Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCIe Native PME support
4 *
5 * Copyright (C) 2007 - 2009 Intel Corp
6 * Copyright (C) 2007 - 2009 Shaohua Li <shaohua.li@intel.com>
7 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
8 */
9
10#define dev_fmt(fmt) "PME: " fmt
11
12#include <linux/pci.h>
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/slab.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/device.h>
19#include <linux/pm_runtime.h>
20
21#include "../pci.h"
22#include "portdrv.h"
23
24/*
25 * If this switch is set, MSI will not be used for PCIe PME signaling. This
26 * causes the PCIe port driver to use INTx interrupts only, but it turns out
27 * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based
28 * wake-up from system sleep states.
29 */
30bool pcie_pme_msi_disabled;
31
32static int __init pcie_pme_setup(char *str)
33{
34 if (!strncmp(str, "nomsi", 5))
35 pcie_pme_msi_disabled = true;
36
37 return 1;
38}
39__setup("pcie_pme=", pcie_pme_setup);
40
41struct pcie_pme_service_data {
42 spinlock_t lock;
43 struct pcie_device *srv;
44 struct work_struct work;
45 bool noirq; /* If set, keep the PME interrupt disabled. */
46};
47
48/**
49 * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
50 * @dev: PCIe root port or event collector.
51 * @enable: Enable or disable the interrupt.
52 */
53void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
54{
55 if (enable)
56 pcie_capability_set_word(dev, PCI_EXP_RTCTL,
57 PCI_EXP_RTCTL_PMEIE);
58 else
59 pcie_capability_clear_word(dev, PCI_EXP_RTCTL,
60 PCI_EXP_RTCTL_PMEIE);
61}
62
63/**
64 * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
65 * @bus: PCI bus to scan.
66 *
67 * Scan given PCI bus and all buses under it for devices asserting PME#.
68 */
69static bool pcie_pme_walk_bus(struct pci_bus *bus)
70{
71 struct pci_dev *dev;
72 bool ret = false;
73
74 list_for_each_entry(dev, &bus->devices, bus_list) {
75 /* Skip PCIe devices in case we started from a root port. */
76 if (!pci_is_pcie(dev) && pci_check_pme_status(dev)) {
77 if (dev->pme_poll)
78 dev->pme_poll = false;
79
80 pci_wakeup_event(dev);
81 pm_request_resume(&dev->dev);
82 ret = true;
83 }
84
85 if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
86 ret = true;
87 }
88
89 return ret;
90}
91
92/**
93 * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
94 * @bus: Secondary bus of the bridge.
95 * @devfn: Device/function number to check.
96 *
97 * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
98 * PCIe PME message. In such that case the bridge should use the Requester ID
99 * of device/function number 0 on its secondary bus.
100 */
101static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
102{
103 struct pci_dev *dev;
104 bool found = false;
105
106 if (devfn)
107 return false;
108
109 dev = pci_dev_get(bus->self);
110 if (!dev)
111 return false;
112
113 if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE) {
114 down_read(&pci_bus_sem);
115 if (pcie_pme_walk_bus(bus))
116 found = true;
117 up_read(&pci_bus_sem);
118 }
119
120 pci_dev_put(dev);
121 return found;
122}
123
124/**
125 * pcie_pme_handle_request - Find device that generated PME and handle it.
126 * @port: Root port or event collector that generated the PME interrupt.
127 * @req_id: PCIe Requester ID of the device that generated the PME.
128 */
129static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
130{
131 u8 busnr = req_id >> 8, devfn = req_id & 0xff;
132 struct pci_bus *bus;
133 struct pci_dev *dev;
134 bool found = false;
135
136 /* First, check if the PME is from the root port itself. */
137 if (port->devfn == devfn && port->bus->number == busnr) {
138 if (port->pme_poll)
139 port->pme_poll = false;
140
141 if (pci_check_pme_status(port)) {
142 pm_request_resume(&port->dev);
143 found = true;
144 } else {
145 /*
146 * Apparently, the root port generated the PME on behalf
147 * of a non-PCIe device downstream. If this is done by
148 * a root port, the Requester ID field in its status
149 * register may contain either the root port's, or the
150 * source device's information (PCI Express Base
151 * Specification, Rev. 2.0, Section 6.1.9).
