1 /** 2 * PCI Endpoint *Controller* (EPC) library 3 * 4 * Copyright (C) 2017 Texas Instruments 5 * Author: Kishon Vijay Abraham I <kishon@ti.com> 6 * 7 * This program is free software: you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 of 9 * the License as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/device.h> 21 #include <linux/dma-mapping.h> 22 #include <linux/slab.h> 23 #include <linux/module.h> 24 #include <linux/of_device.h> 25 26 #include <linux/pci-epc.h> 27 #include <linux/pci-epf.h> 28 #include <linux/pci-ep-cfs.h> 29 30 static struct class *pci_epc_class; 31 32 static void devm_pci_epc_release(struct device *dev, void *res) 33 { 34 struct pci_epc *epc = *(struct pci_epc **)res; 35 36 pci_epc_destroy(epc); 37 } 38 39 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data) 40 { 41 struct pci_epc **epc = res; 42 43 return *epc == match_data; 44 } 45 46 /** 47 * pci_epc_put() - release the PCI endpoint controller 48 * @epc: epc returned by pci_epc_get() 49 * 50 * release the refcount the caller obtained by invoking pci_epc_get() 51 */ 52 void pci_epc_put(struct pci_epc *epc) 53 { 54 if (!epc || IS_ERR(epc)) 55 return; 56 57 module_put(epc->ops->owner); 58 put_device(&epc->dev); 59 } 60 EXPORT_SYMBOL_GPL(pci_epc_put); 61 62 /** 63 * pci_epc_get() - get the PCI endpoint controller 64 * @epc_name: device name of the endpoint controller 65 * 66 * Invoke to get struct pci_epc * corresponding to the device name of the 67 * endpoint controller 68 */ 69 struct pci_epc *pci_epc_get(const char *epc_name) 70 { 71 int ret = -EINVAL; 72 struct pci_epc *epc; 73 struct device *dev; 74 struct class_dev_iter iter; 75 76 class_dev_iter_init(&iter, pci_epc_class, NULL, NULL); 77 while ((dev = class_dev_iter_next(&iter))) { 78 if (strcmp(epc_name, dev_name(dev))) 79 continue; 80 81 epc = to_pci_epc(dev); 82 if (!try_module_get(epc->ops->owner)) { 83 ret = -EINVAL; 84 goto err; 85 } 86 87 class_dev_iter_exit(&iter); 88 get_device(&epc->dev); 89 return epc; 90 } 91 92 err: 93 class_dev_iter_exit(&iter); 94 return ERR_PTR(ret); 95 } 96 EXPORT_SYMBOL_GPL(pci_epc_get); 97 98 /** 99 * pci_epc_stop() - stop the PCI link 100 * @epc: the link of the EPC device that has to be stopped 101 * 102 * Invoke to stop the PCI link 103 */ 104 void pci_epc_stop(struct pci_epc *epc) 105 { 106 unsigned long flags; 107 108 if (IS_ERR(epc) || !epc->ops->stop) 109 return; 110 111 spin_lock_irqsave(&epc->lock, flags); 112 epc->ops->stop(epc); 113 spin_unlock_irqrestore(&epc->lock, flags); 114 } 115 EXPORT_SYMBOL_GPL(pci_epc_stop); 116 117 /** 118 * pci_epc_start() - start the PCI link 119 * @epc: the link of *this* EPC device has to be started 120 * 121 * Invoke to start the PCI link 122 */ 123 int pci_epc_start(struct pci_epc *epc) 124 { 125 int ret; 126 unsigned long flags; 127 128 if (IS_ERR(epc)) 129 return -EINVAL; 130 131 if (!epc->ops->start) 132 return 0; 133 134 spin_lock_irqsave(&epc->lock, flags); 135 ret = epc->ops->start(epc); 136 spin_unlock_irqrestore(&epc->lock, flags); 137 138 return ret; 139 } 140 EXPORT_SYMBOL_GPL(pci_epc_start); 141 142 /** 143 * pci_epc_raise_irq() - interrupt the host system 144 * @epc: the EPC device which has to interrupt the host 145 * @type: specify the type of interrupt; legacy or MSI 146 * @interrupt_num: the MSI interrupt number 147 * 148 * Invoke to raise an MSI or legacy interrupt 149 */ 150 int pci_epc_raise_irq(struct pci_epc *epc, enum pci_epc_irq_type type, 151 u8 interrupt_num) 152 { 153 int ret; 154 unsigned long flags; 155 156 if (IS_ERR(epc)) 157 return -EINVAL; 158 159 if (!epc->ops->raise_irq) 160 return 0; 161 162 spin_lock_irqsave(&epc->lock, flags); 163 ret = epc->ops->raise_irq(epc, type, interrupt_num); 164 spin_unlock_irqrestore(&epc->lock, flags); 165 166 return ret; 167 } 