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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/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 if (dev->pme_poll)
88 dev->pme_poll = false;
89
90 pci_wakeup_event(dev);
91 pm_request_resume(&dev->dev);
92 ret = true;
93 }
94
95 if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
96 ret = true;
97 }
98
99 return ret;
100}
101
102/**
103 * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
104 * @bus: Secondary bus of the bridge.
105 * @devfn: Device/function number to check.
106 *
107 * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
108 * PCIe PME message. In such that case the bridge should use the Requester ID
109 * of device/function number 0 on its secondary bus.
110 */
111static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
112{
113 struct pci_dev *dev;
114 bool found = false;
115
116 if (devfn)
117 return false;
118
119 dev = pci_dev_get(bus->self);
120 if (!dev)
121 return false;
122
123 if (pci_is_pcie(dev) && dev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE) {
124 down_read(&pci_bus_sem);
125 if (pcie_pme_walk_bus(bus))
126 found = true;
127 up_read(&pci_bus_sem);
128 }
129
130 pci_dev_put(dev);
131 return found;
132}
133
134/**
135 * pcie_pme_handle_request - Find device that generated PME and handle it.
136 * @port: Root port or event collector that generated the PME interrupt.
137 * @req_id: PCIe Requester ID of the device that generated the PME.
138 */
139static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
140{
141 u8 busnr = req_id >> 8, devfn = req_id & 0xff;
142 struct pci_bus *bus;
143 struct pci_dev *dev;
144 bool found = false;
145
146 /* First, check if the PME is from the root port itself. */
147 if (port->devfn == devfn && port->bus->number == busnr) {
148 if (port->pme_poll)
149 port->pme_poll = false;
150
151 if (pci_check_pme_status(port)) {
152 pm_request_resume(&port->dev);
153 found = true;
154 } else {
155 /*
156 * Apparently, the root port generated the PME on behalf
157 * of a non-PCIe device downstream. If this is done by
158 * a root port, the Requester ID field in its status
159 * register may contain either the root port's, or the
160 * source device's information (PCI Express Base
161 * Specification, Rev. 2.0, Section 6.1.9).
162 */
163 down_read(&pci_bus_sem);
164 found = pcie_pme_walk_bus(port->subordinate);
165 up_read(&pci_bus_sem);
166 }
167 goto out;
168 }
169
170 /* Second, find the bus the source device is on. */
171 bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
172 if (!bus)
173 goto out;
174
175 /* Next, check if the PME is from a PCIe-PCI bridge. */
176 found = pcie_pme_from_pci_bridge(bus, devfn);
177 if (found)
178 goto out;
179
180 /* Finally, try to find the PME source on the bus. */
181 down_read(&pci_bus_sem);
182 list_for_each_entry(dev, &bus->devices, bus_list) {
183 pci_dev_get(dev);
184 if (dev->devfn == devfn) {
185 found = true;
186 break;
187 }
188 pci_dev_put(dev);
189 }
190 up_read(&pci_bus_sem);
191
192 if (found) {
193 /* The device is there, but we have to check its PME status. */
194 found = pci_check_pme_status(dev);
195 if (found) {
196 if (dev->pme_poll)
197 dev->pme_poll = false;
198
199 pci_wakeup_event(dev);
200 pm_request_resume(&dev->dev);
201 }
202 pci_dev_put(dev);
203 } else if (devfn) {
204 /*
205 * The device is not there, but we can still try to recover by
206 * assuming that the PME was reported by a PCIe-PCI bridge that
207 * used devfn different from zero.
208 */
209 dev_dbg(&port->dev, "PME interrupt generated for "
210 "non-existent device %02x:%02x.%d\n",
211 busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
212 found = pcie_pme_from_pci_bridge(bus, 0);
213 }
214
215 out:
216 if (!found)
217 dev_dbg(&port->dev, "Spurious native PME interrupt!\n");
218}
219
220/**
221 * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
222 * @work: Work structure giving access to service data.
