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_stop() - stop the PCI link 88 * @epc: the link of the EPC device that has to be stopped 89 * 90 * Invoke to stop the PCI link 91 */ 92 void pci_epc_stop(struct pci_epc *epc) 93 { 94 unsigned long flags; 95 96 if (IS_ERR(epc) || !epc->ops->stop) 97 return; 98 99 spin_lock_irqsave(&epc->lock, flags); 100 epc->ops->stop(epc); 101 spin_unlock_irqrestore(&epc->lock, flags); 102 } 103 EXPORT_SYMBOL_GPL(pci_epc_stop); 104 105 /** 106 * pci_epc_start() - start the PCI link 107 * @epc: the link of *this* EPC device has to be started 108 * 109 * Invoke to start the PCI link 110 */ 111 int pci_epc_start(struct pci_epc *epc) 112 { 113 int ret; 114 unsigned long flags; 115 116 if (IS_ERR(epc)) 117 return -EINVAL; 118 119 if (!epc->ops->start) 120 return 0; 121 122 spin_lock_irqsave(&epc->lock, flags); 123 ret = epc->ops->start(epc); 124 spin_unlock_irqrestore(&epc->lock, flags); 125 126 return ret; 127 } 128 EXPORT_SYMBOL_GPL(pci_epc_start); 129 130 /** 131 * pci_epc_raise_irq() - interrupt the host system 132 * @epc: the EPC device which has to interrupt the host 133 * @func_no: the endpoint function number in the EPC device 134 * @type: specify the type of interrupt; legacy, MSI or MSI-X 135 * @interrupt_num: the MSI or MSI-X interrupt number 136 * 137 * Invoke to raise an legacy, MSI or MSI-X interrupt 138 */ 139 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, 140 enum pci_epc_irq_type type, u16 interrupt_num) 141 { 142 int ret; 143 unsigned long flags; 144 145 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 146 return -EINVAL; 147 148 if (!epc->ops->raise_irq) 149 return 0; 150 151 spin_lock_irqsave(&epc->lock, flags); 152 ret = epc->ops->raise_irq(epc, func_no, type, interrupt_num); 153 spin_unlock_irqrestore(&epc->lock, flags); 154 155 return ret; 156 } 157 EXPORT_SYMBOL_GPL(pci_epc_raise_irq); 158 159 /** 160 * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated 161 * @epc: the EPC device to which MSI interrupts was requested 162 * @func_no: the endpoint function number in the EPC device 163 * 164 * Invoke to get the number of MSI interrupts allocated by the RC 165 */ 166 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no) 167 { 168 int interrupt; 169 unsigned long flags; 170 171 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 172 return 0; 173 174 if (!epc->ops->get_msi) 175 return 0; 176 177 spin_lock_irqsave(&epc->lock, flags); 178 interrupt = epc->ops->get_msi(epc, func_no); 179 spin_unlock_irqrestore(&epc->lock, flags); 180 181 if (interrupt < 0) 182 return 0; 183 184 interrupt = 1 << interrupt; 185 186 return interrupt; 187 } 188 EXPORT_SYMBOL_GPL(pci_epc_get_msi); 189 190 /** 191 * pci_epc_set_msi() - set the number of MSI interrupt numbers required 192 * @epc: the EPC device on which MSI has to be configured 193 * @func_no: the endpoint function number in the EPC device 194 * @interrupts: number of MSI interrupts required by the EPF 195 * 196 * Invoke to set the required number of MSI interrupts. 197 */ 198 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts) 199 { 200 int ret; 201 u8 encode_int; 202 unsigned long flags; 203 204 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 205 interrupts > 32) 206 return -EINVAL; 207 208 if (!epc->ops->set_msi) 209 return 0; 210 211 encode_int = order_base_2(interrupts); 212 213 spin_lock_irqsave(&epc->lock, flags); 214 ret = epc->ops->set_msi(epc, func_no, encode_int); 215 spin_unlock_irqrestore(&epc->lock, flags); 216 217 return ret; 218 } 219 EXPORT_SYMBOL_GPL(pci_epc_set_msi); 220 221 /** 222 * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated 223 * @epc: the EPC device to which MSI-X interrupts was requested 224 * @func_no: the endpoint function number in the EPC device 225 * 226 * Invoke to get the number of MSI-X interrupts allocated by the RC 227 */ 228 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no) 229 { 230 int interrupt; 231 unsigned long