1 // SPDX-License-Identifier: GPL-2.0 2 /** 3 * PCI Endpoint *Function* (EPF) 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 14 #include <linux/pci-epc.h> 15 #include <linux/pci-epf.h> 16 #include <linux/pci-ep-cfs.h> 17 18 static DEFINE_MUTEX(pci_epf_mutex); 19 20 static struct bus_type pci_epf_bus_type; 21 static const struct device_type pci_epf_type; 22 23 /** 24 * pci_epf_linkup() - Notify the function driver that EPC device has 25 * established a connection with the Root Complex. 26 * @epf: the EPF device bound to the EPC device which has established 27 * the connection with the host 28 * 29 * Invoke to notify the function driver that EPC device has established 30 * a connection with the Root Complex. 31 */ 32 void pci_epf_linkup(struct pci_epf *epf) 33 { 34 if (!epf->driver) { 35 dev_WARN(&epf->dev, "epf device not bound to driver\n"); 36 return; 37 } 38 39 epf->driver->ops->linkup(epf); 40 } 41 EXPORT_SYMBOL_GPL(pci_epf_linkup); 42 43 /** 44 * pci_epf_unbind() - Notify the function driver that the binding between the 45 * EPF device and EPC device has been lost 46 * @epf: the EPF device which has lost the binding with the EPC device 47 * 48 * Invoke to notify the function driver that the binding between the EPF device 49 * and EPC device has been lost. 50 */ 51 void pci_epf_unbind(struct pci_epf *epf) 52 { 53 if (!epf->driver) { 54 dev_WARN(&epf->dev, "epf device not bound to driver\n"); 55 return; 56 } 57 58 epf->driver->ops->unbind(epf); 59 module_put(epf->driver->owner); 60 } 61 EXPORT_SYMBOL_GPL(pci_epf_unbind); 62 63 /** 64 * pci_epf_bind() - Notify the function driver that the EPF device has been 65 * bound to a EPC device 66 * @epf: the EPF device which has been bound to the EPC device 67 * 68 * Invoke to notify the function driver that it has been bound to a EPC device 69 */ 70 int pci_epf_bind(struct pci_epf *epf) 71 { 72 if (!epf->driver) { 73 dev_WARN(&epf->dev, "epf device not bound to driver\n"); 74 return -EINVAL; 75 } 76 77 if (!try_module_get(epf->driver->owner)) 78 return -EAGAIN; 79 80 return epf->driver->ops->bind(epf); 81 } 82 EXPORT_SYMBOL_GPL(pci_epf_bind); 83 84 /** 85 * pci_epf_free_space() - free the allocated PCI EPF register space 86 * @addr: the virtual address of the PCI EPF register space 87 * @bar: the BAR number corresponding to the register space 88 * 89 * Invoke to free the allocated PCI EPF register space. 90 */ 91 void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar) 92 { 93 struct device *dev = epf->epc->dev.parent; 94 95 if (!addr) 96 return; 97 98 dma_free_coherent(dev, epf->bar[bar].size, addr, 99 epf->bar[bar].phys_addr); 100 101 epf->bar[bar].phys_addr = 0; 102 epf->bar[bar].size = 0; 103 epf->bar[bar].barno = 0; 104 epf->bar[bar].flags = 0; 105 } 106 EXPORT_SYMBOL_GPL(pci_epf_free_space); 107 108 /** 109 * pci_epf_alloc_space() - allocate memory for the PCI EPF register space 110 * @size: the size of the memory that has to be allocated 111 * @bar: the BAR number corresponding to the allocated register space 112 * 113 * Invoke to allocate memory for the PCI EPF register space. 