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_msix_add_entry - add entry to given array of MSI-X entries
48 * @entries: Array of MSI-X entries
49 * @new_entry: Index of the entry to add to the array
50 * @nr_entries: Number of entries already in the array
52 * Return value: Position of the added entry in the array
54 static int pcie_port_msix_add_entry(
55 struct msix_entry *entries, int new_entry, int nr_entries)
59 for (j = 0; j < nr_entries; j++)
60 if (entries[j].entry == new_entry)
63 entries[j].entry = new_entry;
68 * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port
69 * @dev: PCI Express port to handle
70 * @vectors: Array of interrupt vectors to populate
71 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
73 * Return value: 0 on success, error code on failure
75 static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask)
77 struct msix_entry *msix_entries;
78 int idx[PCIE_PORT_DEVICE_MAXSERVICES];
79 int nr_entries, status, pos, i, nvec;
83 nr_entries = pci_msix_vec_count(dev);
87 if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES)
88 nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES;
90 msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL);
95 * Allocate as many entries as the port wants, so that we can check
96 * which of them will be useful. Moreover, if nr_entries is correctly
97 * equal to the number of entries this port actually uses, we'll happily
98 * go through without any tricks.
100 for (i = 0; i < nr_entries; i++)
101 msix_entries[i].entry = i;
103 status = pci_enable_msix_exact(dev, msix_entries, nr_entries);
107 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
112 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
116 * The code below follows the PCI Express Base Specification 2.0
117 * stating in Section 6.1.6 that "PME and Hot-Plug Event
118 * interrupts (when both are implemented) always share the same
119 * MSI or MSI-X vector, as indicated by the Interrupt Message
120 * Number field in the PCI Express Capabilities register", where
121 * according to Section 7.8.2 of the specification "For MSI-X,
122 * the value in this field indicates which MSI-X Table entry is
123 * used to generate the interrupt message."
125 pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
126 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
127 if (entry >= nr_entries)
130 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
134 idx[PCIE_PORT_SERVICE_PME_SHIFT] = i;
135 idx[PCIE_PORT_SERVICE_HP_SHIFT] = i;
138 if (mask & PCIE_PORT_SERVICE_AER) {
142 * The code below follows Section 7.10.10 of the PCI Express
143 * Base Specification 2.0 stating that bits 31-27 of the Root
144 * Error Status Register contain a value indicating which of the
145 * MSI/MSI-X vectors assigned to the port is going to be used
146 * for AER, where "For MSI-X, the value in this register
147 * indicates which MSI-X Table entry is used to generate the
148 * interrupt message."
150 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
151 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
153 if (entry >= nr_entries)
156 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
160 idx[PCIE_PORT_SERVICE_AER_SHIFT] = i;
164 * If nvec is equal to the allocated number of entries, we can just use
165 * what we have. Otherwise, the port has some extra entries not for the
166 * services we know and we need to work around that.
168 if (nvec == nr_entries) {
171 /* Drop the temporary MSI-X setup */
172 pci_disable_msix(dev);
174 /* Now allocate the MSI-X vectors for real */
175 status = pci_enable_msix_exact(dev, msix_entries, nvec);
180 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
181 vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1;
188 pci_disable_msix(dev);
193 * init_service_irqs - initialize irqs for PCI Express port services
194 * @dev: PCI Express port to handle
195 * @irqs: Array of irqs to populate
196 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
198 * Return value: Interrupt mode associated with the port
200 static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
205 * If MSI cannot be used for PCIe PME or hotplug, we have to use
206 * INTx or other interrupts, e.g. system shared interrupt.
208 if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
209 ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
215 /* Try to use MSI-X if supported */
216 if (!pcie_port_enable_msix(dev, irqs, mask))
220 * We're not going to use MSI-X, so try MSI and fall back to INTx.
221 * If neither MSI/MSI-X nor INTx available, try other interrupt. On
222 * some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
224 if (!pci_enable_msi(dev) || dev->irq)
228 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
230 irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
237 static void cleanup_service_irqs(struct pci_dev *dev)
239 if (dev->msix_enabled)
240 pci_disable_msix(dev);
241 else if (dev->msi_enabled)
242 pci_disable_msi(dev);
246 * get_port_device_capability - discover capabilities of a PCI Express port
247 * @dev: PCI Express port to examine
249 * The capabilities are read from the port's PCI Express configuration registers
250 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
253 * Return value: Bitmask of discovered port capabilities
255 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 | PCIE_PORT_SERVICE_DPC;
265 if (pci_aer_available())
266 cap_mask |= PCIE_PORT_SERVICE_AER;
269 pcie_port_platform_notify(dev, &cap_mask);
271 /* Hot-Plug Capable */
272 if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
273 services |= PCIE_PORT_SERVICE_HP;
275 * Disable hot-plug interrupts in case they have been enabled
276 * by the BIOS and the hot-plug service driver is not loaded.
278 pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
279 PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
282 if ((cap_mask & PCIE_PORT_SERVICE_AER)
283 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
284 services |= PCIE_PORT_SERVICE_AER;
286 * Disable AER on this port in case it's been enabled by the
287 * BIOS (the AER service driver will enable it when necessary).