223 */
224static void pcie_pme_work_fn(struct work_struct *work)
225{
226 struct pcie_pme_service_data *data =
227 container_of(work, struct pcie_pme_service_data, work);
228 struct pci_dev *port = data->srv->port;
229 int rtsta_pos;
230 u32 rtsta;
231
232 rtsta_pos = pci_pcie_cap(port) + PCI_EXP_RTSTA;
233
234 spin_lock_irq(&data->lock);
235
236 for (;;) {
237 if (data->noirq)
238 break;
239
240 pci_read_config_dword(port, rtsta_pos, &rtsta);
241 if (rtsta & PCI_EXP_RTSTA_PME) {
242 /*
243 * Clear PME status of the port. If there are other
244 * pending PMEs, the status will be set again.
245 */
246 pcie_clear_root_pme_status(port);
247
248 spin_unlock_irq(&data->lock);
249 pcie_pme_handle_request(port, rtsta & 0xffff);
250 spin_lock_irq(&data->lock);
251
252 continue;
253 }
254
255 /* No need to loop if there are no more PMEs pending. */
256 if (!(rtsta & PCI_EXP_RTSTA_PENDING))
257 break;
258
259 spin_unlock_irq(&data->lock);
260 cpu_relax();
261 spin_lock_irq(&data->lock);
262 }
263
264 if (!data->noirq)
265 pcie_pme_interrupt_enable(port, true);
266
267 spin_unlock_irq(&data->lock);
268}
269
270/**
271 * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
272 * @irq: Interrupt vector.
273 * @context: Interrupt context pointer.
274 */
275static irqreturn_t pcie_pme_irq(int irq, void *context)
276{
277 struct pci_dev *port;
278 struct pcie_pme_service_data *data;
279 int rtsta_pos;
280 u32 rtsta;
281 unsigned long flags;
282
283 port = ((struct pcie_device *)context)->port;
284 data = get_service_data((struct pcie_device *)context);
285
286 rtsta_pos = pci_pcie_cap(port) + PCI_EXP_RTSTA;
287
288 spin_lock_irqsave(&data->lock, flags);
289 pci_read_config_dword(port, rtsta_pos, &rtsta);
290
291 if (!(rtsta & PCI_EXP_RTSTA_PME)) {
292 spin_unlock_irqrestore(&data->lock, flags);
293 return IRQ_NONE;
294 }
295
296 pcie_pme_interrupt_enable(port, false);
297 spin_unlock_irqrestore(&data->lock, flags);
298
299 /* We don't use pm_wq, because it's freezable. */
300 schedule_work(&data->work);
301
302 return IRQ_HANDLED;
303}
304
305/**
306 * pcie_pme_set_native - Set the PME interrupt flag for given device.
307 * @dev: PCI device to handle.
308 * @ign: Ignored.
309 */
310static int pcie_pme_set_native(struct pci_dev *dev, void *ign)
311{
312 dev_info(&dev->dev, "Signaling PME through PCIe PME interrupt\n");
313
314 device_set_run_wake(&dev->dev, true);
315 dev->pme_interrupt = true;
316 return 0;
317}
318
319/**
320 * pcie_pme_mark_devices - Set the PME interrupt flag for devices below a port.
321 * @port: PCIe root port or event collector to handle.
322 *
323 * For each device below given root port, including the port itself (or for each
324 * root complex integrated endpoint if @port is a root complex event collector)
325 * set the flag indicating that it can signal run-time wake-up events via PCIe
326 * PME interrupts.
327 */
328static void pcie_pme_mark_devices(struct pci_dev *port)
329{
330 pcie_pme_set_native(port, NULL);
331 if (port->subordinate) {
332 pci_walk_bus(port->subordinate, pcie_pme_set_native, NULL);
333 } else {
334 struct pci_bus *bus = port->bus;
335 struct pci_dev *dev;
336
337 /* Check if this is a root port event collector. */
338 if (port->pcie_type != PCI_EXP_TYPE_RC_EC || !bus)
339 return;
340
341 down_read(&pci_bus_sem);
342 list_for_each_entry(dev, &bus->devices, bus_list)
343 if (pci_is_pcie(dev)
344 && dev->pcie_type == PCI_EXP_TYPE_RC_END)
345 pcie_pme_set_native(dev, NULL);
346 up_read(&pci_bus_sem);
347 }
348}
349
350/**
351 * pcie_pme_probe - Initialize PCIe PME service for given root port.