152 */
153 down_read(&pci_bus_sem);
154 found = pcie_pme_walk_bus(port->subordinate);
155 up_read(&pci_bus_sem);
156 }
157 goto out;
158 }
159
160 /* Second, find the bus the source device is on. */
161 bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
162 if (!bus)
163 goto out;
164
165 /* Next, check if the PME is from a PCIe-PCI bridge. */
166 found = pcie_pme_from_pci_bridge(bus, devfn);
167 if (found)
168 goto out;
169
170 /* Finally, try to find the PME source on the bus. */
171 down_read(&pci_bus_sem);
172 list_for_each_entry(dev, &bus->devices, bus_list) {
173 pci_dev_get(dev);
174 if (dev->devfn == devfn) {
175 found = true;
176 break;
177 }
178 pci_dev_put(dev);
179 }
180 up_read(&pci_bus_sem);
181
182 if (found) {
183 /* The device is there, but we have to check its PME status. */
184 found = pci_check_pme_status(dev);
185 if (found) {
186 if (dev->pme_poll)
187 dev->pme_poll = false;
188
189 pci_wakeup_event(dev);
190 pm_request_resume(&dev->dev);
191 }
192 pci_dev_put(dev);
193 } else if (devfn) {
194 /*
195 * The device is not there, but we can still try to recover by
196 * assuming that the PME was reported by a PCIe-PCI bridge that
197 * used devfn different from zero.
198 */
199 pci_info(port, "interrupt generated for non-existent device %02x:%02x.%d\n",
200 busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
201 found = pcie_pme_from_pci_bridge(bus, 0);
202 }
203
204 out:
205 if (!found)
206 pci_info(port, "Spurious native interrupt!\n");
207}
208
209/**
210 * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
211 * @work: Work structure giving access to service data.
212 */
213static void pcie_pme_work_fn(struct work_struct *work)
214{
215 struct pcie_pme_service_data *data =
216 container_of(work, struct pcie_pme_service_data, work);
217 struct pci_dev *port = data->srv->port;
218 u32 rtsta;
219
220 spin_lock_irq(&data->lock);
221
222 for (;;) {
223 if (data->noirq)
224 break;
225
226 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
227 if (rtsta == (u32) ~0)
228 break;
229
230 if (rtsta & PCI_EXP_RTSTA_PME) {
231 /*
232 * Clear PME status of the port. If there are other
233 * pending PMEs, the status will be set again.
234 */
235 pcie_clear_root_pme_status(port);
236
237 spin_unlock_irq(&data->lock);
238 pcie_pme_handle_request(port, rtsta & 0xffff);
239 spin_lock_irq(&data->lock);
240
241 continue;
242 }
243
244 /* No need to loop if there are no more PMEs pending. */
245 if (!(rtsta & PCI_EXP_RTSTA_PENDING))
246 break;
247
248 spin_unlock_irq(&data->lock);
249 cpu_relax();
250 spin_lock_irq(&data->lock);
251 }
252
253 if (!data->noirq)
254 pcie_pme_interrupt_enable(port, true);
255
256 spin_unlock_irq(&data->lock);
257}
258
259/**
260 * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
261 * @irq: Interrupt vector.
262 * @context: Interrupt context pointer.