168 EXPORT_SYMBOL_GPL(pci_epc_raise_irq); 169 170 /** 171 * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated 172 * @epc: the EPC device to which MSI interrupts was requested 173 * 174 * Invoke to get the number of MSI interrupts allocated by the RC 175 */ 176 int pci_epc_get_msi(struct pci_epc *epc) 177 { 178 int interrupt; 179 unsigned long flags; 180 181 if (IS_ERR(epc)) 182 return 0; 183 184 if (!epc->ops->get_msi) 185 return 0; 186 187 spin_lock_irqsave(&epc->lock, flags); 188 interrupt = epc->ops->get_msi(epc); 189 spin_unlock_irqrestore(&epc->lock, flags); 190 191 if (interrupt < 0) 192 return 0; 193 194 interrupt = 1 << interrupt; 195 196 return interrupt; 197 } 198 EXPORT_SYMBOL_GPL(pci_epc_get_msi); 199 200 /** 201 * pci_epc_set_msi() - set the number of MSI interrupt numbers required 202 * @epc: the EPC device on which MSI has to be configured 203 * @interrupts: number of MSI interrupts required by the EPF 204 * 205 * Invoke to set the required number of MSI interrupts. 206 */ 207 int pci_epc_set_msi(struct pci_epc *epc, u8 interrupts) 208 { 209 int ret; 210 u8 encode_int; 211 unsigned long flags; 212 213 if (IS_ERR(epc)) 214 return -EINVAL; 215 216 if (!epc->ops->set_msi) 217 return 0; 218 219 encode_int = order_base_2(interrupts); 220 221 spin_lock_irqsave(&epc->lock, flags); 222 ret = epc->ops->set_msi(epc, encode_int); 223 spin_unlock_irqrestore(&epc->lock, flags); 224 225 return ret; 226 } 227 EXPORT_SYMBOL_GPL(pci_epc_set_msi); 228 229 /** 230 * pci_epc_unmap_addr() - unmap CPU address from PCI address 231 * @epc: the EPC device on which address is allocated 232 * @phys_addr: physical address of the local system 233 * 234 * Invoke to unmap the CPU address from PCI address. 235 */ 236 void pci_epc_unmap_addr(struct pci_epc *epc, phys_addr_t phys_addr) 237 { 238 unsigned long flags; 239 240 if (IS_ERR(epc)) 241 return; 242 243 if (!epc->ops->unmap_addr) 244 return; 245 246 spin_lock_irqsave(&epc->lock, flags); 247 epc->ops->unmap_addr(epc, phys_addr); 248 spin_unlock_irqrestore(&epc->lock, flags); 249 } 250 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr); 251 252 /** 253 * pci_epc_map_addr() - map CPU address to PCI address 254 * @epc: the EPC device on which address is allocated 255 * @phys_addr: physical address of the local system 256 * @pci_addr: PCI address to which the physical address should be mapped 257 * @size: the size of the allocation 258 * 259 * Invoke to map CPU address with PCI address. 260 */ 261 int pci_epc_map_addr(struct pci_epc *epc, phys_addr_t phys_addr, 262 u64 pci_addr, size_t size) 263 { 264 int ret; 265 unsigned long flags; 266 267 if (IS_ERR(epc)) 268 return -EINVAL; 269 270 if (!epc->ops->map_addr) 271 return 0; 272 273 spin_lock_irqsave(&epc->lock, flags); 274 ret = epc->ops->map_addr(epc, phys_addr, pci_addr, size); 275 spin_unlock_irqrestore(&epc->lock, flags); 276 277 return ret; 278 } 279 EXPORT_SYMBOL_GPL(pci_epc_map_addr); 280 281 /** 282 * pci_epc_clear_bar() - reset the BAR 283 * @epc: the EPC device for which the BAR has to be cleared 284 * @bar: the BAR number that has to be reset 285 * 286 * Invoke to reset the BAR of the endpoint device. 287 */ 288 void pci_epc_clear_bar(struct pci_epc *epc, int bar) 289 { 290 unsigned long flags; 291 292 if (IS_ERR(epc)) 293 return; 294 295 if (!epc->ops->clear_bar) 296 return; 297 298 spin_lock_irqsave(&epc->lock, flags); 299 epc->ops->clear_bar(epc, bar); 300 spin_unlock_irqrestore(&epc->lock, flags); 301 } 302 EXPORT_SYMBOL_GPL(pci_epc_clear_bar); 303 304 /** 305 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space 306 * @epc: the EPC device on which BAR has to be configured 307 * @bar: the BAR number that has to be configured 308 * @size: the size of the addr space 309 * @flags: specify memory allocation/io allocation/32bit address/64 bit address 310 * 311 * Invoke to configure the BAR of the endpoint device. 