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 <linux/ktime.h> 24 #include <xen/platform_pci.h> 25 26 #include <asm/xen/swiotlb-xen.h> 27 #define INVALID_GRANT_REF (0) 28 #define INVALID_EVTCHN (-1) 29 30 struct pci_bus_entry { 31 struct list_head list; 32 struct pci_bus *bus; 33 }; 34 35 #define _PDEVB_op_active (0) 36 #define PDEVB_op_active (1 << (_PDEVB_op_active)) 37 38 struct pcifront_device { 39 struct xenbus_device *xdev; 40 struct list_head root_buses; 41 42 int evtchn; 43 int gnt_ref; 44 45 int irq; 46 47 /* Lock this when doing any operations in sh_info */ 48 spinlock_t sh_info_lock; 49 struct xen_pci_sharedinfo *sh_info; 50 struct work_struct op_work; 51 unsigned long flags; 52 53 }; 54 55 struct pcifront_sd { 56 int domain; 57 struct pcifront_device *pdev; 58 }; 59 60 static inline struct pcifront_device * 61 pcifront_get_pdev(struct pcifront_sd *sd) 62 { 63 return sd->pdev; 64 } 65 66 static inline void pcifront_init_sd(struct pcifront_sd *sd, 67 unsigned int domain, unsigned int bus, 68 struct pcifront_device *pdev) 69 { 70 sd->domain = domain; 71 sd->pdev = pdev; 72 } 73 74 static DEFINE_SPINLOCK(pcifront_dev_lock); 75 static struct pcifront_device *pcifront_dev; 76 77 static int verbose_request; 78 module_param(verbose_request, int, 0644); 79 80 static int errno_to_pcibios_err(int errno) 81 { 82 switch (errno) { 83 case XEN_PCI_ERR_success: 84 return PCIBIOS_SUCCESSFUL; 85 86 case XEN_PCI_ERR_dev_not_found: 87 return PCIBIOS_DEVICE_NOT_FOUND; 88 89 case XEN_PCI_ERR_invalid_offset: 90 case XEN_PCI_ERR_op_failed: 91 return PCIBIOS_BAD_REGISTER_NUMBER; 92 93 case XEN_PCI_ERR_not_implemented: 94 return PCIBIOS_FUNC_NOT_SUPPORTED; 95 96 case XEN_PCI_ERR_access_denied: 97 return PCIBIOS_SET_FAILED; 98 } 99 return errno; 100 } 101 102 static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev) 103 { 104 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags) 105 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) { 106 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n"); 107 schedule_work(&pdev->op_work); 108 } 109 } 110 111 static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op) 112 { 113 int err = 0; 114 struct xen_pci_op *active_op = &pdev->sh_info->op; 115 unsigned long irq_flags; 116 evtchn_port_t port = pdev->evtchn; 117 unsigned irq = pdev->irq; 118 s64 ns, ns_timeout; 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 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC; 136 137 xen_clear_irq_pending(irq); 138 139 while (test_bit(_XEN_PCIF_active, 140 (unsigned long *)&pdev->sh_info->flags)) { 141 xen_poll_irq_timeout(irq, jiffies + 3*HZ); 142 xen_clear_irq_pending(irq); 143 ns = ktime_get_ns(); 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.%d - 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.%d - " 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 static 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 for_each_pci_msi_entry(entry, dev) { 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 if (op.msix_entries[i].vector <= 0) { 282 dev_warn(&dev->dev, "MSI-X entry %d is invalid: %d!