HEAD(resources);
956a9202
RW		 451 struct pcifront_sd *sd = NULL;
452 struct pci_bus_entry *bus_entry = NULL;
453 int err = 0;
515d425b
AB		 454 static struct resource busn_res = {
455 .start = 0,
456 .end = 255,
457 .flags = IORESOURCE_BUS,
458 };
956a9202
RW		 459
460#ifndef CONFIG_PCI_DOMAINS
461 if (domain != 0) {
462 dev_err(&pdev->xdev->dev,
463 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
464 dev_err(&pdev->xdev->dev,
465 "Please compile with CONFIG_PCI_DOMAINS\n");
466 err = -EINVAL;
467 goto err_out;
468 }
469#endif
470
471 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
472 domain, bus);
473
4d8c8bd6
KRW		 474 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
475 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
956a9202
RW		 476 if (!bus_entry || !sd) {
477 err = -ENOMEM;
478 goto err_out;
479 }
515d425b
AB		 480 pci_add_resource(&resources, &ioport_resource);
481 pci_add_resource(&resources, &iomem_resource);
482 pci_add_resource(&resources, &busn_res);
956a9202
RW		 483 pcifront_init_sd(sd, domain, bus, pdev);
484
a83919e0
RW		 485 pci_lock_rescan_remove();
486
515d425b
AB		 487 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
488 &pcifront_bus_ops, sd, &resources);
956a9202
RW		 489 if (!b) {
490 dev_err(&pdev->xdev->dev,
491 "Error creating PCI Frontend Bus!\n");
492 err = -ENOMEM;
a83919e0 493 pci_unlock_rescan_remove();
515d425b 494 pci_free_resource_list(&resources);
956a9202
RW		 495 goto err_out;
496 }
497
498 bus_entry->bus = b;
499
500 list_add(&bus_entry->list, &pdev->root_buses);
501
515d425b 502 /* pci_scan_root_bus skips devices which do not have a
956a9202
RW		 503 * devfn==0. The pcifront_scan_bus enumerates all devfn. */
504 err = pcifront_scan_bus(pdev, domain, bus, b);
505
506 /* Claim resources before going "live" with our devices */
507 pci_walk_bus(b, pcifront_claim_resource, pdev);
508
509 /* Create SysFS and notify udev of the devices. Aka: "going live" */
510 pci_bus_add_devices(b);
511
a83919e0 512 pci_unlock_rescan_remove();
956a9202
RW		 513 return err;
514
515err_out:
516 kfree(bus_entry);
517 kfree(sd);
518
519 return err;
520}
521
15856ad5 522static int pcifront_rescan_root(struct pcifront_device *pdev,
956a9202
RW		 523 unsigned int domain, unsigned int bus)
524{
525 int err;
526 struct pci_bus *b;
527
528#ifndef CONFIG_PCI_DOMAINS
529 if (domain != 0) {
530 dev_err(&pdev->xdev->dev,
531 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
532 dev_err(&pdev->xdev->dev,
533 "Please compile with CONFIG_PCI_DOMAINS\n");
534 return -EINVAL;
535 }
536#endif
537
538 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
539 domain, bus);
540
541 b = pci_find_bus(domain, bus);
542 if (!b)
543 /* If the bus is unknown, create it. */
544 return pcifront_scan_root(pdev, domain, bus);
545
546 err = pcifront_scan_bus(pdev, domain, bus, b);
547
548 /* Claim resources before going "live" with our devices */
549 pci_walk_bus(b, pcifront_claim_resource, pdev);
550
551 /* Create SysFS and notify udev of the devices. Aka: "going live" */
552 pci_bus_add_devices(b);
553
554 return err;
555}
556
557static void free_root_bus_devs(struct pci_bus *bus)
558{
559 struct pci_dev *dev;
560
561 while (!list_empty(&bus->devices)) {
562 dev = container_of(bus->devices.next, struct pci_dev,
