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 29struct 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 37struct 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 54struct pcifront_sd { 55 int domain; 56 struct pcifront_device *pdev; 57}; 58 59static inline struct pcifront_device * 60pcifront_get_pdev(struct pcifront_sd *sd) 61{ 62 return sd->pdev; 63} 64 65static 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 73static DEFINE_SPINLOCK(pcifront_dev_lock); 74static struct pcifront_device *pcifront_dev; 75 76static int verbose_request; 77module_param(verbose_request, int, 0644); 78 79static 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 101static 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 110static 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; 171out: 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 */ 177static 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 */ 216static 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 241static struct pci_ops pcifront_bus_ops = { 242 .read = pcifront_bus_read, 243 .write = pcifront_bus_write, 244}; 245 246#ifdef CONFIG_PCI_MSI 247static 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 303static 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 322static 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 351static 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 374static 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 381static 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 389static 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 */ 393static 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 416static 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 445static 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 504err_out: 505 kfree(bus_entry); 506 kfree(sd); 507 508 return err; 509} 510 511static 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 546static 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 558static 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 580static 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 if (pcidev) 600 pci_dev_put(pcidev); 601 return result; 602 } 603 pdrv = pcidev->driver; 604 605 if (pdrv) { 606 if (pdrv->err_handler && pdrv->err_handler->error_detected) { 607 dev_dbg(&pcidev->dev, 608 "trying to call AER service\n"); 609 if (pcidev) { 610 flag = 1; 611 switch (cmd) { 612 case XEN_PCI_OP_aer_detected: 613 result = pdrv->err_handler-> 614 error_detected(pcidev, state); 615 break; 616 case XEN_PCI_OP_aer_mmio: 617 result = pdrv->err_handler-> 618 mmio_enabled(pcidev); 619 break; 620 case XEN_PCI_OP_aer_slotreset: 621 result = pdrv->err_handler-> 622 slot_reset(pcidev); 623 break; 624 case XEN_PCI_OP_aer_resume: 625 pdrv->err_handler->resume(pcidev); 626 break; 627 default: 628 dev_err(&pdev->xdev->dev, 629 "bad request in aer recovery " 630 "operation!\n"); 631 632 } 633 } 634 } 635 } 636 if (!flag) 637 result = PCI_ERS_RESULT_NONE; 638 639 return result; 640} 641 642 643static void pcifront_do_aer(struct work_struct *data) 644{ 645 struct pcifront_device *pdev = 646 container_of(data, struct pcifront_device, op_work); 647 int cmd = pdev->sh_info->aer_op.cmd; 648 pci_channel_state_t state = 649 (pci_channel_state_t)pdev->sh_info->aer_op.err; 650 651 /*If a pci_conf op is in progress, 652 we have to wait until it is done before service aer op*/ 653 dev_dbg(&pdev->xdev->dev, 654 "pcifront service aer bus %x devfn %x\n", 655 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn); 656 657 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state); 