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_find_capability(dev, PCI_CAP_ID_EXP);
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 * assign_interrupt_mode - choose interrupt mode for PCI Express port services
181 * (INTx, MSI-X, MSI) and set up vectors
182 * @dev: PCI Express port to handle
183 * @vectors: Array of interrupt vectors to populate
184 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
186 * Return value: Interrupt mode associated with the port
188 static int assign_interrupt_mode(struct pci_dev *dev, int *vectors, int mask)
190 int irq, interrupt_mode = PCIE_PORT_NO_IRQ;
193 /* Try to use MSI-X if supported */
194 if (!pcie_port_enable_msix(dev, vectors, mask))
195 return PCIE_PORT_MSIX_MODE;
197 /* We're not going to use MSI-X, so try MSI and fall back to INTx */
198 if (!pci_enable_msi(dev))
199 interrupt_mode = PCIE_PORT_MSI_MODE;
201 if (interrupt_mode == PCIE_PORT_NO_IRQ && dev->pin)
202 interrupt_mode = PCIE_PORT_INTx_MODE;
204 irq = interrupt_mode != PCIE_PORT_NO_IRQ ? dev->irq : -1;
205 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
208 vectors[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
210 return interrupt_mode;
214 * get_port_device_capability - discover capabilities of a PCI Express port
215 * @dev: PCI Express port to examine
217 * The capabilities are read from the port's PCI Express configuration registers
218 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
221 * Return value: Bitmask of discovered port capabilities
223 static int get_port_device_capability(struct pci_dev *dev)
225 int services = 0, pos;
229 pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
230 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®16);
231 /* Hot-Plug Capable */
232 if (reg16 & PORT_TO_SLOT_MASK) {
233 pci_read_config_dword(dev,
234 pos + PCIE_SLOT_CAPABILITIES_REG, ®32);
235 if (reg32 & SLOT_HP_CAPABLE_MASK)
236 services |= PCIE_PORT_SERVICE_HP;
239 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
240 services |= PCIE_PORT_SERVICE_AER;
242 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
243 services |= PCIE_PORT_SERVICE_VC;
249 * pcie_device_init - initialize PCI Express port service device
250 * @dev: Port service device to initialize
251 * @parent: PCI Express port to associate the service device with
252 * @port_type: Type of the port
253 * @service_type: Type of service to associate with the service device
254 * @irq: Interrupt vector to associate with the service device
256 static void pcie_device_init(struct pci_dev *parent, struct pcie_device *dev,
257 int service_type, int irq)
259 struct pcie_port_data *port_data = pci_get_drvdata(parent);
260 struct device *device;
261 int port_type = port_data->port_type;
265 dev->service = service_type;
267 /* Initialize generic device interface */
268 device = &dev->device;
269 memset(device, 0, sizeof(struct device));
270 device->bus = &pcie_port_bus_type;
271 device->driver = NULL;
272 dev_set_drvdata(device, NULL);
273 device->release = release_pcie_device; /* callback to free pcie dev */
274 dev_set_name(device, "%s:pcie%02x",
275 pci_name(parent), get_descriptor_id(port_type, service_type));
276 device->parent = &parent->dev;
280 * alloc_pcie_device - allocate PCI Express port service device structure
281 * @parent: PCI Express port to associate the service device with
282 * @port_type: Type of the port
283 * @service_type: Type of service to associate with the service device
284 * @irq: Interrupt vector to associate with the service device
286 static struct pcie_device* alloc_pcie_device(struct pci_dev *parent,
287 int service_type, int irq)
289 struct pcie_device *device;
291 device = kzalloc(sizeof(struct pcie_device), GFP_KERNEL);
295 pcie_device_init(parent, device, service_type, irq);
300 * pcie_port_device_probe - check if device is a PCI Express port
301 * @dev: Device to check
303 int pcie_port_device_probe(struct pci_dev *dev)
308 if (!(pos = pci_find_capability(dev, PCI_CAP_ID_EXP)))
311 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®);
312 type = (reg >> 4) & PORT_TYPE_MASK;
313 if ( type == PCIE_RC_PORT || type == PCIE_SW_UPSTREAM_PORT ||
314 type == PCIE_SW_DOWNSTREAM_PORT )
321 * pcie_port_device_register - register PCI Express port
322 * @dev: PCI Express port to register
324 * Allocate the port extension structure and register services associated with
327 int pcie_port_device_register(struct pci_dev *dev)
329 struct pcie_port_data *port_data;
330 int status, capabilities, irq_mode, i, nr_serv;
331 int vectors[PCIE_PORT_DEVICE_MAXSERVICES];
334 port_data = kzalloc(sizeof(*port_data), GFP_KERNEL);
337 pci_set_drvdata(dev, port_data);
340 pci_read_config_word(dev,
341 pci_find_capability(dev, PCI_CAP_ID_EXP) +
342 PCIE_CAPABILITIES_REG, ®16);
343 port_data->port_type = (reg16 >> 4) & PORT_TYPE_MASK;
345 capabilities = get_port_device_capability(dev);
346 /* Root ports are capable of generating PME too */
347 if (port_data->port_type == PCIE_RC_PORT)
348 capabilities |= PCIE_PORT_SERVICE_PME;
350 irq_mode = assign_interrupt_mode(dev, vectors, capabilities);
351 if (irq_mode == PCIE_PORT_NO_IRQ) {
353 * Don't use service devices that require interrupts if there is
354 * no way to generate them.
