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#include <linux/aer.h> 18 19#include "../pci.h" 20#include "portdrv.h" 21 22bool pciehp_msi_disabled; 23 24static int __init pciehp_setup(char *str) 25{ 26 if (!strncmp(str, "nomsi", 5)) 27 pciehp_msi_disabled = true; 28 29 return 1; 30} 31__setup("pcie_hp=", pciehp_setup); 32 33/** 34 * release_pcie_device - free PCI Express port service device structure 35 * @dev: Port service device to release 36 * 37 * Invoked automatically when device is being removed in response to 38 * device_unregister(dev). Release all resources being claimed. 39 */ 40static void release_pcie_device(struct device *dev) 41{ 42 kfree(to_pcie_device(dev)); 43} 44 45/** 46 * pcie_port_msix_add_entry - add entry to given array of MSI-X entries 47 * @entries: Array of MSI-X entries 48 * @new_entry: Index of the entry to add to the array 49 * @nr_entries: Number of entries aleady in the array 50 * 51 * Return value: Position of the added entry in the array 52 */ 53static int pcie_port_msix_add_entry( 54 struct msix_entry *entries, int new_entry, int nr_entries) 55{ 56 int j; 57 58 for (j = 0; j < nr_entries; j++) 59 if (entries[j].entry == new_entry) 60 return j; 61 62 entries[j].entry = new_entry; 63 return j; 64} 65 66/** 67 * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port 68 * @dev: PCI Express port to handle 69 * @vectors: Array of interrupt vectors to populate 70 * @mask: Bitmask of port capabilities returned by get_port_device_capability() 71 * 72 * Return value: 0 on success, error code on failure 73 */ 74static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask) 75{ 76 struct msix_entry *msix_entries; 77 int idx[PCIE_PORT_DEVICE_MAXSERVICES]; 78 int nr_entries, status, pos, i, nvec; 79 u16 reg16; 80 u32 reg32; 81 82 nr_entries = pci_msix_table_size(dev); 83 if (!nr_entries) 84 return -EINVAL; 85 if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES) 86 nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES; 87 88 msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL); 89 if (!msix_entries) 90 return -ENOMEM; 91 92 /* 93 * Allocate as many entries as the port wants, so that we can check 94 * which of them will be useful. Moreover, if nr_entries is correctly 95 * equal to the number of entries this port actually uses, we'll happily 96 * go through without any tricks. 97 */ 98 for (i = 0; i < nr_entries; i++) 99 msix_entries[i].entry = i; 100 101 status = pci_enable_msix(dev, msix_entries, nr_entries); 102 if (status) 103 goto Exit; 104 105 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) 106 idx[i] = -1; 107 status = -EIO; 108 nvec = 0; 109 110 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) { 111 int entry; 112 113 /* 114 * The code below follows the PCI Express Base Specification 2.0 115 * stating in Section 6.1.6 that "PME and Hot-Plug Event 116 * interrupts (when both are implemented) always share the same 117 * MSI or MSI-X vector, as indicated by the Interrupt Message 118 * Number field in the PCI Express Capabilities register", where 119 * according to Section 7.8.2 of the specification "For MSI-X, 120 * the value in this field indicates which MSI-X Table entry is 121 * used to generate the interrupt message." 122 */ 123 pos = pci_pcie_cap(dev); 124 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, ®16); 125 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; 126 if (entry >= nr_entries) 127 goto Error; 128 129 i = pcie_port_msix_add_entry(msix_entries, entry, nvec); 130 if (i == nvec) 131 nvec++; 132 133 idx[PCIE_PORT_SERVICE_PME_SHIFT] = i; 134 idx[PCIE_PORT_SERVICE_HP_SHIFT] = i; 135 } 136 137 if (mask & PCIE_PORT_SERVICE_AER) { 138 int entry; 139 140 /* 141 * The code below follows Section 7.10.10 of the PCI Express 142 * Base Specification 2.0 stating that bits 31-27 of the Root 143 * Error Status Register contain a value indicating which of the 144 * MSI/MSI-X vectors assigned to the port is going to be used 145 * for AER, where "For MSI-X, the value in this register 146 * indicates which MSI-X Table entry is used to generate the 147 * interrupt message." 