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 pos = pci_pcie_cap(dev);
124 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, ®16);
125 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
126 if (entry >= nr_entries)
129 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
133 idx[PCIE_PORT_SERVICE_PME_SHIFT] = i;
134 idx[PCIE_PORT_SERVICE_HP_SHIFT] = i;
137 if (mask & PCIE_PORT_SERVICE_AER) {
141 * The code below follows Section 7.10.10 of the PCI Express
142 * Base Specification 2.0 stating that bits 31-27 of the Root
143 * Error Status Register contain a value indicating which of the
144 * MSI/MSI-X vectors assigned to the port is going to be used
145 * for AER, where "For MSI-X, the value in this register
146 * indicates which MSI-X Table entry is used to generate the
147 * interrupt message."
149 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
150 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
152 if (entry >= nr_entries)
155 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
159 idx[PCIE_PORT_SERVICE_AER_SHIFT] = i;
163 * If nvec is equal to the allocated number of entries, we can just use
164 * what we have. Otherwise, the port has some extra entries not for the
165 * services we know and we need to work around that.
167 if (nvec == nr_entries) {
170 /* Drop the temporary MSI-X setup */
171 pci_disable_msix(dev);
173 /* Now allocate the MSI-X vectors for real */
174 status = pci_enable_msix(dev, msix_entries, nvec);
179 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
180 vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1;
187 pci_disable_msix(dev);
192 * init_service_irqs - initialize irqs for PCI Express port services
193 * @dev: PCI Express port to handle
194 * @irqs: Array of irqs to populate
195 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
197 * Return value: Interrupt mode associated with the port
199 static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
203 /* We have to use INTx if MSI cannot be used for PCIe PME or pciehp. */
204 if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
205 ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
211 /* Try to use MSI-X if supported */
212 if (!pcie_port_enable_msix(dev, irqs, mask))
215 /* We're not going to use MSI-X, so try MSI and fall back to INTx */
216 if (!pci_enable_msi(dev) || dev->pin)
220 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
222 irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
229 static void cleanup_service_irqs(struct pci_dev *dev)
231 if (dev->msix_enabled)
232 pci_disable_msix(dev);
233 else if (dev->msi_enabled)
234 pci_disable_msi(dev);
238 * get_port_device_capability - discover capabilities of a PCI Express port
239 * @dev: PCI Express port to examine
241 * The capabilities are read from the port's PCI Express configuration registers
242 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
245 * Return value: Bitmask of discovered port capabilities
247 static int get_port_device_capability(struct pci_dev *dev)
249 int services = 0, pos;
255 if (pcie_ports_disabled)
258 err = pcie_port_platform_notify(dev, &cap_mask);
259 if (!pcie_ports_auto) {
260 cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
261 | PCIE_PORT_SERVICE_VC;
262 if (pci_aer_available())
263 cap_mask |= PCIE_PORT_SERVICE_AER;
268 pos = pci_pcie_cap(dev);
269 pci_read_config_word(dev, pos + PCI_EXP_FLAGS, ®16);
270 /* Hot-Plug Capable */
271 if ((cap_mask & PCIE_PORT_SERVICE_HP) && (reg16 & PCI_EXP_FLAGS_SLOT)) {
272 pci_read_config_dword(dev, pos + PCI_EXP_SLTCAP, ®32);
273 if (reg32 & PCI_EXP_SLTCAP_HPC) {
274 services |= PCIE_PORT_SERVICE_HP;
276 * Disable hot-plug interrupts in case they have been
277 * enabled by the BIOS and the hot-plug service driver
280 pos += PCI_EXP_SLTCTL;
281 pci_read_config_word(dev, pos, ®16);
282 reg16 &= ~(PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
283 pci_write_config_word(dev, pos, reg16);
287 if ((cap_mask & PCIE_PORT_SERVICE_AER)
288 && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
289 services |= PCIE_PORT_SERVICE_AER;
291 * Disable AER on this port in case it's been enabled by the
292 * BIOS (the AER service driver will enable it when necessary).
294 pci_disable_pcie_error_reporting(dev);
297 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
298 services |= PCIE_PORT_SERVICE_VC;
299 /* Root ports are capable of generating PME too */
300 if ((cap_mask & PCIE_PORT_SERVICE_PME)
301 && dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) {
302 services |= PCIE_PORT_SERVICE_PME;
304 * Disable PME interrupt on this port in case it's been enabled
305 * by the BIOS (the PME service driver will enable it when
308 pcie_pme_interrupt_enable(dev, false);
315 * pcie_device_init - allocate and initialize PCI Express port service device
316 * @pdev: PCI Express port to associate the service device with
317 * @service: Type of service to associate with the service device
318 * @irq: Interrupt vector to associate with the service device
320 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
323 struct pcie_device *pcie;
324 struct device *device;
326 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
331 pcie->service = service;
333 /* Initialize generic device interface */
334 device = &pcie->device;
335 device->bus = &pcie_port_bus_type;
336 device->release = release_pcie_device; /* callback to free pcie dev */
337 dev_set_name(device, "%s:pcie%02x",
339 get_descriptor_id(pdev->pcie_type, service));
340 device->parent = &pdev->dev;
341 device_enable_async_suspend(device);
343 retval = device_register(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.
