drivers/pci/pcie/portdrv_core.c

   1 /*
   2  * File:        portdrv_core.c
   3  * Purpose:     PCI Express Port Bus Driver's Core Functions
   4  *
   5  * Copyright (C) 2004 Intel
   6  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/pci.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/pm.h>
  14 #include <linux/string.h>
  15 #include <linux/slab.h>
  16 #include <linux/pcieport_if.h>
  17
  18 #include "../pci.h"
  19 #include "portdrv.h"
  20
  21 /**
  22  * release_pcie_device - free PCI Express port service device structure
  23  * @dev: Port service device to release
  24  *
  25  * Invoked automatically when device is being removed in response to
  26  * device_unregister(dev).  Release all resources being claimed.
  27  */
  28 static void release_pcie_device(struct device *dev)
  29 {
  30         kfree(to_pcie_device(dev));
  31 }
  32
  33 /**
  34  * assign_interrupt_mode - choose interrupt mode for PCI Express port services
  35  *                         (INTx, MSI-X, MSI) and set up vectors
  36  * @dev: PCI Express port to handle
  37  * @vectors: Array of interrupt vectors to populate
  38  * @mask: Bitmask of port capabilities returned by get_port_device_capability()
  39  *
  40  * Return value: Interrupt mode associated with the port
  41  */
  42 static int assign_interrupt_mode(struct pci_dev *dev, int *vectors, int mask)
  43 {
  44         struct pcie_port_data *port_data = pci_get_drvdata(dev);
  45         int i, pos, nvec, status = -EINVAL;
  46         int interrupt_mode = PCIE_PORT_NO_IRQ;
  47
  48         /* Set INTx as default */
  49         for (i = 0, nvec = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
  50                 if (mask & (1 << i))
  51                         nvec++;
  52                 vectors[i] = dev->irq;
  53         }
  54         if (dev->pin)
  55                 interrupt_mode = PCIE_PORT_INTx_MODE;
  56
  57         /* Check MSI quirk */
  58         if (port_data->port_type == PCIE_RC_PORT && pcie_mch_quirk)
  59                 return interrupt_mode;
  60
  61         /* Select MSI-X over MSI if supported */
  62         pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
  63         if (pos) {
  64                 struct msix_entry msix_entries[PCIE_PORT_DEVICE_MAXSERVICES] =
  65                         {{0, 0}, {0, 1}, {0, 2}, {0, 3}};
  66                 status = pci_enable_msix(dev, msix_entries, nvec);
  67                 if (!status) {
  68                         int j = 0;
  69
  70                         interrupt_mode = PCIE_PORT_MSIX_MODE;
  71                         for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
  72                                 if (mask & (1 << i))
  73                                         vectors[i] = msix_entries[j++].vector;
  74                         }
  75                 }
  76         }
  77         if (status) {
  78                 pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
  79                 if (pos) {
  80                         status = pci_enable_msi(dev);
  81                         if (!status) {
  82                                 interrupt_mode = PCIE_PORT_MSI_MODE;
  83                                 for (i = 0;i < PCIE_PORT_DEVICE_MAXSERVICES;i++)
  84                                         vectors[i] = dev->irq;
  85                         }
  86                 }
  87         }
  88         return interrupt_mode;
  89 }
  90
  91 /**
  92  * get_port_device_capability - discover capabilities of a PCI Express port
  93  * @dev: PCI Express port to examine
  94  *
  95  * The capabilities are read from the port's PCI Express configuration registers
  96  * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
  97  * 7.9 - 7.11.
