1 // SPDX-License-Identifier: GPL-2.0
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/aer.h>
22 struct portdrv_service_data {
23 struct pcie_port_service_driver *drv;
29 * release_pcie_device - free PCI Express port service device structure
30 * @dev: Port service device to release
32 * Invoked automatically when device is being removed in response to
33 * device_unregister(dev). Release all resources being claimed.
35 static void release_pcie_device(struct device *dev)
37 kfree(to_pcie_device(dev));
41 * Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if
42 * services are enabled in "mask". Return the number of MSI/MSI-X vectors
43 * required to accommodate the largest Message Number.
45 static int pcie_message_numbers(struct pci_dev *dev, int mask,
46 u32 *pme, u32 *aer, u32 *dpc)
52 * The Interrupt Message Number indicates which vector is used, i.e.,
53 * the MSI-X table entry or the MSI offset between the base Message
54 * Data and the generated interrupt message. See PCIe r3.1, sec
55 * 7.8.2, 7.10.10, 7.31.2.
58 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP |
59 PCIE_PORT_SERVICE_BWNOTIF)) {
60 pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
61 *pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
66 if (mask & PCIE_PORT_SERVICE_AER) {
71 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS,
73 *aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
74 nvec = max(nvec, *aer + 1);
79 if (mask & PCIE_PORT_SERVICE_DPC) {
80 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
82 pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP,
84 *dpc = reg16 & PCI_EXP_DPC_IRQ;
85 nvec = max(nvec, *dpc + 1);
93 * pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
95 * @dev: PCI Express port to handle
96 * @irqs: Array of interrupt vectors to populate
97 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
99 * Return value: 0 on success, error code on failure
101 static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
103 int nr_entries, nvec, pcie_irq;
104 u32 pme = 0, aer = 0, dpc = 0;
106 /* Allocate the maximum possible number of MSI/MSI-X vectors */
107 nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
108 PCI_IRQ_MSIX | PCI_IRQ_MSI);
112 /* See how many and which Interrupt Message Numbers we actually use */
113 nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);
114 if (nvec > nr_entries) {
115 pci_free_irq_vectors(dev);
120 * If we allocated more than we need, free them and reallocate fewer.
122 * Reallocating may change the specific vectors we get, so
123 * pci_irq_vector() must be done *after* the reallocation.
125 * If we're using MSI, hardware is *allowed* to change the Interrupt
126 * Message Numbers when we free and reallocate the vectors, but we
127 * assume it won't because we allocate enough vectors for the
128 * biggest Message Number we found.
130 if (nvec != nr_entries) {
131 pci_free_irq_vectors(dev);
133 nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
134 PCI_IRQ_MSIX | PCI_IRQ_MSI);
139 /* PME, hotplug and bandwidth notification share an MSI/MSI-X vector */
140 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP |
141 PCIE_PORT_SERVICE_BWNOTIF)) {
142 pcie_irq = pci_irq_vector(dev, pme);
143 irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pcie_irq;
144 irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pcie_irq;
145 irqs[PCIE_PORT_SERVICE_BWNOTIF_SHIFT] = pcie_irq;
148 if (mask & PCIE_PORT_SERVICE_AER)
149 irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer);
151 if (mask & PCIE_PORT_SERVICE_DPC)
152 irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);
158 * pcie_init_service_irqs - initialize irqs for PCI Express port services
159 * @dev: PCI Express port to handle
160 * @irqs: Array of irqs to populate
161 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
163 * Return value: Interrupt mode associated with the port
165 static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
169 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
173 * If we support PME but can't use MSI/MSI-X for it, we have to
174 * fall back to INTx or other interrupts, e.g., a system shared
177 if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
180 /* Try to use MSI-X or MSI if supported */
181 if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
185 /* fall back to legacy IRQ */
186 ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
190 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
191 irqs[i] = pci_irq_vector(dev, 0);
197 * get_port_device_capability - discover capabilities of a PCI Express port
198 * @dev: PCI Express port to examine
200 * The capabilities are read from the port's PCI Express configuration registers
201 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
204 * Return value: Bitmask of discovered port capabilities
206 static int get_port_device_capability(struct pci_dev *dev)
208 struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
211 if (dev->is_hotplug_bridge &&
212 (pcie_ports_native || host->native_pcie_hotplug)) {
213 services |= PCIE_PORT_SERVICE_HP;
216 * Disable hot-plug interrupts in case they have been enabled
217 * by the BIOS and the hot-plug service driver is not loaded.
