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 |= upper_32_bits(size) ? 135 PCI_BASE_ADDRESS_MEM_TYPE_64 : 136 PCI_BASE_ADDRESS_MEM_TYPE_32; 137 138 return space; 139 } 140 EXPORT_SYMBOL_GPL(pci_epf_alloc_space); 141 142 static void pci_epf_remove_cfs(struct pci_epf_driver *driver) 143 { 144 struct config_group *group, *tmp; 145 146 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) 147 return; 148 149 mutex_lock(&pci_epf_mutex); 150 list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry) 151 pci_ep_cfs_remove_epf_group(group); 152 list_del(&driver->epf_group); 153 mutex_unlock(&pci_epf_mutex); 154 } 155 156 /** 157 * pci_epf_unregister_driver() - unregister the PCI EPF driver 158 * @driver: the PCI EPF driver that has to be unregistered 159 * 160 * Invoke to unregister the PCI EPF driver. 161 */ 162 void pci_epf_unregister_driver(struct pci_epf_driver *driver) 163 { 164 pci_epf_remove_cfs(driver); 165 driver_unregister(&driver->driver); 166 } 167 EXPORT_SYMBOL_GPL(pci_epf_unregister_driver); 168 169 static int pci_epf_add_cfs(struct pci_epf_driver *driver) 170 { 171 struct config_group *group; 172 const struct pci_epf_device_id *id; 173 174 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS)) 175 return 0; 176 177 INIT_LIST_HEAD(&driver->epf_group); 178 179 id = driver->id_table; 180 while (id->name[0]) { 181 group = pci_ep_cfs_add_epf_group(id->name); 182 if (IS_ERR(group)) { 183 pci_epf_remove_cfs(driver); 184 return PTR_ERR(group); 185 } 186 187 mutex_lock(&pci_epf_mutex); 188 list_add_tail(&group->group_entry, &driver->epf_group); 189 mutex_unlock(&pci_epf_mutex); 190 id++; 191 } 192 193 return 0; 194 } 195 196 /** 197 * __pci_epf_register_driver() - register a new PCI EPF driver 198 * @driver: structure representing PCI EPF driver 199 * @owner: the owner of the module that registers the PCI EPF driver 200 * 201 * Invoke to register a new PCI EPF driver. 202 */ 203 int __pci_epf_register_driver(struct pci_epf_driver *driver, 204 struct module *owner) 205 { 206 int ret; 207 208 if (!driver->ops) 209 return -EINVAL; 210 211 if (!driver->ops->bind || !driver->ops->unbind || !driver->ops->linkup) 212 return -EINVAL; 213 214 driver->driver.bus = &pci_epf_bus_type; 215 driver->driver.owner = owner; 216 217 ret = driver_register(&driver->driver); 218 if (ret) 219 return ret; 220 221 pci_epf_add_cfs(driver); 222 223 return 0; 224 } 225 EXPORT_SYMBOL_GPL(__pci_epf_register_driver); 226 227 /** 228 * pci_epf_destroy() - destroy the created PCI EPF device 229 * @epf: the PCI EPF device that has to be destroyed. 230 * 231 * Invoke to destroy the PCI EPF device created by invoking pci_epf_create(). 232 */ 233 void pci_epf_destroy(struct pci_epf *epf) 234 { 235 device_unregister(&epf->dev); 236 } 237 EXPORT_SYMBOL_GPL(pci_epf_destroy); 238 239 /** 240 * pci_epf_create() - create a new PCI EPF device 241 * @name: the name of the PCI EPF device. This name will be used to bind the 242 * the EPF device to a EPF driver 243 * 244 * Invoke to create a new PCI EPF device by providing the name of the function 245 * device. 246 */ 247 struct pci_epf *pci_epf_create(const char *name) 248 { 249 int ret; 250 struct pci_epf *epf; 251 struct device *dev; 252 int len; 253 254 epf = kzalloc(sizeof(*epf), GFP_KERNEL); 255 if (!epf) 256 return ERR_PTR(-ENOMEM); 257 258 len = strchrnul(name, '.') - name; 259 epf->name = kstrndup(name, len, GFP_KERNEL); 260 if (!epf->name) { 261 kfree(epf); 262 return ERR_PTR(-ENOMEM); 263 } 264 265 dev = &epf->dev; 266 device_initialize(dev); 267 dev->bus = &pci_epf_bus_type; 268 dev->type = &pci_epf_type; 269 270 ret = dev_set_name(dev, "%s", name); 271 if (ret) { 272 put_device(dev); 273 return ERR_PTR(ret); 274 } 275 276 ret = device_add(dev); 277 if (ret) { 278 put_device(dev); 279 return ERR_PTR(ret); 280 } 281 282 return epf; 283 } 284 EXPORT_SYMBOL_GPL(pci_epf_create); 285 286 const struct pci_epf_device_id * 287 pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf) 288 { 289 if (!id || !epf) 290 return NULL; 291 292 while (*id->name) { 293 if (strcmp(epf->name, id->name) == 0) 294 return id; 295 id++; 296 } 297 298 return NULL; 299 } 300 EXPORT_SYMBOL_GPL(pci_epf_match_device); 301 302 static void pci_epf_dev_release(struct device *dev) 303 { 304 struct pci_epf *epf = to_pci_epf(dev); 305 306 kfree(epf->name); 307 kfree(epf); 308 } 309 310 static const struct device_type pci_epf_type = { 311 .release = pci_epf_dev_release, 312 }; 313 314 static int 315 pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf) 316 { 317 while (id->name[0]) { 318 if (strcmp(epf->name, id->name) == 0) 319 return true; 320 id++; 321 } 322 323 return false; 324 } 325 326 static int pci_epf_device_match(struct device *dev, struct device_driver *drv) 327 { 328 struct pci_epf *epf = to_pci_epf(dev); 329 struct pci_epf_driver *driver = to_pci_epf_driver(drv); 330 331 if (driver->id_table) 332 return pci_epf_match_id(driver->id_table, epf); 333 334 return !strcmp(epf->name, drv->name); 335 } 336 337 static int pci_epf_device_probe(struct device *dev) 338 { 339 struct pci_epf *epf = to_pci_epf(dev); 340 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver); 341 342 if (!driver->probe) 343 return -ENODEV; 344 345 epf->driver = driver; 346 347 return driver->probe(epf); 348 } 349 350 static int pci_epf_device_remove(struct device *dev) 351 { 352 int ret = 0; 353 struct pci_epf *epf = to_pci_epf(dev); 354 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver); 355 356 if (driver->remove) 357 ret = driver->remove(epf); 358 epf->driver = NULL; 359 360 return ret; 361 } 362 363 static struct bus_type pci_epf_bus_type = { 364 .name = "pci-epf", 365 .match = pci_epf_device_match, 366 .probe = pci_epf_device_probe, 367 .remove = pci_epf_device_remove, 368 }; 369 370 static int __init pci_epf_init(void) 371 { 372 int ret; 373 374 ret = bus_register(&pci_epf_bus_type); 375 if (ret) { 376 pr_err("failed to register pci epf bus --> %d\n", ret); 377 return ret; 378 } 379 380 return 0; 381 } 382 module_init(pci_epf_init); 383 384 static void __exit pci_epf_exit(void) 385 { 386 bus_unregister(&pci_epf_bus_type); 387 } 388 module_exit(pci_epf_exit); 389 390 MODULE_DESCRIPTION("PCI EPF Library"); 391 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 392 MODULE_LICENSE("GPL v2"); 393