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_irq_vec - try to set up MSI-X or MSI as interrupt mode
49 * @dev: PCI Express port to handle
50 * @irqs: Array of interrupt vectors to populate
51 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
53 * Return value: 0 on success, error code on failure
55 static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
57 int nr_entries, entry, nvec = 0;
60 * Allocate as many entries as the port wants, so that we can check
61 * which of them will be useful. Moreover, if nr_entries is correctly
62 * equal to the number of entries this port actually uses, we'll happily
63 * go through without any tricks.
65 nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
66 PCI_IRQ_MSIX | PCI_IRQ_MSI);
70 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
74 * Per PCIe r3.1, sec 6.1.6, "PME and Hot-Plug Event
75 * interrupts (when both are implemented) always share the
76 * same MSI or MSI-X vector, as indicated by the Interrupt
77 * Message Number field in the PCI Express Capabilities
80 * Per sec 7.8.2, "For MSI, the [Interrupt Message Number]
81 * indicates the offset between the base Message Data and
82 * the interrupt message that is generated."
84 * "For MSI-X, the [Interrupt Message Number] indicates
85 * which MSI-X Table entry is used to generate the
88 pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
89 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
90 if (entry >= nr_entries)
93 irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
94 irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);
96 nvec = max(nvec, entry + 1);
99 if (mask & PCIE_PORT_SERVICE_AER) {
103 * Per PCIe r3.1, sec 7.10.10, the Advanced Error Interrupt
104 * Message Number in the Root Error Status register
105 * indicates which MSI/MSI-X vector is used for AER.
107 * "For MSI, the [Advanced Error Interrupt Message Number]
108 * indicates the offset between the base Message Data and
109 * the interrupt message that is generated."
111 * "For MSI-X, the [Advanced Error Interrupt Message
112 * Number] indicates which MSI-X Table entry is used to
113 * generate the interrupt message."
115 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
116 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
117 entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
118 if (entry >= nr_entries)
121 irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);
123 nvec = max(nvec, entry + 1);
126 if (mask & PCIE_PORT_SERVICE_DPC) {
130 * Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt
131 * Message Number in the DPC Capability register indicates
132 * which MSI/MSI-X vector is used for DPC.
134 * "For MSI, the [DPC Interrupt Message Number] indicates
135 * the offset between the base Message Data and the
136 * interrupt message that is generated."
138 * "For MSI-X, the [DPC Interrupt Message Number] indicates
139 * which MSI-X Table entry is used to generate the
140 * interrupt message."
142 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
143 pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, ®16);
144 entry = reg16 & PCI_EXP_DPC_IRQ;
145 if (entry >= nr_entries)
148 irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);
150 nvec = max(nvec, entry + 1);
154 * If nvec is equal to the allocated number of entries, we can just use
155 * what we have. Otherwise, the port has some extra entries not for the
156 * services we know and we need to work around that.
158 if (nvec != nr_entries) {
159 /* Drop the temporary MSI-X setup */
160 pci_free_irq_vectors(dev);
162 /* Now allocate the MSI-X vectors for real */
163 nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
164 PCI_IRQ_MSIX | PCI_IRQ_MSI);
172 pci_free_irq_vectors(dev);
177 * pcie_init_service_irqs - initialize irqs for PCI Express port services
178 * @dev: PCI Express port to handle
179 * @irqs: Array of irqs to populate
180 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
182 * Return value: Interrupt mode associated with the port
184 static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
188 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
192 * If we support PME or hotplug, but we can't use MSI/MSI-X for
193 * them, we have to fall back to INTx or other interrupts, e.g., a
194 * system shared interrupt.
196 if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
199 if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
202 /* Try to use MSI-X or MSI if supported */
203 if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
207 /* fall back to legacy IRQ */
208 ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
212 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
213 if (i != PCIE_PORT_SERVICE_VC_SHIFT)
214 irqs[i] = pci_irq_vector(dev, 0);
221 * get_port_device_capability - discover capabilities of a PCI Express port
222 * @dev: PCI Express port to examine
224 * The capabilities are read from the port's PCI Express configuration registers
225 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
228 * Return value: Bitmask of discovered port capabilities
230 static int get_port_device_capability(struct pci_dev *dev)
235 if (pcie_ports_disabled)
238 cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
239 | PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
240 if (pci_aer_available())
241 cap_mask |= PCIE_PORT_SERVICE_AER;
244 pcie_port_platform_notify(dev, &cap_mask);
246 /* Hot-Plug Capable */
247 if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
248 services |= PCIE_PORT_SERVICE_HP;
250 * Disable hot-plug interrupts in case they have been enabled
251 * by the BIOS and the hot-plug service driver is not loaded.
253 pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
254 PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
257 if ((cap_mask & PCIE_PORT_SERVICE_AER)
258 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
259 services |= PCIE_PORT_SERVICE_AER;
261 * Disable AER on this port in case it's been enabled by the
262 * BIOS (the AER service driver will enable it when necessary).