563 bus_list);
564 dev_dbg(&dev->dev, "removing device\n");
210647af 565 pci_stop_and_remove_bus_device(dev);
956a9202
RW		 566 }
567}
568
569static void pcifront_free_roots(struct pcifront_device *pdev)
570{
571 struct pci_bus_entry *bus_entry, *t;
572
573 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
574
a83919e0 575 pci_lock_rescan_remove();
956a9202
RW		 576 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
577 list_del(&bus_entry->list);
578
579 free_root_bus_devs(bus_entry->bus);
580
581 kfree(bus_entry->bus->sysdata);
582
583 device_unregister(bus_entry->bus->bridge);
584 pci_remove_bus(bus_entry->bus);
585
586 kfree(bus_entry);
587 }
a83919e0 588 pci_unlock_rescan_remove();
956a9202
RW		 589}
590
591static pci_ers_result_t pcifront_common_process(int cmd,
592 struct pcifront_device *pdev,
593 pci_channel_state_t state)
594{
595 pci_ers_result_t result;
596 struct pci_driver *pdrv;
597 int bus = pdev->sh_info->aer_op.bus;
598 int devfn = pdev->sh_info->aer_op.devfn;
599 struct pci_dev *pcidev;
600 int flag = 0;
601
602 dev_dbg(&pdev->xdev->dev,
603 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
604 cmd, bus, devfn);
605 result = PCI_ERS_RESULT_NONE;
606
607 pcidev = pci_get_bus_and_slot(bus, devfn);
608 if (!pcidev || !pcidev->driver) {
2a63dd72 609 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
ff0387c3 610 pci_dev_put(pcidev);
956a9202
RW		 611 return result;
612 }
613 pdrv = pcidev->driver;
614
07d25146 615 if (pdrv) {
956a9202
RW		 616 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
617 dev_dbg(&pcidev->dev,
618 "trying to call AER service\n");
619 if (pcidev) {
620 flag = 1;
621 switch (cmd) {
622 case XEN_PCI_OP_aer_detected:
623 result = pdrv->err_handler->
624 error_detected(pcidev, state);
625 break;
626 case XEN_PCI_OP_aer_mmio:
627 result = pdrv->err_handler->
628 mmio_enabled(pcidev);
629 break;
630 case XEN_PCI_OP_aer_slotreset:
631 result = pdrv->err_handler->
632 slot_reset(pcidev);
633 break;
634 case XEN_PCI_OP_aer_resume:
635 pdrv->err_handler->resume(pcidev);
636 break;
637 default:
638 dev_err(&pdev->xdev->dev,
639 "bad request in aer recovery "
640 "operation!\n");
641
642 }
643 }
644 }
956a9202
RW		 645 }
646 if (!flag)
647 result = PCI_ERS_RESULT_NONE;
648
649 return result;
650}
651
652
653static void pcifront_do_aer(struct work_struct *data)
654{
655 struct pcifront_device *pdev =
656 container_of(data, struct pcifront_device, op_work);
657 int cmd = pdev->sh_info->aer_op.cmd;
658 pci_channel_state_t state =
659 (pci_channel_state_t)pdev->sh_info->aer_op.err;
660
661 /*If a pci_conf op is in progress,
662 we have to wait until it is done before service aer op*/
663 dev_dbg(&pdev->xdev->dev,
664 "pcifront service aer bus %x devfn %x\n",
665 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
666
667 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
668
669 /* Post the operation to the guest. */
670 wmb();
671 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
672 notify_remote_via_evtchn(pdev->evtchn);
673
674 /*in case of we lost an aer request in four lines time_window*/
4e857c58 675 smp_mb__before_atomic();
956a9202 676 clear_bit(_PDEVB_op_active, &pdev->flags);
4e857c58 677 smp_mb__after_atomic();
956a9202
RW		 678
679 schedule_pcifront_aer_op(pdev);