\n", 283 i, op.msix_entries[i].vector); 284 err = -EINVAL; 285 vector[i] = -1; 286 continue; 287 } 288 vector[i] = op.msix_entries[i].vector; 289 } 290 } else { 291 printk(KERN_DEBUG "enable msix get value %x\n", 292 op.value); 293 err = op.value; 294 } 295 } else { 296 dev_err(&dev->dev, "enable msix get err %x\n", err); 297 } 298 return err; 299 } 300 301 static void pci_frontend_disable_msix(struct pci_dev *dev) 302 { 303 int err; 304 struct xen_pci_op op = { 305 .cmd = XEN_PCI_OP_disable_msix, 306 .domain = pci_domain_nr(dev->bus), 307 .bus = dev->bus->number, 308 .devfn = dev->devfn, 309 }; 310 struct pcifront_sd *sd = dev->bus->sysdata; 311 struct pcifront_device *pdev = pcifront_get_pdev(sd); 312 313 err = do_pci_op(pdev, &op); 314 315 /* What should do for error ? */ 316 if (err) 317 dev_err(&dev->dev, "pci_disable_msix get err %x\n", err); 318 } 319 320 static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[]) 321 { 322 int err; 323 struct xen_pci_op op = { 324 .cmd = XEN_PCI_OP_enable_msi, 325 .domain = pci_domain_nr(dev->bus), 326 .bus = dev->bus->number, 327 .devfn = dev->devfn, 328 }; 329 struct pcifront_sd *sd = dev->bus->sysdata; 330 struct pcifront_device *pdev = pcifront_get_pdev(sd); 331 332 err = do_pci_op(pdev, &op); 333 if (likely(!err)) { 334 vector[0] = op.value; 335 if (op.value <= 0) { 336 dev_warn(&dev->dev, "MSI entry is invalid: %d!\n", 337 op.value); 338 err = -EINVAL; 339 vector[0] = -1; 340 } 341 } else { 342 dev_err(&dev->dev, "pci frontend enable msi failed for dev " 343 "%x:%x\n", op.bus, op.devfn); 344 err = -EINVAL; 345 } 346 return err; 347 } 348 349 static void pci_frontend_disable_msi(struct pci_dev *dev) 350 { 351 int err; 352 struct xen_pci_op op = { 353 .cmd = XEN_PCI_OP_disable_msi, 354 .domain = pci_domain_nr(dev->bus), 355 .bus = dev->bus->number, 356 .devfn = dev->devfn, 357 }; 358 struct pcifront_sd *sd = dev->bus->sysdata; 359 struct pcifront_device *pdev = pcifront_get_pdev(sd); 360 361 err = do_pci_op(pdev, &op); 362 if (err == XEN_PCI_ERR_dev_not_found) { 363 /* XXX No response from backend, what shall we do? */ 364 printk(KERN_DEBUG "get no response from backend for disable MSI\n"); 365 return; 366 } 367 if (err) 368 /* how can pciback notify us fail? */ 369 printk(KERN_DEBUG "get fake response frombackend\n"); 370 } 371 372 static struct xen_pci_frontend_ops pci_frontend_ops = { 373 .enable_msi = pci_frontend_enable_msi, 374 .disable_msi = pci_frontend_disable_msi, 375 .enable_msix = pci_frontend_enable_msix, 376 .disable_msix = pci_frontend_disable_msix, 377 }; 378 379 static void pci_frontend_registrar(int enable) 380 { 381 if (enable) 382 xen_pci_frontend = &pci_frontend_ops; 383 else 384 xen_pci_frontend = NULL; 385 }; 386 #else 387 static inline void pci_frontend_registrar(int enable) { }; 388 #endif /* CONFIG_PCI_MSI */ 389 390 /* Claim resources for the PCI frontend as-is, backend won't allow changes */ 391 static int pcifront_claim_resource(struct pci_dev *dev, void *data) 392 { 393 struct pcifront_device *pdev = data; 394 int i; 395 struct resource *r; 396 397 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 398 r = &dev->resource[i]; 399 400 if (!r->parent && r->start && r->flags) { 401 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n", 402 pci_name(dev), i); 403 if (pci_claim_resource(dev, i)) { 404 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! " 405 "Device offline. Try using e820_host=1 in the guest config.