1 /* 2 * Xen PCI Frontend. 3 * 4 * Author: Ryan Wilson <hap9@epoch.ncsc.mil> 5 */ 6 #include <linux/module.h> 7 #include <linux/init.h> 8 #include <linux/mm.h> 9 #include <xen/xenbus.h> 10 #include <xen/events.h> 11 #include <xen/grant_table.h> 12 #include <xen/page.h> 13 #include <linux/spinlock.h> 14 #include <linux/pci.h> 15 #include <linux/msi.h> 16 #include <xen/interface/io/pciif.h> 17 #include <asm/xen/pci.h> 18 #include <linux/interrupt.h> 19 #include <asm/atomic.h> 20 #include <linux/workqueue.h> 21 #include <linux/bitops.h> 22 #include <linux/time.h> 23 24 #define INVALID_GRANT_REF (0) 25 #define INVALID_EVTCHN (-1) 26 27 struct pci_bus_entry { 28 struct list_head list; 29 struct pci_bus *bus; 30 }; 31 32 #define _PDEVB_op_active (0) 33 #define PDEVB_op_active (1 << (_PDEVB_op_active)) 34 35 struct pcifront_device { 36 struct xenbus_device *xdev; 37 struct list_head root_buses; 38 39 int evtchn; 40 int gnt_ref; 41 42 int irq; 43 44 /* Lock this when doing any operations in sh_info */ 45 spinlock_t sh_info_lock; 46 struct xen_pci_sharedinfo *sh_info; 47 struct work_struct op_work; 48 unsigned long flags; 49 50 }; 51 52 struct pcifront_sd { 53 int domain; 54 struct pcifront_device *pdev; 55 }; 56 57 static inline struct pcifront_device * 58 pcifront_get_pdev(struct pcifront_sd *sd) 59 { 60 return sd->pdev; 61 } 62 63 static inline void pcifront_init_sd(struct pcifront_sd *sd, 64 unsigned int domain, unsigned int bus, 65 struct pcifront_device *pdev) 66 { 67 sd->domain = domain; 68 sd->pdev = pdev; 69 } 70 71 static DEFINE_SPINLOCK(pcifront_dev_lock); 72 static struct pcifront_device *pcifront_dev; 73 74 static int verbose_request; 75 module_param(verbose_request, int, 0644); 76 77 static int errno_to_pcibios_err(int errno) 78 { 79 switch (errno) { 80 case XEN_PCI_ERR_success: 81 return PCIBIOS_SUCCESSFUL; 82 83 case XEN_PCI_ERR_dev_not_found: 84 return PCIBIOS_DEVICE_NOT_FOUND; 85 86 case XEN_PCI_ERR_invalid_offset: 87 case XEN_PCI_ERR_op_failed: 88 return PCIBIOS_BAD_REGISTER_NUMBER; 89 90 case XEN_PCI_ERR_not_implemented: 91 return PCIBIOS_FUNC_NOT_SUPPORTED; 92 93 case XEN_PCI_ERR_access_denied: 94 return PCIBIOS_SET_FAILED; 95 } 96 return errno; 97 } 98 99 static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev) 100 { 101 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags) 102 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) { 103 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n"); 104 schedule_work(&pdev->op_work); 105 } 106 } 107 108 static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op) 109 { 110 int err = 0; 111 struct xen_pci_op *active_op = &pdev->sh_info->op; 112 unsigned long irq_flags; 113 evtchn_port_t port = pdev->evtchn; 114 unsigned irq = pdev->irq; 115 s64 ns, ns_timeout; 116 struct timeval tv; 117 118 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags); 119 120 memcpy(active_op, op, sizeof(struct xen_pci_op)); 121 122 /* Go */ 123 wmb(); 124 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags); 125 notify_remote_via_evtchn(port); 126 127 /* 128 * We set a poll timeout of 3 seconds but give up on return after 129 * 2 seconds. It is better to time out too late rather than too early 130 * (in the latter case we end up continually re-executing poll() with a 131 * timeout in the past). 1s difference gives plenty of slack for error. 132 */ 133 do_gettimeofday(&tv); 134 ns_timeout = timeval_to_ns(&tv) + 2 * (s64)NSEC_PER_SEC; 135 136 xen_clear_irq_pending(irq); 137 138 while (test_bit(_XEN_PCIF_active, 139 (unsigned long *)&pdev->sh_info->flags)) { 140 xen_poll_irq_timeout(irq, jiffies + 3*HZ); 141 xen_clear_irq_pending(irq); 142 do_gettimeofday(&tv); 143 ns = timeval_to_ns(&tv); 144 if (ns > ns_timeout) { 145 dev_err(&pdev->xdev->dev, 146 "pciback not responding!!!