680
681}
682
683static irqreturn_t pcifront_handler_aer(int irq, void *dev)
684{
685 struct pcifront_device *pdev = dev;
686 schedule_pcifront_aer_op(pdev);
687 return IRQ_HANDLED;
688}
3d925320 689static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
956a9202
RW		 690{
691 int err = 0;
692
693 spin_lock(&pcifront_dev_lock);
694
695 if (!pcifront_dev) {
696 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
697 pcifront_dev = pdev;
098b1aea 698 } else
956a9202 699 err = -EEXIST;
098b1aea 700
956a9202
RW		 701 spin_unlock(&pcifront_dev_lock);
702
3d925320
KRW		 703 if (!err && !swiotlb_nr_tbl()) {
704 err = pci_xen_swiotlb_init_late();
705 if (err)
706 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
707 }
956a9202
RW		 708 return err;
709}
710
711static void pcifront_disconnect(struct pcifront_device *pdev)
712{
713 spin_lock(&pcifront_dev_lock);
714
715 if (pdev == pcifront_dev) {
716 dev_info(&pdev->xdev->dev,
717 "Disconnecting PCI Frontend Buses\n");
718 pcifront_dev = NULL;
719 }
720
721 spin_unlock(&pcifront_dev_lock);
722}
723static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
724{
725 struct pcifront_device *pdev;
726
727 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
728 if (pdev == NULL)
729 goto out;
730
731 pdev->sh_info =
732 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
733 if (pdev->sh_info == NULL) {
734 kfree(pdev);
735 pdev = NULL;
736 goto out;
737 }
738 pdev->sh_info->flags = 0;
739
740 /*Flag for registering PV AER handler*/
741 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
742
743 dev_set_drvdata(&xdev->dev, pdev);
744 pdev->xdev = xdev;
745
746 INIT_LIST_HEAD(&pdev->root_buses);
747
748 spin_lock_init(&pdev->sh_info_lock);
749
750 pdev->evtchn = INVALID_EVTCHN;
751 pdev->gnt_ref = INVALID_GRANT_REF;
752 pdev->irq = -1;
753
754 INIT_WORK(&pdev->op_work, pcifront_do_aer);
755
756 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
757 pdev, pdev->sh_info);
758out:
759 return pdev;
760}
761
762static void free_pdev(struct pcifront_device *pdev)
763{
764 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
765
766 pcifront_free_roots(pdev);
767
db2e2e6e 768 cancel_work_sync(&pdev->op_work);
956a9202
RW		 769
770 if (pdev->irq >= 0)
771 unbind_from_irqhandler(pdev->irq, pdev);
772
773 if (pdev->evtchn != INVALID_EVTCHN)
774 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
775
776 if (pdev->gnt_ref != INVALID_GRANT_REF)
777 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */,
778 (unsigned long)pdev->sh_info);
779 else
780 free_page((unsigned long)pdev->sh_info);
781
782 dev_set_drvdata(&pdev->xdev->dev, NULL);
783
784 kfree(pdev);
785}
786
787static int pcifront_publish_info(struct pcifront_device *pdev)
788{
789 int err = 0;
790 struct xenbus_transaction trans;
ccc9d90a 791 grant_ref_t gref;
956a9202 792
ccc9d90a 793 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
956a9202
RW		 794 if (err < 0)
795 goto out;
796
ccc9d90a 797 pdev->gnt_ref = gref;
956a9202
RW		 798
799 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
800 if (err)
801 goto out;
802
803 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
804 0, "pcifront", pdev);
805
806 if (err < 0)
807 return err;
808
809 pdev->irq = err;
810
811do_publish:
812 err = xenbus_transaction_start(&trans);
