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 or MSI 135 * @interrupt_num: the MSI interrupt number 136 * 137 * Invoke to raise an MSI or legacy interrupt 138 */ 139 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, 140 enum pci_epc_irq_type type, u8 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 return -EINVAL; 206 207 if (!epc->ops->set_msi) 208 return 0; 209 210 encode_int = order_base_2(interrupts); 211 212 spin_lock_irqsave(&epc->lock, flags); 213 ret = epc->ops->set_msi(epc, func_no, encode_int); 214 spin_unlock_irqrestore(&epc->lock, flags); 215 216 return ret; 217 } 218 EXPORT_SYMBOL_GPL(pci_epc_set_msi); 219 220 /** 221 * pci_epc_unmap_addr() - unmap CPU address from PCI address 222 * @epc: the EPC device on which address is allocated 223 * @func_no: the endpoint function number in the EPC device 224 * @phys_addr: physical address of the local system 225 * 226 * Invoke to unmap the CPU address from PCI address. 227 */ 228 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no, 229 phys_addr_t phys_addr) 230 { 231 unsigned long flags; 232 233 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 234 return; 235 236 if (!epc->ops->unmap_addr) 237 return; 238 239 spin_lock_irqsave(&epc->lock, flags); 240 epc->ops->unmap_addr(epc, func_no, phys_addr); 241 spin_unlock_irqrestore(&epc->lock, flags); 242 } 243 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); 244 245 /** 246 * pci_epc_map_addr() - map CPU address to PCI address 247 * @epc: the EPC device on which address is allocated 248 * @func_no: the endpoint function number in the EPC device 249 * @phys_addr: physical address of the local system 250 * @pci_addr: PCI address to which the physical address should be mapped 251 * @size: the size of the allocation 252 * 253 * Invoke to map CPU address with PCI address. 254 */ 255 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, 256 phys_addr_t phys_addr, u64 pci_addr, size_t size) 257 { 258 int ret; 259 unsigned long flags; 260 261 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 262 return -EINVAL; 263 264 if (!epc->ops->map_addr) 265 return 0; 266 267 spin_lock_irqsave(&epc->lock, flags); 268 ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size); 269 spin_unlock_irqrestore(&epc->lock, flags); 270 271 return ret; 272 } 273 EXPORT_SYMBOL_GPL(pci_epc_map_addr); 274 275 /** 276 * pci_epc_clear_bar() - reset the BAR 277 * @epc: the EPC device for which the BAR has to be cleared 278 * @func_no: the endpoint function number in the EPC device 279 * @epf_bar: the struct epf_bar that contains the BAR information 280 * 281 * Invoke to reset the BAR of the endpoint device. 282 */ 283 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, 284 struct pci_epf_bar *epf_bar) 285 { 286 unsigned long flags; 287 288 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 289 return; 290 291 if (!epc->ops->clear_bar) 292 return; 293 294 spin_lock_irqsave(&epc->lock, flags); 295 epc->ops->clear_bar(epc, func_no, epf_bar); 296 spin_unlock_irqrestore(&epc->lock, flags); 297 } 298 EXPORT_SYMBOL_GPL(pci_epc_clear_bar); 299 300 /** 301 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space 302 * @epc: the EPC device on which BAR has to be configured 303 * @func_no: the endpoint function number in the EPC device 304 * @epf_bar: the struct epf_bar that contains the BAR information 305 * 306 * Invoke to configure the BAR of the endpoint device. 307 */ 308 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, 309 struct pci_epf_bar *epf_bar) 310 { 311 int ret; 312 unsigned long irq_flags; 313 int flags = epf_bar->flags; 314 315 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || 316 (epf_bar->barno == BAR_5 && 317 flags & PCI_BASE_ADDRESS_MEM_TYPE_64) || 318 (flags & PCI_BASE_ADDRESS_SPACE_IO && 319 flags & PCI_BASE_ADDRESS_IO_MASK) || 320 (upper_32_bits(epf_bar->size) && 321 !