352 * @srv: PCIe service to initialize.
353 */
354static int pcie_pme_probe(struct pcie_device *srv)
355{
356 struct pci_dev *port;
357 struct pcie_pme_service_data *data;
358 int ret;
359
360 data = kzalloc(sizeof(*data), GFP_KERNEL);
361 if (!data)
362 return -ENOMEM;
363
364 spin_lock_init(&data->lock);
365 INIT_WORK(&data->work, pcie_pme_work_fn);
366 data->srv = srv;
367 set_service_data(srv, data);
368
369 port = srv->port;
370 pcie_pme_interrupt_enable(port, false);
371 pcie_clear_root_pme_status(port);
372
373 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
374 if (ret) {
375 kfree(data);
376 } else {
377 pcie_pme_mark_devices(port);
378 pcie_pme_interrupt_enable(port, true);
379 }
380
381 return ret;
382}
383
384/**
385 * pcie_pme_suspend - Suspend PCIe PME service device.
386 * @srv: PCIe service device to suspend.
387 */
388static int pcie_pme_suspend(struct pcie_device *srv)
389{
390 struct pcie_pme_service_data *data = get_service_data(srv);
391 struct pci_dev *port = srv->port;
392
393 spin_lock_irq(&data->lock);
394 pcie_pme_interrupt_enable(port, false);
395 pcie_clear_root_pme_status(port);
396 data->noirq = true;
397 spin_unlock_irq(&data->lock);
398
399 synchronize_irq(srv->irq);
400
401 return 0;
402}
403
404/**
405 * pcie_pme_resume - Resume PCIe PME service device.
406 * @srv - PCIe service device to resume.
407 */
408static int pcie_pme_resume(struct pcie_device *srv)
409{
410 struct pcie_pme_service_data *data = get_service_data(srv);
411 struct pci_dev *port = srv->port;
412
413 spin_lock_irq(&data->lock);
414 data->noirq = false;
415 pcie_clear_root_pme_status(port);
416 pcie_pme_interrupt_enable(port, true);
417 spin_unlock_irq(&data->lock);
418
419 return 0;
420}
421
422/**
423 * pcie_pme_remove - Prepare PCIe PME service device for removal.
424 * @srv - PCIe service device to resume.
425 */
426static void pcie_pme_remove(struct pcie_device *srv)
427{
428 pcie_pme_suspend(srv);
429 free_irq(srv->irq, srv);
430 kfree(get_service_data(srv));
431}
432
433static struct pcie_port_service_driver pcie_pme_driver = {
434 .name = "pcie_pme",
435 .port_type = PCI_EXP_TYPE_ROOT_PORT,
436 .service = PCIE_PORT_SERVICE_PME,
437
438 .probe = pcie_pme_probe,
439 .suspend = pcie_pme_suspend,
440 .resume = pcie_pme_resume,
441 .remove = pcie_pme_remove,
442};
443
444/**
445 * pcie_pme_service_init - Register the PCIe PME service driver.
446 */
447static int __init pcie_pme_service_init(void)
448{
449 return pcie_port_service_register(&pcie_pme_driver);
450}
451
452module_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 (PCI_POSSIBLE_ERROR(rtsta))
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 (PCI_POSSIBLE_ERROR(rtsta) || !(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
314 if (pci_pcie_type(port) == PCI_EXP_TYPE_RC_EC)
315 pcie_walk_rcec(port, pcie_pme_can_wakeup, NULL);
316 else if (port->subordinate)
317 pci_walk_bus(port->subordinate, pcie_pme_can_wakeup, NULL);
318}
319
320/**
321 * pcie_pme_probe - Initialize PCIe PME service for given root port.
322 * @srv: PCIe service to initialize.
