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/dma-mapping.h> 11 #include <linux/slab.h> 12 #include <linux/module.h> 13 #include <linux/of_device.h> 14 15 #include <linux/pci-epc.h> 16 #include <linux/pci-epf.h> 17 #include <linux/pci-ep-cfs.h> 18 19 static struct class *pci_epc_class; 20 21 static void devm_pci_epc_release(struct device *dev, void *res) 22 { 23 struct pci_epc *epc = *(struct pci_epc **)res; 24 25 pci_epc_destroy(epc); 26 } 27 28 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data) 29 { 30 struct pci_epc **epc = res; 31 32 return *epc == match_data; 33 } 34 35 /** 36 * pci_epc_put() - release the PCI endpoint controller 37 * @epc: epc returned by pci_epc_get() 38 * 39 * release the refcount the caller obtained by invoking pci_epc_get() 40 */ 41 void pci_epc_put(struct pci_epc *epc) 42 { 43 if (!epc || IS_ERR(epc)) 44 return; 45 46 module_put(epc->ops->owner); 47 put_device(&epc->dev); 48 } 49 EXPORT_SYMBOL_GPL(pci_epc_put); 50 51 /** 52 * pci_epc_get() - get the PCI endpoint controller 53 * @epc_name: device name of the endpoint controller 54 * 55 * Invoke to get struct pci_epc * corresponding to the device name of the 56 * endpoint controller 57 */ 58 struct pci_epc *pci_epc_get(const char *epc_name) 59 { 60 int ret = -EINVAL; 61 struct pci_epc *epc; 62 struct device *dev; 63 struct class_dev_iter iter; 64 65 class_dev_iter_init(&iter, pci_epc_class, NULL, NULL); 66 while ((dev = class_dev_iter_next(&iter))) { 67 if (strcmp(epc_name, dev_name(dev))) 68 continue; 69 70 epc = to_pci_epc(dev); 71 if (!try_module_get(epc->ops->owner)) { 72 ret = -EINVAL; 73 goto err; 74 } 75 76 class_dev_iter_exit(&iter); 77 get_device(&epc->dev); 78 return epc; 79 } 80 81 err: 82 class_dev_iter_exit(&iter); 83 return ERR_PTR(ret); 84 } 85 EXPORT_SYMBOL_GPL(pci_epc_get); 86 87 /** 88 * pci_epc_stop() - stop the PCI link 89 * @epc: the link of the EPC device that has to be stopped 90 * 91 * Invoke to stop the PCI link 92 */ 93 void pci_epc_stop(struct pci_epc *epc) 94 { 95 unsigned long flags; 96 97 if (IS_ERR(epc) || !epc->ops->stop) 98 return; 99 100 spin_lock_irqsave(&epc->lock, flags); 101 epc->ops->stop(epc); 102 spin_unlock_irqrestore(&epc->lock, flags); 103 } 104 EXPORT_SYMBOL_GPL(pci_epc_stop); 105 106 /** 107 * pci_epc_start() - start the PCI link 108 * @epc: the link of *this* EPC device has to be started 109 * 110 * Invoke to start the PCI link 111 */ 112 int pci_epc_start(struct pci_epc *epc) 113 { 114 int ret; 115 unsigned long flags; 116 117 if (IS_ERR(epc)) 118 return -EINVAL; 119 120 if (!epc->ops->start) 121 return 0; 122 123 spin_lock_irqsave(&epc->lock, flags); 124 ret = epc->ops->start(epc); 125 spin_unlock_irqrestore(&epc->lock, flags); 126 127 return ret; 128 } 129 EXPORT_SYMBOL_GPL(pci_epc_start); 130 131 /** 132 * pci_epc_raise_irq() - interrupt the host system 133 * @epc: the EPC device which has to interrupt the host 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, enum pci_epc_irq_type type, 140 u8 interrupt_num) 141 { 142 int ret; 143 unsigned long flags; 144 145 if (IS_ERR(epc)) 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, 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 * 163 * Invoke to get the number of MSI interrupts allocated by the RC 164 */ 165 int pci_epc_get_msi(struct pci_epc *epc) 166 { 167 int interrupt; 168 unsigned long flags; 169 170 if (IS_ERR(epc)) 171 return 0; 172 173 if (!epc->ops->get_msi) 174 return 0; 175 176 spin_lock_irqsave(&epc->lock, flags); 177 interrupt = epc->ops->get_msi(epc); 178 spin_unlock_irqrestore(&epc->lock, flags); 179 180 if (interrupt < 0) 181 return 0; 182 183 interrupt = 1 << interrupt; 184 185 return interrupt; 186 } 187 EXPORT_SYMBOL_GPL(pci_epc_get_msi); 188 189 /** 190 * pci_epc_set_msi() - set the number of MSI interrupt numbers required 191 * @epc: the EPC device on which MSI has to be configured 192 * @interrupts: number of MSI interrupts required by the EPF 193 * 194 * Invoke to set the required number of MSI interrupts. 