1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2010 Brian King IBM Corporation
4 */
5
6#include <linux/cpu.h>
7#include <linux/delay.h>
8#include <linux/suspend.h>
9#include <linux/stat.h>
10#include <asm/firmware.h>
11#include <asm/hvcall.h>
12#include <asm/machdep.h>
13#include <asm/mmu.h>
14#include <asm/rtas.h>
15#include <asm/topology.h>
16#include "pseries.h"
17
18static struct device suspend_dev;
19
20/**
21 * pseries_suspend_begin - First phase of hibernation
22 *
23 * Check to ensure we are in a valid state to hibernate
24 *
25 * Return value:
26 * 0 on success / other on failure
27 **/
28static int pseries_suspend_begin(u64 stream_id)
29{
30 long vasi_state, rc;
31 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
32
33 /* Make sure the state is valid */
34 rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
35
36 vasi_state = retbuf[0];
37
38 if (rc) {
39 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
40 return rc;
41 } else if (vasi_state == H_VASI_ENABLED) {
42 return -EAGAIN;
43 } else if (vasi_state != H_VASI_SUSPENDING) {
44 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
45 vasi_state);
46 return -EIO;
47 }
48 return 0;
49}
50
51/**
52 * pseries_suspend_enter - Final phase of hibernation
53 *
54 * Return value:
55 * 0 on success / other on failure
56 **/
57static int pseries_suspend_enter(suspend_state_t state)
58{
59 return rtas_ibm_suspend_me(NULL);
60}
61
62/**
63 * store_hibernate - Initiate partition hibernation
64 * @dev: subsys root device
65 * @attr: device attribute struct
66 * @buf: buffer
67 * @count: buffer size
68 *
69 * Write the stream ID received from the HMC to this file
70 * to trigger hibernating the partition
71 *
72 * Return value:
73 * number of bytes printed to buffer / other on failure
74 **/
75static ssize_t store_hibernate(struct device *dev,
76 struct device_attribute *attr,
77 const char *buf, size_t count)
78{
79 u64 stream_id;
80 int rc;
81
82 if (!capable(CAP_SYS_ADMIN))
83 return -EPERM;
84
85 stream_id = simple_strtoul(buf, NULL, 16);
86
87 do {
88 rc = pseries_suspend_begin(stream_id);
89 if (rc == -EAGAIN)
90 ssleep(seconds: 1);
91 } while (rc == -EAGAIN);
92
93 if (!rc)
94 rc = pm_suspend(PM_SUSPEND_MEM);
95
96 if (!rc) {
97 rc = count;
98 post_mobility_fixup();
99 }
100
101
102 return rc;
103}
104
105#define USER_DT_UPDATE 0
106#define KERN_DT_UPDATE 1
107
108/**
109 * show_hibernate - Report device tree update responsibilty
110 * @dev: subsys root device
111 * @attr: device attribute struct
112 * @buf: buffer
113 *
114 * Report whether a device tree update is performed by the kernel after a
115 * resume, or if drmgr must coordinate the update from user space.
116 *
117 * Return value:
118 * 0 if drmgr is to initiate update, and 1 otherwise
119 **/
120static ssize_t show_hibernate(struct device *dev,
121 struct device_attribute *attr,
122 char *buf)
123{
124 return sprintf(buf, fmt: "%d\n", KERN_DT_UPDATE);
125}
126
127static DEVICE_ATTR(hibernate, 0644, show_hibernate, store_hibernate);
128
129static const struct bus_type suspend_subsys = {
130 .name = "power",
131 .dev_name = "power",
132};
133
134static const struct platform_suspend_ops pseries_suspend_ops = {
135 .valid = suspend_valid_only_mem,
136 .enter = pseries_suspend_enter,
137};
138
139/**
140 * pseries_suspend_sysfs_register - Register with sysfs
141 *
142 * Return value:
143 * 0 on success / other on failure
144 **/
145static int pseries_suspend_sysfs_register(struct device *dev)
146{
147 struct device *dev_root;
148 int rc;
149
150 if ((rc = subsys_system_register(subsys: &suspend_subsys, NULL)))
151 return rc;
152
153 dev->id = 0;
154 dev->bus = &suspend_subsys;
155
156 dev_root = bus_get_dev_root(bus: &suspend_subsys);
157 if (dev_root) {
158 rc = device_create_file(device: dev_root, entry: &dev_attr_hibernate);
159 put_device(dev: dev_root);
160 if (rc)
161 goto subsys_unregister;
162 }
163
164 return 0;
165
166subsys_unregister:
167 bus_unregister(bus: &suspend_subsys);
168 return rc;
169}
170
171/**
172 * pseries_suspend_init - initcall for pSeries suspend
173 *
174 * Return value:
175 * 0 on success / other on failure
176 **/
177static int __init pseries_suspend_init(void)
178{
179 int rc;
180
181 if (!firmware_has_feature(FW_FEATURE_LPAR))
182 return 0;
183
184 if ((rc = pseries_suspend_sysfs_register(dev: &suspend_dev)))
185 return rc;
186
187 suspend_set_ops(ops: &pseries_suspend_ops);
188 return 0;
189}
190machine_device_initcall(pseries, pseries_suspend_init);
191

source code of linux/arch/powerpc/platforms/pseries/suspend.c