1 // SPDX-License-Identifier: GPL-2.0
5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
7 #include <linux/module.h>
8 #include <linux/init.h>
10 #include <xen/xenbus.h>
11 #include <xen/events.h>
12 #include <xen/grant_table.h>
14 #include <linux/spinlock.h>
15 #include <linux/pci.h>
16 #include <linux/msi.h>
17 #include <xen/interface/io/pciif.h>
18 #include <asm/xen/pci.h>
19 #include <linux/interrupt.h>
20 #include <linux/atomic.h>
21 #include <linux/workqueue.h>
22 #include <linux/bitops.h>
23 #include <linux/time.h>
24 #include <linux/ktime.h>
25 #include <linux/swiotlb.h>
26 #include <xen/platform_pci.h>
28 #include <asm/xen/swiotlb-xen.h>
30 #define INVALID_EVTCHN (-1)
32 struct pci_bus_entry {
33 struct list_head list;
37 #define _PDEVB_op_active (0)
38 #define PDEVB_op_active (1 << (_PDEVB_op_active))
40 struct pcifront_device {
41 struct xenbus_device *xdev;
42 struct list_head root_buses;
49 /* Lock this when doing any operations in sh_info */
50 spinlock_t sh_info_lock;
51 struct xen_pci_sharedinfo *sh_info;
52 struct work_struct op_work;
58 struct pci_sysdata sd;
59 struct pcifront_device *pdev;
62 static inline struct pcifront_device *
63 pcifront_get_pdev(struct pcifront_sd *sd)
68 static inline void pcifront_init_sd(struct pcifront_sd *sd,
69 unsigned int domain, unsigned int bus,
70 struct pcifront_device *pdev)
72 /* Because we do not expose that information via XenBus. */
73 sd->sd.node = first_online_node;
74 sd->sd.domain = domain;
78 static DEFINE_SPINLOCK(pcifront_dev_lock);
79 static struct pcifront_device *pcifront_dev;
81 static int errno_to_pcibios_err(int errno)
84 case XEN_PCI_ERR_success:
85 return PCIBIOS_SUCCESSFUL;
87 case XEN_PCI_ERR_dev_not_found:
88 return PCIBIOS_DEVICE_NOT_FOUND;
90 case XEN_PCI_ERR_invalid_offset:
91 case XEN_PCI_ERR_op_failed:
92 return PCIBIOS_BAD_REGISTER_NUMBER;
94 case XEN_PCI_ERR_not_implemented:
95 return PCIBIOS_FUNC_NOT_SUPPORTED;
97 case XEN_PCI_ERR_access_denied:
98 return PCIBIOS_SET_FAILED;
103 static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev)
105 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
106 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) {
107 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n");
108 schedule_work(&pdev->op_work);
112 static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
115 struct xen_pci_op *active_op = &pdev->sh_info->op;
116 unsigned long irq_flags;
117 evtchn_port_t port = pdev->evtchn;
118 unsigned int irq = pdev->irq;
121 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
123 memcpy(active_op, op, sizeof(struct xen_pci_op));
127 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
128 notify_remote_via_evtchn(port);
131 * We set a poll timeout of 3 seconds but give up on return after
132 * 2 seconds. It is better to time out too late rather than too early
133 * (in the latter case we end up continually re-executing poll() with a
134 * timeout in the past). 1s difference gives plenty of slack for error.
136 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC;
138 xen_clear_irq_pending(irq);
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);
145 if (ns > ns_timeout) {
146 dev_err(&pdev->xdev->dev,
147 "pciback not responding!!!\n");
148 clear_bit(_XEN_PCIF_active,
149 (unsigned long *)&pdev->sh_info->flags);
150 err = XEN_PCI_ERR_dev_not_found;
156 * We might lose backend service request since we
157 * reuse same evtchn with pci_conf backend response. So re-schedule
158 * aer pcifront service.
