suspend.c

  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(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, "%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(&suspend_subsys, NULL)))
151		return rc;
152
153	dev->id = 0;
154	dev->bus = &suspend_subsys;
155
156	dev_root = bus_get_dev_root(&suspend_subsys);
157	if (dev_root) {
158		rc = device_create_file(dev_root, &dev_attr_hibernate);
159		put_device(dev_root);
160		if (rc)
161			goto subsys_unregister;
162	}
163
164	return 0;
165
166subsys_unregister:
167	bus_unregister(&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(&suspend_dev)))
185		return rc;
186
187	suspend_set_ops(&pseries_suspend_ops);
188	return 0;
189}
190machine_device_initcall(pseries, pseries_suspend_init);