1 // SPDX-License-Identifier: GPL-2.0 2 /** 3 * PCI Endpoint *Controller* (EPC) library 4 * 5 * Copyright (C) 2017 Texas Instruments 6 * Author: Kishon Vijay Abraham I <kishon@ti.com> 7 */ 8 9 #include <linux/device.h> 10 #include <linux/slab.h> 11 #include <linux/module.h> 12 #include <linux/of_device.h> 13 14 #include <linux/pci-epc.h> 15 #include <linux/pci-epf.h> 16 #include <linux/pci-ep-cfs.h> 17 18 static struct class *pci_epc_class; 19 20 static void devm_pci_epc_release(struct device *dev, void *res) 21 { 22 struct pci_epc *epc = *(struct pci_epc **)res; 23 24 pci_epc_destroy(epc); 25 } 26 27 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data) 28 { 29 struct pci_epc **epc = res; 30 31 return *epc == match_data; 32 } 33 34 /** 35 * pci_epc_put() - release the PCI endpoint controller 36 * @epc: epc returned by pci_epc_get() 37 * 38 * release the refcount the caller obtained by invoking pci_epc_get() 39 */ 40 void pci_epc_put(struct pci_epc *epc) 41 { 42 if (!epc || IS_ERR(epc)) 43 return; 44 45 module_put(epc->ops->owner); 46 put_device(&epc->dev); 47 } 48 EXPORT_SYMBOL_GPL(pci_epc_put); 49 50 /** 51 * pci_epc_get() - get the PCI endpoint controller 52 * @epc_name: device name of the endpoint controller 53 * 54 * Invoke to get struct pci_epc * corresponding to the device name of the 55 * endpoint controller 56 */ 57 struct pci_epc *pci_epc_get(const char *epc_name) 58 { 59 int ret = -EINVAL; 60 struct pci_epc *epc; 61 struct device *dev; 62 struct class_dev_iter iter; 63 64 class_dev_iter_init(&iter, pci_epc_class, NULL, NULL); 65 while ((dev = class_dev_iter_next(&iter))) { 66 if (strcmp(epc_name, dev_name(dev))) 67 continue; 68 69 epc = to_pci_epc(dev); 70 if (!try_module_get(epc->ops->owner)) { 71 ret = -EINVAL; 72 goto err; 73 } 74 75 class_dev_iter_exit(&iter); 76 get_device(&epc->dev); 77 return epc; 78 } 79 80 err: 81 class_dev_iter_exit(&iter); 82 return ERR_PTR(ret); 83 } 84 EXPORT_SYMBOL_GPL(pci_epc_get); 85 86 /** 87 * pci_epc_get_first_free_bar() - helper to get first unreserved BAR 88 * @epc_features: pci_epc_features structure that holds the reserved bar bitmap 89 * 90 * Invoke to get the first unreserved BAR that can be used for endpoint 91 * function. For any incorrect value in reserved_bar return '0'. 92 */ 93 unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features 94 *epc_features) 95 { 96 int free_bar; 97 98 if (!epc_features) 99 return 0; 100 101 free_bar = ffz(epc_features->reserved_bar); 102 if (free_bar > 5) 103 return 0; 104 105 return free_bar; 106 } 107 EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar); 108 109 /** 110 * pci_epc_get_features() - get the features supported by EPC 111 * @epc: the features supported by *this* EPC device will be returned 112 * @func_no: the features supported by the EPC device specific to the 113 * endpoint function with func_no will be returned 114 * 115 * Invoke to get the features provided by the EPC which may be 116 * specific to an endpoint function. Returns pci_epc_features on success 117 * and NULL for any failures. 118 */ 119 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc, 120 u8 func_no) 121 { 122 const struct pci_epc_features *epc_features; 123 124 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 125 return NULL; 126 127 if (!epc->ops->get_features) 128 return NULL; 129 130 mutex_lock(&epc->lock); 131 epc_features = epc->ops->get_features(epc, func_no); 132 mutex_unlock(&epc->lock); 133 134 return epc_features; 135 } 136 EXPORT_SYMBOL_GPL(pci_epc_get_features); 137 138 /** 139 * pci_epc_stop() - stop the PCI link 140 * @epc: the link of the EPC device that has to be stopped 141 * 142 * Invoke to stop the PCI link 143 */ 144 void pci_epc_stop(struct pci_epc *epc) 145 { 146 if (IS_ERR(epc) || !epc->ops->stop) 