\n", 406 pci_name(dev), i); 407 } 408 } 409 } 410 411 return 0; 412 } 413 414 static int pcifront_scan_bus(struct pcifront_device *pdev, 415 unsigned int domain, unsigned int bus, 416 struct pci_bus *b) 417 { 418 struct pci_dev *d; 419 unsigned int devfn; 420 421 /* Scan the bus for functions and add. 422 * We omit handling of PCI bridge attachment because pciback prevents 423 * bridges from being exported. 424 */ 425 for (devfn = 0; devfn < 0x100; devfn++) { 426 d = pci_get_slot(b, devfn); 427 if (d) { 428 /* Device is already known. */ 429 pci_dev_put(d); 430 continue; 431 } 432 433 d = pci_scan_single_device(b, devfn); 434 if (d) 435 dev_info(&pdev->xdev->dev, "New device on " 436 "%04x:%02x:%02x.%d found.\n", domain, bus, 437 PCI_SLOT(devfn), PCI_FUNC(devfn)); 438 } 439 440 return 0; 441 } 442 443 static int pcifront_scan_root(struct pcifront_device *pdev, 444 unsigned int domain, unsigned int bus) 445 { 446 struct pci_bus *b; 447 LIST_HEAD(resources); 448 struct pcifront_sd *sd = NULL; 449 struct pci_bus_entry *bus_entry = NULL; 450 int err = 0; 451 static struct resource busn_res = { 452 .start = 0, 453 .end = 255, 454 .flags = IORESOURCE_BUS, 455 }; 456 457 #ifndef CONFIG_PCI_DOMAINS 458 if (domain != 0) { 459 dev_err(&pdev->xdev->dev, 460 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 461 dev_err(&pdev->xdev->dev, 462 "Please compile with CONFIG_PCI_DOMAINS\n"); 463 err = -EINVAL; 464 goto err_out; 465 } 466 #endif 467 468 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", 469 domain, bus); 470 471 bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL); 472 sd = kmalloc(sizeof(*sd), GFP_KERNEL); 473 if (!bus_entry || !sd) { 474 err = -ENOMEM; 475 goto err_out; 476 } 477 pci_add_resource(&resources, &ioport_resource); 478 pci_add_resource(&resources, &iomem_resource); 479 pci_add_resource(&resources, &busn_res); 480 pcifront_init_sd(sd, domain, bus, pdev); 481 482 pci_lock_rescan_remove(); 483 484 b = pci_scan_root_bus(&pdev->xdev->dev, bus, 485 &pcifront_bus_ops, sd, &resources); 486 if (!b) { 487 dev_err(&pdev->xdev->dev, 488 "Error creating PCI Frontend Bus!\n"); 489 err = -ENOMEM; 490 pci_unlock_rescan_remove(); 491 pci_free_resource_list(&resources); 492 goto err_out; 493 } 494 495 bus_entry->bus = b; 496 497 list_add(&bus_entry->list, &pdev->root_buses); 498 499 /* pci_scan_root_bus skips devices which do not have a 500 * devfn==0. The pcifront_scan_bus enumerates all devfn. */ 501 err = pcifront_scan_bus(pdev, domain, bus, b); 502 503 /* Claim resources before going "live" with our devices */ 504 pci_walk_bus(b, pcifront_claim_resource, pdev); 505 506 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 507 pci_bus_add_devices(b); 508 509 pci_unlock_rescan_remove(); 510 return err; 511 512 err_out: 513 kfree(bus_entry); 514 kfree(sd); 515 516 return err; 517 } 518 519 static int pcifront_rescan_root(struct pcifront_device *pdev, 520 unsigned int domain, unsigned int bus) 521 { 522 int err; 523 struct pci_bus *b; 524 525 #ifndef CONFIG_PCI_DOMAINS 526 if (domain != 0) { 527 dev_err(&pdev->xdev->dev, 528 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 529 dev_err(&pdev->xdev->dev, 530 "Please compile with CONFIG_PCI_DOMAINS\n"); 