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->service = service_type;
 144
 145         /* Initialize generic device interface */
 146         device = &dev->device;
 147         memset(device, 0, sizeof(struct device));
 148         device->bus = &pcie_port_bus_type;
 149         device->driver = NULL;
 150         device->driver_data = NULL;
 151         device->release = release_pcie_device;  /* callback to free pcie dev */
 152         dev_set_name(device, "%s:pcie%02x",
 153                  pci_name(parent), get_descriptor_id(port_type, service_type));
 154         device->parent = &parent->dev;
 155 }
 156
 157 /**
 158  * alloc_pcie_device - allocate PCI Express port service device structure
 159  * @parent: PCI Express port to associate the service device with
 160  * @port_type: Type of the port
 161  * @service_type: Type of service to associate with the service device
 162  * @irq: Interrupt vector to associate with the service device
 163  */
 164 static struct pcie_device* alloc_pcie_device(struct pci_dev *parent,
 165         int service_type, int irq)
 166 {
 167         struct pcie_device *device;
 168
 169         device = kzalloc(sizeof(struct pcie_device), GFP_KERNEL);
 170         if (!device)
 171                 return NULL;
 172
 173         pcie_device_init(parent, device, service_type, irq);
 174         return device;
 175 }
 176
 177 /**
 178  * pcie_port_device_probe - check if device is a PCI Express port
 179  * @dev: Device to check
 180  */
 181 int pcie_port_device_probe(struct pci_dev *dev)
 182 {
 183         int pos, type;
 184         u16 reg;
 185
 186         if (!(pos = pci_find_capability(dev, PCI_CAP_ID_EXP)))
 187                 return -ENODEV;
 188
 189         pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, &reg);
 190         type = (reg >> 4) & PORT_TYPE_MASK;
 191         if (    type == PCIE_RC_PORT || type == PCIE_SW_UPSTREAM_PORT ||
 192                 type == PCIE_SW_DOWNSTREAM_PORT )
 193                 return 0;
 194
 195         return -ENODEV;
 196 }
 197
 198 /**
 199  * pcie_port_device_register - register PCI Express port
 200  * @dev: PCI Express port to register
 201  *
 202  * Allocate the port extension structure and register services associated with
 203  * the port.
 204  */
 205 int pcie_port_device_register(struct pci_dev *dev)
 206 {
 207         struct pcie_port_data *port_data;
 208         int status, capabilities, irq_mode, i, nr_serv;
 209         int vectors[PCIE_PORT_DEVICE_MAXSERVICES];
 210         u16 reg16;
 211
 212         port_data = kzalloc(sizeof(*port_data), GFP_KERNEL);
 213         if (!port_data)
 214                 return -ENOMEM;
 215         pci_set_drvdata(dev, port_data);
 216
 217         /* Get port type */
 218         pci_read_config_word(dev,
 219                 pci_find_capability(dev, PCI_CAP_ID_EXP) +
 220                 PCIE_CAPABILITIES_REG, &reg16);
 221         port_data->port_type = (reg16 >> 4) & PORT_TYPE_MASK;
 222
 223         capabilities = get_port_device_capability(dev);
 224         /* Root ports are capable of generating PME too */
 225         if (port_data->port_type == PCIE_RC_PORT)
 226                 capabilities |= PCIE_PORT_SERVICE_PME;
 227
 228         irq_mode = assign_interrupt_mode(dev, vectors, capabilities);
 229         if (irq_mode == PCIE_PORT_NO_IRQ) {
 230                 /*
 231                  * Don't use service devices that require interrupts if there is
 232                  * no way to generate them.
