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