531 return -EINVAL; 532 } 533 #endif 534 535 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n", 536 domain, bus); 537 538 b = pci_find_bus(domain, bus); 539 if (!b) 540 /* If the bus is unknown, create it. */ 541 return pcifront_scan_root(pdev, domain, bus); 542 543 err = pcifront_scan_bus(pdev, domain, bus, b); 544 545 /* Claim resources before going "live" with our devices */ 546 pci_walk_bus(b, pcifront_claim_resource, pdev); 547 548 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 549 pci_bus_add_devices(b); 550 551 return err; 552 } 553 554 static void free_root_bus_devs(struct pci_bus *bus) 555 { 556 struct pci_dev *dev; 557 558 while (!list_empty(&bus->devices)) { 559 dev = container_of(bus->devices.next, struct pci_dev, 560 bus_list); 561 dev_dbg(&dev->dev, "removing device\n"); 562 pci_stop_and_remove_bus_device(dev); 563 } 564 } 565 566 static void pcifront_free_roots(struct pcifront_device *pdev) 567 { 568 struct pci_bus_entry *bus_entry, *t; 569 570 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n"); 571 572 pci_lock_rescan_remove(); 573 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) { 574 list_del(&bus_entry->list); 575 576 free_root_bus_devs(bus_entry->bus); 577 578 kfree(bus_entry->bus->sysdata); 579 580 device_unregister(bus_entry->bus->bridge); 581 pci_remove_bus(bus_entry->bus); 582 583 kfree(bus_entry); 584 } 585 pci_unlock_rescan_remove(); 586 } 587 588 static pci_ers_result_t pcifront_common_process(int cmd, 589 struct pcifront_device *pdev, 590 pci_channel_state_t state) 591 { 592 pci_ers_result_t result; 593 struct pci_driver *pdrv; 594 int bus = pdev->sh_info->aer_op.bus; 595 int devfn = pdev->sh_info->aer_op.devfn; 596 struct pci_dev *pcidev; 597 int flag = 0; 598 599 dev_dbg(&pdev->xdev->dev, 600 "pcifront AER process: cmd %x (bus:%x, devfn%x)", 601 cmd, bus, devfn); 602 result = PCI_ERS_RESULT_NONE; 603 604 pcidev = pci_get_bus_and_slot(bus, devfn); 605 if (!pcidev || !pcidev->driver) { 606 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n"); 607 pci_dev_put(pcidev); 608 return result; 609 } 610 pdrv = pcidev->driver; 611 612 if (pdrv) { 613 if (pdrv->err_handler && pdrv->err_handler->error_detected) { 614 dev_dbg(&pcidev->dev, 615 "trying to call AER service\n"); 616 if (pcidev) { 617 flag = 1; 618 switch (cmd) { 619 case XEN_PCI_OP_aer_detected: 620 result = pdrv->err_handler-> 621 error_detected(pcidev, state); 622 break; 623 case XEN_PCI_OP_aer_mmio: 624 result = pdrv->err_handler-> 625 mmio_enabled(pcidev); 626 break; 627 case XEN_PCI_OP_aer_slotreset: 628 result = pdrv->err_handler-> 629 slot_reset(pcidev); 630 break; 631 case XEN_PCI_OP_aer_resume: 632 pdrv->err_handler->resume(pcidev); 633 break; 634 default: 635 dev_err(&pdev->xdev->dev, 636 "bad request in aer recovery " 637 "operation!