219 pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
220 PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
223 #ifdef CONFIG_PCIEAER
224 if (dev->aer_cap && pci_aer_available() &&
225 (pcie_ports_native || host->native_aer)) {
226 services |= PCIE_PORT_SERVICE_AER;
229 * Disable AER on this port in case it's been enabled by the
230 * BIOS (the AER service driver will enable it when necessary).
232 pci_disable_pcie_error_reporting(dev);
236 /* Root Ports and Root Complex Event Collectors may generate PMEs */
237 if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
238 pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) &&
239 (pcie_ports_native || host->native_pme)) {
240 services |= PCIE_PORT_SERVICE_PME;
243 * Disable PME interrupt on this port in case it's been enabled
244 * by the BIOS (the PME service driver will enable it when
247 pcie_pme_interrupt_enable(dev, false);
251 * With dpc-native, allow Linux to use DPC even if it doesn't have
252 * permission to use AER.
254 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
255 pci_aer_available() &&
256 (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER)))
257 services |= PCIE_PORT_SERVICE_DPC;
259 if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM ||
260 pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
263 pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &linkcap);
264 if (linkcap & PCI_EXP_LNKCAP_LBNC)
265 services |= PCIE_PORT_SERVICE_BWNOTIF;
272 * pcie_device_init - allocate and initialize PCI Express port service device
273 * @pdev: PCI Express port to associate the service device with
274 * @service: Type of service to associate with the service device
275 * @irq: Interrupt vector to associate with the service device
277 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
280 struct pcie_device *pcie;
281 struct device *device;
283 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
288 pcie->service = service;
290 /* Initialize generic device interface */
291 device = &pcie->device;
292 device->bus = &pcie_port_bus_type;
293 device->release = release_pcie_device; /* callback to free pcie dev */
294 dev_set_name(device, "%s:pcie%03x",
296 get_descriptor_id(pci_pcie_type(pdev), service));
297 device->parent = &pdev->dev;
298 device_enable_async_suspend(device);
300 retval = device_register(device);
306 pm_runtime_no_callbacks(device);
312 * pcie_port_device_register - register PCI Express port
313 * @dev: PCI Express port to register
315 * Allocate the port extension structure and register services associated with
318 int pcie_port_device_register(struct pci_dev *dev)
320 int status, capabilities, i, nr_service;
321 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
323 /* Enable PCI Express port device */
324 status = pci_enable_device(dev);
328 /* Get and check PCI Express port services */
329 capabilities = get_port_device_capability(dev);
335 * Initialize service irqs. Don't use service devices that
336 * require interrupts if there is no way to generate them.
337 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
338 * that can be used in the absence of irqs. Allow them to determine
339 * if that is to be used.
341 status = pcie_init_service_irqs(dev, irqs, capabilities);
343 capabilities &= PCIE_PORT_SERVICE_HP;
348 /* Allocate child services if any */
351 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
352 int service = 1 << i;
353 if (!(capabilities & service))
355 if (!pcie_device_init(dev, service, irqs[i]))
359 goto error_cleanup_irqs;
364 pci_free_irq_vectors(dev);
366 pci_disable_device(dev);
371 typedef int (*pcie_pm_callback_t)(struct pcie_device *);
373 static int pm_iter(struct device *dev, void *data)
375 struct pcie_port_service_driver *service_driver;
376 size_t offset = *(size_t *)data;
377 pcie_pm_callback_t cb;
379 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
380 service_driver = to_service_driver(dev->driver);
381 cb = *(pcie_pm_callback_t *)((void *)service_driver + offset);
383 return cb(to_pcie_device(dev));
389 * pcie_port_device_suspend - suspend port services associated with a PCIe port
390 * @dev: PCI Express port to handle
392 int pcie_port_device_suspend(struct device *dev)
394 size_t off = offsetof(struct pcie_port_service_driver, suspend);
395 return device_for_each_child(dev, &off, pm_iter);
398 int pcie_port_device_resume_noirq(struct device *dev)
400 size_t off = offsetof(struct pcie_port_service_driver, resume_noirq);
401 return device_for_each_child(dev, &off, pm_iter);
405 * pcie_port_device_resume - resume port services associated with a PCIe port
406 * @dev: PCI Express port to handle
408 int pcie_port_device_resume(struct device *dev)
410 size_t off = offsetof(struct pcie_port_service_driver, resume);