658 659 /* Post the operation to the guest. */ 660 wmb(); 661 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags); 662 notify_remote_via_evtchn(pdev->evtchn); 663 664 /*in case of we lost an aer request in four lines time_window*/ 665 smp_mb__before_atomic(); 666 clear_bit(_PDEVB_op_active, &pdev->flags); 667 smp_mb__after_atomic(); 668 669 schedule_pcifront_aer_op(pdev); 670 671} 672 673static irqreturn_t pcifront_handler_aer(int irq, void *dev) 674{ 675 struct pcifront_device *pdev = dev; 676 schedule_pcifront_aer_op(pdev); 677 return IRQ_HANDLED; 678} 679static int pcifront_connect_and_init_dma(struct pcifront_device *pdev) 680{ 681 int err = 0; 682 683 spin_lock(&pcifront_dev_lock); 684 685 if (!pcifront_dev) { 686 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n"); 687 pcifront_dev = pdev; 688 } else 689 err = -EEXIST; 690 691 spin_unlock(&pcifront_dev_lock); 692 693 if (!err && !swiotlb_nr_tbl()) { 694 err = pci_xen_swiotlb_init_late(); 695 if (err) 696 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n"); 697 } 698 return err; 699} 700 701static void pcifront_disconnect(struct pcifront_device *pdev) 702{ 703 spin_lock(&pcifront_dev_lock); 704 705 if (pdev == pcifront_dev) { 706 dev_info(&pdev->xdev->dev, 707 "Disconnecting PCI Frontend Buses\n"); 708 pcifront_dev = NULL; 709 } 710 711 spin_unlock(&pcifront_dev_lock); 712} 713static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev) 714{ 715 struct pcifront_device *pdev; 716 717 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL); 718 if (pdev == NULL) 719 goto out; 720 721 pdev->sh_info = 722 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL); 723 if (pdev->sh_info == NULL) { 724 kfree(pdev); 725 pdev = NULL; 726 goto out; 727 } 728 pdev->sh_info->flags = 0; 729 730 /*Flag for registering PV AER handler*/ 731 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags); 732 733 dev_set_drvdata(&xdev->dev, pdev); 734 pdev->xdev = xdev; 735 736 INIT_LIST_HEAD(&pdev->root_buses); 737 738 spin_lock_init(&pdev->sh_info_lock); 739 740 pdev->evtchn = INVALID_EVTCHN; 741 pdev->gnt_ref = INVALID_GRANT_REF; 742 pdev->irq = -1; 743 744 INIT_WORK(&pdev->op_work, pcifront_do_aer); 745 746 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n", 747 pdev, pdev->sh_info); 748out: 749 return pdev; 750} 751 752static void free_pdev(struct pcifront_device *pdev) 753{ 754 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev); 755 756 pcifront_free_roots(pdev); 757 758 cancel_work_sync(&pdev->op_work); 759 760 if (pdev->irq >= 0) 761 unbind_from_irqhandler(pdev->irq, pdev); 762 763 if (pdev->evtchn != INVALID_EVTCHN) 764 xenbus_free_evtchn(pdev->xdev, pdev->evtchn); 765 766 if (pdev->gnt_ref != INVALID_GRANT_REF) 767 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */, 768 (unsigned long)pdev->sh_info); 769 else 770 free_page((unsigned long)pdev->sh_info); 771 772 dev_set_drvdata(&pdev->xdev->dev, NULL); 773 774 kfree(pdev); 775} 776 777static int pcifront_publish_info(struct pcifront_device *pdev) 778{ 779 int err = 0; 780 struct xenbus_transaction trans; 781 782 err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info)); 783 if (err < 0) 784 goto out; 785 786 pdev->gnt_ref = err; 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 800do_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 839out: 840 return err; 841} 842 843static 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 num_roots = 0; 870 } else if (err != 1) { 871 if (err == 0) 872 err = -EINVAL; 873 xenbus_dev_fatal(pdev->xdev, err, 874 "Error reading number of PCI roots"); 875 goto