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1/*
2 * PCIe Native PME support
3 *
4 * Copyright (C) 2007 - 2009 Intel Corp
5 * Copyright (C) 2007 - 2009 Shaohua Li <shaohua.li@intel.com>
6 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License V2. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13#include <linux/module.h>
14#include <linux/pci.h>
15#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19#include <linux/interrupt.h>
20#include <linux/device.h>
21#include <linux/pcieport_if.h>
22#include <linux/pm_runtime.h>
23
24#include "../pci.h"
25#include "portdrv.h"
26
27/*
28 * If this switch is set, MSI will not be used for PCIe PME signaling. This
29 * causes the PCIe port driver to use INTx interrupts only, but it turns out
30 * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based
31 * wake-up from system sleep states.
32 */
33bool pcie_pme_msi_disabled;
34
35static int __init pcie_pme_setup(char *str)
36{
37 if (!strncmp(str, "nomsi", 5))
38 pcie_pme_msi_disabled = true;
39
40 return 1;
41}
42__setup("pcie_pme=", pcie_pme_setup);
43
44struct pcie_pme_service_data {
45 spinlock_t lock;
46 struct pcie_device *srv;
47 struct work_struct work;
48 bool noirq; /* Don't enable the PME interrupt used by this service. */
49};
50
51/**
52 * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
53 * @dev: PCIe root port or event collector.
54 * @enable: Enable or disable the interrupt.
55 */
56void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
57{
58 if (enable)
59 pcie_capability_set_word(dev, PCI_EXP_RTCTL,
60 PCI_EXP_RTCTL_PMEIE);
61 else
62 pcie_capability_clear_word(dev, PCI_EXP_RTCTL,
63 PCI_EXP_RTCTL_PMEIE);
64}
65
66/**
67 * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
68 * @bus: PCI bus to scan.
69 *
70 * Scan given PCI bus and all buses under it for devices asserting PME#.
71 */
72static bool pcie_pme_walk_bus(struct pci_bus *bus)
73{
74 struct pci_dev *dev;
75 bool ret = false;
76
77 list_for_each_entry(dev, &bus->devices, bus_list) {
78 /* Skip PCIe devices in case we started from a root port. */
79 if (!pci_is_pcie(dev) && pci_check_pme_status(dev)) {
80 if (dev->pme_poll)
81 dev->pme_poll = false;
82
83 pci_wakeup_event(dev);
84 pm_request_resume(&dev->dev);
85 ret = true;
86 }
87
88 if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
89 ret = true;
90 }
91
92 return ret;
93}
94
95/**
96 * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
97 * @bus: Secondary bus of the bridge.
98 * @devfn: Device/function number to check.
99 *
100 * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
101 * PCIe PME message. In such that case the bridge should use the Requester ID
102 * of device/function number 0 on its secondary bus.
103 */
104static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
105{
106 struct pci_dev *dev;
107 bool found = false;
108
109 if (devfn)
110 return false;
111
112 dev = pci_dev_get(bus->self);
113 if (!dev)
114 return false;
115
116 if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE) {
117 down_read(&pci_bus_sem);
118 if (pcie_pme_walk_bus(bus))
119 found = true;
120 up_read(&pci_bus_sem);
121 }
122
123 pci_dev_put(dev);
124 return found;
125}
126
127/**
128 * pcie_pme_handle_request - Find device that generated PME and handle it.
129 * @port: Root port or event collector that generated the PME interrupt.
130 * @req_id: PCIe Requester ID of the device that generated the PME.
131 */
132static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
133{
134 u8 busnr = req_id >> 8, devfn = req_id & 0xff;
135 struct pci_bus *bus;
136 struct pci_dev *dev;
137 bool found = false;
138
139 /* First, check if the PME is from the root port itself. */
140 if (port->devfn == devfn && port->bus->number == busnr) {
141 if (port->pme_poll)
142 port->pme_poll = false;
143
144 if (pci_check_pme_status(port)) {
145 pm_request_resume(&port->dev);
146 found = true;
147 } else {
148 /*
149 * Apparently, the root port generated the PME on behalf
150 * of a non-PCIe device downstream. If this is done by
151 * a root port, the Requester ID field in its status
152 * register may contain either the root port's, or the
153 * source device's information (PCI Express Base
154 * Specification, Rev. 2.0, Section 6.1.9).
