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 + PCI_EXP_FLAGS, ®16);
113 entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
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 + PCI_EXP_FLAGS, ®16);
234 /* Hot-Plug Capable */
235 if (reg16 & PCI_EXP_FLAGS_SLOT) {
236 pci_read_config_dword(dev, pos + PCI_EXP_SLTCAP, ®32);
237 if (reg32 & PCI_EXP_SLTCAP_HPC)
238 services |= PCIE_PORT_SERVICE_HP;
241 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
242 services |= PCIE_PORT_SERVICE_AER;
244 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
245 services |= PCIE_PORT_SERVICE_VC;
246 /* Root ports are capable of generating PME too */
247 if (dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
248 services |= PCIE_PORT_SERVICE_PME;
254 * pcie_device_init - allocate and initialize PCI Express port service device
255 * @pdev: PCI Express port to associate the service device with
256 * @service: Type of service to associate with the service device
257 * @irq: Interrupt vector to associate with the service device
259 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
262 struct pcie_device *pcie;
263 struct device *device;
265 pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
270 pcie->service = service;
272 /* Initialize generic device interface */
273 device = &pcie->device;
274 device->bus = &pcie_port_bus_type;
275 device->release = release_pcie_device; /* callback to free pcie dev */
276 dev_set_name(device, "%s:pcie%02x",
278 get_descriptor_id(pdev->pcie_type, service));
279 device->parent = &pdev->dev;
281 retval = device_register(device);
290 * pcie_port_device_register - register PCI Express port
291 * @dev: PCI Express port to register
293 * Allocate the port extension structure and register services associated with
296 int pcie_port_device_register(struct pci_dev *dev)
298 int status, capabilities, i, nr_service;
299 int irqs[PCIE_PORT_DEVICE_MAXSERVICES];
301 /* Get and check PCI Express port services */
302 capabilities = get_port_device_capability(dev);
306 /* Enable PCI Express port device */
307 status = pci_enable_device(dev);
312 * Initialize service irqs. Don't use service devices that
313 * require interrupts if there is no way to generate them.
315 status = init_service_irqs(dev, irqs, capabilities);
317 capabilities &= PCIE_PORT_SERVICE_VC;
322 /* Allocate child services if any */
325 for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
326 int service = 1 << i;
327 if (!(capabilities & service))
329 if (!pcie_device_init(dev, service, irqs[i]))
333 goto error_cleanup_irqs;
338 cleanup_service_irqs(dev);
340 pci_disable_device(dev);
345 static int suspend_iter(struct device *dev, void *data)
347 struct pcie_port_service_driver *service_driver;
349 if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
350 service_driver = to_service_driver(dev->driver);
351 if (service_driver->suspend)
352 service_driver->suspend(to_pcie_device(dev));
358 * pcie_port_device_suspend - suspend port services associated with a PCIe port
359 * @dev: PCI Express port to handle
361 int pcie_port_device_suspend(struct device *dev)
363 return device_for_each_child(dev, NULL, suspend_iter);
366 static int resume_iter(struct device *dev, void *data)
368 struct pcie_port_service_driver *service_driver;
370 if ((dev->bus == &pcie_port_bus_type) &&
372 service_driver = to_service_driver(dev->driver);
373 if (service_driver->resume)
374 service_driver->resume(to_pcie_device(dev));
380 * pcie_port_device_suspend - resume port services associated with a PCIe port
381 * @dev: PCI Express port to handle
383 int pcie_port_device_resume(struct device *dev)
385 return device_for_each_child(dev, NULL, resume_iter);
389 static int remove_iter(struct device *dev, void *data)
391 if (dev->bus == &pcie_port_bus_type) {
393 device_unregister(dev);
399 * pcie_port_device_remove - unregister PCI Express port service devices
400 * @dev: PCI Express port the service devices to unregister are associated with
402 * Remove PCI Express port service devices associated with given port and
403 * disable MSI-X or MSI for the port.
405 void pcie_port_device_remove(struct pci_dev *dev)
407 device_for_each_child(&dev->dev, NULL, remove_iter);
408 cleanup_service_irqs(dev);
409 pci_disable_device(dev);
413 * pcie_port_probe_service - probe driver for given PCI Express port service
414 * @dev: PCI Express port service device to probe against
416 * If PCI Express port service driver is registered with
417 * pcie_port_service_register(), this function will be called by the driver core
418 * whenever match is found between the driver and a port service device.
420 static int pcie_port_probe_service(struct device *dev)
422 struct pcie_device *pciedev;
423 struct pcie_port_service_driver *driver;
426 if (!dev || !dev->driver)
429 driver = to_service_driver(dev->driver);
430 if (!driver || !driver->probe)
433 pciedev = to_pcie_device(dev);
434 status = driver->probe(pciedev);
436 dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n",
444 * pcie_port_remove_service - detach driver from given PCI Express port service
445 * @dev: PCI Express port service device to handle
447 * If PCI Express port service driver is registered with
448 * pcie_port_service_register(), this function will be called by the driver core
449 * when device_unregister() is called for the port service device associated
452 static int pcie_port_remove_service(struct device *dev)
454 struct pcie_device *pciedev;
455 struct pcie_port_service_driver *driver;
457 if (!dev || !dev->driver)
460 pciedev = to_pcie_device(dev);
461 driver = to_service_driver(dev->driver);
462 if (driver && driver->remove) {
463 dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n",
465 driver->remove(pciedev);
472 * pcie_port_shutdown_service - shut down given PCI Express port service
473 * @dev: PCI Express port service device to handle
475 * If PCI Express port service driver is registered with
476 * pcie_port_service_register(), this function will be called by the driver core
477 * when device_shutdown() is called for the port service device associated
480 static void pcie_port_shutdown_service(struct device *dev) {}
483 * pcie_port_service_register - register PCI Express port service driver
484 * @new: PCI Express port service driver to register
486 int pcie_port_service_register(struct pcie_port_service_driver *new)
488 new->driver.name = (char *)new->name;
489 new->driver.bus = &pcie_port_bus_type;
490 new->driver.probe = pcie_port_probe_service;
491 new->driver.remove = pcie_port_remove_service;
492 new->driver.shutdown = pcie_port_shutdown_service;
494 return driver_register(&new->driver);
496 EXPORT_SYMBOL(pcie_port_service_register);
499 * pcie_port_service_unregister - unregister PCI Express port service driver
500 * @drv: PCI Express port service driver to unregister
502 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
504 driver_unregister(&drv->driver);
506 EXPORT_SYMBOL(pcie_port_service_unregister);