\n"); 147 clear_bit(_XEN_PCIF_active, 148 (unsigned long *)&pdev->sh_info->flags); 149 err = XEN_PCI_ERR_dev_not_found; 150 goto out; 151 } 152 } 153 154 /* 155 * We might lose backend service request since we 156 * reuse same evtchn with pci_conf backend response. So re-schedule 157 * aer pcifront service. 158 */ 159 if (test_bit(_XEN_PCIB_active, 160 (unsigned long *)&pdev->sh_info->flags)) { 161 dev_err(&pdev->xdev->dev, 162 "schedule aer pcifront service\n"); 163 schedule_pcifront_aer_op(pdev); 164 } 165 166 memcpy(op, active_op, sizeof(struct xen_pci_op)); 167 168 err = op->err; 169 out: 170 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags); 171 return err; 172 } 173 174 /* Access to this function is spinlocked in drivers/pci/access.c */ 175 static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn, 176 int where, int size, u32 *val) 177 { 178 int err = 0; 179 struct xen_pci_op op = { 180 .cmd = XEN_PCI_OP_conf_read, 181 .domain = pci_domain_nr(bus), 182 .bus = bus->number, 183 .devfn = devfn, 184 .offset = where, 185 .size = size, 186 }; 187 struct pcifront_sd *sd = bus->sysdata; 188 struct pcifront_device *pdev = pcifront_get_pdev(sd); 189 190 if (verbose_request) 191 dev_info(&pdev->xdev->dev, 192 "read dev=%04x:%02x:%02x.%01x - offset %x size %d\n", 193 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), 194 PCI_FUNC(devfn), where, size); 195 196 err = do_pci_op(pdev, &op); 197 198 if (likely(!err)) { 199 if (verbose_request) 200 dev_info(&pdev->xdev->dev, "read got back value %x\n", 201 op.value); 202 203 *val = op.value; 204 } else if (err == -ENODEV) { 205 /* No device here, pretend that it just returned 0 */ 206 err = 0; 207 *val = 0; 208 } 209 210 return errno_to_pcibios_err(err); 211 } 212 213 /* Access to this function is spinlocked in drivers/pci/access.c */ 214 static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn, 215 int where, int size, u32 val) 216 { 217 struct xen_pci_op op = { 218 .cmd = XEN_PCI_OP_conf_write, 219 .domain = pci_domain_nr(bus), 220 .bus = bus->number, 221 .devfn = devfn, 222 .offset = where, 223 .size = size, 224 .value = val, 225 }; 226 struct pcifront_sd *sd = bus->sysdata; 227 struct pcifront_device *pdev = pcifront_get_pdev(sd); 228 229 if (verbose_request) 230 dev_info(&pdev->xdev->dev, 231 "write dev=%04x:%02x:%02x.%01x - " 232 "offset %x size %d val %x\n", 233 pci_domain_nr(bus), bus->number, 234 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val); 235 236 return errno_to_pcibios_err(do_pci_op(pdev, &op)); 237 } 238 239 struct pci_ops pcifront_bus_ops = { 240 .read = pcifront_bus_read, 241 .write = pcifront_bus_write, 242 }; 243 244 #ifdef CONFIG_PCI_MSI 245 static int pci_frontend_enable_msix(struct pci_dev *dev, 246 int **vector, int nvec) 247 { 248 int err; 249 int i; 250 struct xen_pci_op op = { 251 .cmd = XEN_PCI_OP_enable_msix, 252 .domain = pci_domain_nr(dev->bus), 253 .bus = dev->bus->number, 254 .devfn = dev->devfn, 255 .value = nvec, 256 }; 257 struct pcifront_sd *sd = dev->bus->sysdata; 258 struct pcifront_device *pdev = pcifront_get_pdev(sd); 259 struct msi_desc *entry; 260 261 if (nvec > SH_INFO_MAX_VEC) { 262 dev_err(&dev->dev, "too much vector for pci frontend: %x." 263 " Increase SH_INFO_MAX_VEC.