263 */
264static irqreturn_t pcie_pme_irq(int irq, void *context)
265{
266 struct pci_dev *port;
267 struct pcie_pme_service_data *data;
268 u32 rtsta;
269 unsigned long flags;
270
271 port = ((struct pcie_device *)context)->port;
272 data = get_service_data((struct pcie_device *)context);
273
274 spin_lock_irqsave(&data->lock, flags);
275 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
276
277 if (rtsta == (u32) ~0 || !(rtsta & PCI_EXP_RTSTA_PME)) {
278 spin_unlock_irqrestore(&data->lock, flags);
279 return IRQ_NONE;
280 }
281
282 pcie_pme_interrupt_enable(port, false);
283 spin_unlock_irqrestore(&data->lock, flags);
284
285 /* We don't use pm_wq, because it's freezable. */
286 schedule_work(&data->work);
287
288 return IRQ_HANDLED;
289}
290
291/**
292 * pcie_pme_can_wakeup - Set the wakeup capability flag.
293 * @dev: PCI device to handle.
294 * @ign: Ignored.
295 */
296static int pcie_pme_can_wakeup(struct pci_dev *dev, void *ign)
297{
298 device_set_wakeup_capable(&dev->dev, true);
299 return 0;
300}
301
302/**
303 * pcie_pme_mark_devices - Set the wakeup flag for devices below a port.
304 * @port: PCIe root port or event collector to handle.
305 *
306 * For each device below given root port, including the port itself (or for each
307 * root complex integrated endpoint if @port is a root complex event collector)
308 * set the flag indicating that it can signal run-time wake-up events.
309 */
310static void pcie_pme_mark_devices(struct pci_dev *port)
311{
312 pcie_pme_can_wakeup(port, NULL);
313 if (port->subordinate)
314 pci_walk_bus(port->subordinate, pcie_pme_can_wakeup, NULL);
315}
316
317/**
318 * pcie_pme_probe - Initialize PCIe PME service for given root port.
319 * @srv: PCIe service to initialize.
320 */
321static int pcie_pme_probe(struct pcie_device *srv)
322{
323 struct pci_dev *port;
324 struct pcie_pme_service_data *data;
325 int ret;
326
327 data = kzalloc(sizeof(*data), GFP_KERNEL);
328 if (!data)
329 return -ENOMEM;
330
331 spin_lock_init(&data->lock);
332 INIT_WORK(&data->work, pcie_pme_work_fn);
333 data->srv = srv;
334 set_service_data(srv, data);
335
336 port = srv->port;
337 pcie_pme_interrupt_enable(port, false);
338 pcie_clear_root_pme_status(port);
339
340 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
341 if (ret) {
342 kfree(data);
343 return ret;
344 }
345
346 pci_info(port, "Signaling with IRQ %d\n", srv->irq);
347
348 pcie_pme_mark_devices(port);
349 pcie_pme_interrupt_enable(port, true);
350 return 0;
351}
352
353static bool pcie_pme_check_wakeup(struct pci_bus *bus)
354{
355 struct pci_dev *dev;
356
357 if (!bus)
358 return false;
359
360 list_for_each_entry(dev, &bus->devices, bus_list)
361 if (device_may_wakeup(&dev->dev)
362 || pcie_pme_check_wakeup(dev->subordinate))
363 return true;
364
365 return false;
366}
367
368static void pcie_pme_disable_interrupt(struct pci_dev *port,
369 struct pcie_pme_service_data *data)
370{
371 spin_lock_irq(&data->lock);
372 pcie_pme_interrupt_enable(port, false);
373 pcie_clear_root_pme_status(port);
374 data->noirq = true;
375 spin_unlock_irq(&data->lock);
376}
377
378/**
379 * pcie_pme_suspend - Suspend PCIe PME service device.
380 * @srv: PCIe service device to suspend.
381 */
382static int pcie_pme_suspend(struct pcie_device *srv)
383{
384 struct pcie_pme_service_data *data = get_service_data(srv);
385 struct pci_dev *port = srv->port;
386 bool wakeup;
387 int ret;
388
389 if (device_may_wakeup(&port->dev)) {
390 wakeup = true;
391 } else {
392 down_read(&pci_bus_sem);
393 wakeup = pcie_pme_check_wakeup(port->subordinate);
394 up_read(&pci_bus_sem);
395 }
396 if (wakeup) {
397 ret = enable_irq_wake(srv->irq);
398 if (!ret)
399 return 0;
400 }
401
402 pcie_pme_disable_interrupt(port, data);
403
404 synchronize_irq(srv->irq);
405
406 return 0;
407}
408
409/**
410 * pcie_pme_resume - Resume PCIe PME service device.
