3 * Purpose: PCI Express Port Bus Driver's Core Functions
5 * Copyright (C) 2004 Intel
6 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/slab.h>
16 #include <linux/pcieport_if.h>
17 #include <linux/aer.h>
22 bool pciehp_msi_disabled;
24 static int __init pciehp_setup(char *str)
26 if (!strncmp(str, "nomsi", 5))
27 pciehp_msi_disabled = true;
31 __setup("pcie_hp=", pciehp_setup);
34 * release_pcie_device - free PCI Express port service device structure
35 * @dev: Port service device to release
37 * Invoked automatically when device is being removed in response to
38 * device_unregister(dev). Release all resources being claimed.
40 static void release_pcie_device(struct device *dev)
42 kfree(to_pcie_device(dev));
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
51 * Return value: Position of the added entry in the array
53 static int pcie_port_msix_add_entry(
54 struct msix_entry *entries, int new_entry, int nr_entries)
58 for (j = 0; j < nr_entries; j++)
59 if (entries[j].entry == new_entry)
62 entries[j].entry = new_entry;
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()
72 * Return value: 0 on success, error code on failure
74 static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask)
76 struct msix_entry *msix_entries;
77 int idx[PCIE_PORT_DEVICE_MAXSERVICES];
78 int nr_entries, status, pos, i, nvec;
82 nr_entries = pci_msix_table_size(dev);
85 if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES)
86 nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES;
88 msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL);
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.
98 for (i = 0; i < nr_entries; i++)
99 msix_entries[i].entry = i;
101 status = pci_enable_msix(dev, msix_entries, nr_entries);
105 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
110 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
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."
123 pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
124 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
125 if (entry >= nr_entries)
128 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
132 idx[PCIE_PORT_SERVICE_PME_SHIFT] = i;
133 idx[PCIE_PORT_SERVICE_HP_SHIFT] = i;
136 if (mask & PCIE_PORT_SERVICE_AER) {
140 * The code below follows Section 7.10.10 of the PCI Express
141 * Base Specification 2.0 stating that bits 31-27 of the Root
142 * Error Status Register contain a value indicating which of the
143 * MSI/MSI-X vectors assigned to the port is going to be used
144 * for AER, where "For MSI-X, the value in this register
145 * indicates which MSI-X Table entry is used to generate the
146 * interrupt message."
148 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
149 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
151 if (entry >= nr_entries)
154 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
158 idx[PCIE_PORT_SERVICE_AER_SHIFT] = i;
162 * If nvec is equal to the allocated number of entries, we can just use
163 * what we have. Otherwise, the port has some extra entries not for the
164 * services we know and we need to work around that.
166 if (nvec == nr_entries) {
169 /* Drop the temporary MSI-X setup */
170 pci_disable_msix(dev);
172 /* Now allocate the MSI-X vectors for real */
173 status = pci_enable_msix(dev, msix_entries, nvec);
178 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
179 vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1;
186 pci_disable_msix(dev);
191 * init_service_irqs - initialize irqs for PCI Express port services
192 * @dev: PCI Express port to handle
193 * @irqs: Array of irqs to populate
194 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
196 * Return value: Interrupt mode associated with the port
198 static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
203 * If MSI cannot be used for PCIe PME or hotplug, we have to use
204 * INTx or other interrupts, e.g. system shared interrupt.
206 if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
207 ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
213 /* Try to use MSI-X if supported */
214 if (!pcie_port_enable_msix(dev, irqs, mask))
218 * We're not going to use MSI-X, so try MSI and fall back to INTx.