411 return device_for_each_child(dev, &off, pm_iter);
415 * pcie_port_device_runtime_suspend - runtime suspend port services
416 * @dev: PCI Express port to handle
418 int pcie_port_device_runtime_suspend(struct device *dev)
420 size_t off = offsetof(struct pcie_port_service_driver, runtime_suspend);
421 return device_for_each_child(dev, &off, pm_iter);
425 * pcie_port_device_runtime_resume - runtime resume port services
426 * @dev: PCI Express port to handle
428 int pcie_port_device_runtime_resume(struct device *dev)
430 size_t off = offsetof(struct pcie_port_service_driver, runtime_resume);
431 return device_for_each_child(dev, &off, pm_iter);
435 static int remove_iter(struct device *dev, void *data)
437 if (dev->bus == &pcie_port_bus_type)
438 device_unregister(dev);
442 static int find_service_iter(struct device *device, void *data)
444 struct pcie_port_service_driver *service_driver;
445 struct portdrv_service_data *pdrvs;
448 pdrvs = (struct portdrv_service_data *) data;
449 service = pdrvs->service;
451 if (device->bus == &pcie_port_bus_type && device->driver) {
452 service_driver = to_service_driver(device->driver);
453 if (service_driver->service == service) {
454 pdrvs->drv = service_driver;
464 * pcie_port_find_device - find the struct device
465 * @dev: PCI Express port the service is associated with
466 * @service: For the service to find
468 * Find the struct device associated with given service on a pci_dev
470 struct device *pcie_port_find_device(struct pci_dev *dev,
473 struct device *device;
474 struct portdrv_service_data pdrvs;
477 pdrvs.service = service;
478 device_for_each_child(&dev->dev, &pdrvs, find_service_iter);
483 EXPORT_SYMBOL_GPL(pcie_port_find_device);
486 * pcie_port_device_remove - unregister PCI Express port service devices
487 * @dev: PCI Express port the service devices to unregister are associated with
489 * Remove PCI Express port service devices associated with given port and
490 * disable MSI-X or MSI for the port.
492 void pcie_port_device_remove(struct pci_dev *dev)
494 device_for_each_child(&dev->dev, NULL, remove_iter);
495 pci_free_irq_vectors(dev);
496 pci_disable_device(dev);
500 * pcie_port_probe_service - probe driver for given PCI Express port service
501 * @dev: PCI Express port service device to probe against
503 * If PCI Express port service driver is registered with
504 * pcie_port_service_register(), this function will be called by the driver core
505 * whenever match is found between the driver and a port service device.
507 static int pcie_port_probe_service(struct device *dev)
509 struct pcie_device *pciedev;
510 struct pcie_port_service_driver *driver;
513 if (!dev || !dev->driver)
516 driver = to_service_driver(dev->driver);
517 if (!driver || !driver->probe)
520 pciedev = to_pcie_device(dev);
521 status = driver->probe(pciedev);
530 * pcie_port_remove_service - detach driver from given PCI Express port service
531 * @dev: PCI Express port service device to handle
533 * If PCI Express port service driver is registered with
534 * pcie_port_service_register(), this function will be called by the driver core
535 * when device_unregister() is called for the port service device associated
538 static int pcie_port_remove_service(struct device *dev)
540 struct pcie_device *pciedev;
541 struct pcie_port_service_driver *driver;
543 if (!dev || !dev->driver)
546 pciedev = to_pcie_device(dev);
547 driver = to_service_driver(dev->driver);
548 if (driver && driver->remove) {
549 driver->remove(pciedev);
556 * pcie_port_shutdown_service - shut down given PCI Express port service
557 * @dev: PCI Express port service device to handle
559 * If PCI Express port service driver is registered with
560 * pcie_port_service_register(), this function will be called by the driver core
561 * when device_shutdown() is called for the port service device associated
564 static void pcie_port_shutdown_service(struct device *dev) {}
567 * pcie_port_service_register - register PCI Express port service driver
568 * @new: PCI Express port service driver to register
570 int pcie_port_service_register(struct pcie_port_service_driver *new)
572 if (pcie_ports_disabled)
575 new->driver.name = new->name;
576 new->driver.bus = &pcie_port_bus_type;
577 new->driver.probe = pcie_port_probe_service;
578 new->driver.remove = pcie_port_remove_service;
579 new->driver.shutdown = pcie_port_shutdown_service;
581 return driver_register(&new->driver);
583 EXPORT_SYMBOL(pcie_port_service_register);
586 * pcie_port_service_unregister - unregister PCI Express port service driver
587 * @drv: PCI Express port service driver to unregister
589 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
591 driver_unregister(&drv->driver);
593 EXPORT_SYMBOL(pcie_port_service_unregister);