  98  *
  99  * Return value: Bitmask of discovered port capabilities
 100  */
 101 static int get_port_device_capability(struct pci_dev *dev)
 102 {
 103         int services = 0, pos;
 104         u16 reg16;
 105         u32 reg32;
 106
 107         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
 108         pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, &reg16);
 109         /* Hot-Plug Capable */
 110         if (reg16 & PORT_TO_SLOT_MASK) {
 111                 pci_read_config_dword(dev,
 112                         pos + PCIE_SLOT_CAPABILITIES_REG, &reg32);
 113                 if (reg32 & SLOT_HP_CAPABLE_MASK)
 114                         services |= PCIE_PORT_SERVICE_HP;
 115         }
 116         /* AER capable */
 117         if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
 118                 services |= PCIE_PORT_SERVICE_AER;
 119         /* VC support */
 120         if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
 121                 services |= PCIE_PORT_SERVICE_VC;
 122
 123         return services;
 124 }
 125
 126 /**
 127  * pcie_device_init - initialize PCI Express port service device
 128  * @dev: Port service device to initialize
 129  * @parent: PCI Express port to associate the service device with
 130  * @port_type: Type of the port
 131  * @service_type: Type of service to associate with the service device
 132  * @irq: Interrupt vector to associate with the service device
 133  */
 134 static void pcie_device_init(struct pci_dev *parent, struct pcie_device *dev,
 135         int service_type, int irq)
 136 {
 137         struct pcie_port_data *port_data = pci_get_drvdata(parent);
 138         struct device *device;
 139         int port_type = port_data->port_type;
 140
 141         dev->port = parent;
 142         dev->irq = irq;
 143         dev->id.vendor = parent->vendor;
 144         dev->id.device = parent->device;
 145         dev->id.port_type = port_type;
 146         dev->id.service_type = service_type;
 147
 148         /* Initialize generic device interface */
 149         device = &dev->device;
 150         memset(device, 0, sizeof(struct device));
 151         device->bus = &pcie_port_bus_type;
 152         device->driver = NULL;
 153         device->driver_data = NULL;
 154         device->release = release_pcie_device;  /* callback to free pcie dev */
 155         dev_set_name(device, "%s:pcie%02x",
 156                  pci_name(parent), get_descriptor_id(port_type, service_type));
 157         device->parent = &parent->dev;
 158 }
 159
 160 /**
 161  * alloc_pcie_device - allocate PCI Express port service device structure
 162  * @parent: PCI Express port to associate the service device with
 163  * @port_type: Type of the port
 164  * @service_type: Type of service to associate with the service device
 165  * @irq: Interrupt vector to associate with the service device
 166  */
 167 static struct pcie_device* alloc_pcie_device(struct pci_dev *parent,
 168         int service_type, int irq)
 169 {
 170         struct pcie_device *device;
 171
 172         device = kzalloc(sizeof(struct pcie_device), GFP_KERNEL);
 173         if (!device)
 174                 return NULL;
 175
 176         pcie_device_init(parent, device, service_type, irq);
 177         return device;
 178 }
 179
 180 /**
 181  * pcie_port_device_probe - check if device is a PCI Express port
 182  * @dev: Device to check
 183  */
 184 int pcie_port_device_probe(struct pci_dev *dev)
 185 {
 186         int pos, type;
 187         u16 reg;
 188
 189         if (!(pos = pci_find_capability(dev, PCI_CAP_ID_EXP)))
 190                 return -ENODEV;
 191
 192         pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, &reg);
 193         type = (reg >> 4) & PORT_TYPE_MASK;
 194         if (    type == PCIE_RC_PORT || type == PCIE_SW_UPSTREAM_PORT ||
 195                 type == PCIE_SW_DOWNSTREAM_PORT )
 196                 return 0;
 197
 198         return -ENODEV;
 199 }
 200
 201 /**
 202  * pcie_port_device_register - register PCI Express port
 203  * @dev: PCI Express port to register
 204  *
 205  * Allocate the port extension structure and register services associated with
 206  * the port.
 207  */
 208 int pcie_port_device_register(struct pci_dev *dev)
 209 {
 210         struct pcie_port_data *port_data;
 211         int status, capabilities, irq_mode, i, nr_serv;
 212         int vectors[PCIE_PORT_DEVICE_MAXSERVICES];
 213         u16 reg16;
 214
 215         port_data = kzalloc(sizeof(*port_data), GFP_KERNEL);
 216         if (!port_data)
 217                 return -ENOMEM;
 218         pci_set_drvdata(dev, port_data);
 219
 220         /* Get port type */
 221         pci_read_config_word(dev,
 222                 pci_find_capability(dev, PCI_CAP_ID_EXP) +
 223                 PCIE_CAPABILITIES_REG, &reg16);
 224         port_data->port_type = (reg16 >> 4) & PORT_TYPE_MASK;
 225
 226         capabilities = get_port_device_capability(dev);
 227         /* Root ports are capable of generating PME too */
 228         if (port_data->port_type == PCIE_RC_PORT)
 229                 capabilities |= PCIE_PORT_SERVICE_PME;
 230
 231         irq_mode = assign_interrupt_mode(dev, vectors, capabilities);
 232         if (irq_mode == PCIE_PORT_NO_IRQ) {
 233                 /*
 234                  * Don't use service devices that require interrupts if there is
 235                  * no way to generate them.