\n", nvec); 264 return -EINVAL; 265 } 266 267 i = 0; 268 list_for_each_entry(entry, &dev->msi_list, list) { 269 op.msix_entries[i].entry = entry->msi_attrib.entry_nr; 270 /* Vector is useless at this point. */ 271 op.msix_entries[i].vector = -1; 272 i++; 273 } 274 275 err = do_pci_op(pdev, &op); 276 277 if (likely(!err)) { 278 if (likely(!op.value)) { 279 /* we get the result */ 280 for (i = 0; i < nvec; i++) 281 *(*vector+i) = op.msix_entries[i].vector; 282 return 0; 283 } else { 284 printk(KERN_DEBUG "enable msix get value %x\n", 285 op.value); 286 return op.value; 287 } 288 } else { 289 dev_err(&dev->dev, "enable msix get err %x\n", err); 290 return err; 291 } 292 } 293 294 static void pci_frontend_disable_msix(struct pci_dev *dev) 295 { 296 int err; 297 struct xen_pci_op op = { 298 .cmd = XEN_PCI_OP_disable_msix, 299 .domain = pci_domain_nr(dev->bus), 300 .bus = dev->bus->number, 301 .devfn = dev->devfn, 302 }; 303 struct pcifront_sd *sd = dev->bus->sysdata; 304 struct pcifront_device *pdev = pcifront_get_pdev(sd); 305 306 err = do_pci_op(pdev, &op); 307 308 /* What should do for error ? */ 309 if (err) 310 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err); 311 } 312 313 static int pci_frontend_enable_msi(struct pci_dev *dev, int **vector) 314 { 315 int err; 316 struct xen_pci_op op = { 317 .cmd = XEN_PCI_OP_enable_msi, 318 .domain = pci_domain_nr(dev->bus), 319 .bus = dev->bus->number, 320 .devfn = dev->devfn, 321 }; 322 struct pcifront_sd *sd = dev->bus->sysdata; 323 struct pcifront_device *pdev = pcifront_get_pdev(sd); 324 325 err = do_pci_op(pdev, &op); 326 if (likely(!err)) { 327 *(*vector) = op.value; 328 } else { 329 dev_err(&dev->dev, "pci frontend enable msi failed for dev " 330 "%x:%x\n", op.bus, op.devfn); 331 err = -EINVAL; 332 } 333 return err; 334 } 335 336 static void pci_frontend_disable_msi(struct pci_dev *dev) 337 { 338 int err; 339 struct xen_pci_op op = { 340 .cmd = XEN_PCI_OP_disable_msi, 341 .domain = pci_domain_nr(dev->bus), 342 .bus = dev->bus->number, 343 .devfn = dev->devfn, 344 }; 345 struct pcifront_sd *sd = dev->bus->sysdata; 346 struct pcifront_device *pdev = pcifront_get_pdev(sd); 347 348 err = do_pci_op(pdev, &op); 349 if (err == XEN_PCI_ERR_dev_not_found) { 350 /* XXX No response from backend, what shall we do? */ 351 printk(KERN_DEBUG "get no response from backend for disable MSI\n"); 352 return; 353 } 354 if (err) 355 /* how can pciback notify us fail? */ 356 printk(KERN_DEBUG "get fake response frombackend\n"); 357 } 358 359 static struct xen_pci_frontend_ops pci_frontend_ops = { 360 .enable_msi = pci_frontend_enable_msi, 361 .disable_msi = pci_frontend_disable_msi, 362 .enable_msix = pci_frontend_enable_msix, 363 .disable_msix = pci_frontend_disable_msix, 364 }; 365 366 static void pci_frontend_registrar(int enable) 367 { 368 if (enable) 369 xen_pci_frontend = &pci_frontend_ops; 370 else 371 xen_pci_frontend = NULL; 372 }; 373 #else 374 static inline void pci_frontend_registrar(int enable) { }; 375 #endif /* CONFIG_PCI_MSI */ 376 377 /* Claim resources for the PCI frontend as-is, backend won't allow changes */ 378 static int pcifront_claim_resource(struct pci_dev *dev, void *data) 379 { 380 struct pcifront_device *pdev = data; 381 int i; 382 struct resource *r; 383 384 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 385 r = &dev->resource[i]; 386 387 if (!r->parent && r->start && r->flags) { 388 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n", 389 pci_name(dev), i); 390 if (pci_claim_resource(dev, i)) { 391 dev_err(&pdev->xdev->dev, "Could not claim " 392 "resource %s/%d! Device offline. Try " 393 "giving less than 4GB to domain.\n", 394 pci_name(dev), i); 395 } 396 } 397 } 398 399 return 0; 400 } 401 402 static int __devinit pcifront_scan_bus(struct pcifront_device *pdev, 403 unsigned int domain, unsigned int bus, 404 struct pci_bus *b) 405 { 406 struct pci_dev *d; 407 unsigned int devfn; 408 409 /* Scan the bus for functions and add. 410 * We omit handling of PCI bridge attachment because pciback prevents 411 * bridges from being exported. 