160 if (test_bit(_XEN_PCIB_active,
161 (unsigned long *)&pdev->sh_info->flags)) {
162 dev_err(&pdev->xdev->dev,
163 "schedule aer pcifront service\n");
164 schedule_pcifront_aer_op(pdev);
167 memcpy(op, active_op, sizeof(struct xen_pci_op));
171 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
175 /* Access to this function is spinlocked in drivers/pci/access.c */
176 static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
177 int where, int size, u32 *val)
180 struct xen_pci_op op = {
181 .cmd = XEN_PCI_OP_conf_read,
182 .domain = pci_domain_nr(bus),
188 struct pcifront_sd *sd = bus->sysdata;
189 struct pcifront_device *pdev = pcifront_get_pdev(sd);
191 dev_dbg(&pdev->xdev->dev,
192 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n",
193 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
194 PCI_FUNC(devfn), where, size);
196 err = do_pci_op(pdev, &op);
199 dev_dbg(&pdev->xdev->dev, "read got back value %x\n",
203 } else if (err == -ENODEV) {
204 /* No device here, pretend that it just returned 0 */
209 return errno_to_pcibios_err(err);
212 /* Access to this function is spinlocked in drivers/pci/access.c */
213 static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
214 int where, int size, u32 val)
216 struct xen_pci_op op = {
217 .cmd = XEN_PCI_OP_conf_write,
218 .domain = pci_domain_nr(bus),
225 struct pcifront_sd *sd = bus->sysdata;
226 struct pcifront_device *pdev = pcifront_get_pdev(sd);
228 dev_dbg(&pdev->xdev->dev,
229 "write dev=%04x:%02x:%02x.%d - offset %x size %d val %x\n",
230 pci_domain_nr(bus), bus->number,
231 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
233 return errno_to_pcibios_err(do_pci_op(pdev, &op));
236 static struct pci_ops pcifront_bus_ops = {
237 .read = pcifront_bus_read,
238 .write = pcifront_bus_write,
241 #ifdef CONFIG_PCI_MSI
242 static int pci_frontend_enable_msix(struct pci_dev *dev,
243 int vector[], int nvec)
247 struct xen_pci_op op = {
248 .cmd = XEN_PCI_OP_enable_msix,
249 .domain = pci_domain_nr(dev->bus),
250 .bus = dev->bus->number,
254 struct pcifront_sd *sd = dev->bus->sysdata;
255 struct pcifront_device *pdev = pcifront_get_pdev(sd);
256 struct msi_desc *entry;
258 if (nvec > SH_INFO_MAX_VEC) {
259 pci_err(dev, "too many vectors (0x%x) for PCI frontend:"
260 " Increase SH_INFO_MAX_VEC\n", nvec);
265 msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) {
266 op.msix_entries[i].entry = entry->msi_index;
267 /* Vector is useless at this point. */
268 op.msix_entries[i].vector = -1;
272 err = do_pci_op(pdev, &op);
275 if (likely(!op.value)) {
276 /* we get the result */
277 for (i = 0; i < nvec; i++) {
278 if (op.msix_entries[i].vector <= 0) {
279 pci_warn(dev, "MSI-X entry %d is invalid: %d!\n",
280 i, op.msix_entries[i].vector);
285 vector[i] = op.msix_entries[i].vector;
288 pr_info("enable msix get value %x\n", op.value);
292 pci_err(dev, "enable msix get err %x\n", err);
297 static void pci_frontend_disable_msix(struct pci_dev *dev)
300 struct xen_pci_op op = {
301 .cmd = XEN_PCI_OP_disable_msix,
302 .domain = pci_domain_nr(dev->bus),
303 .bus = dev->bus->number,
306 struct pcifront_sd *sd = dev->bus->sysdata;
307 struct pcifront_device *pdev = pcifront_get_pdev(sd);
309 err = do_pci_op(pdev, &op);
311 /* What should do for error ? */
313 pci_err(dev, "pci_disable_msix get err %x\n", err);
316 static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
319 struct xen_pci_op op = {
320 .cmd = XEN_PCI_OP_enable_msi,
321 .domain = pci_domain_nr(dev->bus),
322 .bus = dev->bus->number,
325 struct pcifront_sd *sd = dev->bus->sysdata;
326 struct pcifront_device *pdev = pcifront_get_pdev(sd);