155 */
156 down_read(&pci_bus_sem);
157 found = pcie_pme_walk_bus(port->subordinate);
158 up_read(&pci_bus_sem);
159 }
160 goto out;
161 }
162
163 /* Second, find the bus the source device is on. */
164 bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
165 if (!bus)
166 goto out;
167
168 /* Next, check if the PME is from a PCIe-PCI bridge. */
169 found = pcie_pme_from_pci_bridge(bus, devfn);
170 if (found)
171 goto out;
172
173 /* Finally, try to find the PME source on the bus. */
174 down_read(&pci_bus_sem);
175 list_for_each_entry(dev, &bus->devices, bus_list) {
176 pci_dev_get(dev);
177 if (dev->devfn == devfn) {
178 found = true;
179 break;
180 }
181 pci_dev_put(dev);
182 }
183 up_read(&pci_bus_sem);
184
185 if (found) {
186 /* The device is there, but we have to check its PME status. */
187 found = pci_check_pme_status(dev);
188 if (found) {
189 if (dev->pme_poll)
190 dev->pme_poll = false;
191
192 pci_wakeup_event(dev);
193 pm_request_resume(&dev->dev);
194 }
195 pci_dev_put(dev);
196 } else if (devfn) {
197 /*
198 * The device is not there, but we can still try to recover by
199 * assuming that the PME was reported by a PCIe-PCI bridge that
200 * used devfn different from zero.
201 */
202 dev_dbg(&port->dev, "PME interrupt generated for "
203 "non-existent device %02x:%02x.%d\n",
204 busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
205 found = pcie_pme_from_pci_bridge(bus, 0);
206 }
207
208 out:
209 if (!found)
210 dev_dbg(&port->dev, "Spurious native PME interrupt!\n");
211}
212
213/**
214 * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
215 * @work: Work structure giving access to service data.
216 */
217static void pcie_pme_work_fn(struct work_struct *work)
218{
219 struct pcie_pme_service_data *data =
220 container_of(work, struct pcie_pme_service_data, work);
221 struct pci_dev *port = data->srv->port;
222 u32 rtsta;
223
224 spin_lock_irq(&data->lock);
225
226 for (;;) {
227 if (data->noirq)
228 break;
229
230 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
231 if (rtsta & PCI_EXP_RTSTA_PME) {
232 /*
233 * Clear PME status of the port. If there are other
234 * pending PMEs, the status will be set again.
235 */
236 pcie_clear_root_pme_status(port);
237
238 spin_unlock_irq(&data->lock);
239 pcie_pme_handle_request(port, rtsta & 0xffff);
240 spin_lock_irq(&data->lock);
241
242 continue;
243 }
244
245 /* No need to loop if there are no more PMEs pending. */
246 if (!(rtsta & PCI_EXP_RTSTA_PENDING))
247 break;
248
249 spin_unlock_irq(&data->lock);
250 cpu_relax();
251 spin_lock_irq(&data->lock);
252 }
253
254 if (!data->noirq)
255 pcie_pme_interrupt_enable(port, true);
256
257 spin_unlock_irq(&data->lock);
258}
259
260/**
261 * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
262 * @irq: Interrupt vector.
263 * @context: Interrupt context pointer.
264 */
265static irqreturn_t pcie_pme_irq(int irq, void *context)
266{
267 struct pci_dev *port;
268 struct pcie_pme_service_data *data;
269 u32 rtsta;
270 unsigned long flags;
271
272 port = ((struct pcie_device *)context)->port;
273 data = get_service_data((struct pcie_device *)context);
274
275 spin_lock_irqsave(&data->lock, flags);
276 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
277
278 if (!(rtsta & PCI_EXP_RTSTA_PME)) {
279 spin_unlock_irqrestore(&data->lock, flags);
280 return IRQ_NONE;
281 }
282
283 pcie_pme_interrupt_enable(port, false);
284 spin_unlock_irqrestore(&data->lock, flags);
285
286 /* We don't use pm_wq, because it's freezable. */
287 schedule_work(&data->work);
288
289 return IRQ_HANDLED;
290}
291
292/**
293 * pcie_pme_set_native - Set the PME interrupt flag for given device.
294 * @dev: PCI device to handle.
295 * @ign: Ignored.
296 */
297static int pcie_pme_set_native(struct pci_dev *dev, void *ign)
298{
299 dev_info(&dev->dev, "Signaling PME through PCIe PME interrupt\n");
300
301 device_set_run_wake(&dev->dev, true);
302 dev->pme_interrupt = true;
303 return 0;
304}
305
306/**
307 * pcie_pme_mark_devices - Set the PME interrupt flag for devices below a port.