411 * @srv - PCIe service device to resume.
412 */
413static int pcie_pme_resume(struct pcie_device *srv)
414{
415 struct pcie_pme_service_data *data = get_service_data(srv);
416
417 spin_lock_irq(&data->lock);
418 if (data->noirq) {
419 struct pci_dev *port = srv->port;
420
421 pcie_clear_root_pme_status(port);
422 pcie_pme_interrupt_enable(port, true);
423 data->noirq = false;
424 } else {
425 disable_irq_wake(srv->irq);
426 }
427 spin_unlock_irq(&data->lock);
428
429 return 0;
430}
431
432/**
433 * pcie_pme_remove - Prepare PCIe PME service device for removal.
434 * @srv - PCIe service device to remove.
435 */
436static void pcie_pme_remove(struct pcie_device *srv)
437{
438 struct pcie_pme_service_data *data = get_service_data(srv);
439
440 pcie_pme_disable_interrupt(srv->port, data);
441 free_irq(srv->irq, srv);
442 cancel_work_sync(&data->work);
443 kfree(data);
444}
445
446static struct pcie_port_service_driver pcie_pme_driver = {
447 .name = "pcie_pme",
448 .port_type = PCI_EXP_TYPE_ROOT_PORT,
449 .service = PCIE_PORT_SERVICE_PME,
450
451 .probe = pcie_pme_probe,
452 .suspend = pcie_pme_suspend,
453 .resume = pcie_pme_resume,
454 .remove = pcie_pme_remove,
455};
456
457/**
458 * pcie_pme_service_init - Register the PCIe PME service driver.
459 */
460int __init pcie_pme_init(void)
461{
462 return pcie_port_service_register(&pcie_pme_driver);
463}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCIe Native PME support
4 *
5 * Copyright (C) 2007 - 2009 Intel Corp
6 * Copyright (C) 2007 - 2009 Shaohua Li <shaohua.li@intel.com>
7 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
8 */
9
10#include <linux/pci.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/slab.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/device.h>
17#include <linux/pm_runtime.h>
18
19#include "../pci.h"
20#include "portdrv.h"
21
22/*
23 * If this switch is set, MSI will not be used for PCIe PME signaling. This
24 * causes the PCIe port driver to use INTx interrupts only, but it turns out
25 * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based
26 * wake-up from system sleep states.
27 */
28bool pcie_pme_msi_disabled;
29
30static int __init pcie_pme_setup(char *str)
31{
32 if (!strncmp(str, "nomsi", 5))
33 pcie_pme_msi_disabled = true;
34
35 return 1;
36}
37__setup("pcie_pme=", pcie_pme_setup);
38
39struct pcie_pme_service_data {
40 spinlock_t lock;
41 struct pcie_device *srv;
42 struct work_struct work;
43 bool noirq; /* If set, keep the PME interrupt disabled. */
44};
45
46/**
47 * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
48 * @dev: PCIe root port or event collector.
49 * @enable: Enable or disable the interrupt.
50 */
51void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
52{
53 if (enable)
54 pcie_capability_set_word(dev, PCI_EXP_RTCTL,
55 PCI_EXP_RTCTL_PMEIE);
56 else
57 pcie_capability_clear_word(dev, PCI_EXP_RTCTL,
58 PCI_EXP_RTCTL_PMEIE);
59}
60
61/**
62 * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
63 * @bus: PCI bus to scan.
64 *
65 * Scan given PCI bus and all buses under it for devices asserting PME#.