flags; 232 233 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 234 return 0; 235 236 if (!epc->ops->get_msix) 237 return 0; 238 239 spin_lock_irqsave(&epc->lock, flags); 240 interrupt = epc->ops->get_msix(epc, func_no); 241 spin_unlock_irqrestore(&epc->lock, flags); 242 243 if (interrupt < 0) 244 return 0; 245 246 return interrupt + 1; 247 } 248 EXPORT_SYMBOL_GPL(pci_epc_get_msix); 249 250 /** 251 * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required 252 * @epc: the EPC device on which MSI-X has to be configured 253 * @func_no: the endpoint function number in the EPC device 254 * @interrupts: number of MSI-X interrupts required by the EPF 255 * 256 * Invoke to set the required number of MSI-X interrupts. 257 */ 258 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts) 259 { 260 int ret; 261 unsigned long flags; 262 263 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 264 interrupts < 1 || interrupts > 2048) 265 return -EINVAL; 266 267 if (!epc->ops->set_msix) 268 return 0; 269 270 spin_lock_irqsave(&epc->lock, flags); 271 ret = epc->ops->set_msix(epc, func_no, interrupts - 1); 272 spin_unlock_irqrestore(&epc->lock, flags); 273 274 return ret; 275 } 276 EXPORT_SYMBOL_GPL(pci_epc_set_msix); 277 278 /** 279 * pci_epc_unmap_addr() - unmap CPU address from PCI address 280 * @epc: the EPC device on which address is allocated 281 * @func_no: the endpoint function number in the EPC device 282 * @phys_addr: physical address of the local system 283 * 284 * Invoke to unmap the CPU address from PCI address. 285 */ 286 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no, 287 phys_addr_t phys_addr) 288 { 289 unsigned long flags; 290 291 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 292 return; 293 294 if (!epc->ops->unmap_addr) 295 return; 296 297 spin_lock_irqsave(&epc->lock, flags); 298 epc->ops->unmap_addr(epc, func_no, phys_addr); 299 spin_unlock_irqrestore(&epc->lock, flags); 300 } 301 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); 302 303 /** 304 * pci_epc_map_addr() - map CPU address to PCI address 305 * @epc: the EPC device on which address is allocated 306 * @func_no: the endpoint function number in the EPC device 307 * @phys_addr: physical address of the local system 308 * @pci_addr: PCI address to which the physical address should be mapped 309 * @size: the size of the allocation 310 * 311 * Invoke to map CPU address with PCI address. 312 */ 313 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, 314 phys_addr_t phys_addr, u64 pci_addr, size_t size) 315 { 316 int ret; 317 unsigned long flags; 318 319 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 320 return -EINVAL; 321 322 if (!epc->ops->map_addr) 323 return 0; 324 325 spin_lock_irqsave(&epc->lock, flags); 326 ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size); 327 spin_unlock_irqrestore(&epc->lock, flags); 328 329 return ret; 330 } 331 EXPORT_SYMBOL_GPL(pci_epc_map_addr); 332 333 /** 334 * pci_epc_clear_bar() - reset the BAR 335 * @epc: the EPC device for which the BAR has to be cleared 336 * @func_no: the endpoint function number in the EPC device 337 * @epf_bar: the struct epf_bar that contains the BAR information 338 * 339 * Invoke to reset the BAR of the endpoint device. 340 */ 341 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, 342 struct pci_epf_bar *epf_bar) 343 { 344 unsigned long flags; 345 346 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 347 (epf_bar->barno == BAR_5 && 348 epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) 349 return; 350 351 if (!epc->ops->clear_bar) 352 return; 353 354 spin_lock_irqsave(&epc->lock, flags); 355 epc->ops->clear_bar(epc, func_no, epf_bar); 356 spin_unlock_irqrestore(&epc->lock, flags); 357 } 358 EXPORT_SYMBOL_GPL(pci_epc_clear_bar); 359 360 /** 361 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space 362 * @epc: the EPC device on which BAR has to be configured 363 * @func_no: the endpoint function number in the EPC device 364 * @epf_bar: the struct epf_bar that contains the BAR information 365 * 366 * Invoke to configure the BAR of the endpoint device. 