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 pcie_capability_read_word(dev
, PCI_EXP_FLAGS
, ®16
);
124 entry
= (reg16
& PCI_EXP_FLAGS_IRQ
) >> 9;
125 if (entry
>= nr_entries
)
128 i
= pcie_port_msix_add_entry(msix_entries
, entry
, nvec
);
132 idx
[PCIE_PORT_SERVICE_PME_SHIFT
] = i
;
133 idx
[PCIE_PORT_SERVICE_HP_SHIFT
] = i
;
136 if (mask
& PCIE_PORT_SERVICE_AER
) {
140 * The code below follows Section 7.10.10 of the PCI Express
141 * Base Specification 2.0 stating that bits 31-27 of the Root
142 * Error Status Register contain a value indicating which of the
143 * MSI/MSI-X vectors assigned to the port is going to be used
144 * for AER, where "For MSI-X, the value in this register
145 * indicates which MSI-X Table entry is used to generate the
146 * interrupt message."
148 pos
= pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ERR
);
149 pci_read_config_dword(dev
, pos
+ PCI_ERR_ROOT_STATUS
, ®32
);
151 if (entry
>= nr_entries
)
154 i
= pcie_port_msix_add_entry(msix_entries
, entry
, nvec
);
158 idx
[PCIE_PORT_SERVICE_AER_SHIFT
] = i
;
162 * If nvec is equal to the allocated number of entries, we can just use
163 * what we have. Otherwise, the port has some extra entries not for the
164 * services we know and we need to work around that.
166 if (nvec
== nr_entries
) {
169 /* Drop the temporary MSI-X setup */
170 pci_disable_msix(dev
);
172 /* Now allocate the MSI-X vectors for real */
173 status
= pci_enable_msix(dev
, msix_entries
, nvec
);
178 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++)
179 vectors
[i
] = idx
[i
] >= 0 ? msix_entries
[idx
[i
]].vector
: -1;
186 pci_disable_msix(dev
);
191 * init_service_irqs - initialize irqs for PCI Express port services
192 * @dev: PCI Express port to handle
193 * @irqs: Array of irqs to populate
194 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
196 * Return value: Interrupt mode associated with the port
198 static int init_service_irqs(struct pci_dev
*dev
, int *irqs
, int mask
)
203 * If MSI cannot be used for PCIe PME or hotplug, we have to use
204 * INTx or other interrupts, e.g. system shared interrupt.
206 if (((mask
& PCIE_PORT_SERVICE_PME
) && pcie_pme_no_msi()) ||
207 ((mask
& PCIE_PORT_SERVICE_HP
) && pciehp_no_msi())) {
213 /* Try to use MSI-X if supported */
214 if (!pcie_port_enable_msix(dev
, irqs
, mask
))
218 * We're not going to use MSI-X, so try MSI and fall back to INTx.
219 * If neither MSI/MSI-X nor INTx available, try other interrupt. On
220 * some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
222 if (!pci_enable_msi(dev
) || dev
->irq
)
226 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++)
228 irqs
[PCIE_PORT_SERVICE_VC_SHIFT
] = -1;
235 static void cleanup_service_irqs(struct pci_dev
*dev
)
237 if (dev
->msix_enabled
)
238 pci_disable_msix(dev
);
239 else if (dev
->msi_enabled
)
240 pci_disable_msi(dev
);
244 * get_port_device_capability - discover capabilities of a PCI Express port
245 * @dev: PCI Express port to examine
247 * The capabilities are read from the port's PCI Express configuration registers
248 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
251 * Return value: Bitmask of discovered port capabilities
253 static int get_port_device_capability(struct pci_dev
*dev
)
260 if (pcie_ports_disabled
)
263 err
= pcie_port_platform_notify(dev
, &cap_mask
);
264 if (!pcie_ports_auto
) {
265 cap_mask
= PCIE_PORT_SERVICE_PME
| PCIE_PORT_SERVICE_HP
266 | PCIE_PORT_SERVICE_VC
;
267 if (pci_aer_available())
268 cap_mask
|= PCIE_PORT_SERVICE_AER
;
273 /* Hot-Plug Capable */
274 if ((cap_mask
& PCIE_PORT_SERVICE_HP
) &&
275 pcie_caps_reg(dev
) & PCI_EXP_FLAGS_SLOT
) {
276 pcie_capability_read_dword(dev
, PCI_EXP_SLTCAP
, ®32
);
277 if (reg32
& PCI_EXP_SLTCAP_HPC
) {
278 services
|= PCIE_PORT_SERVICE_HP
;
280 * Disable hot-plug interrupts in case they have been
281 * enabled by the BIOS and the hot-plug service driver
284 pcie_capability_clear_word(dev
, PCI_EXP_SLTCTL
,
285 PCI_EXP_SLTCTL_CCIE
| PCI_EXP_SLTCTL_HPIE
);
289 if ((cap_mask
& PCIE_PORT_SERVICE_AER
)
290 && pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ERR
)) {
291 services
|= PCIE_PORT_SERVICE_AER
;
293 * Disable AER on this port in case it's been enabled by the
294 * BIOS (the AER service driver will enable it when necessary).