195 */ 196 int pci_epc_set_msi(struct pci_epc *epc, u8 interrupts) 197 { 198 int ret; 199 u8 encode_int; 200 unsigned long flags; 201 202 if (IS_ERR(epc)) 203 return -EINVAL; 204 205 if (!epc->ops->set_msi) 206 return 0; 207 208 encode_int = order_base_2(interrupts); 209 210 spin_lock_irqsave(&epc->lock, flags); 211 ret = epc->ops->set_msi(epc, encode_int); 212 spin_unlock_irqrestore(&epc->lock, flags); 213 214 return ret; 215 } 216 EXPORT_SYMBOL_GPL(pci_epc_set_msi); 217 218 /** 219 * pci_epc_unmap_addr() - unmap CPU address from PCI address 220 * @epc: the EPC device on which address is allocated 221 * @phys_addr: physical address of the local system 222 * 223 * Invoke to unmap the CPU address from PCI address. 224 */ 225 void pci_epc_unmap_addr(struct pci_epc *epc, phys_addr_t phys_addr) 226 { 227 unsigned long flags; 228 229 if (IS_ERR(epc)) 230 return; 231 232 if (!epc->ops->unmap_addr) 233 return; 234 235 spin_lock_irqsave(&epc->lock, flags); 236 epc->ops->unmap_addr(epc, phys_addr); 237 spin_unlock_irqrestore(&epc->lock, flags); 238 } 239 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); 240 241 /** 242 * pci_epc_map_addr() - map CPU address to PCI address 243 * @epc: the EPC device on which address is allocated 244 * @phys_addr: physical address of the local system 245 * @pci_addr: PCI address to which the physical address should be mapped 246 * @size: the size of the allocation 247 * 248 * Invoke to map CPU address with PCI address. 249 */ 250 int pci_epc_map_addr(struct pci_epc *epc, phys_addr_t phys_addr, 251 u64 pci_addr, size_t size) 252 { 253 int ret; 254 unsigned long flags; 255 256 if (IS_ERR(epc)) 257 return -EINVAL; 258 259 if (!epc->ops->map_addr) 260 return 0; 261 262 spin_lock_irqsave(&epc->lock, flags); 263 ret = epc->ops->map_addr(epc, phys_addr, pci_addr, size); 264 spin_unlock_irqrestore(&epc->lock, flags); 265 266 return ret; 267 } 268 EXPORT_SYMBOL_GPL(pci_epc_map_addr); 269 270 /** 271 * pci_epc_clear_bar() - reset the BAR 272 * @epc: the EPC device for which the BAR has to be cleared 273 * @bar: the BAR number that has to be reset 274 * 275 * Invoke to reset the BAR of the endpoint device. 276 */ 277 void pci_epc_clear_bar(struct pci_epc *epc, int bar) 278 { 279 unsigned long flags; 280 281 if (IS_ERR(epc)) 282 return; 283 284 if (!epc->ops->clear_bar) 285 return; 286 287 spin_lock_irqsave(&epc->lock, flags); 288 epc->ops->clear_bar(epc, bar); 289 spin_unlock_irqrestore(&epc->lock, flags); 290 } 291 EXPORT_SYMBOL_GPL(pci_epc_clear_bar); 292 293 /** 294 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space 295 * @epc: the EPC device on which BAR has to be configured 296 * @bar: the BAR number that has to be configured 297 * @size: the size of the addr space 298 * @flags: specify memory allocation/io allocation/32bit address/64 bit address 299 * 300 * Invoke to configure the BAR of the endpoint device. 301 */ 302 int pci_epc_set_bar(struct pci_epc *epc, enum pci_barno bar, 303 dma_addr_t bar_phys, size_t size, int flags) 304 { 305 int ret; 306 unsigned long irq_flags; 307 308 if (IS_ERR(epc)) 309 return -EINVAL; 310 311 if (!epc->ops->set_bar) 312 return 0; 313 314 spin_lock_irqsave(&epc->lock, irq_flags); 315 ret = epc->ops->set_bar(epc, bar, bar_phys, size, flags); 316 spin_unlock_irqrestore(&epc->lock, irq_flags); 317 318 return ret; 319 } 320 EXPORT_SYMBOL_GPL(pci_epc_set_bar); 321 322 /** 323 * pci_epc_write_header() - write standard configuration header 324 * @epc: the EPC device to which the configuration header should be written 325 * @header: standard configuration header fields 326 * 327 * Invoke to write the configuration header to the endpoint controller. Every 328 * endpoint controller will have a dedicated location to which the standard 329 * configuration header would be written. The callback function should write 330 * the header fields to this dedicated location. 