\n"); 638 639 } 640 } 641 } 642 } 643 if (!flag) 644 result = PCI_ERS_RESULT_NONE; 645 646 return result; 647 } 648 649 650 static void pcifront_do_aer(struct work_struct *data) 651 { 652 struct pcifront_device *pdev = 653 container_of(data, struct pcifront_device, op_work); 654 int cmd = pdev->sh_info->aer_op.cmd; 655 pci_channel_state_t state = 656 (pci_channel_state_t)pdev->sh_info->aer_op.err; 657 658 /*If a pci_conf op is in progress, 659 we have to wait until it is done before service aer op*/ 660 dev_dbg(&pdev->xdev->dev, 661 "pcifront service aer bus %x devfn %x\n", 662 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn); 663 664 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state); 665 666 /* Post the operation to the guest. */ 667 wmb(); 668 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags); 669 notify_remote_via_evtchn(pdev->evtchn); 670 671 /*in case of we lost an aer request in four lines time_window*/ 672 smp_mb__before_atomic(); 673 clear_bit(_PDEVB_op_active, &pdev->flags); 674 smp_mb__after_atomic(); 675 676 schedule_pcifront_aer_op(pdev); 677 678 } 679 680 static irqreturn_t pcifront_handler_aer(int irq, void *dev) 681 { 682 struct pcifront_device *pdev = dev; 683 schedule_pcifront_aer_op(pdev); 684 return IRQ_HANDLED; 685 } 686 static int pcifront_connect_and_init_dma(struct pcifront_device *pdev) 687 { 688 int err = 0; 689 690 spin_lock(&pcifront_dev_lock); 691 692 if (!pcifront_dev) { 693 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n"); 694 pcifront_dev = pdev; 695 } else 696 err = -EEXIST; 697 698 spin_unlock(&pcifront_dev_lock); 699 700 if (!err && !swiotlb_nr_tbl()) { 701 err = pci_xen_swiotlb_init_late(); 702 if (err) 703 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n"); 704 } 705 return err; 706 } 707 708 static void pcifront_disconnect(struct pcifront_device *pdev) 709 { 710 spin_lock(&pcifront_dev_lock); 711 712 if (pdev == pcifront_dev) { 713 dev_info(&pdev->xdev->dev, 714 "Disconnecting PCI Frontend Buses\n"); 715 pcifront_dev = NULL; 716 } 717 718 spin_unlock(&pcifront_dev_lock); 719 } 720 static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev) 721 { 722 struct pcifront_device *pdev; 723 724 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL); 725 if (pdev == NULL) 726 goto out; 727 728 pdev->sh_info = 729 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL); 730 if (pdev->sh_info == NULL) { 731 kfree(pdev); 732 pdev = NULL; 733 goto out; 734 } 735 pdev->sh_info->flags = 0; 736 737 /*Flag for registering PV AER handler*/ 738 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags); 739 740 dev_set_drvdata(&xdev->dev, pdev); 741 pdev->xdev = xdev; 742 743 INIT_LIST_HEAD(&pdev->root_buses); 744 745 spin_lock_init(&pdev->sh_info_lock); 746 747 pdev->evtchn = INVALID_EVTCHN; 748 pdev->gnt_ref = INVALID_GRANT_REF; 749 pdev->irq = -1; 750 751 INIT_WORK(&pdev->op_work, pcifront_do_aer); 752 753 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n", 754 pdev, pdev->sh_info); 755 out: 756 return pdev; 757 } 758 759 static void free_pdev(struct pcifront_device *pdev) 760 { 761 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev); 762 763 pcifront_free_roots(pdev); 764 765 cancel_work_sync(&pdev->op_work); 766 767 if (pdev->irq >= 0) 768 unbind_from_irqhandler(pdev->irq, pdev); 769 770 if (pdev->evtchn != INVALID_EVTCHN) 771 xenbus_free_evtchn(pdev->xdev, pdev->evtchn); 772 773 if (pdev->gnt_ref != INVALID_GRANT_REF) 774 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */, 775 (unsigned long)pdev->sh_info); 776 else 777 free_page((unsigned long)pdev->sh_info); 778 779 dev_set_drvdata(&pdev->xdev->dev, NULL); 780 781 kfree(pdev); 782 } 783 784 static int