219 * If neither MSI/MSI-X nor INTx available, try other interrupt. On
220 * some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
222 if (!pci_enable_msi(dev) || dev->irq)
226 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
228 irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
235 static void cleanup_service_irqs(struct pci_dev *dev)
237 if (dev->msix_enabled)
238 pci_disable_msix(dev);
239 else if (dev->msi_enabled)
240 pci_disable_msi(dev);
244 * get_port_device_capability - discover capabilities of a PCI Express port
245 * @dev: PCI Express port to examine
247 * The capabilities are read from the port's PCI Express configuration registers
248 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
251 * Return value: Bitmask of discovered port capabilities
253 static int get_port_device_capability(struct pci_dev *dev)
260 if (pcie_ports_disabled)
263 cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
264 | PCIE_PORT_SERVICE_VC;
265 if (pci_aer_available())
266 cap_mask |= PCIE_PORT_SERVICE_AER;
268 if (pcie_ports_auto) {
269 err = pcie_port_platform_notify(dev, &cap_mask);
274 /* Hot-Plug Capable */
275 if ((cap_mask & PCIE_PORT_SERVICE_HP) &&
276 pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT) {
277 pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, ®32);
278 if (reg32 & PCI_EXP_SLTCAP_HPC) {
279 services |= PCIE_PORT_SERVICE_HP;
281 * Disable hot-plug interrupts in case they have been
282 * enabled by the BIOS and the hot-plug service driver
285 pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
286 PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
290 if ((cap_mask & PCIE_PORT_SERVICE_AER)
291 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
292 services |= PCIE_PORT_SERVICE_AER;
294 * Disable AER on this port in case it's been enabled by the
295 * BIOS (the AER service driver will enable it when necessary).
297 pci_disable_pcie_error_reporting(dev);
300 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
301 services |= PCIE_PORT_SERVICE_VC;
302 /* Root ports are capable of generating PME too */
303 if ((cap_mask & PCIE_PORT_SERVICE_PME)
304 && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
305 services |= PCIE_PORT_SERVICE_PME;
307 * Disable PME interrupt on this port in case it's been enabled
308 * by the BIOS (the PME service driver will enable it when
311 pcie_pme_interrupt_enable(dev, false);
318 * pcie_device_init - allocate and initialize PCI Express port service device
319 * @pdev: PCI Express port to associate the service device with
320 * @service: Type of service to associate with the service device
321 * @irq: Interrupt vector to associate with the service device
323 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
326 struct pcie_device *pcie;
327 struct device *device;
329 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
334 pcie->service = service;
336 /* Initialize generic device interface */
337 device = &pcie->device;
338 device->bus = &pcie_port_bus_type;
339 device->release = release_pcie_device; /* callback to free pcie dev */
340 dev_set_name(device, "%s:pcie%02x",
342 get_descriptor_id(pci_pcie_type(pdev), service));
343 device->parent = &pdev->dev;
344 device_enable_async_suspend(device);
346 retval = device_register(device);
355 * pcie_port_device_register - register PCI Express port
356 * @dev: PCI Express port to register
358 * Allocate the port extension structure and register services associated with
361 int pcie_port_device_register(struct pci_dev *dev)
363 int status, capabilities, i, nr_service;
364 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
366 /* Enable PCI Express port device */
367 status = pci_enable_device(dev);
371 /* Get and check PCI Express port services */
372 capabilities = get_port_device_capability(dev);
378 * Initialize service irqs. Don't use service devices that
379 * require interrupts if there is no way to generate them.