412 */ 413 for (devfn = 0; devfn < 0x100; devfn++) { 414 d = pci_get_slot(b, devfn); 415 if (d) { 416 /* Device is already known. */ 417 pci_dev_put(d); 418 continue; 419 } 420 421 d = pci_scan_single_device(b, devfn); 422 if (d) 423 dev_info(&pdev->xdev->dev, "New device on " 424 "%04x:%02x:%02x.%02x found.\n", domain, bus, 425 PCI_SLOT(devfn), PCI_FUNC(devfn)); 426 } 427 428 return 0; 429 } 430 431 static int __devinit pcifront_scan_root(struct pcifront_device *pdev, 432 unsigned int domain, unsigned int bus) 433 { 434 struct pci_bus *b; 435 struct pcifront_sd *sd = NULL; 436 struct pci_bus_entry *bus_entry = NULL; 437 int err = 0; 438 439 #ifndef CONFIG_PCI_DOMAINS 440 if (domain != 0) { 441 dev_err(&pdev->xdev->dev, 442 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 443 dev_err(&pdev->xdev->dev, 444 "Please compile with CONFIG_PCI_DOMAINS\n"); 445 err = -EINVAL; 446 goto err_out; 447 } 448 #endif 449 450 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", 451 domain, bus); 452 453 bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL); 454 sd = kmalloc(sizeof(*sd), GFP_KERNEL); 455 if (!bus_entry || !sd) { 456 err = -ENOMEM; 457 goto err_out; 458 } 459 pcifront_init_sd(sd, domain, bus, pdev); 460 461 b = pci_scan_bus_parented(&pdev->xdev->dev, bus, 462 &pcifront_bus_ops, sd); 463 if (!b) { 464 dev_err(&pdev->xdev->dev, 465 "Error creating PCI Frontend Bus!\n"); 466 err = -ENOMEM; 467 goto err_out; 468 } 469 470 bus_entry->bus = b; 471 472 list_add(&bus_entry->list, &pdev->root_buses); 473 474 /* pci_scan_bus_parented skips devices which do not have a have 475 * devfn==0. The pcifront_scan_bus enumerates all devfn. */ 476 err = pcifront_scan_bus(pdev, domain, bus, b); 477 478 /* Claim resources before going "live" with our devices */ 479 pci_walk_bus(b, pcifront_claim_resource, pdev); 480 481 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 482 pci_bus_add_devices(b); 483 484 return err; 485 486 err_out: 487 kfree(bus_entry); 488 kfree(sd); 489 490 return err; 491 } 492 493 static int __devinit pcifront_rescan_root(struct pcifront_device *pdev, 494 unsigned int domain, unsigned int bus) 495 { 496 int err; 497 struct pci_bus *b; 498 499 #ifndef CONFIG_PCI_DOMAINS 500 if (domain != 0) { 501 dev_err(&pdev->xdev->dev, 502 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 503 dev_err(&pdev->xdev->dev, 504 "Please compile with CONFIG_PCI_DOMAINS\n"); 505 return -EINVAL; 506 } 507 #endif 508 509 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n", 510 domain, bus); 511 512 b = pci_find_bus(domain, bus); 513 if (!b) 514 /* If the bus is unknown, create it. */ 515 return pcifront_scan_root(pdev, domain, bus); 516 517 err = pcifront_scan_bus(pdev, domain, bus, b); 518 519 /* Claim resources before going "live" with our devices */ 520 pci_walk_bus(b, pcifront_claim_resource, pdev); 521 522 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 523 pci_bus_add_devices(b); 524 525 return err; 526 } 527 528 static void free_root_bus_devs(struct pci_bus *bus) 529 { 530 struct pci_dev *dev; 531 532 while (!list_empty(&bus->devices)) { 533 dev = container_of(bus->devices.next, struct pci_dev, 534 bus_list); 535 dev_dbg(&dev->dev, "removing device\n"); 536 pci_remove_bus_device(dev); 537 } 538 } 539 540 static void pcifront_free_roots(struct pcifront_device *pdev) 541 { 542 struct pci_bus_entry *bus_entry, *t; 543 544 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n"); 545 546 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) { 547 list_del(&bus_entry->list); 548 549 free_root_bus_devs(bus_entry->bus); 550 551 kfree(bus_entry->bus->sysdata); 552 553 device_unregister(bus_entry->bus->bridge); 554 