1 // SPDX-License-Identifier: GPL-2.0 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> 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 <xen/platform_pci.h> 26 27 #include <asm/xen/swiotlb-xen.h> 28 #define INVALID_GRANT_REF (0) 29 #define INVALID_EVTCHN (-1) 30 31 struct 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 39 struct 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 56 struct pcifront_sd { 57 struct pci_sysdata sd; 58 struct pcifront_device *pdev; 59 }; 60 61 static inline struct pcifront_device * 62 pcifront_get_pdev(struct pcifront_sd *sd) 63 { 64 return sd->pdev; 65 } 66 67 static inline void pcifront_init_sd(struct pcifront_sd *sd, 68 unsigned int domain, unsigned int bus, 69 struct pcifront_device *pdev) 70 { 71 /* Because we do not expose that information via XenBus. */ 72 sd->sd.node = first_online_node; 73 sd->sd.domain = domain; 74 sd->pdev = pdev; 75 } 76 77 static DEFINE_SPINLOCK(pcifront_dev_lock); 78 static struct pcifront_device *pcifront_dev; 79 80 static int verbose_request; 81 module_param(verbose_request, int, 0644); 82 83 static 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 } 104 105 static 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 } 113 114 static 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; 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 */ 138 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC; 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); 146 ns = ktime_get_ns(); 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; 172 out: 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 */ 178 static 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, 195 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n", 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 */ 217 static 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, 234 "write dev=%04x:%02x:%02x.%d - " 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 } 241 242 static struct pci_ops pcifront_bus_ops = { 243 .read = pcifront_bus_read, 244 .write = pcifront_bus_write, 245 }; 246 247 #ifdef CONFIG_PCI_MSI 248 static int pci_frontend_enable_msix(struct pci_dev *dev, 249 int vector[], int nvec) 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 pci_err(dev, "too many vectors (0x%x) for PCI frontend:" 266 " Increase SH_INFO_MAX_VEC\n", nvec); 267 return -EINVAL; 268 } 269 270 i = 0; 271 for_each_pci_msi_entry(entry, dev) { 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 */ 283 for (i = 0; i < nvec; i++) { 284 if (op.msix_entries[i].vector <= 0) { 285 pci_warn(dev, "MSI-X entry %d is invalid: %d!\n", 286 i, op.msix_entries[i].vector); 287 err = -EINVAL; 288 vector[i] = -1; 289 continue; 290 } 291 vector[i] = op.msix_entries[i].vector; 292 } 293 } else { 294 pr_info("enable msix get value %x\n", op.value); 295 err = op.value; 296 } 297 } else { 298 pci_err(dev, "enable msix get err %x\n", err); 299 } 300 return err; 301 } 302 303 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 pci_err(dev, "pci_disable_msix get err %x\n", err); 320 } 321 322 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 pci_warn(dev, "MSI entry is invalid: %d!\n", 339 op.value); 340 err = -EINVAL; 341 vector[0] = -1; 342 } 343 } else { 344 pci_err(dev, "pci frontend enable msi failed for dev " 345 "%x:%x\n", op.bus, op.devfn); 346 err = -EINVAL; 347 } 348 return err; 349 } 350 351 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 pr_info("get no response from backend for disable MSI\n"); 367 return; 368 } 369 if (err) 370 /* how can pciback notify us fail? */ 371 pr_info("get fake response from backend\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 }; 380 381 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 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 */ 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 } 415 416 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 } 444 445 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 } 520 521 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 } 555 556 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 pci_dbg(dev, "removing device\n"); 564 pci_stop_and_remove_bus_device(dev); 565 } 566 } 567 568 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 } 589 590 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 int domain = pdev->sh_info->aer_op.domain; 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_domain_bus_and_slot(domain, bus, devfn); 608 if (!pcidev || !pcidev->driver) { 609 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n"); 610 pci_dev_put(pcidev); 611 return result; 612 } 613 