66 */
67static bool pcie_pme_walk_bus(struct pci_bus *bus)
68{
69 struct pci_dev *dev;
70 bool ret = false;
71
72 list_for_each_entry(dev, &bus->devices, bus_list) {
73 /* Skip PCIe devices in case we started from a root port. */
74 if (!pci_is_pcie(dev) && pci_check_pme_status(dev)) {
75 if (dev->pme_poll)
76 dev->pme_poll = false;
77
78 pci_wakeup_event(dev);
79 pm_request_resume(&dev->dev);
80 ret = true;
81 }
82
83 if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
84 ret = true;
85 }
86
87 return ret;
88}
89
90/**
91 * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
92 * @bus: Secondary bus of the bridge.
93 * @devfn: Device/function number to check.
94 *
95 * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
96 * PCIe PME message. In such that case the bridge should use the Requester ID
97 * of device/function number 0 on its secondary bus.
98 */
99static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
100{
101 struct pci_dev *dev;
102 bool found = false;
103
104 if (devfn)
105 return false;
106
107 dev = pci_dev_get(bus->self);
108 if (!dev)
109 return false;
110
111 if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE) {
112 down_read(&pci_bus_sem);
113 if (pcie_pme_walk_bus(bus))
114 found = true;
115 up_read(&pci_bus_sem);
116 }
117
118 pci_dev_put(dev);
119 return found;
120}
121
122/**
123 * pcie_pme_handle_request - Find device that generated PME and handle it.
124 * @port: Root port or event collector that generated the PME interrupt.
125 * @req_id: PCIe Requester ID of the device that generated the PME.
126 */
127static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
128{
129 u8 busnr = req_id >> 8, devfn = req_id & 0xff;
130 struct pci_bus *bus;
131 struct pci_dev *dev;
132 bool found = false;
133
134 /* First, check if the PME is from the root port itself. */
135 if (port->devfn == devfn && port->bus->number == busnr) {
136 if (port->pme_poll)
137 port->pme_poll = false;
138
139 if (pci_check_pme_status(port)) {
140 pm_request_resume(&port->dev);
141 found = true;
142 } else {
143 /*
144 * Apparently, the root port generated the PME on behalf
145 * of a non-PCIe device downstream. If this is done by
146 * a root port, the Requester ID field in its status
147 * register may contain either the root port's, or the
148 * source device's information (PCI Express Base
149 * Specification, Rev. 2.0, Section 6.1.9).
150 */
151 down_read(&pci_bus_sem);
152 found = pcie_pme_walk_bus(port->subordinate);
153 up_read(&pci_bus_sem);
154 }
155 goto out;
156 }
157
158 /* Second, find the bus the source device is on. */
159 bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
160 if (!bus)
161 goto out;
162
163 /* Next, check if the PME is from a PCIe-PCI bridge. */
164 found = pcie_pme_from_pci_bridge(bus, devfn);
165 if (found)
166 goto out;
167
168 /* Finally, try to find the PME source on the bus. */
169 down_read(&pci_bus_sem);
170 list_for_each_entry(dev, &bus->devices, bus_list) {
171 pci_dev_get(dev);
172 if (dev->devfn == devfn) {
173 found = true;
174 break;
175 }
176 pci_dev_put(dev);
177 }
178 up_read(&pci_bus_sem);
179
180 if (found) {
181 /* The device is there, but we have to check its PME status. */
182 found = pci_check_pme_status(dev);
183 if (found) {
184 if (dev->pme_poll)
185 dev->pme_poll = false;
186
187 pci_wakeup_event(dev);
188 pm_request_resume(&dev->dev);
189 }
190 pci_dev_put(dev);
191 } else if (devfn) {
192 /*
193 * The device is not there, but we can still try to recover by
194 * assuming that the PME was reported by a PCIe-PCI bridge that
195 * used devfn different from zero.
