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/pm_runtime.h>
15 #include <linux/string.h>
16 #include <linux/slab.h>
17 #include <linux/pcieport_if.h>
18 #include <linux/aer.h>
23 bool pciehp_msi_disabled;
25 static int __init pciehp_setup(char *str)
27 if (!strncmp(str, "nomsi", 5))
28 pciehp_msi_disabled = true;
32 __setup("pcie_hp=", pciehp_setup);
35 * release_pcie_device - free PCI Express port service device structure
36 * @dev: Port service device to release
38 * Invoked automatically when device is being removed in response to
39 * device_unregister(dev). Release all resources being claimed.
41 static void release_pcie_device(struct device *dev)
43 kfree(to_pcie_device(dev));
47 * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port
48 * @dev: PCI Express port to handle
49 * @irqs: Array of interrupt vectors to populate
50 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
52 * Return value: 0 on success, error code on failure
54 static int pcie_port_enable_msix(struct pci_dev *dev, int *irqs, int mask)
56 int nr_entries, entry, nvec = 0;
59 * Allocate as many entries as the port wants, so that we can check
60 * which of them will be useful. Moreover, if nr_entries is correctly
61 * equal to the number of entries this port actually uses, we'll happily
62 * go through without any tricks.
64 nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSIX_ENTRIES,
69 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
73 * The code below follows the PCI Express Base Specification 2.0
74 * stating in Section 6.1.6 that "PME and Hot-Plug Event
75 * interrupts (when both are implemented) always share the same
76 * MSI or MSI-X vector, as indicated by the Interrupt Message
77 * Number field in the PCI Express Capabilities register", where
78 * according to Section 7.8.2 of the specification "For MSI-X,
79 * the value in this field indicates which MSI-X Table entry is
80 * used to generate the interrupt message."
82 pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
83 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
84 if (entry >= nr_entries)
87 irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
88 irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);
90 nvec = max(nvec, entry + 1);
93 if (mask & PCIE_PORT_SERVICE_AER) {
97 * The code below follows Section 7.10.10 of the PCI Express
98 * Base Specification 2.0 stating that bits 31-27 of the Root
99 * Error Status Register contain a value indicating which of the
100 * MSI/MSI-X vectors assigned to the port is going to be used
101 * for AER, where "For MSI-X, the value in this register
102 * indicates which MSI-X Table entry is used to generate the
103 * interrupt message."
105 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
106 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
108 if (entry >= nr_entries)
111 irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);
113 nvec = max(nvec, entry + 1);
117 * If nvec is equal to the allocated number of entries, we can just use
118 * what we have. Otherwise, the port has some extra entries not for the
119 * services we know and we need to work around that.
121 if (nvec != nr_entries) {
122 /* Drop the temporary MSI-X setup */
123 pci_free_irq_vectors(dev);
125 /* Now allocate the MSI-X vectors for real */
126 nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
135 pci_free_irq_vectors(dev);
140 * pcie_init_service_irqs - initialize irqs for PCI Express port services
141 * @dev: PCI Express port to handle
142 * @irqs: Array of irqs to populate
143 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
145 * Return value: Interrupt mode associated with the port
147 static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
149 unsigned flags = PCI_IRQ_LEGACY | PCI_IRQ_MSI;
152 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
156 * If MSI cannot be used for PCIe PME or hotplug, we have to use
157 * INTx or other interrupts, e.g. system shared interrupt.
159 if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
160 ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
161 flags &= ~PCI_IRQ_MSI;
163 /* Try to use MSI-X if supported */
164 if (!pcie_port_enable_msix(dev, irqs, mask))
168 ret = pci_alloc_irq_vectors(dev, 1, 1, flags);
172 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
173 if (i != PCIE_PORT_SERVICE_VC_SHIFT)
174 irqs[i] = pci_irq_vector(dev, 0);
181 * get_port_device_capability - discover capabilities of a PCI Express port
182 * @dev: PCI Express port to examine
184 * The capabilities are read from the port's PCI Express configuration registers
185 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
188 * Return value: Bitmask of discovered port capabilities
190 static int get_port_device_capability(struct pci_dev *dev)
195 if (pcie_ports_disabled)
198 cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
199 | PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
200 if (pci_aer_available())
201 cap_mask |= PCIE_PORT_SERVICE_AER;
204 pcie_port_platform_notify(dev, &cap_mask);
206 /* Hot-Plug Capable */
207 if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
208 services |= PCIE_PORT_SERVICE_HP;
210 * Disable hot-plug interrupts in case they have been enabled
211 * by the BIOS and the hot-plug service driver is not loaded.
213 pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
214 PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
217 if ((cap_mask & PCIE_PORT_SERVICE_AER)
218 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
219 services |= PCIE_PORT_SERVICE_AER;
221 * Disable AER on this port in case it's been enabled by the
222 * BIOS (the AER service driver will enable it when necessary).