367 */ 368 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, 369 struct pci_epf_bar *epf_bar) 370 { 371 int ret; 372 unsigned long irq_flags; 373 int flags = epf_bar->flags; 374 375 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 376 (epf_bar->barno == BAR_5 && 377 flags & PCI_BASE_ADDRESS_MEM_TYPE_64) || 378 (flags & PCI_BASE_ADDRESS_SPACE_IO && 379 flags & PCI_BASE_ADDRESS_IO_MASK) || 380 (upper_32_bits(epf_bar->size) && 381 !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64))) 382 return -EINVAL; 383 384 if (!epc->ops->set_bar) 385 return 0; 386 387 spin_lock_irqsave(&epc->lock, irq_flags); 388 ret = epc->ops->set_bar(epc, func_no, epf_bar); 389 spin_unlock_irqrestore(&epc->lock, irq_flags); 390 391 return ret; 392 } 393 EXPORT_SYMBOL_GPL(pci_epc_set_bar); 394 395 /** 396 * pci_epc_write_header() - write standard configuration header 397 * @epc: the EPC device to which the configuration header should be written 398 * @func_no: the endpoint function number in the EPC device 399 * @header: standard configuration header fields 400 * 401 * Invoke to write the configuration header to the endpoint controller. Every 402 * endpoint controller will have a dedicated location to which the standard 403 * configuration header would be written. The callback function should write 404 * the header fields to this dedicated location. 405 */ 406 int pci_epc_write_header(struct pci_epc *epc, u8 func_no, 407 struct pci_epf_header *header) 408 { 409 int ret; 410 unsigned long flags; 411 412 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 413 return -EINVAL; 414 415 if (!epc->ops->write_header) 416 return 0; 417 418 spin_lock_irqsave(&epc->lock, flags); 419 ret = epc->ops->write_header(epc, func_no, header); 420 spin_unlock_irqrestore(&epc->lock, flags); 421 422 return ret; 423 } 424 EXPORT_SYMBOL_GPL(pci_epc_write_header); 425 426 /** 427 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller 428 * @epc: the EPC device to which the endpoint function should be added 429 * @epf: the endpoint function to be added 430 * 431 * A PCI endpoint device can have one or more functions. In the case of PCIe, 432 * the specification allows up to 8 PCIe endpoint functions. Invoke 433 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. 434 */ 435 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 436 { 437 unsigned long flags; 438 439 if (epf->epc) 440 return -EBUSY; 441 442 if (IS_ERR(epc)) 443 return -EINVAL; 444 445 if (epf->func_no > epc->max_functions - 1) 446 return -EINVAL; 447 448 epf->epc = epc; 449 450 spin_lock_irqsave(&epc->lock, flags); 451 list_add_tail(&epf->list, &epc->pci_epf); 452 spin_unlock_irqrestore(&epc->lock, flags); 453 454 return 0; 455 } 456 EXPORT_SYMBOL_GPL(pci_epc_add_epf); 457 458 /** 459 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller 460 * @epc: the EPC device from which the endpoint function should be removed 461 * @epf: the endpoint function to be removed 462 * 463 * Invoke to remove PCI endpoint function from the endpoint controller. 464 */ 465 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) 466 { 467 unsigned long flags; 468 469 if (!epc || IS_ERR(epc)) 470 return; 471 472 spin_lock_irqsave(&epc->lock, flags); 473 list_del(&epf->list); 474 spin_unlock_irqrestore(&epc->lock, flags); 475 } 476 EXPORT_SYMBOL_GPL(pci_epc_remove_epf); 477 478 /** 479 * pci_epc_linkup() - Notify the EPF device that EPC device has established a 480 * connection with the Root Complex. 481 * @epc: the EPC device which has established link with the host 482 * 483 * Invoke to Notify the EPF device that the EPC device has established a 484 * connection with the Root Complex. 