196 */
197 pci_dbg(port, "PME interrupt generated for non-existent device %02x:%02x.%d\n",
198 busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
199 found = pcie_pme_from_pci_bridge(bus, 0);
200 }
201
202 out:
203 if (!found)
204 pci_dbg(port, "Spurious native PME interrupt!\n");
205}
206
207/**
208 * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
209 * @work: Work structure giving access to service data.
210 */
211static void pcie_pme_work_fn(struct work_struct *work)
212{
213 struct pcie_pme_service_data *data =
214 container_of(work, struct pcie_pme_service_data, work);
215 struct pci_dev *port = data->srv->port;
216 u32 rtsta;
217
218 spin_lock_irq(&data->lock);
219
220 for (;;) {
221 if (data->noirq)
222 break;
223
224 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
225 if (rtsta == (u32) ~0)
226 break;
227
228 if (rtsta & PCI_EXP_RTSTA_PME) {
229 /*
230 * Clear PME status of the port. If there are other
231 * pending PMEs, the status will be set again.
232 */
233 pcie_clear_root_pme_status(port);
234
235 spin_unlock_irq(&data->lock);
236 pcie_pme_handle_request(port, rtsta & 0xffff);
237 spin_lock_irq(&data->lock);
238
239 continue;
240 }
241
242 /* No need to loop if there are no more PMEs pending. */
243 if (!(rtsta & PCI_EXP_RTSTA_PENDING))
244 break;
245
246 spin_unlock_irq(&data->lock);
247 cpu_relax();
248 spin_lock_irq(&data->lock);
249 }
250
251 if (!data->noirq)
252 pcie_pme_interrupt_enable(port, true);
253
254 spin_unlock_irq(&data->lock);
255}
256
257/**
258 * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
259 * @irq: Interrupt vector.
260 * @context: Interrupt context pointer.
261 */
262static irqreturn_t pcie_pme_irq(int irq, void *context)
263{
264 struct pci_dev *port;
265 struct pcie_pme_service_data *data;
266 u32 rtsta;
267 unsigned long flags;
268
269 port = ((struct pcie_device *)context)->port;
270 data = get_service_data((struct pcie_device *)context);
271
272 spin_lock_irqsave(&data->lock, flags);
273 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
274
275 if (rtsta == (u32) ~0 || !(rtsta & PCI_EXP_RTSTA_PME)) {
276 spin_unlock_irqrestore(&data->lock, flags);
277 return IRQ_NONE;
278 }
279
280 pcie_pme_interrupt_enable(port, false);
281 spin_unlock_irqrestore(&data->lock, flags);
282
283 /* We don't use pm_wq, because it's freezable. */
284 schedule_work(&data->work);
285
286 return IRQ_HANDLED;
287}
288
289/**
290 * pcie_pme_can_wakeup - Set the wakeup capability flag.
291 * @dev: PCI device to handle.
292 * @ign: Ignored.
293 */
294static int pcie_pme_can_wakeup(struct pci_dev *dev, void *ign)
295{
296 device_set_wakeup_capable(&dev->dev, true);
297 return 0;
298}
299
300/**
301 * pcie_pme_mark_devices - Set the wakeup flag for devices below a port.
302 * @port: PCIe root port or event collector to handle.
303 *
304 * For each device below given root port, including the port itself (or for each
305 * root complex integrated endpoint if @port is a root complex event collector)
306 * set the flag indicating that it can signal run-time wake-up events.
307 */
308static void pcie_pme_mark_devices(struct pci_dev *port)
309{
310 pcie_pme_can_wakeup(port, NULL);
311 if (port->subordinate)
312 pci_walk_bus(port->subordinate, pcie_pme_can_wakeup, NULL);
313}
314
315/**
316 * pcie_pme_probe - Initialize PCIe PME service for given root port.
317 * @srv: PCIe service to initialize.