147 return; 148 149 mutex_lock(&epc->lock); 150 epc->ops->stop(epc); 151 mutex_unlock(&epc->lock); 152 } 153 EXPORT_SYMBOL_GPL(pci_epc_stop); 154 155 /** 156 * pci_epc_start() - start the PCI link 157 * @epc: the link of *this* EPC device has to be started 158 * 159 * Invoke to start the PCI link 160 */ 161 int pci_epc_start(struct pci_epc *epc) 162 { 163 int ret; 164 165 if (IS_ERR(epc)) 166 return -EINVAL; 167 168 if (!epc->ops->start) 169 return 0; 170 171 mutex_lock(&epc->lock); 172 ret = epc->ops->start(epc); 173 mutex_unlock(&epc->lock); 174 175 return ret; 176 } 177 EXPORT_SYMBOL_GPL(pci_epc_start); 178 179 /** 180 * pci_epc_raise_irq() - interrupt the host system 181 * @epc: the EPC device which has to interrupt the host 182 * @func_no: the endpoint function number in the EPC device 183 * @type: specify the type of interrupt; legacy, MSI or MSI-X 184 * @interrupt_num: the MSI or MSI-X interrupt number 185 * 186 * Invoke to raise an legacy, MSI or MSI-X interrupt 187 */ 188 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, 189 enum pci_epc_irq_type type, u16 interrupt_num) 190 { 191 int ret; 192 193 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 194 return -EINVAL; 195 196 if (!epc->ops->raise_irq) 197 return 0; 198 199 mutex_lock(&epc->lock); 200 ret = epc->ops->raise_irq(epc, func_no, type, interrupt_num); 201 mutex_unlock(&epc->lock); 202 203 return ret; 204 } 205 EXPORT_SYMBOL_GPL(pci_epc_raise_irq); 206 207 /** 208 * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated 209 * @epc: the EPC device to which MSI interrupts was requested 210 * @func_no: the endpoint function number in the EPC device 211 * 212 * Invoke to get the number of MSI interrupts allocated by the RC 213 */ 214 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no) 215 { 216 int interrupt; 217 218 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 219 return 0; 220 221 if (!epc->ops->get_msi) 222 return 0; 223 224 mutex_lock(&epc->lock); 225 interrupt = epc->ops->get_msi(epc, func_no); 226 mutex_unlock(&epc->lock); 227 228 if (interrupt < 0) 229 return 0; 230 231 interrupt = 1 << interrupt; 232 233 return interrupt; 234 } 235 EXPORT_SYMBOL_GPL(pci_epc_get_msi); 236 237 /** 238 * pci_epc_set_msi() - set the number of MSI interrupt numbers required 239 * @epc: the EPC device on which MSI has to be configured 240 * @func_no: the endpoint function number in the EPC device 241 * @interrupts: number of MSI interrupts required by the EPF 242 * 243 * Invoke to set the required number of MSI interrupts. 244 */ 245 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts) 246 { 247 int ret; 248 u8 encode_int; 249 250 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 251 interrupts > 32) 252 return -EINVAL; 253 254 if (!epc->ops->set_msi) 255 return 0; 256 257 encode_int = order_base_2(interrupts); 258 259 mutex_lock(&epc->lock); 260 ret = epc->ops->set_msi(epc, func_no, encode_int); 261 mutex_unlock(&epc->lock); 262 263 return ret; 264 } 265 EXPORT_SYMBOL_GPL(pci_epc_set_msi); 266 267 /** 268 * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated 269 * @epc: the EPC device to which MSI-X interrupts was requested 270 * @func_no: the endpoint function number in the EPC device 271 * 272 * Invoke to get the number of MSI-X interrupts allocated by the RC 273 */ 274 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no) 275 { 276 int interrupt; 277 278 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 279 return 0; 280 281 if (!epc->ops->get_msix) 282 return 0; 283 284 mutex_lock(&epc->lock); 285 interrupt = epc->ops->get_msix(epc, func_no); 286 mutex_unlock(&epc->lock); 287 288 if (interrupt < 0) 289 return 0; 290 291 return interrupt + 1; 292 } 293 EXPORT_SYMBOL_GPL(pci_epc_get_msix); 294 295 /** 296 * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required 297 * @epc: the EPC device on which MSI-X has to be configured 298 * @func_no: the endpoint function number in the EPC device 299 * @interrupts: number of MSI-X interrupts required by the EPF 300 * 301 * Invoke to set the required number of MSI-X interrupts. 