323 */
324static int pcie_pme_probe(struct pcie_device *srv)
325{
326 struct pci_dev *port = srv->port;
327 struct pcie_pme_service_data *data;
328 int type = pci_pcie_type(port);
329 int ret;
330
331 /* Limit to Root Ports or Root Complex Event Collectors */
332 if (type != PCI_EXP_TYPE_RC_EC &&
333 type != PCI_EXP_TYPE_ROOT_PORT)
334 return -ENODEV;
335
336 data = kzalloc(sizeof(*data), GFP_KERNEL);
337 if (!data)
338 return -ENOMEM;
339
340 spin_lock_init(&data->lock);
341 INIT_WORK(&data->work, pcie_pme_work_fn);
342 data->srv = srv;
343 set_service_data(srv, data);
344
345 pcie_pme_interrupt_enable(port, false);
346 pcie_clear_root_pme_status(port);
347
348 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
349 if (ret) {
350 kfree(data);
351 return ret;
352 }
353
354 pci_info(port, "Signaling with IRQ %d\n", srv->irq);
355
356 pcie_pme_mark_devices(port);
357 pcie_pme_interrupt_enable(port, true);
358 return 0;
359}
360
361static bool pcie_pme_check_wakeup(struct pci_bus *bus)
362{
363 struct pci_dev *dev;
364
365 if (!bus)
366 return false;
367
368 list_for_each_entry(dev, &bus->devices, bus_list)
369 if (device_may_wakeup(&dev->dev)
370 || pcie_pme_check_wakeup(dev->subordinate))
371 return true;
372
373 return false;
374}
375
376static void pcie_pme_disable_interrupt(struct pci_dev *port,
377 struct pcie_pme_service_data *data)
378{
379 spin_lock_irq(&data->lock);
380 pcie_pme_interrupt_enable(port, false);
381 pcie_clear_root_pme_status(port);
382 data->noirq = true;
383 spin_unlock_irq(&data->lock);
384}
385
386/**
387 * pcie_pme_suspend - Suspend PCIe PME service device.
388 * @srv: PCIe service device to suspend.
389 */
390static int pcie_pme_suspend(struct pcie_device *srv)
391{
392 struct pcie_pme_service_data *data = get_service_data(srv);
393 struct pci_dev *port = srv->port;
394 bool wakeup;
395 int ret;
396
397 if (device_may_wakeup(&port->dev)) {
398 wakeup = true;
399 } else {
400 down_read(&pci_bus_sem);
401 wakeup = pcie_pme_check_wakeup(port->subordinate);
402 up_read(&pci_bus_sem);
403 }
404 if (wakeup) {
405 ret = enable_irq_wake(srv->irq);
406 if (!ret)
407 return 0;
408 }
409
410 pcie_pme_disable_interrupt(port, data);
411
412 synchronize_irq(srv->irq);
413
414 return 0;
415}
416
417/**
418 * pcie_pme_resume - Resume PCIe PME service device.
419 * @srv: PCIe service device to resume.
420 */
421static int pcie_pme_resume(struct pcie_device *srv)
422{
423 struct pcie_pme_service_data *data = get_service_data(srv);
424
425 spin_lock_irq(&data->lock);
426 if (data->noirq) {
427 struct pci_dev *port = srv->port;
428
429 pcie_clear_root_pme_status(port);
430 pcie_pme_interrupt_enable(port, true);
431 data->noirq = false;
432 } else {
433 disable_irq_wake(srv->irq);
434 }
435 spin_unlock_irq(&data->lock);
436
437 return 0;
438}
439
440/**
441 * pcie_pme_remove - Prepare PCIe PME service device for removal.
442 * @srv: PCIe service device to remove.
443 */
444static void pcie_pme_remove(struct pcie_device *srv)
445{
446 struct pcie_pme_service_data *data = get_service_data(srv);
447
448 pcie_pme_disable_interrupt(srv->port, data);
449 free_irq(srv->irq, srv);
450 cancel_work_sync(&data->work);
451 kfree(data);
452}
453
454static struct pcie_port_service_driver pcie_pme_driver = {
455 .name = "pcie_pme",
456 .port_type = PCIE_ANY_PORT,
457 .service = PCIE_PORT_SERVICE_PME,
458
459 .probe = pcie_pme_probe,
460 .suspend = pcie_pme_suspend,
461 .resume = pcie_pme_resume,
462 .remove = pcie_pme_remove,
463};
464
465/**
466 * pcie_pme_init - Register the PCIe PME service driver.
467 */
468int __init pcie_pme_init(void)
469{
470 return pcie_port_service_register(&pcie_pme_driver);
471}