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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
44enum pme_suspend_level {
45 PME_SUSPEND_NONE = 0,
46 PME_SUSPEND_WAKEUP,
47 PME_SUSPEND_NOIRQ,
48};
49
50struct pcie_pme_service_data {
51 spinlock_t lock;
52 struct pcie_device *srv;
53 struct work_struct work;
54 enum pme_suspend_level suspend_level;
55};
56
57/**
58 * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
59 * @dev: PCIe root port or event collector.
60 * @enable: Enable or disable the interrupt.
61 */
62void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
63{
64 if (enable)
65 pcie_capability_set_word(dev, PCI_EXP_RTCTL,
66 PCI_EXP_RTCTL_PMEIE);
67 else
68 pcie_capability_clear_word(dev, PCI_EXP_RTCTL,
69 PCI_EXP_RTCTL_PMEIE);
70}
71
72/**
73 * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
74 * @bus: PCI bus to scan.
75 *
76 * Scan given PCI bus and all buses under it for devices asserting PME#.
77 */
78static bool pcie_pme_walk_bus(struct pci_bus *bus)
79{
80 struct pci_dev *dev;
81 bool ret = false;
82
83 list_for_each_entry(dev, &bus->devices, bus_list) {
84 /* Skip PCIe devices in case we started from a root port. */
85 if (!pci_is_pcie(dev) && pci_check_pme_status(dev)) {
86 if (dev->pme_poll)
87 dev->pme_poll = false;
88
89 pci_wakeup_event(dev);
90 pm_request_resume(&dev->dev);
91 ret = true;
92 }
93
94 if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))
95 ret = true;
96 }
97
98 return ret;
99}
100
101/**
102 * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
103 * @bus: Secondary bus of the bridge.
104 * @devfn: Device/function number to check.
105 *
106 * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
107 * PCIe PME message. In such that case the bridge should use the Requester ID
108 * of device/function number 0 on its secondary bus.
109 */
110static bool pcie_pme_from_pci_bridge(struct pci_bus *bus, u8 devfn)
111{
112 struct pci_dev *dev;
113 bool found = false;
114
115 if (devfn)
116 return false;
117
118 dev = pci_dev_get(bus->self);
119 if (!dev)
120 return false;
121
122 if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE) {
123 down_read(&pci_bus_sem);
124 if (pcie_pme_walk_bus(bus))
125 found = true;
126 up_read(&pci_bus_sem);
127 }
128
129 pci_dev_put(dev);
130 return found;
131}
132
133/**
134 * pcie_pme_handle_request - Find device that generated PME and handle it.
135 * @port: Root port or event collector that generated the PME interrupt.
136 * @req_id: PCIe Requester ID of the device that generated the PME.
137 */
138static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)
139{
140 u8 busnr = req_id >> 8, devfn = req_id & 0xff;
141 struct pci_bus *bus;
142 struct pci_dev *dev;
143 bool found = false;
144
145 /* First, check if the PME is from the root port itself. */
146 if (port->devfn == devfn && port->bus->number == busnr) {
147 if (port->pme_poll)
148 port->pme_poll = false;
149
150 if (pci_check_pme_status(port)) {
151 pm_request_resume(&port->dev);
152 found = true;
153 } else {
154 /*
155 * Apparently, the root port generated the PME on behalf
156 * of a non-PCIe device downstream. If this is done by
157 * a root port, the Requester ID field in its status
158 * register may contain either the root port's, or the
159 * source device's information (PCI Express Base
160 * Specification, Rev. 2.0, Section 6.1.9).
161 */
162 down_read(&pci_bus_sem);
163 found = pcie_pme_walk_bus(port->subordinate);
164 up_read(&pci_bus_sem);
165 }
166 goto out;
167 }
168
169 /* Second, find the bus the source device is on. */
170 bus = pci_find_bus(pci_domain_nr(port->bus), busnr);
171 if (!bus)
172 goto out;
173
174 /* Next, check if the PME is from a PCIe-PCI bridge. */
175 found = pcie_pme_from_pci_bridge(bus, devfn);
176 if (found)
177 goto out;
178
179 /* Finally, try to find the PME source on the bus. */
180 down_read(&pci_bus_sem);
181 list_for_each_entry(dev, &bus->devices, bus_list) {
182 pci_dev_get(dev);
183 if (dev->devfn == devfn) {
184 found = true;
185 break;
186 }
187 pci_dev_put(dev);
188 }
189 up_read(&pci_bus_sem);
190
191 if (found) {
192 /* The device is there, but we have to check its PME status. */
193 found = pci_check_pme_status(dev);
194 if (found) {
195 if (dev->pme_poll)
196 dev->pme_poll = false;
197
198 pci_wakeup_event(dev);
199 pm_request_resume(&dev->dev);
200 }
201 pci_dev_put(dev);
202 } else if (devfn) {
203 /*
204 * The device is not there, but we can still try to recover by
205 * assuming that the PME was reported by a PCIe-PCI bridge that
206 * used devfn different from zero.