out; 876 } 877 878 for (i = 0; i < num_roots; i++) { 879 len = snprintf(str, sizeof(str), "root-%d", i); 880 if (unlikely(len >= (sizeof(str) - 1))) { 881 err = -ENOMEM; 882 goto out; 883 } 884 885 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 886 "%x:%x", &domain, &bus); 887 if (err != 2) { 888 if (err >= 0) 889 err = -EINVAL; 890 xenbus_dev_fatal(pdev->xdev, err, 891 "Error reading PCI root %d", i); 892 goto out; 893 } 894 895 err = pcifront_scan_root(pdev, domain, bus); 896 if (err) { 897 xenbus_dev_fatal(pdev->xdev, err, 898 "Error scanning PCI root %04x:%02x", 899 domain, bus); 900 goto out; 901 } 902 } 903 904 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); 905 906out: 907 return err; 908} 909 910static int pcifront_try_disconnect(struct pcifront_device *pdev) 911{ 912 int err = 0; 913 enum xenbus_state prev_state; 914 915 916 prev_state = xenbus_read_driver_state(pdev->xdev->nodename); 917 918 if (prev_state >= XenbusStateClosing) 919 goto out; 920 921 if (prev_state == XenbusStateConnected) { 922 pcifront_free_roots(pdev); 923 pcifront_disconnect(pdev); 924 } 925 926 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed); 927 928out: 929 930 return err; 931} 932 933static int pcifront_attach_devices(struct pcifront_device *pdev) 934{ 935 int err = -EFAULT; 936 int i, num_roots, len; 937 unsigned int domain, bus; 938 char str[64]; 939 940 if (xenbus_read_driver_state(pdev->xdev->nodename) != 941 XenbusStateReconfiguring) 942 goto out; 943 944 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 945 "root_num", "%d", &num_roots); 946 if (err == -ENOENT) { 947 xenbus_dev_error(pdev->xdev, err, 948 "No PCI Roots found, trying 0000:00"); 949 err = pcifront_rescan_root(pdev, 0, 0); 950 num_roots = 0; 951 } else if (err != 1) { 952 if (err == 0) 953 err = -EINVAL; 954 xenbus_dev_fatal(pdev->xdev, err, 955 "Error reading number of PCI roots"); 956 goto out; 957 } 958 959 for (i = 0; i < num_roots; i++) { 960 len = snprintf(str, sizeof(str), "root-%d", i); 961 if (unlikely(len >= (sizeof(str) - 1))) { 962 err = -ENOMEM; 963 goto out; 964 } 965 966 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 967 "%x:%x", &domain, &bus); 968 if (err != 2) { 969 if (err >= 0) 970 err = -EINVAL; 971 xenbus_dev_fatal(pdev->xdev, err, 972 "Error reading PCI root %d", i); 973 goto out; 974 } 975 976 err = pcifront_rescan_root(pdev, domain, bus); 977 if (err) { 978 xenbus_dev_fatal(pdev->xdev, err, 979 "Error scanning PCI root %04x:%02x", 980 domain, bus); 981 goto out; 982 } 983 } 984 985 xenbus_switch_state(pdev->xdev, XenbusStateConnected); 986 987out: 988 return err; 989} 990 991static int pcifront_detach_devices(struct pcifront_device *pdev) 992{ 993 int err = 0; 994 int i, num_devs; 995 unsigned int domain, bus, slot, func; 996 struct pci_dev *pci_dev; 997 char str[64]; 998 999 if (xenbus_read_driver_state(pdev->xdev->nodename) != 1000 XenbusStateConnected) 1001 goto out; 1002 1003 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d", 1004 &num_devs); 1005 if (err != 1) { 1006 if (err >= 0) 1007 err = -EINVAL; 1008 xenbus_dev_fatal(pdev->xdev, err, 1009 "Error reading number of PCI devices"); 1010 goto out; 1011 } 1012 1013 /* Find devices being detached and remove them. */ 1014 for (i = 0; i < num_devs; i++) { 1015 int l, state; 1016 l = snprintf(str, sizeof(str), "state-%d", i); 1017 if (unlikely(l >= (sizeof(str) - 1))) { 1018 err = -ENOMEM; 1019 goto out; 1020 } 1021 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d", 1022 &state); 1023 if (err != 1) 1024 state = XenbusStateUnknown; 1025 1026 if (state != XenbusStateClosing) 1027 continue; 1028 1029 /* Remove device. */ 1030 l = snprintf(str, sizeof(str), "vdev-%d", i); 1031 if (unlikely(l >= (sizeof(str) - 1))) { 1032 err = -ENOMEM; 1033 goto out; 1034 } 1035 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 1036 "%x:%x:%x.