148 */ 149 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); 150 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); 151 entry = reg32 >> 27; 152 if (entry >= nr_entries) 153 goto Error; 154 155 i = pcie_port_msix_add_entry(msix_entries, entry, nvec); 156 if (i == nvec) 157 nvec++; 158 159 idx[PCIE_PORT_SERVICE_AER_SHIFT] = i; 160 } 161 162 /* 163 * If nvec is equal to the allocated number of entries, we can just use 164 * what we have. Otherwise, the port has some extra entries not for the 165 * services we know and we need to work around that. 166 */ 167 if (nvec == nr_entries) { 168 status = 0; 169 } else { 170 /* Drop the temporary MSI-X setup */ 171 pci_disable_msix(dev); 172 173 /* Now allocate the MSI-X vectors for real */ 174 status = pci_enable_msix(dev, msix_entries, nvec); 175 if (status) 176 goto Exit; 177 } 178 179 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) 180 vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1; 181 182 Exit: 183 kfree(msix_entries); 184 return status; 185 186 Error: 187 pci_disable_msix(dev); 188 goto Exit; 189} 190 191/** 192 * init_service_irqs - initialize irqs for PCI Express port services 193 * @dev: PCI Express port to handle 194 * @irqs: Array of irqs to populate 195 * @mask: Bitmask of port capabilities returned by get_port_device_capability() 196 * 197 * Return value: Interrupt mode associated with the port 198 */ 199static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask) 200{ 201 int i, irq = -1; 202 203 /* We have to use INTx if MSI cannot be used for PCIe PME or pciehp. */ 204 if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) || 205 ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) { 206 if (dev->pin) 207 irq = dev->irq; 208 goto no_msi; 209 } 210 211 /* Try to use MSI-X if supported */ 212 if (!pcie_port_enable_msix(dev, irqs, mask)) 213 return 0; 214 215 /* We're not going to use MSI-X, so try MSI and fall back to INTx */ 216 if (!pci_enable_msi(dev) || dev->pin) 217 irq = dev->irq; 218 219 no_msi: 220 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) 221 irqs[i] = irq; 222 irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1; 223 224 if (irq < 0) 225 return -ENODEV; 226 return 0; 227} 228 229static void cleanup_service_irqs(struct pci_dev *dev) 230{ 231 if (dev->msix_enabled) 232 pci_disable_msix(dev); 233 else if (dev->msi_enabled) 234 pci_disable_msi(dev); 235} 236 237/** 238 * get_port_device_capability - discover capabilities of a PCI Express port 239 * @dev: PCI Express port to examine 240 * 241 * The capabilities are read from the port's PCI Express configuration registers 242 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and 243 * 7.9 - 7.11. 244 * 245 * Return value: Bitmask of discovered port capabilities 246 */ 247static int get_port_device_capability(struct pci_dev *dev) 248{ 249 int services = 0, pos; 250 u16 reg16; 251 u32 reg32; 252 int cap_mask; 253 int err; 254 255 if (pcie_ports_disabled) 256 return 0; 257 258 err = pcie_port_platform_notify(dev, &cap_mask); 259 if (!pcie_ports_auto) { 260 cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP 261 | PCIE_PORT_SERVICE_VC; 262 if (pci_aer_available()) 263 cap_mask |= PCIE_PORT_SERVICE_AER; 264 } else if (err) { 265 return 0; 266 } 267 268 pos = pci_pcie_cap(dev); 269 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, ®16); 270 /* Hot-Plug Capable */ 271 if ((cap_mask & PCIE_PORT_SERVICE_HP) && (reg16 & PCI_EXP_FLAGS_SLOT)) { 272 pci_read_config_dword(dev, pos + PCI_EXP_SLTCAP, ®32); 273 if (reg32 & PCI_EXP_SLTCAP_HPC) { 274 services |= PCIE_PORT_SERVICE_HP; 275 /* 276 * Disable hot-plug interrupts in case they have been 277 * enabled by the BIOS and the hot-plug service driver 278 * is not loaded. 279 */ 280 pos += PCI_EXP_SLTCTL; 281 pci_read_config_word(dev, pos, ®16); 282 reg16 &= ~(PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE); 283 pci_write_config_word(dev, pos, reg16); 284 } 285 } 286 /* AER capable */ 287 if ((cap_mask & PCIE_PORT_SERVICE_AER) 288 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) { 289 services |= PCIE_PORT_SERVICE_AER; 290 /* 291 * Disable AER on this port in case it's been enabled by the 292 * BIOS (the AER service driver will enable it when necessary). 