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 struct pcie_port_data *port_data = pci_get_drvdata(dev);
191 int irq, interrupt_mode = PCIE_PORT_NO_IRQ;
194 /* Try to use MSI-X if supported */
195 if (!pcie_port_enable_msix(dev, vectors, mask))
196 return PCIE_PORT_MSIX_MODE;
198 /* We're not going to use MSI-X, so try MSI and fall back to INTx */
199 if (!pci_enable_msi(dev))
200 interrupt_mode = PCIE_PORT_MSI_MODE;
202 if (interrupt_mode == PCIE_PORT_NO_IRQ && dev->pin)
203 interrupt_mode = PCIE_PORT_INTx_MODE;
205 irq = interrupt_mode != PCIE_PORT_NO_IRQ ? dev->irq : -1;
206 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
209 vectors[PCIE_PORT_SERVICE_VC_SHIFT] = -1;
211 return interrupt_mode;
215 * get_port_device_capability - discover capabilities of a PCI Express port
216 * @dev: PCI Express port to examine
218 * The capabilities are read from the port's PCI Express configuration registers
219 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
222 * Return value: Bitmask of discovered port capabilities
224 static int get_port_device_capability(struct pci_dev *dev)
226 int services = 0, pos;
230 pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
231 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®16);
232 /* Hot-Plug Capable */
233 if (reg16 & PORT_TO_SLOT_MASK) {
234 pci_read_config_dword(dev,
235 pos + PCIE_SLOT_CAPABILITIES_REG, ®32);
236 if (reg32 & SLOT_HP_CAPABLE_MASK)
237 services |= PCIE_PORT_SERVICE_HP;
240 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
241 services |= PCIE_PORT_SERVICE_AER;
243 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
244 services |= PCIE_PORT_SERVICE_VC;
250 * pcie_device_init - initialize PCI Express port service device
251 * @dev: Port service device to initialize
252 * @parent: PCI Express port to associate the service device with
253 * @port_type: Type of the port
254 * @service_type: Type of service to associate with the service device
255 * @irq: Interrupt vector to associate with the service device
257 static void pcie_device_init(struct pci_dev *parent, struct pcie_device *dev,
258 int service_type, int irq)
260 struct pcie_port_data *port_data = pci_get_drvdata(parent);
261 struct device *device;
262 int port_type = port_data->port_type;
266 dev->service = service_type;
268 /* Initialize generic device interface */
269 device = &dev->device;
270 memset(device, 0, sizeof(struct device));
271 device->bus = &pcie_port_bus_type;
272 device->driver = NULL;
273 dev_set_drvdata(device, NULL);
274 device->release = release_pcie_device; /* callback to free pcie dev */
275 dev_set_name(device, "%s:pcie%02x",
276 pci_name(parent), get_descriptor_id(port_type, service_type));
277 device->parent = &parent->dev;
281 * alloc_pcie_device - allocate PCI Express port service device structure
282 * @parent: PCI Express port to associate the service device with
283 * @port_type: Type of the port
284 * @service_type: Type of service to associate with the service device
285 * @irq: Interrupt vector to associate with the service device
287 static struct pcie_device* alloc_pcie_device(struct pci_dev *parent,
288 int service_type, int irq)
290 struct pcie_device *device;
292 device = kzalloc(sizeof(struct pcie_device), GFP_KERNEL);
296 pcie_device_init(parent, device, service_type, irq);
301 * pcie_port_device_probe - check if device is a PCI Express port
302 * @dev: Device to check
304 int pcie_port_device_probe(struct pci_dev *dev)
309 if (!(pos = pci_find_capability(dev, PCI_CAP_ID_EXP)))
312 pci_read_config_word(dev, pos + PCIE_CAPABILITIES_REG, ®);
313 type = (reg >> 4) & PORT_TYPE_MASK;
314 if ( type == PCIE_RC_PORT || type == PCIE_SW_UPSTREAM_PORT ||
315 type == PCIE_SW_DOWNSTREAM_PORT )
322 * pcie_port_device_register - register PCI Express port
323 * @dev: PCI Express port to register
325 * Allocate the port extension structure and register services associated with
328 int pcie_port_device_register(struct pci_dev *dev)
330 struct pcie_port_data *port_data;
331 int status, capabilities, irq_mode, i, nr_serv;
332 int vectors[PCIE_PORT_DEVICE_MAXSERVICES];
335 port_data = kzalloc(sizeof(*port_data), GFP_KERNEL);
338 pci_set_drvdata(dev, port_data);
341 pci_read_config_word(dev,
342 pci_find_capability(dev, PCI_CAP_ID_EXP) +
343 PCIE_CAPABILITIES_REG, ®16);
344 port_data->port_type = (reg16 >> 4) & PORT_TYPE_MASK;
346 capabilities = get_port_device_capability(dev);
347 /* Root ports are capable of generating PME too */
348 if (port_data->port_type == PCIE_RC_PORT)
349 capabilities |= PCIE_PORT_SERVICE_PME;
351 irq_mode = assign_interrupt_mode(dev, vectors, capabilities);
352 if (irq_mode == PCIE_PORT_NO_IRQ) {
354 * Don't use service devices that require interrupts if there is
355 * no way to generate them.