381 status = init_service_irqs(dev, irqs, capabilities);
383 capabilities &= PCIE_PORT_SERVICE_VC;
388 /* Allocate child services if any */
391 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
392 int service = 1 << i;
393 if (!(capabilities & service))
395 if (!pcie_device_init(dev, service, irqs[i]))
399 goto error_cleanup_irqs;
404 cleanup_service_irqs(dev);
406 pci_disable_device(dev);
411 static int suspend_iter(struct device *dev, void *data)
413 struct pcie_port_service_driver *service_driver;
415 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
416 service_driver = to_service_driver(dev->driver);
417 if (service_driver->suspend)
418 service_driver->suspend(to_pcie_device(dev));
424 * pcie_port_device_suspend - suspend port services associated with a PCIe port
425 * @dev: PCI Express port to handle
427 int pcie_port_device_suspend(struct device *dev)
429 return device_for_each_child(dev, NULL, suspend_iter);
432 static int resume_iter(struct device *dev, void *data)
434 struct pcie_port_service_driver *service_driver;
436 if ((dev->bus == &pcie_port_bus_type) &&
438 service_driver = to_service_driver(dev->driver);
439 if (service_driver->resume)
440 service_driver->resume(to_pcie_device(dev));
446 * pcie_port_device_suspend - resume port services associated with a PCIe port
447 * @dev: PCI Express port to handle
449 int pcie_port_device_resume(struct device *dev)
451 return device_for_each_child(dev, NULL, resume_iter);
455 static int remove_iter(struct device *dev, void *data)
457 if (dev->bus == &pcie_port_bus_type) {
459 device_unregister(dev);
465 * pcie_port_device_remove - unregister PCI Express port service devices
466 * @dev: PCI Express port the service devices to unregister are associated with
468 * Remove PCI Express port service devices associated with given port and
469 * disable MSI-X or MSI for the port.
471 void pcie_port_device_remove(struct pci_dev *dev)
473 device_for_each_child(&dev->dev, NULL, remove_iter);
474 cleanup_service_irqs(dev);
475 pci_disable_device(dev);
479 * pcie_port_probe_service - probe driver for given PCI Express port service
480 * @dev: PCI Express port service device to probe against
482 * If PCI Express port service driver is registered with
483 * pcie_port_service_register(), this function will be called by the driver core
484 * whenever match is found between the driver and a port service device.
486 static int pcie_port_probe_service(struct device *dev)
488 struct pcie_device *pciedev;
489 struct pcie_port_service_driver *driver;
492 if (!dev || !dev->driver)
495 driver = to_service_driver(dev->driver);
496 if (!driver || !driver->probe)
499 pciedev = to_pcie_device(dev);
500 status = driver->probe(pciedev);
502 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
510 * pcie_port_remove_service - detach driver from given PCI Express port service
511 * @dev: PCI Express port service device to handle
513 * If PCI Express port service driver is registered with
514 * pcie_port_service_register(), this function will be called by the driver core
515 * when device_unregister() is called for the port service device associated
518 static int pcie_port_remove_service(struct device *dev)
520 struct pcie_device *pciedev;
521 struct pcie_port_service_driver *driver;
523 if (!dev || !dev->driver)
526 pciedev = to_pcie_device(dev);
527 driver = to_service_driver(dev->driver);
528 if (driver && driver->remove) {
529 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
531 driver->remove(pciedev);
538 * pcie_port_shutdown_service - shut down given PCI Express port service
539 * @dev: PCI Express port service device to handle
541 * If PCI Express port service driver is registered with
542 * pcie_port_service_register(), this function will be called by the driver core
543 * when device_shutdown() is called for the port service device associated
546 static void pcie_port_shutdown_service(struct device *dev) {}
549 * pcie_port_service_register - register PCI Express port service driver
550 * @new: PCI Express port service driver to register
552 int pcie_port_service_register(struct pcie_port_service_driver *new)
554 if (pcie_ports_disabled)
557 new->driver.name = (char *)new->name;
558 new->driver.bus = &pcie_port_bus_type;
559 new->driver.probe = pcie_port_probe_service;
560 new->driver.remove = pcie_port_remove_service;
561 new->driver.shutdown = pcie_port_shutdown_service;
563 return driver_register(&new->driver);
565 EXPORT_SYMBOL(pcie_port_service_register);
568 * pcie_port_service_unregister - unregister PCI Express port service driver
569 * @drv: PCI Express port service driver to unregister
571 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
573 driver_unregister(&drv->driver);
575 EXPORT_SYMBOL(pcie_port_service_unregister);