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>
22 * release_pcie_device - free PCI Express port service device structure
23 * @dev: Port service device to release
25 * Invoked automatically when device is being removed in response to
26 * device_unregister(dev). Release all resources being claimed.
28 static void release_pcie_device(struct device *dev)
30 kfree(to_pcie_device(dev));
34 * pcie_port_msix_add_entry - add entry to given array of MSI-X entries
35 * @entries: Array of MSI-X entries
36 * @new_entry: Index of the entry to add to the array
37 * @nr_entries: Number of entries aleady in the array
39 * Return value: Position of the added entry in the array
41 static int pcie_port_msix_add_entry(
42 struct msix_entry *entries, int new_entry, int nr_entries)
46 for (j = 0; j < nr_entries; j++)
47 if (entries[j].entry == new_entry)
50 entries[j].entry = new_entry;
55 * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port
56 * @dev: PCI Express port to handle
57 * @vectors: Array of interrupt vectors to populate
58 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
60 * Return value: 0 on success, error code on failure
62 static int pcie_port_enable_msix(struct pci_dev *dev, int *vectors, int mask)
64 struct msix_entry *msix_entries;
65 int idx[PCIE_PORT_DEVICE_MAXSERVICES];
66 int nr_entries, status, pos, i, nvec;
70 nr_entries = pci_msix_table_size(dev);
73 if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES)
74 nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES;
76 msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL);
81 * Allocate as many entries as the port wants, so that we can check
82 * which of them will be useful. Moreover, if nr_entries is correctly
83 * equal to the number of entries this port actually uses, we'll happily
84 * go through without any tricks.
86 for (i = 0; i < nr_entries; i++)
87 msix_entries[i].entry = i;
89 status = pci_enable_msix(dev, msix_entries, nr_entries);
93 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
98 if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
102 * The code below follows the PCI Express Base Specification 2.0
103 * stating in Section 6.1.6 that "PME and Hot-Plug Event
104 * interrupts (when both are implemented) always share the same
105 * MSI or MSI-X vector, as indicated by the Interrupt Message
106 * Number field in the PCI Express Capabilities register", where
107 * according to Section 7.8.2 of the specification "For MSI-X,
108 * the value in this field indicates which MSI-X Table entry is
109 * used to generate the interrupt message."
111 pos = pci_pcie_cap(dev);
112 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®16);
113 entry = (reg16 >> 9) & PCIE_PORT_MSI_VECTOR_MASK;
114 if (entry >= nr_entries)
117 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
121 idx[PCIE_PORT_SERVICE_PME_SHIFT] = i;
122 idx[PCIE_PORT_SERVICE_HP_SHIFT] = i;
125 if (mask & PCIE_PORT_SERVICE_AER) {
129 * The code below follows Section 7.10.10 of the PCI Express
130 * Base Specification 2.0 stating that bits 31-27 of the Root
131 * Error Status Register contain a value indicating which of the
132 * MSI/MSI-X vectors assigned to the port is going to be used
133 * for AER, where "For MSI-X, the value in this register
134 * indicates which MSI-X Table entry is used to generate the
135 * interrupt message."
137 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
138 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
140 if (entry >= nr_entries)
143 i = pcie_port_msix_add_entry(msix_entries, entry, nvec);
147 idx[PCIE_PORT_SERVICE_AER_SHIFT] = i;
151 * If nvec is equal to the allocated number of entries, we can just use
152 * what we have. Otherwise, the port has some extra entries not for the
153 * services we know and we need to work around that.
155 if (nvec == nr_entries) {
158 /* Drop the temporary MSI-X setup */
159 pci_disable_msix(dev);
161 /* Now allocate the MSI-X vectors for real */
162 status = pci_enable_msix(dev, msix_entries, nvec);
167 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
168 vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1;
175 pci_disable_msix(dev);
180 * init_service_irqs - initialize irqs for PCI Express port services
181 * @dev: PCI Express port to handle
182 * @irqs: Array of irqs to populate
183 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
185 * Return value: Interrupt mode associated with the port
187 static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
191 /* Try to use MSI-X if supported */
192 if (!pcie_port_enable_msix(dev, irqs, mask))
194 /* We're not going to use MSI-X, so try MSI and fall back to INTx */
196 if (!pci_enable_msi(dev) || dev->pin)
199 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
201 irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
208 static void cleanup_service_irqs(struct pci_dev *dev)
210 if (dev->msix_enabled)
211 pci_disable_msix(dev);
212 else if (dev->msi_enabled)
213 pci_disable_msi(dev);
217 * get_port_device_capability - discover capabilities of a PCI Express port
218 * @dev: PCI Express port to examine
220 * The capabilities are read from the port's PCI Express configuration registers
221 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
224 * Return value: Bitmask of discovered port capabilities
226 static int get_port_device_capability(struct pci_dev *dev)
228 int services = 0, pos;
232 pos = pci_pcie_cap(dev);
233 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®16);
234 /* Hot-Plug Capable */
235 if (reg16 & PORT_TO_SLOT_MASK) {
236 pci_read_config_dword(dev,
237 pos + PCIE_SLOT_CAPABILITIES_REG, ®32);
238 if (reg32 & SLOT_HP_CAPABLE_MASK)
239 services |= PCIE_PORT_SERVICE_HP;
242 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
243 services |= PCIE_PORT_SERVICE_AER;
245 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
246 services |= PCIE_PORT_SERVICE_VC;
247 /* Root ports are capable of generating PME too */
248 if (dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
249 services |= PCIE_PORT_SERVICE_PME;
255 * pcie_device_init - allocate and initialize PCI Express port service device
256 * @pdev: PCI Express port to associate the service device with
257 * @service: Type of service to associate with the service device
258 * @irq: Interrupt vector to associate with the service device
260 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
263 struct pcie_device *pcie;
264 struct device *device;
266 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
271 pcie->service = service;
273 /* Initialize generic device interface */
274 device = &pcie->device;
275 device->bus = &pcie_port_bus_type;
276 device->release = release_pcie_device; /* callback to free pcie dev */
277 dev_set_name(device, "%s:pcie%02x",
279 get_descriptor_id(pdev->pcie_type, service));
280 device->parent = &pdev->dev;
282 retval = device_register(device);
291 * pcie_port_device_register - register PCI Express port
292 * @dev: PCI Express port to register
294 * Allocate the port extension structure and register services associated with
297 int pcie_port_device_register(struct pci_dev *dev)
299 int status, capabilities, i, nr_service;
300 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
302 /* Get and check PCI Express port services */
303 capabilities = get_port_device_capability(dev);
307 /* Enable PCI Express port device */
308 status = pci_enable_device(dev);
313 * Initialize service irqs. Don't use service devices that
314 * require interrupts if there is no way to generate them.