pci_remove_bus(bus_entry->bus); 555 556 kfree(bus_entry); 557 } 558 } 559 560 static pci_ers_result_t pcifront_common_process(int cmd, 561 struct pcifront_device *pdev, 562 pci_channel_state_t state) 563 { 564 pci_ers_result_t result; 565 struct pci_driver *pdrv; 566 int bus = pdev->sh_info->aer_op.bus; 567 int devfn = pdev->sh_info->aer_op.devfn; 568 struct pci_dev *pcidev; 569 int flag = 0; 570 571 dev_dbg(&pdev->xdev->dev, 572 "pcifront AER process: cmd %x (bus:%x, devfn%x)", 573 cmd, bus, devfn); 574 result = PCI_ERS_RESULT_NONE; 575 576 pcidev = pci_get_bus_and_slot(bus, devfn); 577 if (!pcidev || !pcidev->driver) { 578 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n"); 579 if (pcidev) 580 pci_dev_put(pcidev); 581 return result; 582 } 583 pdrv = pcidev->driver; 584 585 if (get_driver(&pdrv->driver)) { 586 if (pdrv->err_handler && pdrv->err_handler->error_detected) { 587 dev_dbg(&pcidev->dev, 588 "trying to call AER service\n"); 589 if (pcidev) { 590 flag = 1; 591 switch (cmd) { 592 case XEN_PCI_OP_aer_detected: 593 result = pdrv->err_handler-> 594 error_detected(pcidev, state); 595 break; 596 case XEN_PCI_OP_aer_mmio: 597 result = pdrv->err_handler-> 598 mmio_enabled(pcidev); 599 break; 600 case XEN_PCI_OP_aer_slotreset: 601 result = pdrv->err_handler-> 602 slot_reset(pcidev); 603 break; 604 case XEN_PCI_OP_aer_resume: 605 pdrv->err_handler->resume(pcidev); 606 break; 607 default: 608 dev_err(&pdev->xdev->dev, 609 "bad request in aer recovery " 610 "operation!\n"); 611 612 } 613 } 614 } 615 put_driver(&pdrv->driver); 616 } 617 if (!flag) 618 result = PCI_ERS_RESULT_NONE; 619 620 return result; 621 } 622 623 624 static void pcifront_do_aer(struct work_struct *data) 625 { 626 struct pcifront_device *pdev = 627 container_of(data, struct pcifront_device, op_work); 628 int cmd = pdev->sh_info->aer_op.cmd; 629 pci_channel_state_t state = 630 (pci_channel_state_t)pdev->sh_info->aer_op.err; 631 632 /*If a pci_conf op is in progress, 633 we have to wait until it is done before service aer op*/ 634 dev_dbg(&pdev->xdev->dev, 635 "pcifront service aer bus %x devfn %x\n", 636 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn); 637 638 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state); 639 640 /* Post the operation to the guest. */ 641 wmb(); 642 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags); 643 notify_remote_via_evtchn(pdev->evtchn); 644 645 /*in case of we lost an aer request in four lines time_window*/ 646 smp_mb__before_clear_bit(); 647 clear_bit(_PDEVB_op_active, &pdev->flags); 648 smp_mb__after_clear_bit(); 649 650 schedule_pcifront_aer_op(pdev); 651 652 } 653 654 static irqreturn_t pcifront_handler_aer(int irq, void *dev) 655 { 656 struct pcifront_device *pdev = dev; 657 schedule_pcifront_aer_op(pdev); 658 return IRQ_HANDLED; 659 } 660 static int pcifront_connect(struct pcifront_device *pdev) 661 { 662 int err = 0; 663 664 spin_lock(&pcifront_dev_lock); 665 666 if (!pcifront_dev) { 667 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n"); 668 pcifront_dev = pdev; 669 } else { 670 dev_err(&pdev->xdev->dev, "PCI frontend already installed!\n"); 671 err = -EEXIST; 672 } 673 674 spin_unlock(&pcifront_dev_lock); 675 676 return err; 677 } 678 679 static void pcifront_disconnect(struct pcifront_device *pdev) 680 { 681 spin_lock(&pcifront_dev_lock); 682 683 if (pdev == pcifront_dev) { 684 dev_info(&pdev->xdev->dev, 685 "Disconnecting PCI Frontend Buses\n"); 686 pcifront_dev = NULL; 687 } 688 689 spin_unlock(&pcifront_dev_lock); 690 } 691 static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev) 692 { 693 struct pcifront_device *pdev; 694 695 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL); 696 if (pdev == NULL) 