264 pci_disable_pcie_error_reporting(dev);
267 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
268 services |= PCIE_PORT_SERVICE_VC;
269 /* Root ports are capable of generating PME too */
270 if ((cap_mask & PCIE_PORT_SERVICE_PME)
271 && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
272 services |= PCIE_PORT_SERVICE_PME;
274 * Disable PME interrupt on this port in case it's been enabled
275 * by the BIOS (the PME service driver will enable it when
278 pcie_pme_interrupt_enable(dev, false);
280 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
281 services |= PCIE_PORT_SERVICE_DPC;
287 * pcie_device_init - allocate and initialize PCI Express port service device
288 * @pdev: PCI Express port to associate the service device with
289 * @service: Type of service to associate with the service device
290 * @irq: Interrupt vector to associate with the service device
292 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
295 struct pcie_device *pcie;
296 struct device *device;
298 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
303 pcie->service = service;
305 /* Initialize generic device interface */
306 device = &pcie->device;
307 device->bus = &pcie_port_bus_type;
308 device->release = release_pcie_device; /* callback to free pcie dev */
309 dev_set_name(device, "%s:pcie%03x",
311 get_descriptor_id(pci_pcie_type(pdev), service));
312 device->parent = &pdev->dev;
313 device_enable_async_suspend(device);
315 retval = device_register(device);
321 pm_runtime_no_callbacks(device);
327 * pcie_port_device_register - register PCI Express port
328 * @dev: PCI Express port to register
330 * Allocate the port extension structure and register services associated with
333 int pcie_port_device_register(struct pci_dev *dev)
335 int status, capabilities, i, nr_service;
336 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
338 /* Enable PCI Express port device */
339 status = pci_enable_device(dev);
343 /* Get and check PCI Express port services */
344 capabilities = get_port_device_capability(dev);
350 * Initialize service irqs. Don't use service devices that
351 * require interrupts if there is no way to generate them.
352 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
353 * that can be used in the absence of irqs. Allow them to determine
354 * if that is to be used.
356 status = pcie_init_service_irqs(dev, irqs, capabilities);
358 capabilities &= PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_HP;
363 /* Allocate child services if any */
366 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
367 int service = 1 << i;
368 if (!(capabilities & service))
370 if (!pcie_device_init(dev, service, irqs[i]))
374 goto error_cleanup_irqs;
379 pci_free_irq_vectors(dev);
381 pci_disable_device(dev);
386 static int suspend_iter(struct device *dev, void *data)
388 struct pcie_port_service_driver *service_driver;
390 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
391 service_driver = to_service_driver(dev->driver);
392 if (service_driver->suspend)
393 service_driver->suspend(to_pcie_device(dev));
399 * pcie_port_device_suspend - suspend port services associated with a PCIe port
400 * @dev: PCI Express port to handle
402 int pcie_port_device_suspend(struct device *dev)
404 return device_for_each_child(dev, NULL, suspend_iter);
407 static int resume_iter(struct device *dev, void *data)
409 struct pcie_port_service_driver *service_driver;
411 if ((dev->bus == &pcie_port_bus_type) &&
413 service_driver = to_service_driver(dev->driver);
414 if (service_driver->resume)
415 service_driver->resume(to_pcie_device(dev));
421 * pcie_port_device_resume - resume port services associated with a PCIe port
422 * @dev: PCI Express port to handle
424 int pcie_port_device_resume(struct device *dev)
426 return device_for_each_child(dev, NULL, resume_iter);
430 static int remove_iter(struct device *dev, void *data)
432 if (dev->bus == &pcie_port_bus_type)
433 device_unregister(dev);
438 * pcie_port_device_remove - unregister PCI Express port service devices
439 * @dev: PCI Express port the service devices to unregister are associated with
441 * Remove PCI Express port service devices associated with given port and
442 * disable MSI-X or MSI for the port.
444 void pcie_port_device_remove(struct pci_dev *dev)
446 device_for_each_child(&dev->dev, NULL, remove_iter);
447 pci_free_irq_vectors(dev);
448 pci_disable_device(dev);
452 * pcie_port_probe_service - probe driver for given PCI Express port service
453 * @dev: PCI Express port service device to probe against
455 * If PCI Express port service driver is registered with
456 * pcie_port_service_register(), this function will be called by the driver core
457 * whenever match is found between the driver and a port service device.
459 static int pcie_port_probe_service(struct device *dev)
461 struct pcie_device *pciedev;
462 struct pcie_port_service_driver *driver;
465 if (!dev || !dev->driver)
468 driver = to_service_driver(dev->driver);
469 if (!driver || !driver->probe)
472 pciedev = to_pcie_device(dev);
473 status = driver->probe(pciedev);
482 * pcie_port_remove_service - detach driver from given PCI Express port service
483 * @dev: PCI Express port service device to handle
485 * If PCI Express port service driver is registered with
486 * pcie_port_service_register(), this function will be called by the driver core
487 * when device_unregister() is called for the port service device associated
490 static int pcie_port_remove_service(struct device *dev)
492 struct pcie_device *pciedev;
493 struct pcie_port_service_driver *driver;
495 if (!dev || !dev->driver)
498 pciedev = to_pcie_device(dev);
499 driver = to_service_driver(dev->driver);
500 if (driver && driver->remove) {
501 driver->remove(pciedev);
508 * pcie_port_shutdown_service - shut down 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_shutdown() is called for the port service device associated
516 static void pcie_port_shutdown_service(struct device *dev) {}
519 * pcie_port_service_register - register PCI Express port service driver
520 * @new: PCI Express port service driver to register
522 int pcie_port_service_register(struct pcie_port_service_driver *new)
524 if (pcie_ports_disabled)
527 new->driver.name = new->name;
528 new->driver.bus = &pcie_port_bus_type;
529 new->driver.probe = pcie_port_probe_service;
530 new->driver.remove = pcie_port_remove_service;
531 new->driver.shutdown = pcie_port_shutdown_service;
533 return driver_register(&new->driver);
535 EXPORT_SYMBOL(pcie_port_service_register);
538 * pcie_port_service_unregister - unregister PCI Express port service driver
539 * @drv: PCI Express port service driver to unregister
541 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
543 driver_unregister(&drv->driver);
545 EXPORT_SYMBOL(pcie_port_service_unregister);