296 pci_disable_pcie_error_reporting(dev
);
299 if (pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_VC
))
300 services
|= PCIE_PORT_SERVICE_VC
;
301 /* Root ports are capable of generating PME too */
302 if ((cap_mask
& PCIE_PORT_SERVICE_PME
)
303 && pci_pcie_type(dev
) == PCI_EXP_TYPE_ROOT_PORT
) {
304 services
|= PCIE_PORT_SERVICE_PME
;
306 * Disable PME interrupt on this port in case it's been enabled
307 * by the BIOS (the PME service driver will enable it when
310 pcie_pme_interrupt_enable(dev
, false);
317 * pcie_device_init - allocate and initialize PCI Express port service device
318 * @pdev: PCI Express port to associate the service device with
319 * @service: Type of service to associate with the service device
320 * @irq: Interrupt vector to associate with the service device
322 static int pcie_device_init(struct pci_dev
*pdev
, int service
, int irq
)
325 struct pcie_device
*pcie
;
326 struct device
*device
;
328 pcie
= kzalloc(sizeof(*pcie
), GFP_KERNEL
);
333 pcie
->service
= service
;
335 /* Initialize generic device interface */
336 device
= &pcie
->device
;
337 device
->bus
= &pcie_port_bus_type
;
338 device
->release
= release_pcie_device
; /* callback to free pcie dev */
339 dev_set_name(device
, "%s:pcie%02x",
341 get_descriptor_id(pci_pcie_type(pdev
), service
));
342 device
->parent
= &pdev
->dev
;
343 device_enable_async_suspend(device
);
345 retval
= device_register(device
);
354 * pcie_port_device_register - register PCI Express port
355 * @dev: PCI Express port to register
357 * Allocate the port extension structure and register services associated with
360 int pcie_port_device_register(struct pci_dev
*dev
)
362 int status
, capabilities
, i
, nr_service
;
363 int irqs
[PCIE_PORT_DEVICE_MAXSERVICES
];
365 /* Enable PCI Express port device */
366 status
= pci_enable_device(dev
);
370 /* Get and check PCI Express port services */
371 capabilities
= get_port_device_capability(dev
);
377 * Initialize service irqs. Don't use service devices that
378 * require interrupts if there is no way to generate them.