328 err = do_pci_op(pdev, &op);
330 vector[0] = op.value;
332 pci_warn(dev, "MSI entry is invalid: %d!\n",
338 pci_err(dev, "pci frontend enable msi failed for dev "
339 "%x:%x\n", op.bus, op.devfn);
345 static void pci_frontend_disable_msi(struct pci_dev *dev)
348 struct xen_pci_op op = {
349 .cmd = XEN_PCI_OP_disable_msi,
350 .domain = pci_domain_nr(dev->bus),
351 .bus = dev->bus->number,
354 struct pcifront_sd *sd = dev->bus->sysdata;
355 struct pcifront_device *pdev = pcifront_get_pdev(sd);
357 err = do_pci_op(pdev, &op);
358 if (err == XEN_PCI_ERR_dev_not_found) {
359 /* XXX No response from backend, what shall we do? */
360 pr_info("get no response from backend for disable MSI\n");
364 /* how can pciback notify us fail? */
365 pr_info("get fake response from backend\n");
368 static struct xen_pci_frontend_ops pci_frontend_ops = {
369 .enable_msi = pci_frontend_enable_msi,
370 .disable_msi = pci_frontend_disable_msi,
371 .enable_msix = pci_frontend_enable_msix,
372 .disable_msix = pci_frontend_disable_msix,
375 static void pci_frontend_registrar(int enable)
378 xen_pci_frontend = &pci_frontend_ops;
380 xen_pci_frontend = NULL;
383 static inline void pci_frontend_registrar(int enable) { };
384 #endif /* CONFIG_PCI_MSI */
386 /* Claim resources for the PCI frontend as-is, backend won't allow changes */
387 static int pcifront_claim_resource(struct pci_dev *dev, void *data)
389 struct pcifront_device *pdev = data;
393 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
394 r = &dev->resource[i];
396 if (!r->parent && r->start && r->flags) {
397 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n",
399 if (pci_claim_resource(dev, i)) {
400 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! "
401 "Device offline. Try using e820_host=1 in the guest config.\n",
410 static int pcifront_scan_bus(struct pcifront_device *pdev,
411 unsigned int domain, unsigned int bus,
418 * Scan the bus for functions and add.
419 * We omit handling of PCI bridge attachment because pciback prevents
420 * bridges from being exported.
422 for (devfn = 0; devfn < 0x100; devfn++) {
423 d = pci_get_slot(b, devfn);
425 /* Device is already known. */
430 d = pci_scan_single_device(b, devfn);
432 dev_info(&pdev->xdev->dev, "New device on "
433 "%04x:%02x:%02x.%d found.\n", domain, bus,
434 PCI_SLOT(devfn), PCI_FUNC(devfn));
440 static int pcifront_scan_root(struct pcifront_device *pdev,
441 unsigned int domain, unsigned int bus)
444 LIST_HEAD(resources);
445 struct pcifront_sd *sd = NULL;
446 struct pci_bus_entry *bus_entry = NULL;
448 static struct resource busn_res = {
451 .flags = IORESOURCE_BUS,
454 #ifndef CONFIG_PCI_DOMAINS
456 dev_err(&pdev->xdev->dev,
457 "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
458 dev_err(&pdev->xdev->dev,
459 "Please compile with CONFIG_PCI_DOMAINS\n");
465 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
468 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
469 sd = kzalloc(sizeof(*sd), GFP_KERNEL);
470 if (!bus_entry || !sd) {
474 pci_add_resource(&resources, &ioport_resource);
475 pci_add_resource(&resources, &iomem_resource);
476 pci_add_resource(&resources, &busn_res);
477 pcifront_init_sd(sd, domain, bus, pdev);
479 pci_lock_rescan_remove();
481 b = pci_scan_root_bus(&pdev->xdev->dev, bus,
482 &pcifront_bus_ops, sd, &resources);
484 dev_err(&pdev->xdev->dev,
485 "Error creating PCI Frontend Bus!\n");
487 pci_unlock_rescan_remove();
488 pci_free_resource_list(&resources);
494 list_add(&bus_entry->list, &pdev->root_buses);
497 * pci_scan_root_bus skips devices which do not have a
498 * devfn==0. The pcifront_scan_bus enumerates all devfn.
