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