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