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