289 pci_disable_pcie_error_reporting(dev);
292 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
293 services |= PCIE_PORT_SERVICE_VC;
294 /* Root ports are capable of generating PME too */
295 if ((cap_mask & PCIE_PORT_SERVICE_PME)
296 && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
297 services |= PCIE_PORT_SERVICE_PME;
299 * Disable PME interrupt on this port in case it's been enabled
300 * by the BIOS (the PME service driver will enable it when
303 pcie_pme_interrupt_enable(dev, false);
305 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
306 services |= PCIE_PORT_SERVICE_DPC;
312 * pcie_device_init - allocate and initialize PCI Express port service device
313 * @pdev: PCI Express port to associate the service device with
314 * @service: Type of service to associate with the service device
315 * @irq: Interrupt vector to associate with the service device
317 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
320 struct pcie_device *pcie;
321 struct device *device;
323 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
328 pcie->service = service;
330 /* Initialize generic device interface */
331 device = &pcie->device;
332 device->bus = &pcie_port_bus_type;
333 device->release = release_pcie_device; /* callback to free pcie dev */
334 dev_set_name(device, "%s:pcie%03x",
336 get_descriptor_id(pci_pcie_type(pdev), service));
337 device->parent = &pdev->dev;
338 device_enable_async_suspend(device);
340 retval = device_register(device);
346 pm_runtime_no_callbacks(device);
352 * pcie_port_device_register - register PCI Express port
353 * @dev: PCI Express port to register
355 * Allocate the port extension structure and register services associated with
358 int pcie_port_device_register(struct pci_dev *dev)
360 int status, capabilities, i, nr_service;
361 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
363 /* Enable PCI Express port device */
364 status = pci_enable_device(dev);
368 /* Get and check PCI Express port services */
369 capabilities = get_port_device_capability(dev);
375 * Initialize service irqs. Don't use service devices that
376 * require interrupts if there is no way to generate them.
377 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
378 * that can be used in the absence of irqs. Allow them to determine
379 * if that is to be used.
381 status = init_service_irqs(dev, irqs, capabilities);
383 capabilities &= PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_HP;
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_resume - 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)
458 device_unregister(dev);
463 * pcie_port_device_remove - unregister PCI Express port service devices
464 * @dev: PCI Express port the service devices to unregister are associated with
466 * Remove PCI Express port service devices associated with given port and
467 * disable MSI-X or MSI for the port.
469 void pcie_port_device_remove(struct pci_dev *dev)
471 device_for_each_child(&dev->dev, NULL, remove_iter);
472 cleanup_service_irqs(dev);
473 pci_disable_device(dev);
477 * pcie_port_probe_service - probe driver for given PCI Express port service
478 * @dev: PCI Express port service device to probe against
480 * If PCI Express port service driver is registered with
481 * pcie_port_service_register(), this function will be called by the driver core
482 * whenever match is found between the driver and a port service device.
484 static int pcie_port_probe_service(struct device *dev)
486 struct pcie_device *pciedev;
487 struct pcie_port_service_driver *driver;
490 if (!dev || !dev->driver)
493 driver = to_service_driver(dev->driver);
494 if (!driver || !driver->probe)
497 pciedev = to_pcie_device(dev);
498 status = driver->probe(pciedev);
502 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n", driver->name);
508 * pcie_port_remove_service - detach driver from given PCI Express port service
509 * @dev: PCI Express port service device to handle
511 * If PCI Express port service driver is registered with
512 * pcie_port_service_register(), this function will be called by the driver core
513 * when device_unregister() is called for the port service device associated
516 static int pcie_port_remove_service(struct device *dev)
518 struct pcie_device *pciedev;
519 struct pcie_port_service_driver *driver;
521 if (!dev || !dev->driver)
524 pciedev = to_pcie_device(dev);
525 driver = to_service_driver(dev->driver);
526 if (driver && driver->remove) {
527 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
529 driver->remove(pciedev);
536 * pcie_port_shutdown_service - shut down given PCI Express port service
537 * @dev: PCI Express port service device to handle
539 * If PCI Express port service driver is registered with
540 * pcie_port_service_register(), this function will be called by the driver core
541 * when device_shutdown() is called for the port service device associated
544 static void pcie_port_shutdown_service(struct device *dev) {}
547 * pcie_port_service_register - register PCI Express port service driver
548 * @new: PCI Express port service driver to register
550 int pcie_port_service_register(struct pcie_port_service_driver *new)
552 if (pcie_ports_disabled)
555 new->driver.name = new->name;
556 new->driver.bus = &pcie_port_bus_type;
557 new->driver.probe = pcie_port_probe_service;
558 new->driver.remove = pcie_port_remove_service;
559 new->driver.shutdown = pcie_port_shutdown_service;
561 return driver_register(&new->driver);
563 EXPORT_SYMBOL(pcie_port_service_register);
566 * pcie_port_service_unregister - unregister PCI Express port service driver
567 * @drv: PCI Express port service driver to unregister
569 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
571 driver_unregister(&drv->driver);
573 EXPORT_SYMBOL(pcie_port_service_unregister);