114 */ 115 void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar) 116 { 117 void *space; 118 struct device *dev = epf->epc->dev.parent; 119 dma_addr_t phys_addr; 120 121 if (size < 128) 122 size = 128; 123 size = roundup_pow_of_two(size); 124 125 space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL); 126 if (!space) { 127 dev_err(dev, "failed to allocate mem space\n"); 128 return NULL; 129 } 130 131 epf->bar[bar].phys_addr = phys_addr; 132 epf->bar[bar].size = size; 133 epf->bar[bar].barno = bar; 134 epf->bar[bar].flags = PCI_BASE_ADDRESS_SPACE_MEMORY; 135 136 return space; 137 } 138 EXPORT_SYMBOL_GPL(pci_epf_alloc_space); 139 140 static void pci_epf_remove_cfs(struct pci_epf_driver *driver) 141 { 142 struct config_group *group, *tmp; 143 144 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) 145 return; 146 147 mutex_lock(&pci_epf_mutex); 148 list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry) 149 pci_ep_cfs_remove_epf_group(group); 150 list_del(&driver->epf_group); 151 mutex_unlock(&pci_epf_mutex); 152 } 153 154 /** 155 * pci_epf_unregister_driver() - unregister the PCI EPF driver 156 * @driver: the PCI EPF driver that has to be unregistered 157 * 158 * Invoke to unregister the PCI EPF driver. 159 */ 160 void pci_epf_unregister_driver(struct pci_epf_driver *driver) 161 { 162 pci_epf_remove_cfs(driver); 163 driver_unregister(&driver->driver); 164 } 165 EXPORT_SYMBOL_GPL(pci_epf_unregister_driver); 166 167 static int pci_epf_add_cfs(struct pci_epf_driver *driver) 168 { 169 struct config_group *group; 170 const struct pci_epf_device_id *id; 171 172 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) 173 return 0; 174 175 INIT_LIST_HEAD(&driver->epf_group); 176 177 id = driver->id_table; 178 while (id->name[0]) { 179 group = pci_ep_cfs_add_epf_group(id->name); 180 if (IS_ERR(group)) { 181 pci_epf_remove_cfs(driver); 182 return PTR_ERR(group); 183 } 184 185 mutex_lock(&pci_epf_mutex); 186 list_add_tail(&group->group_entry, &driver->epf_group); 187 mutex_unlock(&pci_epf_mutex); 188 id++; 189 } 190 191 return 0; 192 } 193 194 /** 195 * __pci_epf_register_driver() - register a new PCI EPF driver 196 * @driver: structure representing PCI EPF driver 197 * @owner: the owner of the module that registers the PCI EPF driver 198 * 199 * Invoke to register a new PCI EPF driver. 200 */ 201 int __pci_epf_register_driver(struct pci_epf_driver *driver, 202 struct module *owner) 203 { 204 int ret; 205 206 if (!driver->ops) 207 return -EINVAL; 208 209 if (!driver->ops->bind || !driver->ops->unbind || !driver->ops->linkup) 210 return -EINVAL; 211 212 driver->driver.bus = &pci_epf_bus_type; 213 driver->driver.owner = owner; 214 215 ret = driver_register(&driver->driver); 216 if (ret) 217 return ret; 218 219 pci_epf_add_cfs(driver); 220 221 return 0; 222 } 223 EXPORT_SYMBOL_GPL(__pci_epf_register_driver); 224 225 /** 226 * pci_epf_destroy() - destroy the created PCI EPF device 227 * @epf: the PCI EPF device that has to be destroyed. 228 * 229 * Invoke to destroy the PCI EPF device created by invoking pci_epf_create(). 230 */ 231 void pci_epf_destroy(struct pci_epf *epf) 232 { 233 device_unregister(&epf->dev); 234 } 235 EXPORT_SYMBOL_GPL(pci_epf_destroy); 236 237 /** 238 * pci_epf_create() - create a new PCI EPF device 239 * @name: the name of the PCI EPF device. This name will be used to bind the 240 * the EPF device to a EPF driver 241 * 242 * Invoke to create a new PCI EPF device by providing the name of the function 243 * device. 