813 if (err) {
814 xenbus_dev_fatal(pdev->xdev, err,
815 "Error writing configuration for backend "
816 "(start transaction)");
817 goto out;
818 }
819
820 err = xenbus_printf(trans, pdev->xdev->nodename,
821 "pci-op-ref", "%u", pdev->gnt_ref);
822 if (!err)
823 err = xenbus_printf(trans, pdev->xdev->nodename,
824 "event-channel", "%u", pdev->evtchn);
825 if (!err)
826 err = xenbus_printf(trans, pdev->xdev->nodename,
827 "magic", XEN_PCI_MAGIC);
828
829 if (err) {
830 xenbus_transaction_end(trans, 1);
831 xenbus_dev_fatal(pdev->xdev, err,
832 "Error writing configuration for backend");
833 goto out;
834 } else {
835 err = xenbus_transaction_end(trans, 0);
836 if (err == -EAGAIN)
837 goto do_publish;
838 else if (err) {
839 xenbus_dev_fatal(pdev->xdev, err,
840 "Error completing transaction "
841 "for backend");
842 goto out;
843 }
844 }
845
846 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
847
848 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
849
850out:
851 return err;
852}
853
15856ad5 854static int pcifront_try_connect(struct pcifront_device *pdev)
956a9202
RW		 855{
856 int err = -EFAULT;
857 int i, num_roots, len;
858 char str[64];
859 unsigned int domain, bus;
860
861
862 /* Only connect once */
863 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
864 XenbusStateInitialised)
865 goto out;
866
3d925320 867 err = pcifront_connect_and_init_dma(pdev);
098b1aea 868 if (err && err != -EEXIST) {
956a9202 869 xenbus_dev_fatal(pdev->xdev, err,
3d925320 870 "Error setting up PCI Frontend");
956a9202
RW		 871 goto out;
872 }
873
874 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
875 "root_num", "%d", &num_roots);
876 if (err == -ENOENT) {
877 xenbus_dev_error(pdev->xdev, err,
878 "No PCI Roots found, trying 0000:00");
879 err = pcifront_scan_root(pdev, 0, 0);
23cf1d00
CG		 880 if (err) {
881 xenbus_dev_fatal(pdev->xdev, err,
882 "Error scanning PCI root 0000:00");
883 goto out;
884 }
956a9202
RW		 885 num_roots = 0;
886 } else if (err != 1) {
887 if (err == 0)
888 err = -EINVAL;
889 xenbus_dev_fatal(pdev->xdev, err,
890 "Error reading number of PCI roots");
891 goto out;
892 }
893
894 for (i = 0; i < num_roots; i++) {
895 len = snprintf(str, sizeof(str), "root-%d", i);
896 if (unlikely(len >= (sizeof(str) - 1))) {
897 err = -ENOMEM;
898 goto out;
899 }
900
901 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
902 "%x:%x", &domain, &bus);
903 if (err != 2) {
904 if (err >= 0)
905 err = -EINVAL;
906 xenbus_dev_fatal(pdev->xdev, err,
907 "Error reading PCI root %d", i);
908 goto out;
909 }
910
911 err = pcifront_scan_root(pdev, domain, bus);
912 if (err) {
913 xenbus_dev_fatal(pdev->xdev, err,
914 "Error scanning PCI root %04x:%02x",
915 domain, bus);
916 goto out;
917 }
918 }
919
920 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
921
922out:
923 return err;
924}
925
926static int pcifront_try_disconnect(struct pcifront_device *pdev)
927{
928 int err = 0;
929 enum xenbus_state prev_state;
930
931
932 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
933
934 if (prev_state >= XenbusStateClosing)
935 goto out;
936
937 if (prev_state == XenbusStateConnected) {
938 pcifront_free_roots(pdev);
939 pcifront_disconnect(pdev);
940 }
941
942 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
943