378 status = init_service_irqs(dev, irqs, capabilities);
380 capabilities &= PCIE_PORT_SERVICE_VC;
385 /* Allocate child services if any */
388 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
389 int service = 1 << i;
390 if (!(capabilities & service))
392 if (!pcie_device_init(dev, service, irqs[i]))
396 goto error_cleanup_irqs;
401 cleanup_service_irqs(dev);
403 pci_disable_device(dev);
408 static int suspend_iter(struct device *dev, void *data)
410 struct pcie_port_service_driver *service_driver;
412 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
413 service_driver = to_service_driver(dev->driver);
414 if (service_driver->suspend)
415 service_driver->suspend(to_pcie_device(dev));
421 * pcie_port_device_suspend - suspend port services associated with a PCIe port
422 * @dev: PCI Express port to handle
424 int pcie_port_device_suspend(struct device *dev)
426 return device_for_each_child(dev, NULL, suspend_iter);
429 static int resume_iter(struct device *dev, void *data)
431 struct pcie_port_service_driver *service_driver;
433 if ((dev->bus == &pcie_port_bus_type) &&
435 service_driver = to_service_driver(dev->driver);
436 if (service_driver->resume)
437 service_driver->resume(to_pcie_device(dev));
443 * pcie_port_device_suspend - resume port services associated with a PCIe port
444 * @dev: PCI Express port to handle
446 int pcie_port_device_resume(struct device *dev)
448 return device_for_each_child(dev, NULL, resume_iter);
452 static int remove_iter(struct device *dev, void *data)
454 if (dev->bus == &pcie_port_bus_type) {
456 device_unregister(dev);
462 * pcie_port_device_remove - unregister PCI Express port service devices
463 * @dev: PCI Express port the service devices to unregister are associated with
465 * Remove PCI Express port service devices associated with given port and
466 * disable MSI-X or MSI for the port.
468 void pcie_port_device_remove(struct pci_dev *dev)
470 device_for_each_child(&dev->dev, NULL, remove_iter);
471 cleanup_service_irqs(dev);
472 pci_disable_device(dev);
476 * pcie_port_probe_service - probe driver for given PCI Express port service
477 * @dev: PCI Express port service device to probe against
479 * If PCI Express port service driver is registered with
480 * pcie_port_service_register(), this function will be called by the driver core
481 * whenever match is found between the driver and a port service device.
483 static int pcie_port_probe_service(struct device *dev)
485 struct pcie_device *pciedev;
486 struct pcie_port_service_driver *driver;
489 if (!dev || !dev->driver)
492 driver = to_service_driver(dev->driver);
493 if (!driver || !driver->probe)
496 pciedev = to_pcie_device(dev);
497 status = driver->probe(pciedev);
499 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
507 * pcie_port_remove_service - detach driver from given PCI Express port service
508 * @dev: PCI Express port service device to handle
510 * If PCI Express port service driver is registered with
511 * pcie_port_service_register(), this function will be called by the driver core
512 * when device_unregister() is called for the port service device associated
515 static int pcie_port_remove_service(struct device *dev)
517 struct pcie_device *pciedev;
518 struct pcie_port_service_driver *driver;
520 if (!dev || !dev->driver)
523 pciedev = to_pcie_device(dev);
524 driver = to_service_driver(dev->driver);
525 if (driver && driver->remove) {
526 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
528 driver->remove(pciedev);
535 * pcie_port_shutdown_service - shut down given PCI Express port service
536 * @dev: PCI Express port service device to handle
538 * If PCI Express port service driver is registered with
539 * pcie_port_service_register(), this function will be called by the driver core
540 * when device_shutdown() is called for the port service device associated
543 static void pcie_port_shutdown_service(struct device *dev) {}
546 * pcie_port_service_register - register PCI Express port service driver
547 * @new: PCI Express port service driver to register
549 int pcie_port_service_register(struct pcie_port_service_driver *new)
551 if (pcie_ports_disabled)
554 new->driver.name = (char *)new->name;
555 new->driver.bus = &pcie_port_bus_type;
556 new->driver.probe = pcie_port_probe_service;
557 new->driver.remove = pcie_port_remove_service;
558 new->driver.shutdown = pcie_port_shutdown_service;
560 return driver_register(&new->driver);
562 EXPORT_SYMBOL(pcie_port_service_register);
565 * pcie_port_service_unregister - unregister PCI Express port service driver
566 * @drv: PCI Express port service driver to unregister
568 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
570 driver_unregister(&drv->driver);
572 EXPORT_SYMBOL(pcie_port_service_unregister);