207 */
208 dev_dbg(&port->dev, "PME interrupt generated for non-existent device %02x:%02x.%d\n",
209 busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
210 found = pcie_pme_from_pci_bridge(bus, 0);
211 }
212
213 out:
214 if (!found)
215 dev_dbg(&port->dev, "Spurious native PME interrupt!\n");
216}
217
218/**
219 * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
220 * @work: Work structure giving access to service data.
221 */
222static void pcie_pme_work_fn(struct work_struct *work)
223{
224 struct pcie_pme_service_data *data =
225 container_of(work, struct pcie_pme_service_data, work);
226 struct pci_dev *port = data->srv->port;
227 u32 rtsta;
228
229 spin_lock_irq(&data->lock);
230
231 for (;;) {
232 if (data->suspend_level != PME_SUSPEND_NONE)
233 break;
234
235 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
236 if (rtsta & PCI_EXP_RTSTA_PME) {
237 /*
238 * Clear PME status of the port. If there are other
239 * pending PMEs, the status will be set again.
240 */
241 pcie_clear_root_pme_status(port);
242
243 spin_unlock_irq(&data->lock);
244 pcie_pme_handle_request(port, rtsta & 0xffff);
245 spin_lock_irq(&data->lock);
246
247 continue;
248 }
249
250 /* No need to loop if there are no more PMEs pending. */
251 if (!(rtsta & PCI_EXP_RTSTA_PENDING))
252 break;
253
254 spin_unlock_irq(&data->lock);
255 cpu_relax();
256 spin_lock_irq(&data->lock);
257 }
258
259 if (data->suspend_level == PME_SUSPEND_NONE)
260 pcie_pme_interrupt_enable(port, true);
261
262 spin_unlock_irq(&data->lock);
263}
264
265/**
266 * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
267 * @irq: Interrupt vector.
268 * @context: Interrupt context pointer.
269 */
270static irqreturn_t pcie_pme_irq(int irq, void *context)
271{
272 struct pci_dev *port;
273 struct pcie_pme_service_data *data;
274 u32 rtsta;
275 unsigned long flags;
276
277 port = ((struct pcie_device *)context)->port;
278 data = get_service_data((struct pcie_device *)context);
279
280 spin_lock_irqsave(&data->lock, flags);
281 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
282
283 if (!(rtsta & PCI_EXP_RTSTA_PME)) {
284 spin_unlock_irqrestore(&data->lock, flags);
285 return IRQ_NONE;
286 }
287
288 pcie_pme_interrupt_enable(port, false);
289 spin_unlock_irqrestore(&data->lock, flags);
290
291 /* We don't use pm_wq, because it's freezable. */
292 schedule_work(&data->work);
293
294 return IRQ_HANDLED;
295}
296
297/**
298 * pcie_pme_set_native - Set the PME interrupt flag for given device.
299 * @dev: PCI device to handle.
300 * @ign: Ignored.
301 */
302static int pcie_pme_set_native(struct pci_dev *dev, void *ign)
303{
304 dev_info(&dev->dev, "Signaling PME through PCIe PME interrupt\n");
305
306 device_set_run_wake(&dev->dev, true);
307 dev->pme_interrupt = true;
308 return 0;
309}
310
311/**
312 * pcie_pme_mark_devices - Set the PME interrupt flag for devices below a port.
313 * @port: PCIe root port or event collector to handle.
314 *
315 * For each device below given root port, including the port itself (or for each
316 * root complex integrated endpoint if @port is a root complex event collector)
317 * set the flag indicating that it can signal run-time wake-up events via PCIe
318 * PME interrupts.
319 */
320static void pcie_pme_mark_devices(struct pci_dev *port)
321{
322 pcie_pme_set_native(port, NULL);
323 if (port->subordinate) {
324 pci_walk_bus(port->subordinate, pcie_pme_set_native, NULL);
325 } else {
326 struct pci_bus *bus = port->bus;
327 struct pci_dev *dev;
328
329 /* Check if this is a root port event collector. */
330 if (pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC || !bus)
331 return;
332
333 down_read(&pci_bus_sem);
334 list_for_each_entry(dev, &bus->devices, bus_list)
335 if (pci_is_pcie(dev)
336 && pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)
337 pcie_pme_set_native(dev, NULL);
338 up_read(&pci_bus_sem);
339 }
340}
341
342/**
343 * pcie_pme_probe - Initialize PCIe PME service for given root port.