485 */ 486 void pci_epc_linkup(struct pci_epc *epc) 487 { 488 unsigned long flags; 489 struct pci_epf *epf; 490 491 if (!epc || IS_ERR(epc)) 492 return; 493 494 spin_lock_irqsave(&epc->lock, flags); 495 list_for_each_entry(epf, &epc->pci_epf, list) 496 pci_epf_linkup(epf); 497 spin_unlock_irqrestore(&epc->lock, flags); 498 } 499 EXPORT_SYMBOL_GPL(pci_epc_linkup); 500 501 /** 502 * pci_epc_destroy() - destroy the EPC device 503 * @epc: the EPC device that has to be destroyed 504 * 505 * Invoke to destroy the PCI EPC device 506 */ 507 void pci_epc_destroy(struct pci_epc *epc) 508 { 509 pci_ep_cfs_remove_epc_group(epc->group); 510 device_unregister(&epc->dev); 511 kfree(epc); 512 } 513 EXPORT_SYMBOL_GPL(pci_epc_destroy); 514 515 /** 516 * devm_pci_epc_destroy() - destroy the EPC device 517 * @dev: device that wants to destroy the EPC 518 * @epc: the EPC device that has to be destroyed 519 * 520 * Invoke to destroy the devres associated with this 521 * pci_epc and destroy the EPC device. 522 */ 523 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc) 524 { 525 int r; 526 527 r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match, 528 epc); 529 dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n"); 530 } 531 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy); 532 533 /** 534 * __pci_epc_create() - create a new endpoint controller (EPC) device 535 * @dev: device that is creating the new EPC 536 * @ops: function pointers for performing EPC operations 537 * @owner: the owner of the module that creates the EPC device 538 * 539 * Invoke to create a new EPC device and add it to pci_epc class. 540 */ 541 struct pci_epc * 542 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 543 struct module *owner) 544 { 545 int ret; 546 struct pci_epc *epc; 547 548 if (WARN_ON(!dev)) { 549 ret = -EINVAL; 550 goto err_ret; 551 } 552 553 epc = kzalloc(sizeof(*epc), GFP_KERNEL); 554 if (!epc) { 555 ret = -ENOMEM; 556 goto err_ret; 557 } 558 559 spin_lock_init(&epc->lock); 560 INIT_LIST_HEAD(&epc->pci_epf); 561 562 device_initialize(&epc->dev); 563 epc->dev.class = pci_epc_class; 564 epc->dev.parent = dev; 565 epc->ops = ops; 566 567 ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); 568 if (ret) 569 goto put_dev; 570 571 ret = device_add(&epc->dev); 572 if (ret) 573 goto put_dev; 574 575 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); 576 577 return epc; 578 579 put_dev: 580 put_device(&epc->dev); 581 kfree(epc); 582 583 err_ret: 584 return ERR_PTR(ret); 585 } 586 EXPORT_SYMBOL_GPL(__pci_epc_create); 587 588 /** 589 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device 590 * @dev: device that is creating the new EPC 591 * @ops: function pointers for performing EPC operations 592 * @owner: the owner of the module that creates the EPC device 593 * 594 * Invoke to create a new EPC device and add it to pci_epc class. 595 * While at that, it also associates the device with the pci_epc using devres. 596 * On driver detach, release function is invoked on the devres data, 597 * then, devres data is freed. 598 */ 599 struct pci_epc * 600 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 601 struct module *owner) 602 { 603 struct pci_epc **ptr, *epc; 604 605 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); 606 if (!ptr) 607 return ERR_PTR(-ENOMEM); 608 609 epc = __pci_epc_create(dev, ops, owner); 610 if (!IS_ERR(epc)) { 611 *ptr = epc; 612 devres_add(dev, ptr); 613 } else { 614 devres_free(ptr); 615 } 616 617 return epc; 618 } 619 EXPORT_SYMBOL_GPL(__devm_pci_epc_create); 620 621 static int __init pci_epc_init(void) 622 { 623 pci_epc_class = class_create(THIS_MODULE, "pci_epc"); 624 if (IS_ERR(pci_epc_class)) { 625 pr_err("failed to create pci epc class --> %ld\n", 626 PTR_ERR(pci_epc_class)); 627 return PTR_ERR(pci_epc_class); 628 } 629 630 return 0; 631 } 632 module_init(pci_epc_init); 633 634 static void __exit pci_epc_exit(void) 635 { 636 class_destroy(pci_epc_class); 637 } 638 module_exit(pci_epc_exit); 639 640 MODULE_DESCRIPTION("PCI EPC Library"); 641 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 642 MODULE_LICENSE("GPL v2"); 643