380 status
= init_service_irqs(dev
, irqs
, capabilities
);
382 capabilities
&= PCIE_PORT_SERVICE_VC
;
387 /* Allocate child services if any */
390 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++) {
391 int service
= 1 << i
;
392 if (!(capabilities
& service
))
394 if (!pcie_device_init(dev
, service
, irqs
[i
]))
398 goto error_cleanup_irqs
;
403 cleanup_service_irqs(dev
);
405 pci_disable_device(dev
);
410 static int suspend_iter(struct device
*dev
, void *data
)
412 struct pcie_port_service_driver
*service_driver
;
414 if ((dev
->bus
== &pcie_port_bus_type
) && dev
->driver
) {
415 service_driver
= to_service_driver(dev
->driver
);
416 if (service_driver
->suspend
)
417 service_driver
->suspend(to_pcie_device(dev
));
423 * pcie_port_device_suspend - suspend port services associated with a PCIe port
424 * @dev: PCI Express port to handle
426 int pcie_port_device_suspend(struct device
*dev
)
428 return device_for_each_child(dev
, NULL
, suspend_iter
);
431 static int resume_iter(struct device
*dev
, void *data
)
433 struct pcie_port_service_driver
*service_driver
;
435 if ((dev
->bus
== &pcie_port_bus_type
) &&
437 service_driver
= to_service_driver(dev
->driver
);
438 if (service_driver
->resume
)
439 service_driver
->resume(to_pcie_device(dev
));
445 * pcie_port_device_suspend - resume port services associated with a PCIe port
446 * @dev: PCI Express port to handle
448 int pcie_port_device_resume(struct device
*dev
)
450 return device_for_each_child(dev
, NULL
, resume_iter
);
454 static int remove_iter(struct device
*dev
, void *data
)
456 if (dev
->bus
== &pcie_port_bus_type
) {
458 device_unregister(dev
);
464 * pcie_port_device_remove - unregister PCI Express port service devices
465 * @dev: PCI Express port the service devices to unregister are associated with
467 * Remove PCI Express port service devices associated with given port and
468 * disable MSI-X or MSI for the port.
470 void pcie_port_device_remove(struct pci_dev
*dev
)
472 device_for_each_child(&dev
->dev
, NULL
, remove_iter
);
473 cleanup_service_irqs(dev
);
474 pci_disable_device(dev
);
478 * pcie_port_probe_service - probe driver for given PCI Express port service
479 * @dev: PCI Express port service device to probe against
481 * If PCI Express port service driver is registered with
482 * pcie_port_service_register(), this function will be called by the driver core
483 * whenever match is found between the driver and a port service device.
485 static int pcie_port_probe_service(struct device
*dev
)
487 struct pcie_device
*pciedev
;
488 struct pcie_port_service_driver
*driver
;
491 if (!dev
|| !dev
->driver
)
494 driver
= to_service_driver(dev
->driver
);
495 if (!driver
|| !driver
->probe
)
498 pciedev
= to_pcie_device(dev
);
499 status
= driver
->probe(pciedev
);
501 dev_printk(KERN_DEBUG
, dev
, "service driver %s loaded\n",
509 * pcie_port_remove_service - detach driver from given PCI Express port service
510 * @dev: PCI Express port service device to handle
512 * If PCI Express port service driver is registered with
513 * pcie_port_service_register(), this function will be called by the driver core
514 * when device_unregister() is called for the port service device associated
517 static int pcie_port_remove_service(struct device
*dev
)
519 struct pcie_device
*pciedev
;
520 struct pcie_port_service_driver
*driver
;
522 if (!dev
|| !dev
->driver
)
525 pciedev
= to_pcie_device(dev
);
526 driver
= to_service_driver(dev
->driver
);
527 if (driver
&& driver
->remove
) {
528 dev_printk(KERN_DEBUG
, dev
, "unloading service driver %s\n",
530 driver
->remove(pciedev
);
537 * pcie_port_shutdown_service - shut down given PCI Express port service
538 * @dev: PCI Express port service device to handle
540 * If PCI Express port service driver is registered with
541 * pcie_port_service_register(), this function will be called by the driver core
542 * when device_shutdown() is called for the port service device associated
545 static void pcie_port_shutdown_service(struct device
*dev
) {}
548 * pcie_port_service_register - register PCI Express port service driver
549 * @new: PCI Express port service driver to register
551 int pcie_port_service_register(struct pcie_port_service_driver
*new)
553 if (pcie_ports_disabled
)
556 new->driver
.name
= (char *)new->name
;
557 new->driver
.bus
= &pcie_port_bus_type
;
558 new->driver
.probe
= pcie_port_probe_service
;
559 new->driver
.remove
= pcie_port_remove_service
;
560 new->driver
.shutdown
= pcie_port_shutdown_service
;
562 return driver_register(&new->driver
);
564 EXPORT_SYMBOL(pcie_port_service_register
);
567 * pcie_port_service_unregister - unregister PCI Express port service driver
568 * @drv: PCI Express port service driver to unregister
570 void pcie_port_service_unregister(struct pcie_port_service_driver
*drv
)
572 driver_unregister(&drv
->driver
);
574 EXPORT_SYMBOL(pcie_port_service_unregister
);