302 */ 303 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts) 304 { 305 int ret; 306 307 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 308 interrupts < 1 || interrupts > 2048) 309 return -EINVAL; 310 311 if (!epc->ops->set_msix) 312 return 0; 313 314 mutex_lock(&epc->lock); 315 ret = epc->ops->set_msix(epc, func_no, interrupts - 1); 316 mutex_unlock(&epc->lock); 317 318 return ret; 319 } 320 EXPORT_SYMBOL_GPL(pci_epc_set_msix); 321 322 /** 323 * pci_epc_unmap_addr() - unmap CPU address from PCI address 324 * @epc: the EPC device on which address is allocated 325 * @func_no: the endpoint function number in the EPC device 326 * @phys_addr: physical address of the local system 327 * 328 * Invoke to unmap the CPU address from PCI address. 329 */ 330 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no, 331 phys_addr_t phys_addr) 332 { 333 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 334 return; 335 336 if (!epc->ops->unmap_addr) 337 return; 338 339 mutex_lock(&epc->lock); 340 epc->ops->unmap_addr(epc, func_no, phys_addr); 341 mutex_unlock(&epc->lock); 342 } 343 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); 344 345 /** 346 * pci_epc_map_addr() - map CPU address to PCI address 347 * @epc: the EPC device on which address is allocated 348 * @func_no: the endpoint function number in the EPC device 349 * @phys_addr: physical address of the local system 350 * @pci_addr: PCI address to which the physical address should be mapped 351 * @size: the size of the allocation 352 * 353 * Invoke to map CPU address with PCI address. 354 */ 355 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, 356 phys_addr_t phys_addr, u64 pci_addr, size_t size) 357 { 358 int ret; 359 360 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 361 return -EINVAL; 362 363 if (!epc->ops->map_addr) 364 return 0; 365 366 mutex_lock(&epc->lock); 367 ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size); 368 mutex_unlock(&epc->lock); 369 370 return ret; 371 } 372 EXPORT_SYMBOL_GPL(pci_epc_map_addr); 373 374 /** 375 * pci_epc_clear_bar() - reset the BAR 376 * @epc: the EPC device for which the BAR has to be cleared 377 * @func_no: the endpoint function number in the EPC device 378 * @epf_bar: the struct epf_bar that contains the BAR information 379 * 380 * Invoke to reset the BAR of the endpoint device. 381 */ 382 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, 383 struct pci_epf_bar *epf_bar) 384 { 385 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 386 (epf_bar->barno == BAR_5 && 387 epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) 388 return; 389 390 if (!epc->ops->clear_bar) 391 return; 392 393 mutex_lock(&epc->lock); 394 epc->ops->clear_bar(epc, func_no, epf_bar); 395 mutex_unlock(&epc->lock); 396 } 397 EXPORT_SYMBOL_GPL(pci_epc_clear_bar); 398 399 /** 400 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space 401 * @epc: the EPC device on which BAR has to be configured 402 * @func_no: the endpoint function number in the EPC device 403 * @epf_bar: the struct epf_bar that contains the BAR information 404 * 405 * Invoke to configure the BAR of the endpoint device. 406 */ 407 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, 408 struct pci_epf_bar *epf_bar) 409 { 410 int ret; 411 int flags = epf_bar->flags; 412 413 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 414 (epf_bar->barno == BAR_5 && 415 flags & PCI_BASE_ADDRESS_MEM_TYPE_64) || 416 (flags & PCI_BASE_ADDRESS_SPACE_IO && 417 flags & PCI_BASE_ADDRESS_IO_MASK) || 418 (upper_32_bits(epf_bar->size) && 419 !