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 already 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_vec_count(dev
);
86 if (nr_entries
> PCIE_PORT_MAX_MSIX_ENTRIES
)
87 nr_entries
= PCIE_PORT_MAX_MSIX_ENTRIES
;
89 msix_entries
= kzalloc(sizeof(*msix_entries
) * nr_entries
, GFP_KERNEL
);
94 * Allocate as many entries as the port wants, so that we can check
95 * which of them will be useful. Moreover, if nr_entries is correctly
96 * equal to the number of entries this port actually uses, we'll happily
97 * go through without any tricks.
99 for (i
= 0; i
< nr_entries
; i
++)
100 msix_entries
[i
].entry
= i
;
102 status
= pci_enable_msix_exact(dev
, msix_entries
, nr_entries
);
106 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++)
111 if (mask
& (PCIE_PORT_SERVICE_PME
| PCIE_PORT_SERVICE_HP
)) {
115 * The code below follows the PCI Express Base Specification 2.0
116 * stating in Section 6.1.6 that "PME and Hot-Plug Event
117 * interrupts (when both are implemented) always share the same
118 * MSI or MSI-X vector, as indicated by the Interrupt Message
119 * Number field in the PCI Express Capabilities register", where
120 * according to Section 7.8.2 of the specification "For MSI-X,
121 * the value in this field indicates which MSI-X Table entry is
122 * used to generate the interrupt message."
124 pcie_capability_read_word(dev
, PCI_EXP_FLAGS
, ®16
);
125 entry
= (reg16
& PCI_EXP_FLAGS_IRQ
) >> 9;
126 if (entry
>= nr_entries
)
129 i
= pcie_port_msix_add_entry(msix_entries
, entry
, nvec
);
133 idx
[PCIE_PORT_SERVICE_PME_SHIFT
] = i
;
134 idx
[PCIE_PORT_SERVICE_HP_SHIFT
] = i
;
137 if (mask
& PCIE_PORT_SERVICE_AER
) {
141 * The code below follows Section 7.10.10 of the PCI Express
142 * Base Specification 2.0 stating that bits 31-27 of the Root
143 * Error Status Register contain a value indicating which of the
144 * MSI/MSI-X vectors assigned to the port is going to be used
145 * for AER, where "For MSI-X, the value in this register
146 * indicates which MSI-X Table entry is used to generate the
147 * interrupt message."
149 pos
= pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ERR
);
150 pci_read_config_dword(dev
, pos
+ PCI_ERR_ROOT_STATUS
, ®32
);
152 if (entry
>= nr_entries
)
155 i
= pcie_port_msix_add_entry(msix_entries
, entry
, nvec
);
159 idx
[PCIE_PORT_SERVICE_AER_SHIFT
] = i
;
163 * If nvec is equal to the allocated number of entries, we can just use
164 * what we have. Otherwise, the port has some extra entries not for the
165 * services we know and we need to work around that.
167 if (nvec
== nr_entries
) {
170 /* Drop the temporary MSI-X setup */
171 pci_disable_msix(dev
);
173 /* Now allocate the MSI-X vectors for real */
174 status
= pci_enable_msix_exact(dev
, msix_entries
, nvec
);
179 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++)
180 vectors
[i
] = idx
[i
] >= 0 ? msix_entries
[idx
[i
]].vector
: -1;
187 pci_disable_msix(dev
);
192 * init_service_irqs - initialize irqs for PCI Express port services
193 * @dev: PCI Express port to handle
194 * @irqs: Array of irqs to populate
195 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
197 * Return value: Interrupt mode associated with the port
199 static int init_service_irqs(struct pci_dev
*dev
, int *irqs
, int mask
)
204 * If MSI cannot be used for PCIe PME or hotplug, we have to use
205 * INTx or other interrupts, e.g. system shared interrupt.
207 if (((mask
& PCIE_PORT_SERVICE_PME
) && pcie_pme_no_msi()) ||
208 ((mask
& PCIE_PORT_SERVICE_HP
) && pciehp_no_msi())) {
214 /* Try to use MSI-X if supported */
215 if (!pcie_port_enable_msix(dev
, irqs
, mask
))
219 * We're not going to use MSI-X, so try MSI and fall back to INTx.