500 err = pcifront_scan_bus(pdev, domain, bus, b);
502 /* Claim resources before going "live" with our devices */
503 pci_walk_bus(b, pcifront_claim_resource, pdev);
505 /* Create SysFS and notify udev of the devices. Aka: "going live" */
506 pci_bus_add_devices(b);
508 pci_unlock_rescan_remove();
518 static int pcifront_rescan_root(struct pcifront_device *pdev,
519 unsigned int domain, unsigned int bus)
524 b = pci_find_bus(domain, bus);
526 /* If the bus is unknown, create it. */
527 return pcifront_scan_root(pdev, domain, bus);
529 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n",
532 err = pcifront_scan_bus(pdev, domain, bus, b);
534 /* Claim resources before going "live" with our devices */
535 pci_walk_bus(b, pcifront_claim_resource, pdev);
537 /* Create SysFS and notify udev of the devices. Aka: "going live" */
538 pci_bus_add_devices(b);
543 static void free_root_bus_devs(struct pci_bus *bus)
547 while (!list_empty(&bus->devices)) {
548 dev = container_of(bus->devices.next, struct pci_dev,
550 pci_dbg(dev, "removing device\n");
551 pci_stop_and_remove_bus_device(dev);
555 static void pcifront_free_roots(struct pcifront_device *pdev)
557 struct pci_bus_entry *bus_entry, *t;
559 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
561 pci_lock_rescan_remove();
562 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
563 list_del(&bus_entry->list);
565 free_root_bus_devs(bus_entry->bus);
567 kfree(bus_entry->bus->sysdata);
569 device_unregister(bus_entry->bus->bridge);
570 pci_remove_bus(bus_entry->bus);
574 pci_unlock_rescan_remove();
577 static pci_ers_result_t pcifront_common_process(int cmd,
578 struct pcifront_device *pdev,
579 pci_channel_state_t state)
581 struct pci_driver *pdrv;
582 int bus = pdev->sh_info->aer_op.bus;
583 int devfn = pdev->sh_info->aer_op.devfn;
584 int domain = pdev->sh_info->aer_op.domain;
585 struct pci_dev *pcidev;
587 dev_dbg(&pdev->xdev->dev,
588 "pcifront AER process: cmd %x (bus:%x, devfn%x)",
591 pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
592 if (!pcidev || !pcidev->dev.driver) {
593 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
595 return PCI_ERS_RESULT_NONE;
597 pdrv = to_pci_driver(pcidev->dev.driver);
599 if (pdrv->err_handler && pdrv->err_handler->error_detected) {
600 pci_dbg(pcidev, "trying to call AER service\n");
602 case XEN_PCI_OP_aer_detected:
603 return pdrv->err_handler->error_detected(pcidev, state);
604 case XEN_PCI_OP_aer_mmio:
605 return pdrv->err_handler->mmio_enabled(pcidev);
606 case XEN_PCI_OP_aer_slotreset:
607 return pdrv->err_handler->slot_reset(pcidev);
608 case XEN_PCI_OP_aer_resume:
609 pdrv->err_handler->resume(pcidev);
610 return PCI_ERS_RESULT_NONE;
612 dev_err(&pdev->xdev->dev,
613 "bad request in aer recovery operation!\n");
617 return PCI_ERS_RESULT_NONE;
621 static void pcifront_do_aer(struct work_struct *data)
623 struct pcifront_device *pdev =
624 container_of(data, struct pcifront_device, op_work);
625 int cmd = pdev->sh_info->aer_op.cmd;
626 pci_channel_state_t state =
627 (pci_channel_state_t)pdev->sh_info->aer_op.err;
630 * If a pci_conf op is in progress, we have to wait until it is done
631 * before service aer op
633 dev_dbg(&pdev->xdev->dev,
634 "pcifront service aer bus %x devfn %x\n",
635 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn);
637 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state);
639 /* Post the operation to the guest. */
641 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags);
642 notify_remote_via_evtchn(pdev->evtchn);
644 /*in case of we lost an aer request in four lines time_window*/
645 smp_mb__before_atomic();
646 clear_bit(_PDEVB_op_active, &pdev->flags);
647 smp_mb__after_atomic();
649 schedule_pcifront_aer_op(pdev);
653 static irqreturn_t pcifront_handler_aer(int irq, void *dev)
655 struct pcifront_device *pdev = dev;
657 schedule_pcifront_aer_op(pdev);
660 static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
664 spin_lock(&pcifront_dev_lock);
667 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n");
672 spin_unlock(&pcifront_dev_lock);
674 if (!err && !is_swiotlb_active(&pdev->xdev->dev)) {