224 pci_disable_pcie_error_reporting(dev);
227 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
228 services |= PCIE_PORT_SERVICE_VC;
229 /* Root ports are capable of generating PME too */
230 if ((cap_mask & PCIE_PORT_SERVICE_PME)
231 && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
232 services |= PCIE_PORT_SERVICE_PME;
234 * Disable PME interrupt on this port in case it's been enabled
235 * by the BIOS (the PME service driver will enable it when
238 pcie_pme_interrupt_enable(dev, false);
240 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
241 services |= PCIE_PORT_SERVICE_DPC;
247 * pcie_device_init - allocate and initialize PCI Express port service device
248 * @pdev: PCI Express port to associate the service device with
249 * @service: Type of service to associate with the service device
250 * @irq: Interrupt vector to associate with the service device
252 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
255 struct pcie_device *pcie;
256 struct device *device;
258 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
263 pcie->service = service;
265 /* Initialize generic device interface */
266 device = &pcie->device;
267 device->bus = &pcie_port_bus_type;
268 device->release = release_pcie_device; /* callback to free pcie dev */
269 dev_set_name(device, "%s:pcie%03x",
271 get_descriptor_id(pci_pcie_type(pdev), service));
272 device->parent = &pdev->dev;
273 device_enable_async_suspend(device);
275 retval = device_register(device);
281 pm_runtime_no_callbacks(device);
287 * pcie_port_device_register - register PCI Express port
288 * @dev: PCI Express port to register
290 * Allocate the port extension structure and register services associated with
293 int pcie_port_device_register(struct pci_dev *dev)
295 int status, capabilities, i, nr_service;
296 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
298 /* Enable PCI Express port device */
299 status = pci_enable_device(dev);
303 /* Get and check PCI Express port services */
304 capabilities = get_port_device_capability(dev);
310 * Initialize service irqs. Don't use service devices that
311 * require interrupts if there is no way to generate them.
312 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
313 * that can be used in the absence of irqs. Allow them to determine
314 * if that is to be used.
316 status = pcie_init_service_irqs(dev, irqs, capabilities);
318 capabilities &= PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_HP;
323 /* Allocate child services if any */
326 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
327 int service = 1 << i;
328 if (!(capabilities & service))
330 if (!pcie_device_init(dev, service, irqs[i]))
334 goto error_cleanup_irqs;
339 pci_free_irq_vectors(dev);
341 pci_disable_device(dev);
346 static int suspend_iter(struct device *dev, void *data)
348 struct pcie_port_service_driver *service_driver;
350 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
351 service_driver = to_service_driver(dev->driver);
352 if (service_driver->suspend)
353 service_driver->suspend(to_pcie_device(dev));
359 * pcie_port_device_suspend - suspend port services associated with a PCIe port
360 * @dev: PCI Express port to handle
362 int pcie_port_device_suspend(struct device *dev)
364 return device_for_each_child(dev, NULL, suspend_iter);
367 static int resume_iter(struct device *dev, void *data)
369 struct pcie_port_service_driver *service_driver;
371 if ((dev->bus == &pcie_port_bus_type) &&
373 service_driver = to_service_driver(dev->driver);
374 if (service_driver->resume)
375 service_driver->resume(to_pcie_device(dev));
381 * pcie_port_device_resume - resume port services associated with a PCIe port
382 * @dev: PCI Express port to handle
384 int pcie_port_device_resume(struct device *dev)
386 return device_for_each_child(dev, NULL, resume_iter);
390 static int remove_iter(struct device *dev, void *data)
392 if (dev->bus == &pcie_port_bus_type)
393 device_unregister(dev);
398 * pcie_port_device_remove - unregister PCI Express port service devices
399 * @dev: PCI Express port the service devices to unregister are associated with
401 * Remove PCI Express port service devices associated with given port and
402 * disable MSI-X or MSI for the port.
404 void pcie_port_device_remove(struct pci_dev *dev)
406 device_for_each_child(&dev->dev, NULL, remove_iter);
407 pci_free_irq_vectors(dev);
408 pci_disable_device(dev);
412 * pcie_port_probe_service - probe driver for given PCI Express port service
413 * @dev: PCI Express port service device to probe against
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 * whenever match is found between the driver and a port service device.
419 static int pcie_port_probe_service(struct device *dev)
421 struct pcie_device *pciedev;
422 struct pcie_port_service_driver *driver;
425 if (!dev || !dev->driver)
428 driver = to_service_driver(dev->driver);
429 if (!driver || !driver->probe)
432 pciedev = to_pcie_device(dev);
433 status = driver->probe(pciedev);
442 * pcie_port_remove_service - detach driver from given PCI Express port service
443 * @dev: PCI Express port service device to handle
445 * If PCI Express port service driver is registered with
446 * pcie_port_service_register(), this function will be called by the driver core
447 * when device_unregister() is called for the port service device associated
450 static int pcie_port_remove_service(struct device *dev)
452 struct pcie_device *pciedev;
453 struct pcie_port_service_driver *driver;
455 if (!dev || !dev->driver)
458 pciedev = to_pcie_device(dev);
459 driver = to_service_driver(dev->driver);
460 if (driver && driver->remove) {
461 driver->remove(pciedev);
468 * pcie_port_shutdown_service - shut down given PCI Express port service
469 * @dev: PCI Express port service device to handle
471 * If PCI Express port service driver is registered with
472 * pcie_port_service_register(), this function will be called by the driver core
473 * when device_shutdown() is called for the port service device associated
476 static void pcie_port_shutdown_service(struct device *dev) {}
479 * pcie_port_service_register - register PCI Express port service driver
480 * @new: PCI Express port service driver to register
482 int pcie_port_service_register(struct pcie_port_service_driver *new)
484 if (pcie_ports_disabled)
487 new->driver.name = new->name;
488 new->driver.bus = &pcie_port_bus_type;
489 new->driver.probe = pcie_port_probe_service;
490 new->driver.remove = pcie_port_remove_service;
491 new->driver.shutdown = pcie_port_shutdown_service;
493 return driver_register(&new->driver);
495 EXPORT_SYMBOL(pcie_port_service_register);
498 * pcie_port_service_unregister - unregister PCI Express port service driver
499 * @drv: PCI Express port service driver to unregister
501 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
503 driver_unregister(&drv->driver);
505 EXPORT_SYMBOL(pcie_port_service_unregister);