244 */ 245 struct pci_epf *pci_epf_create(const char *name) 246 { 247 int ret; 248 struct pci_epf *epf; 249 struct device *dev; 250 int len; 251 252 epf = kzalloc(sizeof(*epf), GFP_KERNEL); 253 if (!epf) 254 return ERR_PTR(-ENOMEM); 255 256 len = strchrnul(name, '.') - name; 257 epf->name = kstrndup(name, len, GFP_KERNEL); 258 if (!epf->name) { 259 kfree(epf); 260 return ERR_PTR(-ENOMEM); 261 } 262 263 dev = &epf->dev; 264 device_initialize(dev); 265 dev->bus = &pci_epf_bus_type; 266 dev->type = &pci_epf_type; 267 268 ret = dev_set_name(dev, "%s", name); 269 if (ret) { 270 put_device(dev); 271 return ERR_PTR(ret); 272 } 273 274 ret = device_add(dev); 275 if (ret) { 276 put_device(dev); 277 return ERR_PTR(ret); 278 } 279 280 return epf; 281 } 282 EXPORT_SYMBOL_GPL(pci_epf_create); 283 284 const struct pci_epf_device_id * 285 pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf) 286 { 287 if (!id || !epf) 288 return NULL; 289 290 while (*id->name) { 291 if (strcmp(epf->name, id->name) == 0) 292 return id; 293 id++; 294 } 295 296 return NULL; 297 } 298 EXPORT_SYMBOL_GPL(pci_epf_match_device); 299 300 static void pci_epf_dev_release(struct device *dev) 301 { 302 struct pci_epf *epf = to_pci_epf(dev); 303 304 kfree(epf->name); 305 kfree(epf); 306 } 307 308 static const struct device_type pci_epf_type = { 309 .release = pci_epf_dev_release, 310 }; 311 312 static int 313 pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf) 314 { 315 while (id->name[0]) { 316 if (strcmp(epf->name, id->name) == 0) 317 return true; 318 id++; 319 } 320 321 return false; 322 } 323 324 static int pci_epf_device_match(struct device *dev, struct device_driver *drv) 325 { 326 struct pci_epf *epf = to_pci_epf(dev); 327 struct pci_epf_driver *driver = to_pci_epf_driver(drv); 328 329 if (driver->id_table) 330 return pci_epf_match_id(driver->id_table, epf); 331 332 return !strcmp(epf->name, drv->name); 333 } 334 335 static int pci_epf_device_probe(struct device *dev) 336 { 337 struct pci_epf *epf = to_pci_epf(dev); 338 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver); 339 340 if (!driver->probe) 341 return -ENODEV; 342 343 epf->driver = driver; 344 345 return driver->probe(epf); 346 } 347 348 static int pci_epf_device_remove(struct device *dev) 349 { 350 int ret = 0; 351 struct pci_epf *epf = to_pci_epf(dev); 352 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver); 353 354 if (driver->remove) 355 ret = driver->remove(epf); 356 epf->driver = NULL; 357 358 return ret; 359 } 360 361 static struct bus_type pci_epf_bus_type = { 362 .name = "pci-epf", 363 .match = pci_epf_device_match, 364 .probe = pci_epf_device_probe, 365 .remove = pci_epf_device_remove, 366 }; 367 368 static int __init pci_epf_init(void) 369 { 370 int ret; 371 372 ret = bus_register(&pci_epf_bus_type); 373 if (ret) { 374 pr_err("failed to register pci epf bus --> %d\n", ret); 375 return ret; 376 } 377 378 return 0; 379 } 380 module_init(pci_epf_init); 381 382 static void __exit pci_epf_exit(void) 383 { 384 bus_unregister(&pci_epf_bus_type); 385 } 386 module_exit(pci_epf_exit); 387 388 MODULE_DESCRIPTION("PCI EPF Library"); 389 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 390 MODULE_LICENSE("GPL v2"); 391