summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/pseries/suspend.c
blob: 81e0ac58d62047a18fdf4ec60f1af0cb5347eb66 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
  * Copyright (C) 2010 Brian King IBM Corporation
  */

#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/suspend.h>
#include <linux/stat.h>
#include <asm/firmware.h>
#include <asm/hvcall.h>
#include <asm/machdep.h>
#include <asm/mmu.h>
#include <asm/rtas.h>
#include <asm/topology.h>
#include "../../kernel/cacheinfo.h"

static u64 stream_id;
static struct device suspend_dev;
static DECLARE_COMPLETION(suspend_work);
static struct rtas_suspend_me_data suspend_data;
static atomic_t suspending;

/**
 * pseries_suspend_begin - First phase of hibernation
 *
 * Check to ensure we are in a valid state to hibernate
 *
 * Return value:
 * 	0 on success / other on failure
 **/
static int pseries_suspend_begin(suspend_state_t state)
{
	long vasi_state, rc;
	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];

	/* Make sure the state is valid */
	rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);

	vasi_state = retbuf[0];

	if (rc) {
		pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
		return rc;
	} else if (vasi_state == H_VASI_ENABLED) {
		return -EAGAIN;
	} else if (vasi_state != H_VASI_SUSPENDING) {
		pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
		       vasi_state);
		return -EIO;
	}

	return 0;
}

/**
 * pseries_suspend_cpu - Suspend a single CPU
 *
 * Makes the H_JOIN call to suspend the CPU
 *
 **/
static int pseries_suspend_cpu(void)
{
	if (atomic_read(&suspending))
		return rtas_suspend_cpu(&suspend_data);
	return 0;
}

/**
 * pseries_suspend_enable_irqs
 *
 * Post suspend configuration updates
 *
 **/
static void pseries_suspend_enable_irqs(void)
{
	/*
	 * Update configuration which can be modified based on device tree
	 * changes during resume.
	 */
	cacheinfo_cpu_offline(smp_processor_id());
	post_mobility_fixup();
	cacheinfo_cpu_online(smp_processor_id());
}

/**
 * pseries_suspend_enter - Final phase of hibernation
 *
 * Return value:
 * 	0 on success / other on failure
 **/
static int pseries_suspend_enter(suspend_state_t state)
{
	int rc = rtas_suspend_last_cpu(&suspend_data);

	atomic_set(&suspending, 0);
	atomic_set(&suspend_data.done, 1);
	return rc;
}

/**
 * pseries_prepare_late - Prepare to suspend all other CPUs
 *
 * Return value:
 * 	0 on success / other on failure
 **/
static int pseries_prepare_late(void)
{
	atomic_set(&suspending, 1);
	atomic_set(&suspend_data.working, 0);
	atomic_set(&suspend_data.done, 0);
	atomic_set(&suspend_data.error, 0);
	suspend_data.complete = &suspend_work;
	reinit_completion(&suspend_work);
	return 0;
}

/**
 * store_hibernate - Initiate partition hibernation
 * @dev:		subsys root device
 * @attr:		device attribute struct
 * @buf:		buffer
 * @count:		buffer size
 *
 * Write the stream ID received from the HMC to this file
 * to trigger hibernating the partition
 *
 * Return value:
 * 	number of bytes printed to buffer / other on failure
 **/
static ssize_t store_hibernate(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int rc;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	stream_id = simple_strtoul(buf, NULL, 16);

	do {
		rc = pseries_suspend_begin(PM_SUSPEND_MEM);
		if (rc == -EAGAIN)
			ssleep(1);
	} while (rc == -EAGAIN);

	if (!rc)
		rc = pm_suspend(PM_SUSPEND_MEM);

	stream_id = 0;

	if (!rc)
		rc = count;

	return rc;
}

#define USER_DT_UPDATE	0
#define KERN_DT_UPDATE	1

/**
 * show_hibernate - Report device tree update responsibilty
 * @dev:		subsys root device
 * @attr:		device attribute struct
 * @buf:		buffer
 *
 * Report whether a device tree update is performed by the kernel after a
 * resume, or if drmgr must coordinate the update from user space.
 *
 * Return value:
 *	0 if drmgr is to initiate update, and 1 otherwise
 **/
static ssize_t show_hibernate(struct device *dev,
			      struct device_attribute *attr,
			      char *buf)
{
	return sprintf(buf, "%d\n", KERN_DT_UPDATE);
}

static DEVICE_ATTR(hibernate, 0644, show_hibernate, store_hibernate);

static struct bus_type suspend_subsys = {
	.name = "power",
	.dev_name = "power",
};

static const struct platform_suspend_ops pseries_suspend_ops = {
	.valid		= suspend_valid_only_mem,
	.begin		= pseries_suspend_begin,
	.prepare_late	= pseries_prepare_late,
	.enter		= pseries_suspend_enter,
};

/**
 * pseries_suspend_sysfs_register - Register with sysfs
 *
 * Return value:
 * 	0 on success / other on failure
 **/
static int pseries_suspend_sysfs_register(struct device *dev)
{
	int rc;

	if ((rc = subsys_system_register(&suspend_subsys, NULL)))
		return rc;

	dev->id = 0;
	dev->bus = &suspend_subsys;

	if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
		goto subsys_unregister;

	return 0;

subsys_unregister:
	bus_unregister(&suspend_subsys);
	return rc;
}

/**
 * pseries_suspend_init - initcall for pSeries suspend
 *
 * Return value:
 * 	0 on success / other on failure
 **/
static int __init pseries_suspend_init(void)
{
	int rc;

	if (!firmware_has_feature(FW_FEATURE_LPAR))
		return 0;

	suspend_data.token = rtas_token("ibm,suspend-me");
	if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
		return 0;

	if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
		return rc;

	ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
	ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs;
	suspend_set_ops(&pseries_suspend_ops);
	return 0;
}
machine_device_initcall(pseries, pseries_suspend_init);