 233                  */
 234                 if (!(capabilities & PCIE_PORT_SERVICE_VC)) {
 235                         status = -ENODEV;
 236                         goto Error;
 237                 }
 238                 capabilities = PCIE_PORT_SERVICE_VC;
 239         }
 240         port_data->port_irq_mode = irq_mode;
 241
 242         status = pci_enable_device(dev);
 243         if (status)
 244                 goto Error;
 245         pci_set_master(dev);
 246
 247         /* Allocate child services if any */
 248         for (i = 0, nr_serv = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
 249                 struct pcie_device *child;
 250                 int service = 1 << i;
 251
 252                 if (!(capabilities & service))
 253                         continue;
 254
 255                 child = alloc_pcie_device(dev, service, vectors[i]);
 256                 if (!child)
 257                         continue;
 258
 259                 status = device_register(&child->device);
 260                 if (status) {
 261                         kfree(child);
 262                         continue;
 263                 }
 264
 265                 get_device(&child->device);
 266                 nr_serv++;
 267         }
 268         if (!nr_serv) {
 269                 pci_disable_device(dev);
 270                 status = -ENODEV;
 271                 goto Error;
 272         }
 273
 274         return 0;
 275
 276  Error:
 277         kfree(port_data);
 278         return status;
 279 }
 280
 281 #ifdef CONFIG_PM
 282 static int suspend_iter(struct device *dev, void *data)
 283 {
 284         struct pcie_port_service_driver *service_driver;
 285         pm_message_t state = * (pm_message_t *) data;
 286
 287         if ((dev->bus == &pcie_port_bus_type) &&
 288             (dev->driver)) {
 289                 service_driver = to_service_driver(dev->driver);
 290                 if (service_driver->suspend)
 291                         service_driver->suspend(to_pcie_device(dev), state);
 292         }
 293         return 0;
 294 }
 295
 296 /**
 297  * pcie_port_device_suspend - suspend port services associated with a PCIe port
 298  * @dev: PCI Express port to handle
 299  * @state: Representation of system power management transition in progress
 300  */
 301 int pcie_port_device_suspend(struct pci_dev *dev, pm_message_t state)
 302 {
 303         return device_for_each_child(&dev->dev, &state, suspend_iter);
 304 }
 305
 306 static int resume_iter(struct device *dev, void *data)
 307 {
 308         struct pcie_port_service_driver *service_driver;
 309
 310         if ((dev->bus == &pcie_port_bus_type) &&
 311             (dev->driver)) {
 312                 service_driver = to_service_driver(dev->driver);
 313                 if (service_driver->resume)
 314                         service_driver->resume(to_pcie_device(dev));
 315         }
 316         return 0;
 317 }
 318
 319 /**
 320  * pcie_port_device_suspend - resume port services associated with a PCIe port
 321  * @dev: PCI Express port to handle
 322  */
 323 int pcie_port_device_resume(struct pci_dev *dev)
 324 {
 325         return device_for_each_child(&dev->dev, NULL, resume_iter);
 326 }
 327 #endif
 328
 329 static int remove_iter(struct device *dev, void *data)
 330 {
 331         struct pcie_port_service_driver *service_driver;
 332
 333         if (dev->bus == &pcie_port_bus_type) {
 334                 if (dev->driver) {
 335                         service_driver = to_service_driver(dev->driver);
 336                         if (service_driver->remove)
 337                                 service_driver->remove(to_pcie_device(dev));
 338                 }
 339                 *(unsigned long*)data = (unsigned long)dev;
 340                 return 1;
 341         }
 342         return 0;
 343 }
 344
 345 /**
 346  * pcie_port_device_remove - unregister PCI Express port service devices
 347  * @dev: PCI Express port the service devices to unregister are associated with
 348  *
 349  * Remove PCI Express port service devices associated with given port and
 350  * disable MSI-X or MSI for the port.
