drivers/pci/endpoint/pci-epf-core.c

   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");