944out:
945
946 return err;
947}
948
15856ad5 949static int pcifront_attach_devices(struct pcifront_device *pdev)
956a9202
RW		 950{
951 int err = -EFAULT;
952 int i, num_roots, len;
953 unsigned int domain, bus;
954 char str[64];
955
956 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
957 XenbusStateReconfiguring)
958 goto out;
959
960 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
961 "root_num", "%d", &num_roots);
962 if (err == -ENOENT) {
963 xenbus_dev_error(pdev->xdev, err,
964 "No PCI Roots found, trying 0000:00");
965 err = pcifront_rescan_root(pdev, 0, 0);
23cf1d00
CG		 966 if (err) {
967 xenbus_dev_fatal(pdev->xdev, err,
968 "Error scanning PCI root 0000:00");
969 goto out;
970 }
956a9202
RW		 971 num_roots = 0;
972 } else if (err != 1) {
973 if (err == 0)
974 err = -EINVAL;
975 xenbus_dev_fatal(pdev->xdev, err,
976 "Error reading number of PCI roots");
977 goto out;
978 }
979
980 for (i = 0; i < num_roots; i++) {
981 len = snprintf(str, sizeof(str), "root-%d", i);
982 if (unlikely(len >= (sizeof(str) - 1))) {
983 err = -ENOMEM;
984 goto out;
985 }
986
987 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
988 "%x:%x", &domain, &bus);
989 if (err != 2) {
990 if (err >= 0)
991 err = -EINVAL;
992 xenbus_dev_fatal(pdev->xdev, err,
993 "Error reading PCI root %d", i);
994 goto out;
995 }
996
997 err = pcifront_rescan_root(pdev, domain, bus);
998 if (err) {
999 xenbus_dev_fatal(pdev->xdev, err,
1000 "Error scanning PCI root %04x:%02x",
1001 domain, bus);
1002 goto out;
1003 }
1004 }
1005
1006 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
1007
1008out:
1009 return err;
1010}
1011
1012static int pcifront_detach_devices(struct pcifront_device *pdev)
1013{
1014 int err = 0;
1015 int i, num_devs;
1016 unsigned int domain, bus, slot, func;
956a9202
RW		 1017 struct pci_dev *pci_dev;
1018 char str[64];
1019
1020 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
1021 XenbusStateConnected)
1022 goto out;
1023
1024 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
1025 &num_devs);
1026 if (err != 1) {
1027 if (err >= 0)
1028 err = -EINVAL;
1029 xenbus_dev_fatal(pdev->xdev, err,
1030 "Error reading number of PCI devices");
1031 goto out;
1032 }
1033
1034 /* Find devices being detached and remove them. */
1035 for (i = 0; i < num_devs; i++) {
1036 int l, state;
1037 l = snprintf(str, sizeof(str), "state-%d", i);
1038 if (unlikely(l >= (sizeof(str) - 1))) {
1039 err = -ENOMEM;
1040 goto out;
1041 }
58faf07b
JG		 1042 state = xenbus_read_unsigned(pdev->xdev->otherend, str,
1043 XenbusStateUnknown);
956a9202
RW		 1044
1045 if (state != XenbusStateClosing)
1046 continue;
1047
1048 /* Remove device. */
1049 l = snprintf(str, sizeof(str), "vdev-%d", i);
1050 if (unlikely(l >= (sizeof(str) - 1))) {
1051 err = -ENOMEM;
1052 goto out;
1053 }
1054 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
1055 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
1056 if (err != 4) {
1057 if (err >= 0)
1058 err = -EINVAL;
1059 xenbus_dev_fatal(pdev->xdev, err,
1060 "Error reading PCI device %d", i);
1061 goto out;
1062 }
1063
2ccc246d
JL		 1064 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
1065 PCI_DEVFN(slot, func));
956a9202
RW		 1066 if (!pci_dev) {
1067 dev_dbg(&pdev->xdev->dev,