675 err = pci_xen_swiotlb_init_late();
677 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
682 static void pcifront_disconnect(struct pcifront_device *pdev)
684 spin_lock(&pcifront_dev_lock);
686 if (pdev == pcifront_dev) {
687 dev_info(&pdev->xdev->dev,
688 "Disconnecting PCI Frontend Buses\n");
692 spin_unlock(&pcifront_dev_lock);
694 static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
696 struct pcifront_device *pdev;
698 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL);
702 if (xenbus_setup_ring(xdev, GFP_KERNEL, (void **)&pdev->sh_info, 1,
708 pdev->sh_info->flags = 0;
710 /*Flag for registering PV AER handler*/
711 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags);
713 dev_set_drvdata(&xdev->dev, pdev);
716 INIT_LIST_HEAD(&pdev->root_buses);
718 spin_lock_init(&pdev->sh_info_lock);
720 pdev->evtchn = INVALID_EVTCHN;
723 INIT_WORK(&pdev->op_work, pcifront_do_aer);
725 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
726 pdev, pdev->sh_info);
731 static void free_pdev(struct pcifront_device *pdev)
733 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
735 pcifront_free_roots(pdev);
737 cancel_work_sync(&pdev->op_work);
740 unbind_from_irqhandler(pdev->irq, pdev);
742 if (pdev->evtchn != INVALID_EVTCHN)
743 xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
745 xenbus_teardown_ring((void **)&pdev->sh_info, 1, &pdev->gnt_ref);
747 dev_set_drvdata(&pdev->xdev->dev, NULL);
752 static int pcifront_publish_info(struct pcifront_device *pdev)
755 struct xenbus_transaction trans;
757 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
761 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer,
762 0, "pcifront", pdev);
770 err = xenbus_transaction_start(&trans);
772 xenbus_dev_fatal(pdev->xdev, err,
773 "Error writing configuration for backend "
774 "(start transaction)");
778 err = xenbus_printf(trans, pdev->xdev->nodename,
779 "pci-op-ref", "%u", pdev->gnt_ref);
781 err = xenbus_printf(trans, pdev->xdev->nodename,
782 "event-channel", "%u", pdev->evtchn);
784 err = xenbus_printf(trans, pdev->xdev->nodename,
785 "magic", XEN_PCI_MAGIC);
788 xenbus_transaction_end(trans, 1);
789 xenbus_dev_fatal(pdev->xdev, err,
790 "Error writing configuration for backend");
793 err = xenbus_transaction_end(trans, 0);
797 xenbus_dev_fatal(pdev->xdev, err,
798 "Error completing transaction "
804 xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
806 dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
812 static void pcifront_connect(struct pcifront_device *pdev)
815 int i, num_roots, len;
817 unsigned int domain, bus;
819 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
820 "root_num", "%d", &num_roots);
821 if (err == -ENOENT) {
822 xenbus_dev_error(pdev->xdev, err,
823 "No PCI Roots found, trying 0000:00");
824 err = pcifront_rescan_root(pdev, 0, 0);
826 xenbus_dev_fatal(pdev->xdev, err,
827 "Error scanning PCI root 0000:00");
831 } else if (err != 1) {
832 xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err,
833 "Error reading number of PCI roots");
837 for (i = 0; i < num_roots; i++) {
838 len = snprintf(str, sizeof(str), "root-%d", i);
839 if (unlikely(len >= (sizeof(str) - 1)))
842 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
843 "%x:%x", &domain, &bus);
845 xenbus_dev_fatal(pdev->xdev, err >= 0 ? -EINVAL : err,
846 "Error reading PCI root %d", i);
850 err = pcifront_rescan_root(pdev, domain, bus);
852 xenbus_dev_fatal(pdev->xdev, err,
853 "Error scanning PCI root %04x:%02x",
859 xenbus_switch_state(pdev->xdev, XenbusStateConnected);
862 static void pcifront_try_connect(struct pcifront_device *pdev)
866 /* Only connect once */
867 if (xenbus_read_driver_state(pdev->xdev->nodename) !=
868 XenbusStateInitialised)
871 err = pcifront_connect_and_init_dma(pdev);
872 if (err && err != -EEXIST) {
873 xenbus_dev_fatal(pdev->xdev, err,
874 "Error setting up PCI Frontend");
878 pcifront_connect(pdev);
881 static int pcifront_try_disconnect(struct pcifront_device *pdev)
884 enum xenbus_state prev_state;
887 prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
889 if (prev_state >= XenbusStateClosing)