pcifront_publish_info(struct pcifront_device *pdev) 785 { 786 int err = 0; 787 struct xenbus_transaction trans; 788 grant_ref_t gref; 789 790 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref); 791 if (err < 0) 792 goto out; 793 794 pdev->gnt_ref = gref; 795 796 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn); 797 if (err) 798 goto out; 799 800 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer, 801 0, "pcifront", pdev); 802 803 if (err < 0) 804 return err; 805 806 pdev->irq = err; 807 808 do_publish: 809 err = xenbus_transaction_start(&trans); 810 if (err) { 811 xenbus_dev_fatal(pdev->xdev, err, 812 "Error writing configuration for backend " 813 "(start transaction)"); 814 goto out; 815 } 816 817 err = xenbus_printf(trans, pdev->xdev->nodename, 818 "pci-op-ref", "%u", pdev->gnt_ref); 819 if (!err) 820 err = xenbus_printf(trans, pdev->xdev->nodename, 821 "event-channel", "%u", pdev->evtchn); 822 if (!err) 823 err = xenbus_printf(trans, pdev->xdev->nodename, 824 "magic", XEN_PCI_MAGIC); 825 826 if (err) { 827 xenbus_transaction_end(trans, 1); 828 xenbus_dev_fatal(pdev->xdev, err, 829 "Error writing configuration for backend"); 830 goto out; 831 } else { 832 err = xenbus_transaction_end(trans, 0); 833 if (err == -EAGAIN) 834 goto do_publish; 835 else if (err) { 836 xenbus_dev_fatal(pdev->xdev, err, 837 "Error completing transaction " 838 "for backend"); 839 goto out; 840 } 841 } 842 843 xenbus_switch_state(pdev->xdev, XenbusStateInitialised); 844 845 dev_dbg(&pdev->xdev->dev, "publishing successful!\n"); 846 847 out: 848 return err; 849 } 850 851 static int pcifront_try_connect(struct pcifront_device *pdev) 852 { 853 int err = -EFAULT; 854 int i, num_roots, len; 855 char str[64]; 856 unsigned int domain, bus; 857 858 859 /* Only connect once */ 860 if (xenbus_read_driver_state(pdev->xdev->nodename) != 861 XenbusStateInitialised) 862 goto out; 863 864 err = pcifront_connect_and_init_dma(pdev); 865 if (err && err != -EEXIST) { 866 xenbus_dev_fatal(pdev->xdev, err, 867 "Error setting up PCI Frontend"); 868 goto out; 869 } 870 871 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 872 "root_num", "%d", &num_roots); 873 if (err == -ENOENT) { 874 xenbus_dev_error(pdev->xdev, err, 875 "No PCI Roots found, trying 0000:00"); 876 err = pcifront_scan_root(pdev, 0, 0); 877 if (err) { 878 xenbus_dev_fatal(pdev->xdev, err, 879 "Error scanning PCI root 0000:00"); 880 goto out; 881 } 882 num_roots = 0; 883 } else if (err != 1) { 884 if (err == 0) 885 err = -EINVAL; 886 xenbus_dev_fatal(pdev->xdev, err, 887 "Error reading number of PCI roots"); 888 goto out; 889 } 890 891 for (i = 0; i < num_roots; i++) { 892 len = snprintf(str, sizeof(str), "root-%d", i); 893 if (unlikely(len >= (sizeof(str) - 1))) { 894 err = -ENOMEM; 895 goto out; 896 } 897 898 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 899 "%x:%x", &domain, &bus); 900 if (err != 2) { 901 if (err >= 0) 902 err = -EINVAL; 903 xenbus_dev_fatal(pdev->xdev, err, 904 "Error reading PCI root %d", i); 905 goto out; 906 } 907 908 err = pcifront_scan_root(pdev, domain, bus); 909 if (err) { 910 xenbus_dev_fatal(pdev->xdev, err, 911 "Error scanning PCI root %04x:%02x", 912 domain, bus); 913 goto out; 914 } 915 } 916 917 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); 