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64))) 420 return -EINVAL; 421 422 if (!epc->ops->set_bar) 423 return 0; 424 425 mutex_lock(&epc->lock); 426 ret = epc->ops->set_bar(epc, func_no, epf_bar); 427 mutex_unlock(&epc->lock); 428 429 return ret; 430 } 431 EXPORT_SYMBOL_GPL(pci_epc_set_bar); 432 433 /** 434 * pci_epc_write_header() - write standard configuration header 435 * @epc: the EPC device to which the configuration header should be written 436 * @func_no: the endpoint function number in the EPC device 437 * @header: standard configuration header fields 438 * 439 * Invoke to write the configuration header to the endpoint controller. Every 440 * endpoint controller will have a dedicated location to which the standard 441 * configuration header would be written. The callback function should write 442 * the header fields to this dedicated location. 443 */ 444 int pci_epc_write_header(struct pci_epc *epc, u8 func_no, 445 struct pci_epf_header *header) 446 { 447 int ret; 448 449 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 450 return -EINVAL; 451 452 if (!epc->ops->write_header) 453 return 0; 454 455 mutex_lock(&epc->lock); 456 ret = epc->ops->write_header(epc, func_no, header); 457 mutex_unlock(&epc->lock); 458 459 return ret; 460 } 461 EXPORT_SYMBOL_GPL(pci_epc_write_header); 462 463 /** 464 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller 465 * @epc: the EPC device to which the endpoint function should be added 466 * @epf: the endpoint function to be added 467 * 468 * A PCI endpoint device can have one or more functions. In the case of PCIe, 469 * the specification allows up to 8 PCIe endpoint functions. Invoke 470 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. 471 */ 472 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 473 { 474 u32 func_no; 475 int ret = 0; 476 477 if (epf->epc) 478 return -EBUSY; 479 480 if (IS_ERR(epc)) 481 return -EINVAL; 482 483 mutex_lock(&epc->lock); 484 func_no = find_first_zero_bit(&epc->function_num_map, 485 BITS_PER_LONG); 486 if (func_no >= BITS_PER_LONG) { 487 ret = -EINVAL; 488 goto ret; 489 } 490 491 if (func_no > epc->max_functions - 1) { 492 dev_err(&epc->dev, "Exceeding max supported Function Number\n"); 493 ret = -EINVAL; 494 goto ret; 495 } 496 497 set_bit(func_no, &epc->function_num_map); 498 epf->func_no = func_no; 499 epf->epc = epc; 500 501 list_add_tail(&epf->list, &epc->pci_epf); 502 503 ret: 504 mutex_unlock(&epc->lock); 505 506 return ret; 507 } 508 EXPORT_SYMBOL_GPL(pci_epc_add_epf); 509 510 /** 511 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller 512 * @epc: the EPC device from which the endpoint function should be removed 513 * @epf: the endpoint function to be removed 514 * 515 * Invoke to remove PCI endpoint function from the endpoint controller. 516 */ 517 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) 518 { 519 if (!epc || IS_ERR(epc) || !epf) 520 return; 521 522 mutex_lock(&epc->lock); 523 clear_bit(epf->func_no, &epc->function_num_map); 524 list_del(&epf->list); 525 epf->epc = NULL; 526 mutex_unlock(&epc->lock); 527 } 528 EXPORT_SYMBOL_GPL(pci_epc_remove_epf); 529 530 /** 531 * pci_epc_linkup() - Notify the EPF device that EPC device has established a 532 * connection with the Root Complex. 533 * @epc: the EPC device which has established link with the host 534 * 535 * Invoke to Notify the EPF device that the EPC device has established a 536 * connection with the Root Complex. 