697 goto out; 698 699 pdev->sh_info = 700 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL); 701 if (pdev->sh_info == NULL) { 702 kfree(pdev); 703 pdev = NULL; 704 goto out; 705 } 706 pdev->sh_info->flags = 0; 707 708 /*Flag for registering PV AER handler*/ 709 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags); 710 711 dev_set_drvdata(&xdev->dev, pdev); 712 pdev->xdev = xdev; 713 714 INIT_LIST_HEAD(&pdev->root_buses); 715 716 spin_lock_init(&pdev->sh_info_lock); 717 718 pdev->evtchn = INVALID_EVTCHN; 719 pdev->gnt_ref = INVALID_GRANT_REF; 720 pdev->irq = -1; 721 722 INIT_WORK(&pdev->op_work, pcifront_do_aer); 723 724 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n", 725 pdev, pdev->sh_info); 726 out: 727 return pdev; 728 } 729 730 static void free_pdev(struct pcifront_device *pdev) 731 { 732 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev); 733 734 pcifront_free_roots(pdev); 735 736 /*For PCIE_AER error handling job*/ 737 flush_scheduled_work(); 738 739 if (pdev->irq >= 0) 740 unbind_from_irqhandler(pdev->irq, pdev); 741 742 if (pdev->evtchn != INVALID_EVTCHN) 743 xenbus_free_evtchn(pdev->xdev, pdev->evtchn); 744 745 if (pdev->gnt_ref != INVALID_GRANT_REF) 746 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */, 747 (unsigned long)pdev->sh_info); 748 else 749 free_page((unsigned long)pdev->sh_info); 750 751 dev_set_drvdata(&pdev->xdev->dev, NULL); 752 753 kfree(pdev); 754 } 755 756 static int pcifront_publish_info(struct pcifront_device *pdev) 757 { 758 int err = 0; 759 struct xenbus_transaction trans; 760 761 err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info)); 762 if (err < 0) 763 goto out; 764 765 pdev->gnt_ref = err; 766 767 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn); 768 if (err) 769 goto out; 770 771 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer, 772 0, "pcifront", pdev); 773 774 if (err < 0) 775 return err; 776 777 pdev->irq = err; 778 779 do_publish: 780 err = xenbus_transaction_start(&trans); 781 if (err) { 782 xenbus_dev_fatal(pdev->xdev, err, 783 "Error writing configuration for backend " 784 "(start transaction)"); 785 goto out; 786 } 787 788 err = xenbus_printf(trans, pdev->xdev->nodename, 789 "pci-op-ref", "%u", pdev->gnt_ref); 790 if (!err) 791 err = xenbus_printf(trans, pdev->xdev->nodename, 792 "event-channel", "%u", pdev->evtchn); 793 if (!err) 794 err = xenbus_printf(trans, pdev->xdev->nodename, 795 "magic", XEN_PCI_MAGIC); 796 797 if (err) { 798 xenbus_transaction_end(trans, 1); 799 xenbus_dev_fatal(pdev->xdev, err, 800 "Error writing configuration for backend"); 801 goto out; 802 } else { 803 err = xenbus_transaction_end(trans, 0); 804 if (err == -EAGAIN) 805 goto do_publish; 806 else if (err) { 807 xenbus_dev_fatal(pdev->xdev, err, 808 "Error completing transaction " 809 "for backend"); 810 goto out; 811 } 812 } 813 814 xenbus_switch_state(pdev->xdev, XenbusStateInitialised); 815 816 dev_dbg(&pdev->xdev->dev, "publishing successful!\n"); 817 818 out: 819 return err; 820 } 821 822 static int __devinit pcifront_try_connect(struct pcifront_device *pdev) 823 { 824 int err = -EFAULT; 825 int i, num_roots, len; 826 char str[64]; 827 unsigned int domain, bus; 828 829 830 /* Only connect once */ 831 if (xenbus_read_driver_state(pdev->xdev->nodename) != 832 XenbusStateInitialised) 833 goto out; 834 835 err = pcifront_connect(pdev); 836 if (err) { 837 xenbus_dev_fatal(pdev->xdev, err, 838 "Error connecting PCI Frontend"); 839 goto out; 840 } 841 842 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 843 "root_num", "%d", &num_roots); 844 if (err == -ENOENT) { 845 xenbus_dev_error(pdev->xdev, err, 846 "No PCI Roots found, trying 0000:00"); 847 err = pcifront_scan_root(pdev, 0, 0); 848 num_roots = 0; 849 } else if (err != 1) { 850 if (err == 0) 851 err = -EINVAL; 852 xenbus_dev_fatal(pdev->xdev, err, 853 "Error reading number of PCI roots"); 854 goto out; 855 } 856 857 for (i = 0; i < num_roots; i++) { 858 len = snprintf(str, sizeof(str), "root-%d", i); 859 if (unlikely(len >= (sizeof(str) - 1))) { 860 err = -ENOMEM; 861 goto out; 862 } 863 864 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 865 "%x:%x", &domain, &bus); 866 if (err != 2) { 867 if (err >= 0) 868 err = -EINVAL; 869 xenbus_dev_fatal(pdev->xdev, err, 870 "Error reading PCI root %d", i); 871 goto out; 872 } 873 874 err = pcifront_scan_root(pdev, domain, bus); 875 if (err) { 876 xenbus_dev_fatal(pdev->xdev, err, 877 "Error scanning PCI root %04x:%02x", 878 domain, bus); 879 goto out; 880 } 881 } 882 883 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); 884 885 out: 886 return err; 887 } 888 889 static int pcifront_try_disconnect(struct pcifront_device *pdev) 890 { 891 int err = 0; 892 enum xenbus_state prev_state; 893 894 895 prev_state = xenbus_read_driver_state(pdev->xdev->nodename); 896 897 if (prev_state >= XenbusStateClosing) 898 goto out; 899 900 if (prev_state == XenbusStateConnected) { 901 pcifront_free_roots(pdev); 902 pcifront_disconnect(pdev); 903 } 904 905 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed); 906 907 out: 908 909 return err; 910 } 911 912 static int __devinit pcifront_attach_devices(struct pcifront_device *pdev) 913 { 914 int err = -EFAULT; 915 int i, num_roots, len; 916 unsigned int domain, bus; 917 char str[64]; 918 919 if (xenbus_read_driver_state(pdev->xdev->nodename) != 920 XenbusStateReconfiguring) 921 goto out; 922 923 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 924 "root_num", "%d", &num_roots); 925 if (err == -ENOENT) { 926 xenbus_dev_error(pdev->xdev, err, 927 "No PCI Roots found, trying 0000:00"); 928 err = pcifront_rescan_root(pdev, 0, 0); 929 num_roots = 0; 930 } else if (err != 1) { 931 if (err == 0) 932 err = -EINVAL; 933 xenbus_dev_fatal(pdev->xdev, err, 934 "Error reading number of PCI roots"); 935 goto out; 936 } 937 938 for (i = 0; i < num_roots; i++) { 939 len = snprintf(str, sizeof(str), "root-%d", i); 940 if (unlikely(len >= (sizeof(str) - 1))) { 941 err = -ENOMEM; 942 goto out; 943 } 944 945 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 946 "%x:%x", &domain, &bus); 947 if (err != 2) { 948 if (err >= 0) 949 err = -EINVAL; 950 xenbus_dev_fatal(pdev->xdev, err, 951 "Error reading PCI root %d", i); 952 goto out; 953 } 954 955 err = pcifront_rescan_root(pdev, domain, bus); 956 if (err) { 957 xenbus_dev_fatal(pdev->xdev, err, 958 "Error scanning PCI root %04x:%02x", 959 domain, bus); 960 goto out; 961 } 962 } 963 964 xenbus_switch_state(pdev->xdev, XenbusStateConnected); 965 966 out: 967 return err; 968 } 969 970 static int pcifront_detach_devices(struct pcifront_device *pdev) 971 { 972 int err = 0; 973 int i, num_devs; 974 unsigned int domain, bus, slot, func; 975 struct pci_bus *pci_bus; 976 struct pci_dev *pci_dev; 977 char str[64]; 978 979 if (xenbus_read_driver_state(pdev->xdev->nodename) != 980 XenbusStateConnected) 981 goto out; 982 983 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d", 984 &num_devs); 985 if (err != 1) { 986 if (err >= 0) 987 err = -EINVAL; 988 xenbus_dev_fatal(pdev->xdev, err, 989 "Error reading number of PCI devices"); 990 goto out; 991 } 992 993 /* Find devices being detached and remove them. */ 994 for (i = 0; i < num_devs; i++) { 995 int l, state; 996 l = snprintf(str, sizeof(str), "state-%d", i); 997 if (unlikely(l >= (sizeof(str) - 1))) { 998 err = -ENOMEM; 999 goto out; 1000 } 1001 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d", 1002 &state); 1003 if (err != 1) 1004 state = XenbusStateUnknown; 1005 1006 if (state != XenbusStateClosing) 1007 continue; 1008 1009 /* Remove device. */ 1010 l = snprintf(str, sizeof(str), "vdev-%d", i); 1011 if (unlikely(l >= (sizeof(str) - 1))) { 1012 err = -ENOMEM; 1013 goto out; 1014 } 1015 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 1016 "%x:%x:%x.