summaryrefslogtreecommitdiff
path: root/drivers/pci/pci-acpi.c
blob: dee5dddaa292a04ad2200c005ad59b959ed5ad7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
/*
 * File:	pci-acpi.c
 * Purpose:	Provide PCI support in ACPI
 *
 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
 * Copyright (C) 2004 Intel Corp.
 */

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/pci-aspm.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>

#include <linux/pci-acpi.h>
#include <linux/pm_runtime.h>
#include <linux/pm_qos.h>
#include "pci.h"

/**
 * pci_acpi_wake_bus - Wake-up notification handler for root buses.
 * @handle: ACPI handle of a device the notification is for.
 * @event: Type of the signaled event.
 * @context: PCI root bus to wake up devices on.
 */
static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
{
	struct pci_bus *pci_bus = context;

	if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
		pci_pme_wakeup_bus(pci_bus);
}

/**
 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
 * @handle: ACPI handle of a device the notification is for.
 * @event: Type of the signaled event.
 * @context: PCI device object to wake up.
 */
static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
{
	struct pci_dev *pci_dev = context;

	if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
		return;

	if (pci_dev->current_state == PCI_D3cold) {
		pci_wakeup_event(pci_dev);
		pm_runtime_resume(&pci_dev->dev);
		return;
	}

	if (!pci_dev->pm_cap || !pci_dev->pme_support
	     || pci_check_pme_status(pci_dev)) {
		if (pci_dev->pme_poll)
			pci_dev->pme_poll = false;

		pci_wakeup_event(pci_dev);
		pm_runtime_resume(&pci_dev->dev);
	}

	if (pci_dev->subordinate)
		pci_pme_wakeup_bus(pci_dev->subordinate);
}

/**
 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 * @dev: ACPI device to add the notifier for.
 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 */
acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
					 struct pci_bus *pci_bus)
{
	return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
}

/**
 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 * @dev: ACPI device to remove the notifier from.
 */
acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
{
	return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus);
}

/**
 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 * @dev: ACPI device to add the notifier for.
 * @pci_dev: PCI device to check for the PME status if an event is signaled.
 */
acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
				     struct pci_dev *pci_dev)
{
	return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
}

/**
 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 * @dev: ACPI device to remove the notifier from.
 */
acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
{
	return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev);
}

phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
{
	acpi_status status = AE_NOT_EXIST;
	unsigned long long mcfg_addr;

	if (handle)
		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
					       NULL, &mcfg_addr);
	if (ACPI_FAILURE(status))
		return 0;

	return (phys_addr_t)mcfg_addr;
}

/*
 * _SxD returns the D-state with the highest power
 * (lowest D-state number) supported in the S-state "x".
 *
 * If the devices does not have a _PRW
 * (Power Resources for Wake) supporting system wakeup from "x"
 * then the OS is free to choose a lower power (higher number
 * D-state) than the return value from _SxD.
 *
 * But if _PRW is enabled at S-state "x", the OS
 * must not choose a power lower than _SxD --
 * unless the device has an _SxW method specifying
 * the lowest power (highest D-state number) the device
 * may enter while still able to wake the system.
 *
 * ie. depending on global OS policy:
 *
 * if (_PRW at S-state x)
 *	choose from highest power _SxD to lowest power _SxW
 * else // no _PRW at S-state x
 * 	choose highest power _SxD or any lower power
 */

static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
{
	int acpi_state, d_max;

	if (pdev->no_d3cold)
		d_max = ACPI_STATE_D3_HOT;
	else
		d_max = ACPI_STATE_D3_COLD;
	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
	if (acpi_state < 0)
		return PCI_POWER_ERROR;

	switch (acpi_state) {
	case ACPI_STATE_D0:
		return PCI_D0;
	case ACPI_STATE_D1:
		return PCI_D1;
	case ACPI_STATE_D2:
		return PCI_D2;
	case ACPI_STATE_D3_HOT:
		return PCI_D3hot;
	case ACPI_STATE_D3_COLD:
		return PCI_D3cold;
	}
	return PCI_POWER_ERROR;
}

static bool acpi_pci_power_manageable(struct pci_dev *dev)
{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

	return handle ? acpi_bus_power_manageable(handle) : false;
}

static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
	acpi_handle tmp;
	static const u8 state_conv[] = {
		[PCI_D0] = ACPI_STATE_D0,
		[PCI_D1] = ACPI_STATE_D1,
		[PCI_D2] = ACPI_STATE_D2,
		[PCI_D3hot] = ACPI_STATE_D3,
		[PCI_D3cold] = ACPI_STATE_D3
	};
	int error = -EINVAL;