892 if (prev_state == XenbusStateConnected) {
893 pcifront_free_roots(pdev);
894 pcifront_disconnect(pdev);
897 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed);
904 static void pcifront_attach_devices(struct pcifront_device *pdev)
906 if (xenbus_read_driver_state(pdev->xdev->nodename) ==
907 XenbusStateReconfiguring)
908 pcifront_connect(pdev);
911 static int pcifront_detach_devices(struct pcifront_device *pdev)
915 enum xenbus_state state;
916 unsigned int domain, bus, slot, func;
917 struct pci_dev *pci_dev;
920 state = xenbus_read_driver_state(pdev->xdev->nodename);
921 if (state == XenbusStateInitialised) {
922 dev_dbg(&pdev->xdev->dev, "Handle skipped connect.\n");
923 /* We missed Connected and need to initialize. */
924 err = pcifront_connect_and_init_dma(pdev);
925 if (err && err != -EEXIST) {
926 xenbus_dev_fatal(pdev->xdev, err,
927 "Error setting up PCI Frontend");
931 goto out_switch_state;
932 } else if (state != XenbusStateConnected) {
936 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d",
941 xenbus_dev_fatal(pdev->xdev, err,
942 "Error reading number of PCI devices");
946 /* Find devices being detached and remove them. */
947 for (i = 0; i < num_devs; i++) {
950 l = snprintf(str, sizeof(str), "state-%d", i);
951 if (unlikely(l >= (sizeof(str) - 1))) {
955 state = xenbus_read_unsigned(pdev->xdev->otherend, str,
958 if (state != XenbusStateClosing)
962 l = snprintf(str, sizeof(str), "vdev-%d", i);
963 if (unlikely(l >= (sizeof(str) - 1))) {
967 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
968 "%x:%x:%x.%x", &domain, &bus, &slot, &func);
972 xenbus_dev_fatal(pdev->xdev, err,
973 "Error reading PCI device %d", i);
977 pci_dev = pci_get_domain_bus_and_slot(domain, bus,
978 PCI_DEVFN(slot, func));
980 dev_dbg(&pdev->xdev->dev,
981 "Cannot get PCI device %04x:%02x:%02x.%d\n",
982 domain, bus, slot, func);
985 pci_lock_rescan_remove();
986 pci_stop_and_remove_bus_device(pci_dev);
987 pci_dev_put(pci_dev);
988 pci_unlock_rescan_remove();
990 dev_dbg(&pdev->xdev->dev,
991 "PCI device %04x:%02x:%02x.%d removed.\n",
992 domain, bus, slot, func);
996 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring);
1002 static void pcifront_backend_changed(struct xenbus_device *xdev,
1003 enum xenbus_state be_state)
1005 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1008 case XenbusStateUnknown:
1009 case XenbusStateInitialising:
1010 case XenbusStateInitWait:
1011 case XenbusStateInitialised:
1014 case XenbusStateConnected:
1015 pcifront_try_connect(pdev);
1018 case XenbusStateClosed:
1019 if (xdev->state == XenbusStateClosed)
1021 fallthrough; /* Missed the backend's CLOSING state */
1022 case XenbusStateClosing:
1023 dev_warn(&xdev->dev, "backend going away!\n");
1024 pcifront_try_disconnect(pdev);
1027 case XenbusStateReconfiguring:
1028 pcifront_detach_devices(pdev);
1031 case XenbusStateReconfigured:
1032 pcifront_attach_devices(pdev);
1037 static int pcifront_xenbus_probe(struct xenbus_device *xdev,
1038 const struct xenbus_device_id *id)
1041 struct pcifront_device *pdev = alloc_pdev(xdev);
1045 xenbus_dev_fatal(xdev, err,
1046 "Error allocating pcifront_device struct");
1050 err = pcifront_publish_info(pdev);
1058 static int pcifront_xenbus_remove(struct xenbus_device *xdev)
1060 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev);
1068 static const struct xenbus_device_id xenpci_ids[] = {
1073 static struct xenbus_driver xenpci_driver = {
1076 .probe = pcifront_xenbus_probe,
1077 .remove = pcifront_xenbus_remove,
1078 .otherend_changed = pcifront_backend_changed,
1081 static int __init pcifront_init(void)
1083 if (!xen_pv_domain() || xen_initial_domain())
1086 if (!xen_has_pv_devices())
1089 pci_frontend_registrar(1 /* enable */);
1091 return xenbus_register_frontend(&xenpci_driver);
1094 static void __exit pcifront_cleanup(void)
1096 xenbus_unregister_driver(&xenpci_driver);
1097 pci_frontend_registrar(0 /* disable */);
1099 module_init(pcifront_init);
1100 module_exit(pcifront_cleanup);
1102 MODULE_DESCRIPTION("Xen PCI passthrough frontend.");
1103 MODULE_LICENSE("GPL");
1104 MODULE_ALIAS("xen:pci");