312 */ 313 int pci_epc_set_bar(struct pci_epc *epc, enum pci_barno bar, 314 dma_addr_t bar_phys, size_t size, int flags) 315 { 316 int ret; 317 unsigned long irq_flags; 318 319 if (IS_ERR(epc)) 320 return -EINVAL; 321 322 if (!epc->ops->set_bar) 323 return 0; 324 325 spin_lock_irqsave(&epc->lock, irq_flags); 326 ret = epc->ops->set_bar(epc, bar, bar_phys, size, flags); 327 spin_unlock_irqrestore(&epc->lock, irq_flags); 328 329 return ret; 330 } 331 EXPORT_SYMBOL_GPL(pci_epc_set_bar); 332 333 /** 334 * pci_epc_write_header() - write standard configuration header 335 * @epc: the EPC device to which the configuration header should be written 336 * @header: standard configuration header fields 337 * 338 * Invoke to write the configuration header to the endpoint controller. Every 339 * endpoint controller will have a dedicated location to which the standard 340 * configuration header would be written. The callback function should write 341 * the header fields to this dedicated location. 342 */ 343 int pci_epc_write_header(struct pci_epc *epc, struct pci_epf_header *header) 344 { 345 int ret; 346 unsigned long flags; 347 348 if (IS_ERR(epc)) 349 return -EINVAL; 350 351 if (!epc->ops->write_header) 352 return 0; 353 354 spin_lock_irqsave(&epc->lock, flags); 355 ret = epc->ops->write_header(epc, header); 356 spin_unlock_irqrestore(&epc->lock, flags); 357 358 return ret; 359 } 360 EXPORT_SYMBOL_GPL(pci_epc_write_header); 361 362 /** 363 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller 364 * @epc: the EPC device to which the endpoint function should be added 365 * @epf: the endpoint function to be added 366 * 367 * A PCI endpoint device can have one or more functions. In the case of PCIe, 368 * the specification allows up to 8 PCIe endpoint functions. Invoke 369 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller. 370 */ 371 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 372 { 373 unsigned long flags; 374 struct device *dev = epc->dev.parent; 375 376 if (epf->epc) 377 return -EBUSY; 378 379 if (IS_ERR(epc)) 380 return -EINVAL; 381 382 if (epf->func_no > epc->max_functions - 1) 383 return -EINVAL; 384 385 epf->epc = epc; 386 if (dev->of_node) { 387 of_dma_configure(&epf->dev, dev->of_node); 388 } else { 389 dma_set_coherent_mask(&epf->dev, epc->dev.coherent_dma_mask); 390 epf->dev.dma_mask = epc->dev.dma_mask; 391 } 392 393 spin_lock_irqsave(&epc->lock, flags); 394 list_add_tail(&epf->list, &epc->pci_epf); 395 spin_unlock_irqrestore(&epc->lock, flags); 396 397 return 0; 398 } 399 EXPORT_SYMBOL_GPL(pci_epc_add_epf); 400 401 /** 402 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller 403 * @epc: the EPC device from which the endpoint function should be removed 404 * @epf: the endpoint function to be removed 405 * 406 * Invoke to remove PCI endpoint function from the endpoint controller. 407 */ 408 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf) 409 { 410 unsigned long flags; 411 412 if (!epc || IS_ERR(epc)) 413 return; 414 415 spin_lock_irqsave(&epc->lock, flags); 416 list_del(&epf->list); 417 spin_unlock_irqrestore(&epc->lock, flags); 418 } 419 EXPORT_SYMBOL_GPL(pci_epc_remove_epf); 420 421 /** 422 * pci_epc_linkup() - Notify the EPF device that EPC device has established a 423 * connection with the Root Complex. 424 * @epc: the EPC device which has established link with the host 425 * 426 * Invoke to Notify the EPF device that the EPC device has established a 427 * connection with the Root Complex. 