316 status = init_service_irqs(dev, irqs, capabilities);
318 capabilities &= PCIE_PORT_SERVICE_VC;
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 cleanup_service_irqs(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) &&
352 service_driver = to_service_driver(dev->driver);
353 if (service_driver->suspend)
354 service_driver->suspend(to_pcie_device(dev));
360 * pcie_port_device_suspend - suspend port services associated with a PCIe port
361 * @dev: PCI Express port to handle
363 int pcie_port_device_suspend(struct device *dev)
365 return device_for_each_child(dev, NULL, suspend_iter);
368 static int resume_iter(struct device *dev, void *data)
370 struct pcie_port_service_driver *service_driver;
372 if ((dev->bus == &pcie_port_bus_type) &&
374 service_driver = to_service_driver(dev->driver);
375 if (service_driver->resume)
376 service_driver->resume(to_pcie_device(dev));
382 * pcie_port_device_suspend - resume port services associated with a PCIe port
383 * @dev: PCI Express port to handle
385 int pcie_port_device_resume(struct device *dev)
387 return device_for_each_child(dev, NULL, resume_iter);
391 static int remove_iter(struct device *dev, void *data)
393 if (dev->bus == &pcie_port_bus_type) {
395 device_unregister(dev);
401 * pcie_port_device_remove - unregister PCI Express port service devices
402 * @dev: PCI Express port the service devices to unregister are associated with
404 * Remove PCI Express port service devices associated with given port and
405 * disable MSI-X or MSI for the port.
407 void pcie_port_device_remove(struct pci_dev *dev)
409 device_for_each_child(&dev->dev, NULL, remove_iter);
410 cleanup_service_irqs(dev);
411 pci_disable_device(dev);
415 * pcie_port_probe_service - probe driver for given PCI Express port service
416 * @dev: PCI Express port service device to probe against
418 * If PCI Express port service driver is registered with
419 * pcie_port_service_register(), this function will be called by the driver core
420 * whenever match is found between the driver and a port service device.
422 static int pcie_port_probe_service(struct device *dev)
424 struct pcie_device *pciedev;
425 struct pcie_port_service_driver *driver;
428 if (!dev || !dev->driver)
431 driver = to_service_driver(dev->driver);
432 if (!driver || !driver->probe)
435 pciedev = to_pcie_device(dev);
436 status = driver->probe(pciedev);
438 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
446 * pcie_port_remove_service - detach driver from given PCI Express port service
447 * @dev: PCI Express port service device to handle
449 * If PCI Express port service driver is registered with
450 * pcie_port_service_register(), this function will be called by the driver core
451 * when device_unregister() is called for the port service device associated
454 static int pcie_port_remove_service(struct device *dev)
456 struct pcie_device *pciedev;
457 struct pcie_port_service_driver *driver;
459 if (!dev || !dev->driver)
462 pciedev = to_pcie_device(dev);
463 driver = to_service_driver(dev->driver);
464 if (driver && driver->remove) {
465 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
467 driver->remove(pciedev);
474 * pcie_port_shutdown_service - shut down given PCI Express port service
475 * @dev: PCI Express port service device to handle
477 * If PCI Express port service driver is registered with
478 * pcie_port_service_register(), this function will be called by the driver core
479 * when device_shutdown() is called for the port service device associated
482 static void pcie_port_shutdown_service(struct device *dev) {}
485 * pcie_port_service_register - register PCI Express port service driver
486 * @new: PCI Express port service driver to register
488 int pcie_port_service_register(struct pcie_port_service_driver *new)
490 new->driver.name = (char *)new->name;
491 new->driver.bus = &pcie_port_bus_type;
492 new->driver.probe = pcie_port_probe_service;
493 new->driver.remove = pcie_port_remove_service;
494 new->driver.shutdown = pcie_port_shutdown_service;
496 return driver_register(&new->driver);
500 * pcie_port_service_unregister - unregister PCI Express port service driver
501 * @drv: PCI Express port service driver to unregister
503 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
505 driver_unregister(&drv->driver);
508 EXPORT_SYMBOL(pcie_port_service_register);
509 EXPORT_SYMBOL(pcie_port_service_unregister);