344 * @srv: PCIe service to initialize.
345 */
346static int pcie_pme_probe(struct pcie_device *srv)
347{
348 struct pci_dev *port;
349 struct pcie_pme_service_data *data;
350 int ret;
351
352 data = kzalloc(sizeof(*data), GFP_KERNEL);
353 if (!data)
354 return -ENOMEM;
355
356 spin_lock_init(&data->lock);
357 INIT_WORK(&data->work, pcie_pme_work_fn);
358 data->srv = srv;
359 set_service_data(srv, data);
360
361 port = srv->port;
362 pcie_pme_interrupt_enable(port, false);
363 pcie_clear_root_pme_status(port);
364
365 ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
366 if (ret) {
367 kfree(data);
368 } else {
369 pcie_pme_mark_devices(port);
370 pcie_pme_interrupt_enable(port, true);
371 }
372
373 return ret;
374}
375
376static bool pcie_pme_check_wakeup(struct pci_bus *bus)
377{
378 struct pci_dev *dev;
379
380 if (!bus)
381 return false;
382
383 list_for_each_entry(dev, &bus->devices, bus_list)
384 if (device_may_wakeup(&dev->dev)
385 || pcie_pme_check_wakeup(dev->subordinate))
386 return true;
387
388 return false;
389}
390
391/**
392 * pcie_pme_suspend - Suspend PCIe PME service device.
393 * @srv: PCIe service device to suspend.
394 */
395static int pcie_pme_suspend(struct pcie_device *srv)
396{
397 struct pcie_pme_service_data *data = get_service_data(srv);
398 struct pci_dev *port = srv->port;
399 bool wakeup, wake_irq_enabled = false;
400 int ret;
401
402 if (device_may_wakeup(&port->dev)) {
403 wakeup = true;
404 } else {
405 down_read(&pci_bus_sem);
406 wakeup = pcie_pme_check_wakeup(port->subordinate);
407 up_read(&pci_bus_sem);
408 }
409 spin_lock_irq(&data->lock);
410 if (wakeup) {
411 ret = enable_irq_wake(srv->irq);
412 if (ret == 0) {
413 data->suspend_level = PME_SUSPEND_WAKEUP;
414 wake_irq_enabled = true;
415 }
416 }
417 if (!wake_irq_enabled) {
418 pcie_pme_interrupt_enable(port, false);
419 pcie_clear_root_pme_status(port);
420 data->suspend_level = PME_SUSPEND_NOIRQ;
421 }
422 spin_unlock_irq(&data->lock);
423
424 synchronize_irq(srv->irq);
425
426 return 0;
427}
428
429/**
430 * pcie_pme_resume - Resume PCIe PME service device.
431 * @srv - PCIe service device to resume.
432 */
433static int pcie_pme_resume(struct pcie_device *srv)
434{
435 struct pcie_pme_service_data *data = get_service_data(srv);
436
437 spin_lock_irq(&data->lock);
438 if (data->suspend_level == PME_SUSPEND_NOIRQ) {
439 struct pci_dev *port = srv->port;
440
441 pcie_clear_root_pme_status(port);
442 pcie_pme_interrupt_enable(port, true);
443 } else {
444 disable_irq_wake(srv->irq);
445 }
446 data->suspend_level = PME_SUSPEND_NONE;
447 spin_unlock_irq(&data->lock);
448
449 return 0;
450}
451
452/**
453 * pcie_pme_remove - Prepare PCIe PME service device for removal.
454 * @srv - PCIe service device to remove.
455 */
456static void pcie_pme_remove(struct pcie_device *srv)
457{
458 pcie_pme_suspend(srv);
459 free_irq(srv->irq, srv);
460 kfree(get_service_data(srv));
461}
462
463static struct pcie_port_service_driver pcie_pme_driver = {
464 .name = "pcie_pme",
465 .port_type = PCI_EXP_TYPE_ROOT_PORT,
466 .service = PCIE_PORT_SERVICE_PME,
467
468 .probe = pcie_pme_probe,
469 .suspend = pcie_pme_suspend,
470 .resume = pcie_pme_resume,
471 .remove = pcie_pme_remove,
472};
473
474/**
475 * pcie_pme_service_init - Register the PCIe PME service driver.
476 */
477static int __init pcie_pme_service_init(void)
478{
479 return pcie_port_service_register(&pcie_pme_driver);
480}
481
482module_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}