%x", &domain, &bus, &slot, &func); 1037 if (err != 4) { 1038 if (err >= 0) 1039 err = -EINVAL; 1040 xenbus_dev_fatal(pdev->xdev, err, 1041 "Error reading PCI device %d", i); 1042 goto out; 1043 } 1044 1045 pci_dev = pci_get_domain_bus_and_slot(domain, bus, 1046 PCI_DEVFN(slot, func)); 1047 if (!pci_dev) { 1048 dev_dbg(&pdev->xdev->dev, 1049 "Cannot get PCI device %04x:%02x:%02x.%d\n", 1050 domain, bus, slot, func); 1051 continue; 1052 } 1053 pci_lock_rescan_remove(); 1054 pci_stop_and_remove_bus_device(pci_dev); 1055 pci_dev_put(pci_dev); 1056 pci_unlock_rescan_remove(); 1057 1058 dev_dbg(&pdev->xdev->dev, 1059 "PCI device %04x:%02x:%02x.%d removed.\n", 1060 domain, bus, slot, func); 1061 } 1062 1063 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring); 1064 1065out: 1066 return err; 1067} 1068 1069static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev, 1070 enum xenbus_state be_state) 1071{ 1072 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1073 1074 switch (be_state) { 1075 case XenbusStateUnknown: 1076 case XenbusStateInitialising: 1077 case XenbusStateInitWait: 1078 case XenbusStateInitialised: 1079 break; 1080 1081 case XenbusStateConnected: 1082 pcifront_try_connect(pdev); 1083 break; 1084 1085 case XenbusStateClosed: 1086 if (xdev->state == XenbusStateClosed) 1087 break; 1088 /* Missed the backend's CLOSING state -- fallthrough */ 1089 case XenbusStateClosing: 1090 dev_warn(&xdev->dev, "backend going away!\n"); 1091 pcifront_try_disconnect(pdev); 1092 break; 1093 1094 case XenbusStateReconfiguring: 1095 pcifront_detach_devices(pdev); 1096 break; 1097 1098 case XenbusStateReconfigured: 1099 pcifront_attach_devices(pdev); 1100 break; 1101 } 1102} 1103 1104static int pcifront_xenbus_probe(struct xenbus_device *xdev, 1105 const struct xenbus_device_id *id) 1106{ 1107 int err = 0; 1108 struct pcifront_device *pdev = alloc_pdev(xdev); 1109 1110 if (pdev == NULL) { 1111 err = -ENOMEM; 1112 xenbus_dev_fatal(xdev, err, 1113 "Error allocating pcifront_device struct"); 1114 goto out; 1115 } 1116 1117 err = pcifront_publish_info(pdev); 1118 if (err) 1119 free_pdev(pdev); 1120 1121out: 1122 return err; 1123} 1124 1125static int pcifront_xenbus_remove(struct xenbus_device *xdev) 1126{ 1127 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1128 if (pdev) 1129 free_pdev(pdev); 1130 1131 return 0; 1132} 1133 1134static const struct xenbus_device_id xenpci_ids[] = { 1135 {"pci"}, 1136 {""}, 1137}; 1138 1139static struct xenbus_driver xenpci_driver = { 1140 .name = "pcifront", 1141 .ids = xenpci_ids, 1142 .probe = pcifront_xenbus_probe, 1143 .remove = pcifront_xenbus_remove, 1144 .otherend_changed = pcifront_backend_changed, 1145}; 1146 1147static int __init pcifront_init(void) 1148{ 1149 if (!xen_pv_domain() || xen_initial_domain()) 1150 return -ENODEV; 1151 1152 if (!xen_has_pv_devices()) 1153 return -ENODEV; 1154 1155 pci_frontend_registrar(1 /* enable */); 1156 1157 return xenbus_register_frontend(&xenpci_driver); 1158} 1159 1160static void __exit pcifront_cleanup(void) 1161{ 1162 xenbus_unregister_driver(&xenpci_driver); 1163 pci_frontend_registrar(0 /* disable */); 1164} 1165module_init(pcifront_init); 1166module_exit(pcifront_cleanup); 1167 1168MODULE_DESCRIPTION("Xen PCI passthrough frontend."); 1169MODULE_LICENSE("GPL"); 1170MODULE_ALIAS("xen:pci"); 1171