537 */ 538 void pci_epc_linkup(struct pci_epc *epc) 539 { 540 if (!epc || IS_ERR(epc)) 541 return; 542 543 atomic_notifier_call_chain(&epc->notifier, 0, NULL); 544 } 545 EXPORT_SYMBOL_GPL(pci_epc_linkup); 546 547 /** 548 * pci_epc_destroy() - destroy the EPC device 549 * @epc: the EPC device that has to be destroyed 550 * 551 * Invoke to destroy the PCI EPC device 552 */ 553 void pci_epc_destroy(struct pci_epc *epc) 554 { 555 pci_ep_cfs_remove_epc_group(epc->group); 556 device_unregister(&epc->dev); 557 kfree(epc); 558 } 559 EXPORT_SYMBOL_GPL(pci_epc_destroy); 560 561 /** 562 * devm_pci_epc_destroy() - destroy the EPC device 563 * @dev: device that wants to destroy the EPC 564 * @epc: the EPC device that has to be destroyed 565 * 566 * Invoke to destroy the devres associated with this 567 * pci_epc and destroy the EPC device. 568 */ 569 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc) 570 { 571 int r; 572 573 r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match, 574 epc); 575 dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n"); 576 } 577 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy); 578 579 /** 580 * __pci_epc_create() - create a new endpoint controller (EPC) device 581 * @dev: device that is creating the new EPC 582 * @ops: function pointers for performing EPC operations 583 * @owner: the owner of the module that creates the EPC device 584 * 585 * Invoke to create a new EPC device and add it to pci_epc class. 586 */ 587 struct pci_epc * 588 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 589 struct module *owner) 590 { 591 int ret; 592 struct pci_epc *epc; 593 594 if (WARN_ON(!dev)) { 595 ret = -EINVAL; 596 goto err_ret; 597 } 598 599 epc = kzalloc(sizeof(*epc), GFP_KERNEL); 600 if (!epc) { 601 ret = -ENOMEM; 602 goto err_ret; 603 } 604 605 mutex_init(&epc->lock); 606 INIT_LIST_HEAD(&epc->pci_epf); 607 ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier); 608 609 device_initialize(&epc->dev); 610 epc->dev.class = pci_epc_class; 611 epc->dev.parent = dev; 612 epc->ops = ops; 613 614 ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); 615 if (ret) 616 goto put_dev; 617 618 ret = device_add(&epc->dev); 619 if (ret) 620 goto put_dev; 621 622 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); 623 624 return epc; 625 626 put_dev: 627 put_device(&epc->dev); 628 kfree(epc); 629 630 err_ret: 631 return ERR_PTR(ret); 632 } 633 EXPORT_SYMBOL_GPL(__pci_epc_create); 634 635 /** 636 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device 637 * @dev: device that is creating the new EPC 638 * @ops: function pointers for performing EPC operations 639 * @owner: the owner of the module that creates the EPC device 640 * 641 * Invoke to create a new EPC device and add it to pci_epc class. 642 * While at that, it also associates the device with the pci_epc using devres. 643 * On driver detach, release function is invoked on the devres data, 644 * then, devres data is freed. 645 */ 646 struct pci_epc * 647 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 648 struct module *owner) 649 { 650 struct pci_epc **ptr, *epc; 651 652 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); 653 if (!ptr) 654 return ERR_PTR(-ENOMEM); 655 656 epc = __pci_epc_create(dev, ops, owner); 657 if (!IS_ERR(epc)) { 658 *ptr = epc; 659 devres_add(dev, ptr); 660 } else { 661 devres_free(ptr); 662 } 663 664 return epc; 665 } 666 EXPORT_SYMBOL_GPL(__devm_pci_epc_create); 667 668 static int __init pci_epc_init(void) 669 { 670 pci_epc_class = class_create(THIS_MODULE, "pci_epc"); 671 if (IS_ERR(pci_epc_class)) { 672 pr_err("failed to create pci epc class --> %ld\n", 673 PTR_ERR(pci_epc_class)); 674 return PTR_ERR(pci_epc_class); 675 } 676 677 return 0; 678 } 679 module_init(pci_epc_init); 680 681 static void __exit pci_epc_exit(void) 682 { 683 class_destroy(pci_epc_class); 684 } 685 module_exit(pci_epc_exit); 686 687 MODULE_DESCRIPTION("PCI EPC Library"); 688 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 689 MODULE_LICENSE("GPL v2"); 690