331 */ 332 int pci_epc_write_header(struct pci_epc *epc, struct pci_epf_header *header) 333 { 334 int ret; 335 unsigned long flags; 336 337 if (IS_ERR(epc)) 338 return -EINVAL; 339 340 if (!epc->ops->write_header) 341 return 0; 342 343 spin_lock_irqsave(&epc->lock, flags); 344 ret = epc->ops->write_header(epc, header); 345 spin_unlock_irqrestore(&epc->lock, flags); 346 347 return ret; 348 } 349 EXPORT_SYMBOL_GPL(pci_epc_write_header); 350 351 /** 352 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller 353 * @epc: the EPC device to which the endpoint function should be added 354 * @epf: the endpoint function to be added 355 * 356 * A PCI endpoint device can have one or more functions. In the case of PCIe, 357 * the specification allows up to 8 PCIe endpoint functions. Invoke 358 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. 359 */ 360 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 361 { 362 unsigned long flags; 363 struct device *dev = epc->dev.parent; 364 365 if (epf->epc) 366 return -EBUSY; 367 368 if (IS_ERR(epc)) 369 return -EINVAL; 370 371 if (epf->func_no > epc->max_functions - 1) 372 return -EINVAL; 373 374 epf->epc = epc; 375 if (dev->of_node) { 376 of_dma_configure(&epf->dev, dev->of_node); 377 } else { 378 dma_set_coherent_mask(&epf->dev, epc->dev.coherent_dma_mask); 379 epf->dev.dma_mask = epc->dev.dma_mask; 380 } 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 dma_set_coherent_mask(&epc->dev, dev->coherent_dma_mask); 496 epc->dev.class = pci_epc_class; 497 epc->dev.dma_mask = dev->dma_mask; 498 epc->dev.parent = dev; 499 epc->ops = ops; 500 501 ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); 502 if (ret) 503 goto put_dev; 504 505 ret = device_add(&epc->dev); 506 if (ret) 507 goto put_dev; 508 509 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); 510 511 return epc; 512 513 put_dev: 514 put_device(&epc->dev); 515 kfree(epc); 516 517 err_ret: 518 return ERR_PTR(ret); 519 } 520 EXPORT_SYMBOL_GPL(__pci_epc_create); 521 522 /** 523 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device 524 * @dev: device that is creating the new EPC 525 * @ops: function pointers for performing EPC operations 526 * @owner: the owner of the module that creates the EPC device 527 * 528 * Invoke to create a new EPC device and add it to pci_epc class. 529 * While at that, it also associates the device with the pci_epc using devres. 530 * On driver detach, release function is invoked on the devres data, 531 * then, devres data is freed. 532 */ 533 struct pci_epc * 534 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 535 struct module *owner) 536 { 537 struct pci_epc **ptr, *epc; 538 539 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); 540 if (!ptr) 541 return ERR_PTR(-ENOMEM); 542 543 epc = __pci_epc_create(dev, ops, owner); 544 if (!IS_ERR(epc)) { 545 *ptr = epc; 546 devres_add(dev, ptr); 547 } else { 548 devres_free(ptr); 549 } 550 551 return epc; 552 } 553 EXPORT_SYMBOL_GPL(__devm_pci_epc_create); 554 555 static int __init pci_epc_init(void) 556 { 557 pci_epc_class = class_create(THIS_MODULE, "pci_epc"); 558 if (IS_ERR(pci_epc_class)) { 559 pr_err("failed to create pci epc class --> %ld\n", 560 PTR_ERR(pci_epc_class)); 561 return PTR_ERR(pci_epc_class); 562 } 563 564 return 0; 565 } 566 module_init(pci_epc_init); 567 568 static void __exit pci_epc_exit(void) 569 { 570 class_destroy(pci_epc_class); 571 } 572 module_exit(pci_epc_exit); 573 574 MODULE_DESCRIPTION("PCI EPC Library"); 575 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 576 MODULE_LICENSE("GPL v2"); 577