293 */ 294 pci_disable_pcie_error_reporting(dev); 295 } 296 /* VC support */ 297 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC)) 298 services |= PCIE_PORT_SERVICE_VC; 299 /* Root ports are capable of generating PME too */ 300 if ((cap_mask & PCIE_PORT_SERVICE_PME) 301 && dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) { 302 services |= PCIE_PORT_SERVICE_PME; 303 /* 304 * Disable PME interrupt on this port in case it's been enabled 305 * by the BIOS (the PME service driver will enable it when 306 * necessary). 307 */ 308 pcie_pme_interrupt_enable(dev, false); 309 } 310 311 return services; 312} 313 314/** 315 * pcie_device_init - allocate and initialize PCI Express port service device 316 * @pdev: PCI Express port to associate the service device with 317 * @service: Type of service to associate with the service device 318 * @irq: Interrupt vector to associate with the service device 319 */ 320static int pcie_device_init(struct pci_dev *pdev, int service, int irq) 321{ 322 int retval; 323 struct pcie_device *pcie; 324 struct device *device; 325 326 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL); 327 if (!pcie) 328 return -ENOMEM; 329 pcie->port = pdev; 330 pcie->irq = irq; 331 pcie->service = service; 332 333 /* Initialize generic device interface */ 334 device = &pcie->device; 335 device->bus = &pcie_port_bus_type; 336 device->release = release_pcie_device; /* callback to free pcie dev */ 337 dev_set_name(device, "%s:pcie%02x", 338 pci_name(pdev), 339 get_descriptor_id(pdev->pcie_type, service)); 340 device->parent = &pdev->dev; 341 device_enable_async_suspend(device); 342 343 retval = device_register(device); 344 if (retval) 345 kfree(pcie); 346 else 347 get_device(device); 348 return retval; 349} 350 351/** 352 * pcie_port_device_register - register PCI Express port 353 * @dev: PCI Express port to register 354 * 355 * Allocate the port extension structure and register services associated with 356 * the port. 357 */ 358int pcie_port_device_register(struct pci_dev *dev) 359{ 360 int status, capabilities, i, nr_service; 361 int irqs[PCIE_PORT_DEVICE_MAXSERVICES]; 362 363 /* Enable PCI Express port device */ 364 status = pci_enable_device(dev); 365 if (status) 366 return status; 367 368 /* Get and check PCI Express port services */ 369 capabilities = get_port_device_capability(dev); 370 if (!capabilities) 371 return 0; 372 373 pci_set_master(dev); 374 /* 375 * Initialize service irqs. Don't use service devices that 376 * require interrupts if there is no way to generate them. 377 */ 378 status = init_service_irqs(dev, irqs, capabilities); 379 if (status) { 380 capabilities &= PCIE_PORT_SERVICE_VC; 381 if (!capabilities) 382 goto error_disable; 383 } 384 385 /* Allocate child services if any */ 386 status = -ENODEV; 387 nr_service = 0; 388 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) { 389 int service = 1 << i; 390 if (!(capabilities & service)) 391 continue; 392 if (!pcie_device_init(dev, service, irqs[i])) 393 nr_service++; 394 } 395 if (!nr_service) 396 goto error_cleanup_irqs; 397 398 return 0; 399 400error_cleanup_irqs: 401 cleanup_service_irqs(dev); 402error_disable: 403 pci_disable_device(dev); 404 return status; 405} 406 407#ifdef CONFIG_PM 408static int suspend_iter(struct device *dev, void *data) 409{ 410 struct pcie_port_service_driver *service_driver; 411 412 if ((dev->bus == &pcie_port_bus_type) && dev->driver) { 413 service_driver = to_service_driver(dev->driver); 414 if (service_driver->suspend) 415 service_driver->suspend(to_pcie_device(dev)); 416 } 417 return 0; 418} 419 420/** 421 * pcie_port_device_suspend - suspend port services associated with a PCIe port 422 * @dev: PCI Express port to handle 423 */ 424int pcie_port_device_suspend(struct device *dev) 425{ 426 return device_for_each_child(dev, NULL, suspend_iter); 427} 428 429static int resume_iter(struct device *dev, void *data) 430{ 431 struct pcie_port_service_driver *service_driver; 432 433 if ((dev->bus == &pcie_port_bus_type) && 434 (dev->driver)) { 435 service_driver = to_service_driver(dev->driver); 436 if (service_driver->resume) 437 service_driver->resume(to_pcie_device(dev)); 