318 */
319static int pcie_pme_probe(struct pcie_device *srv)
320{
321 struct pci_dev *port;
322 struct pcie_pme_service_data *data;
323 int ret;
324
325 data = kzalloc(sizeof(*data), GFP_KERNEL);
326 if (!data)
327 return -ENOMEM;
328
329 spin_lock_init(&data->lock);
330 INIT_WORK(&data->work, pcie_pme_work_fn);
331 data->srv = srv;
332 set_service_data(srv, data);
333
334 port = srv->port;
335 pcie_pme_interrupt_enable(port, false);
336 pcie_clear_root_pme_status(port);
337
338 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
339 if (ret) {
340 kfree(data);
341 return ret;
342 }
343
344 pci_info(port, "Signaling PME with IRQ %d\n", srv->irq);
345
346 pcie_pme_mark_devices(port);
347 pcie_pme_interrupt_enable(port, true);
348 return 0;
349}
350
351static bool pcie_pme_check_wakeup(struct pci_bus *bus)
352{
353 struct pci_dev *dev;
354
355 if (!bus)
356 return false;
357
358 list_for_each_entry(dev, &bus->devices, bus_list)
359 if (device_may_wakeup(&dev->dev)
360 || pcie_pme_check_wakeup(dev->subordinate))
361 return true;
362
363 return false;
364}
365
366/**
367 * pcie_pme_suspend - Suspend PCIe PME service device.
368 * @srv: PCIe service device to suspend.
369 */
370static int pcie_pme_suspend(struct pcie_device *srv)
371{
372 struct pcie_pme_service_data *data = get_service_data(srv);
373 struct pci_dev *port = srv->port;
374 bool wakeup;
375 int ret;
376
377 if (device_may_wakeup(&port->dev)) {
378 wakeup = true;
379 } else {
380 down_read(&pci_bus_sem);
381 wakeup = pcie_pme_check_wakeup(port->subordinate);
382 up_read(&pci_bus_sem);
383 }
384 if (wakeup) {
385 ret = enable_irq_wake(srv->irq);
386 if (!ret)
387 return 0;
388 }
389
390 spin_lock_irq(&data->lock);
391 pcie_pme_interrupt_enable(port, false);
392 pcie_clear_root_pme_status(port);
393 data->noirq = true;
394 spin_unlock_irq(&data->lock);
395
396 synchronize_irq(srv->irq);
397
398 return 0;
399}
400
401/**
402 * pcie_pme_resume - Resume PCIe PME service device.
403 * @srv - PCIe service device to resume.
404 */
405static int pcie_pme_resume(struct pcie_device *srv)
406{
407 struct pcie_pme_service_data *data = get_service_data(srv);
408
409 spin_lock_irq(&data->lock);
410 if (data->noirq) {
411 struct pci_dev *port = srv->port;
412
413 pcie_clear_root_pme_status(port);
414 pcie_pme_interrupt_enable(port, true);
415 data->noirq = false;
416 } else {
417 disable_irq_wake(srv->irq);
418 }
419 spin_unlock_irq(&data->lock);
420
421 return 0;
422}
423
424/**
425 * pcie_pme_remove - Prepare PCIe PME service device for removal.
426 * @srv - PCIe service device to remove.
427 */
428static void pcie_pme_remove(struct pcie_device *srv)
429{
430 pcie_pme_suspend(srv);
431 free_irq(srv->irq, srv);
432 kfree(get_service_data(srv));
433}
434
435static struct pcie_port_service_driver pcie_pme_driver = {
436 .name = "pcie_pme",
437 .port_type = PCI_EXP_TYPE_ROOT_PORT,
438 .service = PCIE_PORT_SERVICE_PME,
439
440 .probe = pcie_pme_probe,
441 .suspend = pcie_pme_suspend,
442 .resume = pcie_pme_resume,
443 .remove = pcie_pme_remove,
444};
445
446/**
447 * pcie_pme_service_init - Register the PCIe PME service driver.
448 */
449static int __init pcie_pme_service_init(void)
450{
451 return pcie_port_service_register(&pcie_pme_driver);
452}
453device_initcall(pcie_pme_service_init);