220 * If neither MSI/MSI-X nor INTx available, try other interrupt. On
221 * some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
223 if (!pci_enable_msi(dev
) || dev
->irq
)
227 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++)
229 irqs
[PCIE_PORT_SERVICE_VC_SHIFT
] = -1;
236 static void cleanup_service_irqs(struct pci_dev
*dev
)
238 if (dev
->msix_enabled
)
239 pci_disable_msix(dev
);
240 else if (dev
->msi_enabled
)
241 pci_disable_msi(dev
);
245 * get_port_device_capability - discover capabilities of a PCI Express port
246 * @dev: PCI Express port to examine
248 * The capabilities are read from the port's PCI Express configuration registers
249 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
252 * Return value: Bitmask of discovered port capabilities
254 static int get_port_device_capability(struct pci_dev
*dev
)
259 if (pcie_ports_disabled
)
262 cap_mask
= PCIE_PORT_SERVICE_PME
| PCIE_PORT_SERVICE_HP
263 | PCIE_PORT_SERVICE_VC
| PCIE_PORT_SERVICE_DPC
;
264 if (pci_aer_available())
265 cap_mask
|= PCIE_PORT_SERVICE_AER
;
268 pcie_port_platform_notify(dev
, &cap_mask
);
270 /* Hot-Plug Capable */
271 if ((cap_mask
& PCIE_PORT_SERVICE_HP
) && dev
->is_hotplug_bridge
) {
272 services
|= PCIE_PORT_SERVICE_HP
;
274 * Disable hot-plug interrupts in case they have been enabled
275 * by the BIOS and the hot-plug service driver is not loaded.
277 pcie_capability_clear_word(dev
, PCI_EXP_SLTCTL
,
278 PCI_EXP_SLTCTL_CCIE
| PCI_EXP_SLTCTL_HPIE
);
281 if ((cap_mask
& PCIE_PORT_SERVICE_AER
)
282 && pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_ERR
)) {
283 services
|= PCIE_PORT_SERVICE_AER
;
285 * Disable AER on this port in case it's been enabled by the
286 * BIOS (the AER service driver will enable it when necessary).
288 pci_disable_pcie_error_reporting(dev
);
291 if (pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_VC
))
292 services
|= PCIE_PORT_SERVICE_VC
;
293 /* Root ports are capable of generating PME too */
294 if ((cap_mask
& PCIE_PORT_SERVICE_PME
)
295 && pci_pcie_type(dev
) == PCI_EXP_TYPE_ROOT_PORT
) {
296 services
|= PCIE_PORT_SERVICE_PME
;
298 * Disable PME interrupt on this port in case it's been enabled
299 * by the BIOS (the PME service driver will enable it when
302 pcie_pme_interrupt_enable(dev
, false);
304 if (pci_find_ext_capability(dev
, PCI_EXT_CAP_ID_DPC
))
305 services
|= PCIE_PORT_SERVICE_DPC
;
311 * pcie_device_init - allocate and initialize PCI Express port service device
312 * @pdev: PCI Express port to associate the service device with
313 * @service: Type of service to associate with the service device
314 * @irq: Interrupt vector to associate with the service device
316 static int pcie_device_init(struct pci_dev
*pdev
, int service
, int irq
)
319 struct pcie_device
*pcie
;
320 struct device
*device
;
322 pcie
= kzalloc(sizeof(*pcie
), GFP_KERNEL
);
327 pcie
->service
= service
;
329 /* Initialize generic device interface */
330 device
= &pcie
->device
;
331 device
->bus
= &pcie_port_bus_type
;
332 device
->release
= release_pcie_device
; /* callback to free pcie dev */
333 dev_set_name(device
, "%s:pcie%03x",
335 get_descriptor_id(pci_pcie_type(pdev
), service
));
336 device
->parent
= &pdev
->dev
;
337 device_enable_async_suspend(device
);
339 retval
= device_register(device
);
349 * pcie_port_device_register - register PCI Express port
350 * @dev: PCI Express port to register
352 * Allocate the port extension structure and register services associated with
355 int pcie_port_device_register(struct pci_dev
*dev
)
357 int status
, capabilities
, i
, nr_service
;
358 int irqs
[PCIE_PORT_DEVICE_MAXSERVICES
];
360 /* Enable PCI Express port device */
361 status
= pci_enable_device(dev
);
365 /* Get and check PCI Express port services */
366 capabilities
= get_port_device_capability(dev
);
372 * Initialize service irqs. Don't use service devices that
373 * require interrupts if there is no way to generate them.
374 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
375 * that can be used in the absence of irqs. Allow them to determine
376 * if that is to be used.