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64))) 322 return -EINVAL; 323 324 if (!epc->ops->set_bar) 325 return 0; 326 327 spin_lock_irqsave(&epc->lock, irq_flags); 328 ret = epc->ops->set_bar(epc, func_no, epf_bar); 329 spin_unlock_irqrestore(&epc->lock, irq_flags); 330 331 return ret; 332 } 333 EXPORT_SYMBOL_GPL(pci_epc_set_bar); 334 335 /** 336 * pci_epc_write_header() - write standard configuration header 337 * @epc: the EPC device to which the configuration header should be written 338 * @func_no: the endpoint function number in the EPC device 339 * @header: standard configuration header fields 340 * 341 * Invoke to write the configuration header to the endpoint controller. Every 342 * endpoint controller will have a dedicated location to which the standard 343 * configuration header would be written. The callback function should write 344 * the header fields to this dedicated location. 345 */ 346 int pci_epc_write_header(struct pci_epc *epc, u8 func_no, 347 struct pci_epf_header *header) 348 { 349 int ret; 350 unsigned long flags; 351 352 if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) 353 return -EINVAL; 354 355 if (!epc->ops->write_header) 356 return 0; 357 358 spin_lock_irqsave(&epc->lock, flags); 359 ret = epc->ops->write_header(epc, func_no, header); 360 spin_unlock_irqrestore(&epc->lock, flags); 361 362 return ret; 363 } 364 EXPORT_SYMBOL_GPL(pci_epc_write_header); 365 366 /** 367 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller 368 * @epc: the EPC device to which the endpoint function should be added 369 * @epf: the endpoint function to be added 370 * 371 * A PCI endpoint device can have one or more functions. In the case of PCIe, 372 * the specification allows up to 8 PCIe endpoint functions. Invoke 373 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. 374 */ 375 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 376 { 377 unsigned long flags; 378 379 if (epf->epc) 380 return -EBUSY; 381 382 if (IS_ERR(epc)) 383 return -EINVAL; 384 385 if (epf->func_no > epc->max_functions - 1) 386 return -EINVAL; 387 388 epf->epc = epc; 389 390 spin_lock_irqsave(&epc->lock, flags); 391 list_add_tail(&epf->list, &epc->pci_epf); 392 spin_unlock_irqrestore(&epc->lock, flags); 393 394 return 0; 395 } 396 EXPORT_SYMBOL_GPL(pci_epc_add_epf); 397 398 /** 399 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller 400 * @epc: the EPC device from which the endpoint function should be removed 401 * @epf: the endpoint function to be removed 402 * 403 * Invoke to remove PCI endpoint function from the endpoint controller. 404 */ 405 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) 406 { 407 unsigned long flags; 408 409 if (!epc || IS_ERR(epc)) 410 return; 411 412 spin_lock_irqsave(&epc->lock, flags); 413 list_del(&epf->list); 414 spin_unlock_irqrestore(&epc->lock, flags); 415 } 416 EXPORT_SYMBOL_GPL(pci_epc_remove_epf); 417 418 /** 419 * pci_epc_linkup() - Notify the EPF device that EPC device has established a 420 * connection with the Root Complex. 421 * @epc: the EPC device which has established link with the host 422 * 423 * Invoke to Notify the EPF device that the EPC device has established a 424 * connection with the Root Complex. 