 236                  */
 237                 if (!(capabilities & PCIE_PORT_SERVICE_VC)) {
 238                         status = -ENODEV;
 239                         goto Error;
 240                 }
 241                 capabilities = PCIE_PORT_SERVICE_VC;
 242         }
 243         port_data->port_irq_mode = irq_mode;
 244
 245         status = pci_enable_device(dev);
 246         if (status)
 247                 goto Error;
 248         pci_set_master(dev);
 249
 250         /* Allocate child services if any */
 251         for (i = 0, nr_serv = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
 252                 struct pcie_device *child;
 253                 int service = 1 << i;
 254
 255                 if (!(capabilities & service))
 256                         continue;
 257
 258                 child = alloc_pcie_device(dev, service, vectors[i]);
 259                 if (!child)
 260                         continue;
 261
 262                 status = device_register(&child->device);
 263                 if (status) {
 264                         kfree(child);
 265                         continue;
 266                 }
 267
 268                 get_device(&child->device);
 269                 nr_serv++;
 270         }
 271         if (!nr_serv) {
 272                 pci_disable_device(dev);
 273                 status = -ENODEV;
 274                 goto Error;
 275         }
 276
 277         return 0;
 278
 279  Error:
 280         kfree(port_data);
 281         return status;
 282 }
 283
 284 #ifdef CONFIG_PM
 285 static int suspend_iter(struct device *dev, void *data)
 286 {
 287         struct pcie_port_service_driver *service_driver;
 288         pm_message_t state = * (pm_message_t *) data;
 289
 290         if ((dev->bus == &pcie_port_bus_type) &&
 291             (dev->driver)) {
 292                 service_driver = to_service_driver(dev->driver);
 293                 if (service_driver->suspend)
 294                         service_driver->suspend(to_pcie_device(dev), state);
 295         }
 296         return 0;
 297 }
 298
 299 /**
 300  * pcie_port_device_suspend - suspend port services associated with a PCIe port
 301  * @dev: PCI Express port to handle
 302  * @state: Representation of system power management transition in progress
 303  */
 304 int pcie_port_device_suspend(struct pci_dev *dev, pm_message_t state)
 305 {
 306         return device_for_each_child(&dev->dev, &state, suspend_iter);
 307 }
 308
 309 static int resume_iter(struct device *dev, void *data)
 310 {
 311         struct pcie_port_service_driver *service_driver;
 312
 313         if ((dev->bus == &pcie_port_bus_type) &&
 314             (dev->driver)) {
 315                 service_driver = to_service_driver(dev->driver);
 316                 if (service_driver->resume)
 317                         service_driver->resume(to_pcie_device(dev));
 318         }
 319         return 0;
 320 }
 321
 322 /**
 323  * pcie_port_device_suspend - resume port services associated with a PCIe port
 324  * @dev: PCI Express port to handle
 325  */
 326 int pcie_port_device_resume(struct pci_dev *dev)
 327 {
 328         return device_for_each_child(&dev->dev, NULL, resume_iter);
 329 }
 330 #endif
 331
 332 static int remove_iter(struct device *dev, void *data)
 333 {
 334         struct pcie_port_service_driver *service_driver;
 335
 336         if (dev->bus == &pcie_port_bus_type) {
 337                 if (dev->driver) {
 338                         service_driver = to_service_driver(dev->driver);
 339                         if (service_driver->remove)
 340                                 service_driver->remove(to_pcie_device(dev));
 341                 }
 342                 *(unsigned long*)data = (unsigned long)dev;
 343                 return 1;
 344         }
 345         return 0;
 346 }
 347
 348 /**
 349  * pcie_port_device_remove - unregister PCI Express port service devices
 350  * @dev: PCI Express port the service devices to unregister are associated with
 351  *
 352  * Remove PCI Express port service devices associated with given port and
 353  * disable MSI-X or MSI for the port.