918 919 out: 920 return err; 921 } 922 923 static int pcifront_try_disconnect(struct pcifront_device *pdev) 924 { 925 int err = 0; 926 enum xenbus_state prev_state; 927 928 929 prev_state = xenbus_read_driver_state(pdev->xdev->nodename); 930 931 if (prev_state >= XenbusStateClosing) 932 goto out; 933 934 if (prev_state == XenbusStateConnected) { 935 pcifront_free_roots(pdev); 936 pcifront_disconnect(pdev); 937 } 938 939 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed); 940 941 out: 942 943 return err; 944 } 945 946 static int pcifront_attach_devices(struct pcifront_device *pdev) 947 { 948 int err = -EFAULT; 949 int i, num_roots, len; 950 unsigned int domain, bus; 951 char str[64]; 952 953 if (xenbus_read_driver_state(pdev->xdev->nodename) != 954 XenbusStateReconfiguring) 955 goto out; 956 957 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 958 "root_num", "%d", &num_roots); 959 if (err == -ENOENT) { 960 xenbus_dev_error(pdev->xdev, err, 961 "No PCI Roots found, trying 0000:00"); 962 err = pcifront_rescan_root(pdev, 0, 0); 963 if (err) { 964 xenbus_dev_fatal(pdev->xdev, err, 965 "Error scanning PCI root 0000:00"); 966 goto out; 967 } 968 num_roots = 0; 969 } else if (err != 1) { 970 if (err == 0) 971 err = -EINVAL; 972 xenbus_dev_fatal(pdev->xdev, err, 973 "Error reading number of PCI roots"); 974 goto out; 975 } 976 977 for (i = 0; i < num_roots; i++) { 978 len = snprintf(str, sizeof(str), "root-%d", i); 979 if (unlikely(len >= (sizeof(str) - 1))) { 980 err = -ENOMEM; 981 goto out; 982 } 983 984 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 985 "%x:%x", &domain, &bus); 986 if (err != 2) { 987 if (err >= 0) 988 err = -EINVAL; 989 xenbus_dev_fatal(pdev->xdev, err, 990 "Error reading PCI root %d", i); 991 goto out; 992 } 993 994 err = pcifront_rescan_root(pdev, domain, bus); 995 if (err) { 996 xenbus_dev_fatal(pdev->xdev, err, 997 "Error scanning PCI root %04x:%02x", 998 domain, bus); 999 goto out; 1000 } 1001 } 1002 1003 xenbus_switch_state(pdev->xdev, XenbusStateConnected); 1004 1005 out: 1006 return err; 1007 } 1008 1009 static int pcifront_detach_devices(struct pcifront_device *pdev) 1010 { 1011 int err = 0; 1012 int i, num_devs; 1013 unsigned int domain, bus, slot, func; 1014 struct pci_dev *pci_dev; 1015 char str[64]; 1016 1017 if (xenbus_read_driver_state(pdev->xdev->nodename) != 1018 XenbusStateConnected) 1019 goto out; 1020 1021 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d", 1022 &num_devs); 1023 if (err != 1) { 1024 if (err >= 0) 1025 err = -EINVAL; 1026 xenbus_dev_fatal(pdev->xdev, err, 1027 "Error reading number of PCI devices"); 1028 goto out; 1029 } 1030 1031 /* Find devices being detached and remove them. */ 1032 for (i = 0; i < num_devs; i++) { 1033 int l, state; 1034 l = snprintf(str, sizeof(str), "state-%d", i); 1035 if (unlikely(l >= (sizeof(str) - 1))) { 1036 err = -ENOMEM; 1037 goto out; 1038 } 1039 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d", 1040 &state); 1041 if (err != 1) 1042 state = 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 __init_refok 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 /* Missed the backend's CLOSING state -- fallthrough */ 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