%x", &domain, &bus, &slot, &func); 1017 if (err != 4) { 1018 if (err >= 0) 1019 err = -EINVAL; 1020 xenbus_dev_fatal(pdev->xdev, err, 1021 "Error reading PCI device %d", i); 1022 goto out; 1023 } 1024 1025 pci_bus = pci_find_bus(domain, bus); 1026 if (!pci_bus) { 1027 dev_dbg(&pdev->xdev->dev, "Cannot get bus %04x:%02x\n", 1028 domain, bus); 1029 continue; 1030 } 1031 pci_dev = pci_get_slot(pci_bus, PCI_DEVFN(slot, func)); 1032 if (!pci_dev) { 1033 dev_dbg(&pdev->xdev->dev, 1034 "Cannot get PCI device %04x:%02x:%02x.%02x\n", 1035 domain, bus, slot, func); 1036 continue; 1037 } 1038 pci_remove_bus_device(pci_dev); 1039 pci_dev_put(pci_dev); 1040 1041 dev_dbg(&pdev->xdev->dev, 1042 "PCI device %04x:%02x:%02x.%02x removed.\n", 1043 domain, bus, slot, func); 1044 } 1045 1046 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring); 1047 1048 out: 1049 return err; 1050 } 1051 1052 static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev, 1053 enum xenbus_state be_state) 1054 { 1055 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1056 1057 switch (be_state) { 1058 case XenbusStateUnknown: 1059 case XenbusStateInitialising: 1060 case XenbusStateInitWait: 1061 case XenbusStateInitialised: 1062 case XenbusStateClosed: 1063 break; 1064 1065 case XenbusStateConnected: 1066 pcifront_try_connect(pdev); 1067 break; 1068 1069 case XenbusStateClosing: 1070 dev_warn(&xdev->dev, "backend going away!\n"); 1071 pcifront_try_disconnect(pdev); 1072 break; 1073 1074 case XenbusStateReconfiguring: 1075 pcifront_detach_devices(pdev); 1076 break; 1077 1078 case XenbusStateReconfigured: 1079 pcifront_attach_devices(pdev); 1080 break; 1081 } 1082 } 1083 1084 static int pcifront_xenbus_probe(struct xenbus_device *xdev, 1085 const struct xenbus_device_id *id) 1086 { 1087 int err = 0; 1088 struct pcifront_device *pdev = alloc_pdev(xdev); 1089 1090 if (pdev == NULL) { 1091 err = -ENOMEM; 1092 xenbus_dev_fatal(xdev, err, 1093 "Error allocating pcifront_device struct"); 1094 goto out; 1095 } 1096 1097 err = pcifront_publish_info(pdev); 1098 if (err) 1099 free_pdev(pdev); 1100 1101 out: 1102 return err; 1103 } 1104 1105 static int pcifront_xenbus_remove(struct xenbus_device *xdev) 1106 { 1107 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1108 if (pdev) 1109 free_pdev(pdev); 1110 1111 return 0; 1112 } 1113 1114 static const struct xenbus_device_id xenpci_ids[] = { 1115 {"pci"}, 1116 {""}, 1117 }; 1118 1119 static struct xenbus_driver xenbus_pcifront_driver = { 1120 .name = "pcifront", 1121 .owner = THIS_MODULE, 1122 .ids = xenpci_ids, 1123 .probe = pcifront_xenbus_probe, 1124 .remove = pcifront_xenbus_remove, 1125 .otherend_changed = pcifront_backend_changed, 1126 }; 1127 1128 static int __init pcifront_init(void) 1129 { 1130 if (!xen_pv_domain() || xen_initial_domain()) 1131 return -ENODEV; 1132 1133 pci_frontend_registrar(1 /* enable */); 1134 1135 return xenbus_register_frontend(&xenbus_pcifront_driver); 1136 } 1137 1138 static void __exit pcifront_cleanup(void) 1139 { 1140 xenbus_unregister_driver(&xenbus_pcifront_driver); 1141 pci_frontend_registrar(0 /* disable */); 1142 } 1143 module_init(pcifront_init); 1144 module_exit(pcifront_cleanup); 1145 1146 MODULE_DESCRIPTION("Xen PCI passthrough frontend."); 1147 MODULE_LICENSE("GPL"); 1148 MODULE_ALIAS("xen:pci"); 1149