378 status
= init_service_irqs(dev
, irqs
, capabilities
);
380 capabilities
&= PCIE_PORT_SERVICE_VC
| PCIE_PORT_SERVICE_HP
;
385 /* Allocate child services if any */
388 for (i
= 0; i
< PCIE_PORT_DEVICE_MAXSERVICES
; i
++) {
389 int service
= 1 << i
;
390 if (!(capabilities
& service
))
392 if (!pcie_device_init(dev
, service
, irqs
[i
]))
396 goto error_cleanup_irqs
;
401 cleanup_service_irqs(dev
);
403 pci_disable_device(dev
);
408 static int suspend_iter(struct device
*dev
, void *data
)
410 struct pcie_port_service_driver
*service_driver
;
412 if ((dev
->bus
== &pcie_port_bus_type
) && dev
->driver
) {
413 service_driver
= to_service_driver(dev
->driver
);
414 if (service_driver
->suspend
)
415 service_driver
->suspend(to_pcie_device(dev
));
421 * pcie_port_device_suspend - suspend port services associated with a PCIe port
422 * @dev: PCI Express port to handle
424 int pcie_port_device_suspend(struct device
*dev
)
426 return device_for_each_child(dev
, NULL
, suspend_iter
);
429 static int resume_iter(struct device
*dev
, void *data
)
431 struct pcie_port_service_driver
*service_driver
;
433 if ((dev
->bus
== &pcie_port_bus_type
) &&
435 service_driver
= to_service_driver(dev
->driver
);
436 if (service_driver
->resume
)
437 service_driver
->resume(to_pcie_device(dev
));
443 * pcie_port_device_resume - resume port services associated with a PCIe port
444 * @dev: PCI Express port to handle
446 int pcie_port_device_resume(struct device
*dev
)
448 return device_for_each_child(dev
, NULL
, resume_iter
);
452 static int remove_iter(struct device
*dev
, void *data
)
454 if (dev
->bus
== &pcie_port_bus_type
)
455 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 device_for_each_child(&dev
->dev
, NULL
, remove_iter
);
469 cleanup_service_irqs(dev
);
470 pci_disable_device(dev
);
474 * pcie_port_probe_service - probe driver for given PCI Express port service
475 * @dev: PCI Express port service device to probe against
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 * whenever match is found between the driver and a port service device.
481 static int pcie_port_probe_service(struct device
*dev
)
483 struct pcie_device
*pciedev
;
484 struct pcie_port_service_driver
*driver
;
487 if (!dev
|| !dev
->driver
)
490 driver
= to_service_driver(dev
->driver
);
491 if (!driver
|| !driver
->probe
)
494 pciedev
= to_pcie_device(dev
);
495 status
= driver
->probe(pciedev
);
499 dev_printk(KERN_DEBUG
, dev
, "service driver %s loaded\n", driver
->name
);
505 * pcie_port_remove_service - detach driver from given PCI Express port service
506 * @dev: PCI Express port service device to handle
508 * If PCI Express port service driver is registered with
509 * pcie_port_service_register(), this function will be called by the driver core
510 * when device_unregister() is called for the port service device associated
513 static int pcie_port_remove_service(struct device
*dev
)
515 struct pcie_device
*pciedev
;
516 struct pcie_port_service_driver
*driver
;
518 if (!dev
|| !dev
->driver
)
521 pciedev
= to_pcie_device(dev
);
522 driver
= to_service_driver(dev
->driver
);
523 if (driver
&& driver
->remove
) {
524 dev_printk(KERN_DEBUG
, dev
, "unloading service driver %s\n",
526 driver
->remove(pciedev
);
533 * pcie_port_shutdown_service - shut down given PCI Express port service
534 * @dev: PCI Express port service device to handle
536 * If PCI Express port service driver is registered with
537 * pcie_port_service_register(), this function will be called by the driver core
538 * when device_shutdown() is called for the port service device associated
541 static void pcie_port_shutdown_service(struct device
*dev
) {}
544 * pcie_port_service_register - register PCI Express port service driver
545 * @new: PCI Express port service driver to register
547 int pcie_port_service_register(struct pcie_port_service_driver
*new)
549 if (pcie_ports_disabled
)
552 new->driver
.name
= new->name
;
553 new->driver
.bus
= &pcie_port_bus_type
;
554 new->driver
.probe
= pcie_port_probe_service
;
555 new->driver
.remove
= pcie_port_remove_service
;
556 new->driver
.shutdown
= pcie_port_shutdown_service
;
558 return driver_register(&new->driver
);
560 EXPORT_SYMBOL(pcie_port_service_register
);
563 * pcie_port_service_unregister - unregister PCI Express port service driver
564 * @drv: PCI Express port service driver to unregister
566 void pcie_port_service_unregister(struct pcie_port_service_driver
*drv
)
568 driver_unregister(&drv
->driver
);
570 EXPORT_SYMBOL(pcie_port_service_unregister
);