425 */ 426 void pci_epc_linkup(struct pci_epc *epc) 427 { 428 unsigned long flags; 429 struct pci_epf *epf; 430 431 if (!epc || IS_ERR(epc)) 432 return; 433 434 spin_lock_irqsave(&epc->lock, flags); 435 list_for_each_entry(epf, &epc->pci_epf, list) 436 pci_epf_linkup(epf); 437 spin_unlock_irqrestore(&epc->lock, flags); 438 } 439 EXPORT_SYMBOL_GPL(pci_epc_linkup); 440 441 /** 442 * pci_epc_destroy() - destroy the EPC device 443 * @epc: the EPC device that has to be destroyed 444 * 445 * Invoke to destroy the PCI EPC device 446 */ 447 void pci_epc_destroy(struct pci_epc *epc) 448 { 449 pci_ep_cfs_remove_epc_group(epc->group); 450 device_unregister(&epc->dev); 451 kfree(epc); 452 } 453 EXPORT_SYMBOL_GPL(pci_epc_destroy); 454 455 /** 456 * devm_pci_epc_destroy() - destroy the EPC device 457 * @dev: device that wants to destroy the EPC 458 * @epc: the EPC device that has to be destroyed 459 * 460 * Invoke to destroy the devres associated with this 461 * pci_epc and destroy the EPC device. 462 */ 463 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc) 464 { 465 int r; 466 467 r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match, 468 epc); 469 dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n"); 470 } 471 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy); 472 473 /** 474 * __pci_epc_create() - create a new endpoint controller (EPC) device 475 * @dev: device that is creating the new EPC 476 * @ops: function pointers for performing EPC operations 477 * @owner: the owner of the module that creates the EPC device 478 * 479 * Invoke to create a new EPC device and add it to pci_epc class. 480 */ 481 struct pci_epc * 482 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 483 struct module *owner) 484 { 485 int ret; 486 struct pci_epc *epc; 487 488 if (WARN_ON(!dev)) { 489 ret = -EINVAL; 490 goto err_ret; 491 } 492 493 epc = kzalloc(sizeof(*epc), GFP_KERNEL); 494 if (!epc) { 495 ret = -ENOMEM; 496 goto err_ret; 497 } 498 499 spin_lock_init(&epc->lock); 500 INIT_LIST_HEAD(&epc->pci_epf); 501 502 device_initialize(&epc->dev); 503 epc->dev.class = pci_epc_class; 504 epc->dev.parent = dev; 505 epc->ops = ops; 506 507 ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); 508 if (ret) 509 goto put_dev; 510 511 ret = device_add(&epc->dev); 512 if (ret) 513 goto put_dev; 514 515 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); 516 517 return epc; 518 519 put_dev: 520 put_device(&epc->dev); 521 kfree(epc); 522 523 err_ret: 524 return ERR_PTR(ret); 525 } 526 EXPORT_SYMBOL_GPL(__pci_epc_create); 527 528 /** 529 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device 530 * @dev: device that is creating the new EPC 531 * @ops: function pointers for performing EPC operations 532 * @owner: the owner of the module that creates the EPC device 533 * 534 * Invoke to create a new EPC device and add it to pci_epc class. 535 * While at that, it also associates the device with the pci_epc using devres. 536 * On driver detach, release function is invoked on the devres data, 537 * then, devres data is freed. 538 */ 539 struct pci_epc * 540 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 541 struct module *owner) 542 { 543 struct pci_epc **ptr, *epc; 544 545 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); 546 if (!ptr) 547 return ERR_PTR(-ENOMEM); 548 549 epc = __pci_epc_create(dev, ops, owner); 550 if (!IS_ERR(epc)) { 551 *ptr = epc; 552 devres_add(dev, ptr); 553 } else { 554 devres_free(ptr); 555 } 556 557 return epc; 558 } 559 EXPORT_SYMBOL_GPL(__devm_pci_epc_create); 560 561 static int __init pci_epc_init(void) 562 { 563 pci_epc_class = class_create(THIS_MODULE, "pci_epc"); 564 if (IS_ERR(pci_epc_class)) { 565 pr_err("failed to create pci epc class --> %ld\n", 566 PTR_ERR(pci_epc_class)); 567 return PTR_ERR(pci_epc_class); 568 } 569 570 return 0; 571 } 572 module_init(pci_epc_init); 573 574 static void __exit pci_epc_exit(void) 575 { 576 class_destroy(pci_epc_class); 577 } 578 module_exit(pci_epc_exit); 579 580 MODULE_DESCRIPTION("PCI EPC Library"); 581 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 582 MODULE_LICENSE("GPL v2"); 583