308 * @port: PCIe root port or event collector to handle.
309 *
310 * For each device below given root port, including the port itself (or for each
311 * root complex integrated endpoint if @port is a root complex event collector)
312 * set the flag indicating that it can signal run-time wake-up events via PCIe
313 * PME interrupts.
314 */
315static void pcie_pme_mark_devices(struct pci_dev *port)
316{
317 pcie_pme_set_native(port, NULL);
318 if (port->subordinate) {
319 pci_walk_bus(port->subordinate, pcie_pme_set_native, NULL);
320 } else {
321 struct pci_bus *bus = port->bus;
322 struct pci_dev *dev;
323
324 /* Check if this is a root port event collector. */
325 if (pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC || !bus)
326 return;
327
328 down_read(&pci_bus_sem);
329 list_for_each_entry(dev, &bus->devices, bus_list)
330 if (pci_is_pcie(dev)
331 && pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
332 pcie_pme_set_native(dev, NULL);
333 up_read(&pci_bus_sem);
334 }
335}
336
337/**
338 * pcie_pme_probe - Initialize PCIe PME service for given root port.
339 * @srv: PCIe service to initialize.
340 */
341static int pcie_pme_probe(struct pcie_device *srv)
342{
343 struct pci_dev *port;
344 struct pcie_pme_service_data *data;
345 int ret;
346
347 data = kzalloc(sizeof(*data), GFP_KERNEL);
348 if (!data)
349 return -ENOMEM;
350
351 spin_lock_init(&data->lock);
352 INIT_WORK(&data->work, pcie_pme_work_fn);
353 data->srv = srv;
354 set_service_data(srv, data);
355
356 port = srv->port;
357 pcie_pme_interrupt_enable(port, false);
358 pcie_clear_root_pme_status(port);
359
360 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
361 if (ret) {
362 kfree(data);
363 } else {
364 pcie_pme_mark_devices(port);
365 pcie_pme_interrupt_enable(port, true);
366 }
367
368 return ret;
369}
370
371/**
372 * pcie_pme_suspend - Suspend PCIe PME service device.
373 * @srv: PCIe service device to suspend.
374 */
375static int pcie_pme_suspend(struct pcie_device *srv)
376{
377 struct pcie_pme_service_data *data = get_service_data(srv);
378 struct pci_dev *port = srv->port;
379
380 spin_lock_irq(&data->lock);
381 pcie_pme_interrupt_enable(port, false);
382 pcie_clear_root_pme_status(port);
383 data->noirq = true;
384 spin_unlock_irq(&data->lock);
385
386 synchronize_irq(srv->irq);
387
388 return 0;
389}
390
391/**
392 * pcie_pme_resume - Resume PCIe PME service device.
393 * @srv - PCIe service device to resume.
394 */
395static int pcie_pme_resume(struct pcie_device *srv)
396{
397 struct pcie_pme_service_data *data = get_service_data(srv);
398 struct pci_dev *port = srv->port;
399
400 spin_lock_irq(&data->lock);
401 data->noirq = false;
402 pcie_clear_root_pme_status(port);
403 pcie_pme_interrupt_enable(port, true);
404 spin_unlock_irq(&data->lock);
405
406 return 0;
407}
408
409/**
410 * pcie_pme_remove - Prepare PCIe PME service device for removal.
411 * @srv - PCIe service device to remove.
412 */
413static void pcie_pme_remove(struct pcie_device *srv)
414{
415 pcie_pme_suspend(srv);
416 free_irq(srv->irq, srv);
417 kfree(get_service_data(srv));
418}
419
420static struct pcie_port_service_driver pcie_pme_driver = {
421 .name = "pcie_pme",
422 .port_type = PCI_EXP_TYPE_ROOT_PORT,
423 .service = PCIE_PORT_SERVICE_PME,
424
425 .probe = pcie_pme_probe,
426 .suspend = pcie_pme_suspend,
427 .resume = pcie_pme_resume,
428 .remove = pcie_pme_remove,
429};
430
431/**
432 * pcie_pme_service_init - Register the PCIe PME service driver.
433 */
434static int __init pcie_pme_service_init(void)
435{
436 return pcie_port_service_register(&pcie_pme_driver);
437}
438
439module_init(pcie_pme_service_init);
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}