	/* If the ACPI device has _EJ0, ignore the device */
	if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
		return -ENODEV;

	switch (state) {
	case PCI_D3cold:
		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
				PM_QOS_FLAGS_ALL) {
			error = -EBUSY;
			break;
		}
	case PCI_D0:
	case PCI_D1:
	case PCI_D2:
	case PCI_D3hot:
		error = acpi_bus_set_power(handle, state_conv[state]);
	}

	if (!error)
		dev_info(&dev->dev, "power state changed by ACPI to %s\n",
			 pci_power_name(state));

	return error;
}

static bool acpi_pci_can_wakeup(struct pci_dev *dev)
{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

	return handle ? acpi_bus_can_wakeup(handle) : false;
}

static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
{
	while (bus->parent) {
		if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
			return;
		bus = bus->parent;
	}

	/* We have reached the root bus. */
	if (bus->bridge)
		acpi_pm_device_sleep_wake(bus->bridge, enable);
}

static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
{
	if (acpi_pci_can_wakeup(dev))
		return acpi_pm_device_sleep_wake(&dev->dev, enable);

	acpi_pci_propagate_wakeup_enable(dev->bus, enable);
	return 0;
}

static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
{
	while (bus->parent) {
		struct pci_dev *bridge = bus->self;

		if (bridge->pme_interrupt)
			return;
		if (!acpi_pm_device_run_wake(&bridge->dev, enable))
			return;
		bus = bus->parent;
	}

	/* We have reached the root bus. */
	if (bus->bridge)
		acpi_pm_device_run_wake(bus->bridge, enable);
}

static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
{
	/*
	 * Per PCI Express Base Specification Revision 2.0 section
	 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
	 * waking up to power on the main link even if there is PME
	 * support for D3cold
	 */
	if (dev->pme_interrupt && !dev->runtime_d3cold)
		return 0;

	if (!acpi_pm_device_run_wake(&dev->dev, enable))
		return 0;

	acpi_pci_propagate_run_wake(dev->bus, enable);
	return 0;
}

static struct pci_platform_pm_ops acpi_pci_platform_pm = {
	.is_manageable = acpi_pci_power_manageable,
	.set_state = acpi_pci_set_power_state,
	.choose_state = acpi_pci_choose_state,
	.sleep_wake = acpi_pci_sleep_wake,
	.run_wake = acpi_pci_run_wake,
};

/* ACPI bus type */
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
{
	struct pci_dev * pci_dev;
	u64	addr;

	pci_dev = to_pci_dev(dev);
	/* Please ref to ACPI spec for the syntax of _ADR */
	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
	if (!*handle)
		return -ENODEV;
	return 0;
}

static void pci_acpi_setup(struct device *dev)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	acpi_handle handle = ACPI_HANDLE(dev);
	struct acpi_device *adev;

	if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
		return;

	device_set_wakeup_capable(dev, true);
	acpi_pci_sleep_wake(pci_dev, false);

	pci_acpi_add_pm_notifier(adev, pci_dev);
	if (adev->wakeup.flags.run_wake)
		device_set_run_wake(dev, true);
}

static void pci_acpi_cleanup(struct device *dev)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	struct acpi_device *adev;

	if (!acpi_bus_get_device(handle, &adev) && adev->wakeup.flags.valid) {
		device_set_wakeup_capable(dev, false);
		device_set_run_wake(dev, false);
		pci_acpi_remove_pm_notifier(adev);
	}
}

static bool pci_acpi_bus_match(struct device *dev)
{
	return dev->bus == &pci_bus_type;
}

static struct acpi_bus_type acpi_pci_bus = {
	.name = "PCI",
	.match = pci_acpi_bus_match,
	.find_device = acpi_pci_find_device,
	.setup = pci_acpi_setup,
	.cleanup = pci_acpi_cleanup,
};

static int __init acpi_pci_init(void)
{
	int ret;

	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
		printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
		pci_no_msi();
	}

	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
		printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
		pcie_no_aspm();
	}

	ret = register_acpi_bus_type(&acpi_pci_bus);
	if (ret)
		return 0;
	pci_set_platform_pm(&acpi_pci_platform_pm);
	return 0;
}
arch_initcall(acpi_pci_init);