428 */ 429 void pci_epc_linkup(struct pci_epc *epc) 430 { 431 unsigned long flags; 432 struct pci_epf *epf; 433 434 if (!epc || IS_ERR(epc)) 435 return; 436 437 spin_lock_irqsave(&epc->lock, flags); 438 list_for_each_entry(epf, &epc->pci_epf, list) 439 pci_epf_linkup(epf); 440 spin_unlock_irqrestore(&epc->lock, flags); 441 } 442 EXPORT_SYMBOL_GPL(pci_epc_linkup); 443 444 /** 445 * pci_epc_destroy() - destroy the EPC device 446 * @epc: the EPC device that has to be destroyed 447 * 448 * Invoke to destroy the PCI EPC device 449 */ 450 void pci_epc_destroy(struct pci_epc *epc) 451 { 452 pci_ep_cfs_remove_epc_group(epc->group); 453 device_unregister(&epc->dev); 454 kfree(epc); 455 } 456 EXPORT_SYMBOL_GPL(pci_epc_destroy); 457 458 /** 459 * devm_pci_epc_destroy() - destroy the EPC device 460 * @dev: device that wants to destroy the EPC 461 * @epc: the EPC device that has to be destroyed 462 * 463 * Invoke to destroy the devres associated with this 464 * pci_epc and destroy the EPC device. 465 */ 466 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc) 467 { 468 int r; 469 470 r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match, 471 epc); 472 dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n"); 473 } 474 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy); 475 476 /** 477 * __pci_epc_create() - create a new endpoint controller (EPC) device 478 * @dev: device that is creating the new EPC 479 * @ops: function pointers for performing EPC operations 480 * @owner: the owner of the module that creates the EPC device 481 * 482 * Invoke to create a new EPC device and add it to pci_epc class. 483 */ 484 struct pci_epc * 485 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 486 struct module *owner) 487 { 488 int ret; 489 struct pci_epc *epc; 490 491 if (WARN_ON(!dev)) { 492 ret = -EINVAL; 493 goto err_ret; 494 } 495 496 epc = kzalloc(sizeof(*epc), GFP_KERNEL); 497 if (!epc) { 498 ret = -ENOMEM; 499 goto err_ret; 500 } 501 502 spin_lock_init(&epc->lock); 503 INIT_LIST_HEAD(&epc->pci_epf); 504 505 device_initialize(&epc->dev); 506 dma_set_coherent_mask(&epc->dev, dev->coherent_dma_mask); 507 epc->dev.class = pci_epc_class; 508 epc->dev.dma_mask = dev->dma_mask; 509 epc->dev.parent = dev; 510 epc->ops = ops; 511 512 ret = dev_set_name(&epc->dev, "%s", dev_name(dev)); 513 if (ret) 514 goto put_dev; 515 516 ret = device_add(&epc->dev); 517 if (ret) 518 goto put_dev; 519 520 epc->group = pci_ep_cfs_add_epc_group(dev_name(dev)); 521 522 return epc; 523 524 put_dev: 525 put_device(&epc->dev); 526 kfree(epc); 527 528 err_ret: 529 return ERR_PTR(ret); 530 } 531 EXPORT_SYMBOL_GPL(__pci_epc_create); 532 533 /** 534 * __devm_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 * While at that, it also associates the device with the pci_epc using devres. 541 * On driver detach, release function is invoked on the devres data, 542 * then, devres data is freed. 543 */ 544 struct pci_epc * 545 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 546 struct module *owner) 547 { 548 struct pci_epc **ptr, *epc; 549 550 ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL); 551 if (!ptr) 552 return ERR_PTR(-ENOMEM); 553 554 epc = __pci_epc_create(dev, ops, owner); 555 if (!IS_ERR(epc)) { 556 *ptr = epc; 557 devres_add(dev, ptr); 558 } else { 559 devres_free(ptr); 560 } 561 562 return epc; 563 } 564 EXPORT_SYMBOL_GPL(__devm_pci_epc_create); 565 566 static int __init pci_epc_init(void) 567 { 568 pci_epc_class = class_create(THIS_MODULE, "pci_epc"); 569 if (IS_ERR(pci_epc_class)) { 570 pr_err("failed to create pci epc class --> %ld\n", 571 PTR_ERR(pci_epc_class)); 572 return PTR_ERR(pci_epc_class); 573 } 574 575 return 0; 576 } 577 module_init(pci_epc_init); 578 579 static void __exit pci_epc_exit(void) 580 { 581 class_destroy(pci_epc_class); 582 } 583 module_exit(pci_epc_exit); 584 585 MODULE_DESCRIPTION("PCI EPC Library"); 586 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 587 MODULE_LICENSE("GPL v2"); 588