 354  */
 355 void pcie_port_device_remove(struct pci_dev *dev)
 356 {
 357         struct pcie_port_data *port_data = pci_get_drvdata(dev);
 358         int status;
 359
 360         do {
 361                 unsigned long device_addr;
 362
 363                 status = device_for_each_child(&dev->dev, &device_addr, remove_iter);
 364                 if (status) {
 365                         struct device *device = (struct device*)device_addr;
 366                         put_device(device);
 367                         device_unregister(device);
 368                 }
 369         } while (status);
 370
 371         switch (port_data->port_irq_mode) {
 372         case PCIE_PORT_MSIX_MODE:
 373                 pci_disable_msix(dev);
 374                 break;
 375         case PCIE_PORT_MSI_MODE:
 376                 pci_disable_msi(dev);
 377                 break;
 378         }
 379
 380         kfree(port_data);
 381 }
 382
 383 /**
 384  * pcie_port_probe_service - probe driver for given PCI Express port service
 385  * @dev: PCI Express port service device to probe against
 386  *
 387  * If PCI Express port service driver is registered with
 388  * pcie_port_service_register(), this function will be called by the driver core
 389  * whenever match is found between the driver and a port service device.
 390  */
 391 static int pcie_port_probe_service(struct device *dev)
 392 {
 393         struct pcie_device *pciedev;
 394         struct pcie_port_service_driver *driver;
 395         int status;
 396
 397         if (!dev || !dev->driver)
 398                 return -ENODEV;
 399
 400         driver = to_service_driver(dev->driver);
 401         if (!driver || !driver->probe)
 402                 return -ENODEV;
 403
 404         pciedev = to_pcie_device(dev);
 405         status = driver->probe(pciedev);
 406         if (!status) {
 407                 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
 408                         driver->name);
 409                 get_device(dev);
 410         }
 411         return status;
 412 }
 413
 414 /**
 415  * pcie_port_remove_service - detach driver from given PCI Express port service
 416  * @dev: PCI Express port service device to handle
 417  *
 418  * If PCI Express port service driver is registered with
 419  * pcie_port_service_register(), this function will be called by the driver core
 420  * when device_unregister() is called for the port service device associated
 421  * with the driver.
 422  */
 423 static int pcie_port_remove_service(struct device *dev)
 424 {
 425         struct pcie_device *pciedev;
 426         struct pcie_port_service_driver *driver;
 427
 428         if (!dev || !dev->driver)
 429                 return 0;
 430
 431         pciedev = to_pcie_device(dev);
 432         driver = to_service_driver(dev->driver);
 433         if (driver && driver->remove) {
 434                 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
 435                         driver->name);
 436                 driver->remove(pciedev);
 437                 put_device(dev);
 438         }
 439         return 0;
 440 }
 441
 442 /**
 443  * pcie_port_shutdown_service - shut down given PCI Express port service
 444  * @dev: PCI Express port service device to handle
 445  *
 446  * If PCI Express port service driver is registered with
 447  * pcie_port_service_register(), this function will be called by the driver core
 448  * when device_shutdown() is called for the port service device associated
 449  * with the driver.
 450  */
 451 static void pcie_port_shutdown_service(struct device *dev) {}
 452
 453 /**
 454  * pcie_port_service_register - register PCI Express port service driver
 455  * @new: PCI Express port service driver to register
 456  */
 457 int pcie_port_service_register(struct pcie_port_service_driver *new)
 458 {
 459         new->driver.name = (char *)new->name;
 460         new->driver.bus = &pcie_port_bus_type;
 461         new->driver.probe = pcie_port_probe_service;
 462         new->driver.remove = pcie_port_remove_service;
 463         new->driver.shutdown = pcie_port_shutdown_service;
 464
 465         return driver_register(&new->driver);
 466 }
 467
 468 /**
 469  * pcie_port_service_unregister - unregister PCI Express port service driver
 470  * @drv: PCI Express port service driver to unregister
 471  */
 472 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
 473 {
 474         driver_unregister(&drv->driver);
 475 }
 476
 477 EXPORT_SYMBOL(pcie_port_service_register);
 478 EXPORT_SYMBOL(pcie_port_service_unregister);