e4de866a 1068 "Cannot get PCI device %04x:%02x:%02x.%d\n",
956a9202
RW		 1069 domain, bus, slot, func);
1070 continue;
1071 }
a83919e0 1072 pci_lock_rescan_remove();
210647af 1073 pci_stop_and_remove_bus_device(pci_dev);
956a9202 1074 pci_dev_put(pci_dev);
a83919e0 1075 pci_unlock_rescan_remove();
956a9202
RW		 1076
1077 dev_dbg(&pdev->xdev->dev,
e4de866a 1078 "PCI device %04x:%02x:%02x.%d removed.\n",
956a9202
RW		 1079 domain, bus, slot, func);
1080 }
1081
1082 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1083
1084out:
1085 return err;
1086}
1087
bd721ea7 1088static void __ref pcifront_backend_changed(struct xenbus_device *xdev,
956a9202
RW		 1089 enum xenbus_state be_state)
1090{
1091 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1092
1093 switch (be_state) {
1094 case XenbusStateUnknown:
1095 case XenbusStateInitialising:
1096 case XenbusStateInitWait:
1097 case XenbusStateInitialised:
956a9202
RW		 1098 break;
1099
1100 case XenbusStateConnected:
1101 pcifront_try_connect(pdev);
1102 break;
1103
d5af64de
DV		 1104 case XenbusStateClosed:
1105 if (xdev->state == XenbusStateClosed)
1106 break;
1107 /* Missed the backend's CLOSING state -- fallthrough */
956a9202
RW		 1108 case XenbusStateClosing:
1109 dev_warn(&xdev->dev, "backend going away!\n");
1110 pcifront_try_disconnect(pdev);
1111 break;
1112
1113 case XenbusStateReconfiguring:
1114 pcifront_detach_devices(pdev);
1115 break;
1116
1117 case XenbusStateReconfigured:
1118 pcifront_attach_devices(pdev);
1119 break;
1120 }
1121}
1122
1123static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1124 const struct xenbus_device_id *id)
1125{
1126 int err = 0;
1127 struct pcifront_device *pdev = alloc_pdev(xdev);
1128
1129 if (pdev == NULL) {
1130 err = -ENOMEM;
1131 xenbus_dev_fatal(xdev, err,
1132 "Error allocating pcifront_device struct");
1133 goto out;
1134 }
1135
1136 err = pcifront_publish_info(pdev);
1137 if (err)
1138 free_pdev(pdev);
1139
1140out:
1141 return err;
1142}
1143
1144static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1145{
1146 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1147 if (pdev)
1148 free_pdev(pdev);
1149
1150 return 0;
1151}
1152
1153static const struct xenbus_device_id xenpci_ids[] = {
1154 {"pci"},
1155 {""},
1156};
1157
95afae48
DV		 1158static struct xenbus_driver xenpci_driver = {
1159 .name = "pcifront",
1160 .ids = xenpci_ids,
956a9202
RW		 1161 .probe = pcifront_xenbus_probe,
1162 .remove = pcifront_xenbus_remove,
1163 .otherend_changed = pcifront_backend_changed,
95afae48 1164};
956a9202
RW		 1165
1166static int __init pcifront_init(void)
1167{
1168 if (!xen_pv_domain() || xen_initial_domain())
1169 return -ENODEV;
1170
51c71a3b
KRW		 1171 if (!xen_has_pv_devices())
1172 return -ENODEV;
1173
956a9202
RW		 1174 pci_frontend_registrar(1 /* enable */);
1175
73db144b 1176 return xenbus_register_frontend(&xenpci_driver);
956a9202
RW		 1177}
1178
1179static void __exit pcifront_cleanup(void)
1180{
73db144b 1181 xenbus_unregister_driver(&xenpci_driver);
956a9202
RW		 1182 pci_frontend_registrar(0 /* disable */);
1183}
1184module_init(pcifront_init);
1185module_exit(pcifront_cleanup);
1186
1187MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1188MODULE_LICENSE("GPL");
1189MODULE_ALIAS("xen:pci");
Linux 6.x block layer and io_uring tree(s)