356 if (!(capabilities & PCIE_PORT_SERVICE_VC)) {
360 capabilities = PCIE_PORT_SERVICE_VC;
362 port_data->port_irq_mode = irq_mode;
364 status = pci_enable_device(dev);
369 /* Allocate child services if any */
370 for (i = 0, nr_serv = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
371 struct pcie_device *child;
372 int service = 1 << i;
374 if (!(capabilities & service))
377 child = alloc_pcie_device(dev, service, vectors[i]);
381 status = device_register(&child->device);
387 get_device(&child->device);
391 pci_disable_device(dev);
404 static int suspend_iter(struct device *dev, void *data)
406 struct pcie_port_service_driver *service_driver;
408 if ((dev->bus == &pcie_port_bus_type) &&
410 service_driver = to_service_driver(dev->driver);
411 if (service_driver->suspend)
412 service_driver->suspend(to_pcie_device(dev));
418 * pcie_port_device_suspend - suspend port services associated with a PCIe port
419 * @dev: PCI Express port to handle
421 int pcie_port_device_suspend(struct device *dev)
423 return device_for_each_child(dev, NULL, suspend_iter);
426 static int resume_iter(struct device *dev, void *data)
428 struct pcie_port_service_driver *service_driver;
430 if ((dev->bus == &pcie_port_bus_type) &&
432 service_driver = to_service_driver(dev->driver);
433 if (service_driver->resume)
434 service_driver->resume(to_pcie_device(dev));
440 * pcie_port_device_suspend - resume port services associated with a PCIe port
441 * @dev: PCI Express port to handle
443 int pcie_port_device_resume(struct device *dev)
445 return device_for_each_child(dev, NULL, resume_iter);
449 static int remove_iter(struct device *dev, void *data)
451 if (dev->bus == &pcie_port_bus_type) {
453 device_unregister(dev);
459 * pcie_port_device_remove - unregister PCI Express port service devices
460 * @dev: PCI Express port the service devices to unregister are associated with
462 * Remove PCI Express port service devices associated with given port and
463 * disable MSI-X or MSI for the port.
465 void pcie_port_device_remove(struct pci_dev *dev)
467 struct pcie_port_data *port_data = pci_get_drvdata(dev);
469 device_for_each_child(&dev->dev, NULL, remove_iter);
470 pci_disable_device(dev);
472 switch (port_data->port_irq_mode) {
473 case PCIE_PORT_MSIX_MODE:
474 pci_disable_msix(dev);
476 case PCIE_PORT_MSI_MODE:
477 pci_disable_msi(dev);
485 * pcie_port_probe_service - probe driver for given PCI Express port service
486 * @dev: PCI Express port service device to probe against
488 * If PCI Express port service driver is registered with
489 * pcie_port_service_register(), this function will be called by the driver core
490 * whenever match is found between the driver and a port service device.
492 static int pcie_port_probe_service(struct device *dev)
494 struct pcie_device *pciedev;
495 struct pcie_port_service_driver *driver;
498 if (!dev || !dev->driver)
501 driver = to_service_driver(dev->driver);
502 if (!driver || !driver->probe)
505 pciedev = to_pcie_device(dev);
506 status = driver->probe(pciedev);
508 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
516 * pcie_port_remove_service - detach driver from given PCI Express port service
517 * @dev: PCI Express port service device to handle
519 * If PCI Express port service driver is registered with
520 * pcie_port_service_register(), this function will be called by the driver core
521 * when device_unregister() is called for the port service device associated
524 static int pcie_port_remove_service(struct device *dev)
526 struct pcie_device *pciedev;
527 struct pcie_port_service_driver *driver;
529 if (!dev || !dev->driver)
532 pciedev = to_pcie_device(dev);
533 driver = to_service_driver(dev->driver);
534 if (driver && driver->remove) {
535 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
537 driver->remove(pciedev);
544 * pcie_port_shutdown_service - shut down given PCI Express port service
545 * @dev: PCI Express port service device to handle
547 * If PCI Express port service driver is registered with
548 * pcie_port_service_register(), this function will be called by the driver core
549 * when device_shutdown() is called for the port service device associated
552 static void pcie_port_shutdown_service(struct device *dev) {}
555 * pcie_port_service_register - register PCI Express port service driver
556 * @new: PCI Express port service driver to register
558 int pcie_port_service_register(struct pcie_port_service_driver *new)
560 new->driver.name = (char *)new->name;
561 new->driver.bus = &pcie_port_bus_type;
562 new->driver.probe = pcie_port_probe_service;
563 new->driver.remove = pcie_port_remove_service;
564 new->driver.shutdown = pcie_port_shutdown_service;
566 return driver_register(&new->driver);
570 * pcie_port_service_unregister - unregister PCI Express port service driver
571 * @drv: PCI Express port service driver to unregister
573 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
575 driver_unregister(&drv->driver);
578 EXPORT_SYMBOL(pcie_port_service_register);
579 EXPORT_SYMBOL(pcie_port_service_unregister);