 351  */
 352 void pcie_port_device_remove(struct pci_dev *dev)
 353 {
 354         struct pcie_port_data *port_data = pci_get_drvdata(dev);
 355         int status;
 356
 357         do {
 358                 unsigned long device_addr;
 359
 360                 status = device_for_each_child(&dev->dev, &device_addr, remove_iter);
 361                 if (status) {
 362                         struct device *device = (struct device*)device_addr;
 363                         put_device(device);
 364                         device_unregister(device);
 365                 }
 366         } while (status);
 367
 368         switch (port_data->port_irq_mode) {
 369         case PCIE_PORT_MSIX_MODE:
 370                 pci_disable_msix(dev);
 371                 break;
 372         case PCIE_PORT_MSI_MODE:
 373                 pci_disable_msi(dev);
 374                 break;
 375         }
 376
 377         kfree(port_data);
 378 }
 379
 380 /**
 381  * pcie_port_probe_service - probe driver for given PCI Express port service
 382  * @dev: PCI Express port service device to probe against
 383  *
 384  * If PCI Express port service driver is registered with
 385  * pcie_port_service_register(), this function will be called by the driver core
 386  * whenever match is found between the driver and a port service device.
 387  */
 388 static int pcie_port_probe_service(struct device *dev)
 389 {
 390         struct pcie_device *pciedev;
 391         struct pcie_port_service_driver *driver;
 392         int status;
 393
 394         if (!dev || !dev->driver)
 395                 return -ENODEV;
 396
 397         driver = to_service_driver(dev->driver);
 398         if (!driver || !driver->probe)
 399                 return -ENODEV;
 400
 401         pciedev = to_pcie_device(dev);
 402         status = driver->probe(pciedev);
 403         if (!status) {
 404                 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
 405                         driver->name);
 406                 get_device(dev);
 407         }
 408         return status;
 409 }
 410
 411 /**
 412  * pcie_port_remove_service - detach driver from given PCI Express port service
 413  * @dev: PCI Express port service device to handle
 414  *
 415  * If PCI Express port service driver is registered with
 416  * pcie_port_service_register(), this function will be called by the driver core
 417  * when device_unregister() is called for the port service device associated
 418  * with the driver.
 419  */
 420 static int pcie_port_remove_service(struct device *dev)
 421 {
 422         struct pcie_device *pciedev;
 423         struct pcie_port_service_driver *driver;
 424
 425         if (!dev || !dev->driver)
 426                 return 0;
 427
 428         pciedev = to_pcie_device(dev);
 429         driver = to_service_driver(dev->driver);
 430         if (driver && driver->remove) {
 431                 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
 432                         driver->name);
 433                 driver->remove(pciedev);
 434                 put_device(dev);
 435         }
 436         return 0;
 437 }
 438
 439 /**
 440  * pcie_port_shutdown_service - shut down given PCI Express port service
 441  * @dev: PCI Express port service device to handle
 442  *
 443  * If PCI Express port service driver is registered with
 444  * pcie_port_service_register(), this function will be called by the driver core
 445  * when device_shutdown() is called for the port service device associated
 446  * with the driver.
 447  */
 448 static void pcie_port_shutdown_service(struct device *dev) {}
 449
 450 /**
 451  * pcie_port_service_register - register PCI Express port service driver
 452  * @new: PCI Express port service driver to register
 453  */
 454 int pcie_port_service_register(struct pcie_port_service_driver *new)
 455 {
 456         new->driver.name = (char *)new->name;
 457         new->driver.bus = &pcie_port_bus_type;
 458         new->driver.probe = pcie_port_probe_service;
 459         new->driver.remove = pcie_port_remove_service;
 460         new->driver.shutdown = pcie_port_shutdown_service;
 461
 462         return driver_register(&new->driver);
 463 }
 464
 465 /**
 466  * pcie_port_service_unregister - unregister PCI Express port service driver
 467  * @drv: PCI Express port service driver to unregister
 468  */
 469 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
 470 {
 471         driver_unregister(&drv->driver);
 472 }
 473
 474 EXPORT_SYMBOL(pcie_port_service_register);
 475 EXPORT_SYMBOL(pcie_port_service_unregister);