438 } 439 return 0; 440} 441 442/** 443 * pcie_port_device_suspend - resume port services associated with a PCIe port 444 * @dev: PCI Express port to handle 445 */ 446int pcie_port_device_resume(struct device *dev) 447{ 448 return device_for_each_child(dev, NULL, resume_iter); 449} 450#endif /* PM */ 451 452static int remove_iter(struct device *dev, void *data) 453{ 454 if (dev->bus == &pcie_port_bus_type) { 455 put_device(dev); 456 device_unregister(dev); 457 } 458 return 0; 459} 460 461/** 462 * pcie_port_device_remove - unregister PCI Express port service devices 463 * @dev: PCI Express port the service devices to unregister are associated with 464 * 465 * Remove PCI Express port service devices associated with given port and 466 * disable MSI-X or MSI for the port. 467 */ 468void pcie_port_device_remove(struct pci_dev *dev) 469{ 470 device_for_each_child(&dev->dev, NULL, remove_iter); 471 cleanup_service_irqs(dev); 472 pci_disable_device(dev); 473} 474 475/** 476 * pcie_port_probe_service - probe driver for given PCI Express port service 477 * @dev: PCI Express port service device to probe against 478 * 479 * If PCI Express port service driver is registered with 480 * pcie_port_service_register(), this function will be called by the driver core 481 * whenever match is found between the driver and a port service device. 482 */ 483static int pcie_port_probe_service(struct device *dev) 484{ 485 struct pcie_device *pciedev; 486 struct pcie_port_service_driver *driver; 487 int status; 488 489 if (!dev || !dev->driver) 490 return -ENODEV; 491 492 driver = to_service_driver(dev->driver); 493 if (!driver || !driver->probe) 494 return -ENODEV; 495 496 pciedev = to_pcie_device(dev); 497 status = driver->probe(pciedev); 498 if (!status) { 499 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n", 500 driver->name); 501 get_device(dev); 502 } 503 return status; 504} 505 506/** 507 * pcie_port_remove_service - detach driver from given PCI Express port service 508 * @dev: PCI Express port service device to handle 509 * 510 * If PCI Express port service driver is registered with 511 * pcie_port_service_register(), this function will be called by the driver core 512 * when device_unregister() is called for the port service device associated 513 * with the driver. 514 */ 515static int pcie_port_remove_service(struct device *dev) 516{ 517 struct pcie_device *pciedev; 518 struct pcie_port_service_driver *driver; 519 520 if (!dev || !dev->driver) 521 return 0; 522 523 pciedev = to_pcie_device(dev); 524 driver = to_service_driver(dev->driver); 525 if (driver && driver->remove) { 526 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n", 527 driver->name); 528 driver->remove(pciedev); 529 put_device(dev); 530 } 531 return 0; 532} 533 534/** 535 * pcie_port_shutdown_service - shut down given PCI Express port service 536 * @dev: PCI Express port service device to handle 537 * 538 * If PCI Express port service driver is registered with 539 * pcie_port_service_register(), this function will be called by the driver core 540 * when device_shutdown() is called for the port service device associated 541 * with the driver. 542 */ 543static void pcie_port_shutdown_service(struct device *dev) {} 544 545/** 546 * pcie_port_service_register - register PCI Express port service driver 547 * @new: PCI Express port service driver to register 548 */ 549int pcie_port_service_register(struct pcie_port_service_driver *new) 550{ 551 if (pcie_ports_disabled) 552 return -ENODEV; 553 554 new->driver.name = (char *)new->name; 555 new->driver.bus = &pcie_port_bus_type; 556 new->driver.probe = pcie_port_probe_service; 557 new->driver.remove = pcie_port_remove_service; 558 new->driver.shutdown = pcie_port_shutdown_service; 559 560 return driver_register(&new->driver); 561} 562EXPORT_SYMBOL(pcie_port_service_register); 563 564/** 565 * pcie_port_service_unregister - unregister PCI Express port service driver 566 * @drv: PCI Express port service driver to unregister 567 */ 568void pcie_port_service_unregister(struct pcie_port_service_driver *drv) 569{ 570 driver_unregister(&drv->driver); 571} 572EXPORT_SYMBOL(pcie_port_service_unregister); 573