357 if (!(capabilities & PCIE_PORT_SERVICE_VC)) {
361 capabilities = PCIE_PORT_SERVICE_VC;
363 port_data->port_irq_mode = irq_mode;
365 status = pci_enable_device(dev);
370 /* Allocate child services if any */
371 for (i = 0, nr_serv = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
372 struct pcie_device *child;
373 int service = 1 << i;
375 if (!(capabilities & service))
378 child = alloc_pcie_device(dev, service, vectors[i]);
382 status = device_register(&child->device);
388 get_device(&child->device);
392 pci_disable_device(dev);
405 static int suspend_iter(struct device *dev, void *data)
407 struct pcie_port_service_driver *service_driver;
409 if ((dev->bus == &pcie_port_bus_type) &&
411 service_driver = to_service_driver(dev->driver);
412 if (service_driver->suspend)
413 service_driver->suspend(to_pcie_device(dev));
419 * pcie_port_device_suspend - suspend port services associated with a PCIe port
420 * @dev: PCI Express port to handle
422 int pcie_port_device_suspend(struct device *dev)
424 return device_for_each_child(dev, NULL, suspend_iter);
427 static int resume_iter(struct device *dev, void *data)
429 struct pcie_port_service_driver *service_driver;
431 if ((dev->bus == &pcie_port_bus_type) &&
433 service_driver = to_service_driver(dev->driver);
434 if (service_driver->resume)
435 service_driver->resume(to_pcie_device(dev));
441 * pcie_port_device_suspend - resume port services associated with a PCIe port
442 * @dev: PCI Express port to handle
444 int pcie_port_device_resume(struct device *dev)
446 return device_for_each_child(dev, NULL, resume_iter);
450 static int remove_iter(struct device *dev, void *data)
452 if (dev->bus == &pcie_port_bus_type) {
454 device_unregister(dev);
460 * pcie_port_device_remove - unregister PCI Express port service devices
461 * @dev: PCI Express port the service devices to unregister are associated with
463 * Remove PCI Express port service devices associated with given port and
464 * disable MSI-X or MSI for the port.
466 void pcie_port_device_remove(struct pci_dev *dev)
468 struct pcie_port_data *port_data = pci_get_drvdata(dev);
470 device_for_each_child(&dev->dev, NULL, remove_iter);
471 pci_disable_device(dev);
473 switch (port_data->port_irq_mode) {
474 case PCIE_PORT_MSIX_MODE:
475 pci_disable_msix(dev);
477 case PCIE_PORT_MSI_MODE:
478 pci_disable_msi(dev);
486 * pcie_port_probe_service - probe driver for given PCI Express port service
487 * @dev: PCI Express port service device to probe against
489 * If PCI Express port service driver is registered with
490 * pcie_port_service_register(), this function will be called by the driver core
491 * whenever match is found between the driver and a port service device.
493 static int pcie_port_probe_service(struct device *dev)
495 struct pcie_device *pciedev;
496 struct pcie_port_service_driver *driver;
499 if (!dev || !dev->driver)
502 driver = to_service_driver(dev->driver);
503 if (!driver || !driver->probe)
506 pciedev = to_pcie_device(dev);
507 status = driver->probe(pciedev);
509 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
517 * pcie_port_remove_service - detach driver from given PCI Express port service
518 * @dev: PCI Express port service device to handle
520 * If PCI Express port service driver is registered with
521 * pcie_port_service_register(), this function will be called by the driver core
522 * when device_unregister() is called for the port service device associated
525 static int pcie_port_remove_service(struct device *dev)
527 struct pcie_device *pciedev;
528 struct pcie_port_service_driver *driver;
530 if (!dev || !dev->driver)
533 pciedev = to_pcie_device(dev);
534 driver = to_service_driver(dev->driver);
535 if (driver && driver->remove) {
536 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
538 driver->remove(pciedev);
545 * pcie_port_shutdown_service - shut down given PCI Express port service
546 * @dev: PCI Express port service device to handle
548 * If PCI Express port service driver is registered with
549 * pcie_port_service_register(), this function will be called by the driver core
550 * when device_shutdown() is called for the port service device associated
553 static void pcie_port_shutdown_service(struct device *dev) {}
556 * pcie_port_service_register - register PCI Express port service driver
557 * @new: PCI Express port service driver to register
559 int pcie_port_service_register(struct pcie_port_service_driver *new)
561 new->driver.name = (char *)new->name;
562 new->driver.bus = &pcie_port_bus_type;
563 new->driver.probe = pcie_port_probe_service;
564 new->driver.remove = pcie_port_remove_service;
565 new->driver.shutdown = pcie_port_shutdown_service;
567 return driver_register(&new->driver);
571 * pcie_port_service_unregister - unregister PCI Express port service driver
572 * @drv: PCI Express port service driver to unregister
574 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
576 driver_unregister(&drv->driver);
579 EXPORT_SYMBOL(pcie_port_service_register);
580 EXPORT_SYMBOL(pcie_port_service_unregister);