pdrv = pcidev->driver; 614 615 if (pdrv) { 616 if (pdrv->err_handler && pdrv->err_handler->error_detected) { 617 pci_dbg(pcidev, "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 } 650 651 652 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 } 681 682 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 } 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 } 709 710 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 } 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 } 760 761 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 } 785 786 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 } 852 853 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 } 924 925 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 } 947 948 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 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 state = xenbus_read_unsigned(pdev->xdev->otherend, str, 1042 XenbusStateUnknown); 1043 1044 if (state != XenbusStateClosing) 1045 continue; 1046 1047 /* Remove device. */ 1048 l = snprintf(str, sizeof(str), "vdev-%d", i); 1049 if (unlikely(l >= (sizeof(str) - 1))) { 1050 err = -ENOMEM; 1051 goto out; 1052 } 1053 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 1054 "%x:%x:%x.%x", &domain, &bus, &slot, &func); 1055 if (err != 4) { 1056 if (err >= 0) 1057 err = -EINVAL; 1058 xenbus_dev_fatal(pdev->xdev, err, 1059 "Error reading PCI device %d", i); 1060 goto out; 1061 } 1062 1063 pci_dev = pci_get_domain_bus_and_slot(domain, bus, 1064 PCI_DEVFN(slot, func)); 1065 if (!pci_dev) { 1066 dev_dbg(&pdev->xdev->dev, 1067 "Cannot get PCI device %04x:%02x:%02x.%d\n", 1068 domain, bus, slot, func); 1069 continue; 1070 } 1071 pci_lock_rescan_remove(); 1072 pci_stop_and_remove_bus_device(pci_dev); 1073 pci_dev_put(pci_dev); 1074 pci_unlock_rescan_remove(); 1075 1076 dev_dbg(&pdev->xdev->dev, 1077 "PCI device %04x:%02x:%02x.%d removed.\n", 1078 domain, bus, slot, func); 1079 } 1080 1081 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring); 1082 1083 out: 1084 return err; 1085 } 1086 1087 static void __ref pcifront_backend_changed(struct xenbus_device *xdev, 1088 enum xenbus_state be_state) 1089 { 1090 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1091 1092 switch (be_state) { 1093 case XenbusStateUnknown: 1094 case XenbusStateInitialising: 1095 case XenbusStateInitWait: 1096 case XenbusStateInitialised: 1097 break; 1098 1099 case XenbusStateConnected: 1100 pcifront_try_connect(pdev); 1101 break; 1102 1103 case XenbusStateClosed: 1104 if (xdev->state == XenbusStateClosed) 1105 break; 1106 /* fall through - Missed the backend's CLOSING state. */ 1107 case XenbusStateClosing: 1108 dev_warn(&xdev->dev, "backend going away!\n"); 1109 pcifront_try_disconnect(pdev); 1110 break; 1111 1112 case XenbusStateReconfiguring: 1113 pcifront_detach_devices(pdev); 1114 break; 1115 1116 case XenbusStateReconfigured: 1117 pcifront_attach_devices(pdev); 1118 break; 1119 } 1120 } 1121 1122 static int pcifront_xenbus_probe(struct xenbus_device *xdev, 1123 const struct xenbus_device_id *id) 1124 { 1125 int err = 0; 1126 struct pcifront_device *pdev = alloc_pdev(xdev); 1127 1128 if (pdev == NULL) { 1129 err = -ENOMEM; 1130 xenbus_dev_fatal(xdev, err, 1131 "Error allocating pcifront_device struct"); 1132 goto out; 1133 } 1134 1135 err = pcifront_publish_info(pdev); 1136 if (err) 1137 free_pdev(pdev); 1138 1139 out: 1140 return err; 1141 } 1142 1143 static int pcifront_xenbus_remove(struct xenbus_device *xdev) 1144 { 1145 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1146 if (pdev) 1147 free_pdev(pdev); 1148 1149 return 0; 1150 } 1151 1152 static const struct xenbus_device_id xenpci_ids[] = { 1153 {"pci"}, 1154 {""}, 1155 }; 1156 1157 static struct xenbus_driver xenpci_driver = { 1158 .name = "pcifront", 1159 .ids = xenpci_ids, 1160 .probe = pcifront_xenbus_probe, 1161 .remove = pcifront_xenbus_remove, 1162 .otherend_changed = pcifront_backend_changed, 1163 }; 1164 1165 static int __init pcifront_init(void) 1166 { 1167 if (!xen_pv_domain() || xen_initial_domain()) 1168 return -ENODEV; 1169 1170 if (!xen_has_pv_devices()) 1171 return -ENODEV; 1172 1173 pci_frontend_registrar(1 /* enable */); 1174 1175 return xenbus_register_frontend(&xenpci_driver); 1176 } 1177 1178 static void __exit pcifront_cleanup(void) 1179 { 1180 xenbus_unregister_driver(&xenpci_driver); 1181 pci_frontend_registrar(0 /* disable */); 1182 } 1183 module_init(pcifront_init); 1184 module_exit(pcifront_cleanup); 1185 1186 MODULE_DESCRIPTION("Xen PCI passthrough frontend."); 1187 MODULE_LICENSE("GPL"); 1188 MODULE_ALIAS("xen:pci"); 1189