1/*
2  * Copyright (C) 2010 Brian King IBM Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17  */
18
19#include <linux/cpu.h>
20#include <linux/delay.h>
21#include <linux/suspend.h>
22#include <linux/stat.h>
23#include <asm/firmware.h>
24#include <asm/hvcall.h>
25#include <asm/machdep.h>
26#include <asm/mmu.h>
27#include <asm/rtas.h>
28#include <asm/topology.h>
29#include "../../kernel/cacheinfo.h"
30
31static u64 stream_id;
32static struct device suspend_dev;
33static DECLARE_COMPLETION(suspend_work);
34static struct rtas_suspend_me_data suspend_data;
35static atomic_t suspending;
36
37/**
38 * pseries_suspend_begin - First phase of hibernation
39 *
40 * Check to ensure we are in a valid state to hibernate
41 *
42 * Return value:
43 * 	0 on success / other on failure
44 **/
45static int pseries_suspend_begin(suspend_state_t state)
46{
47	long vasi_state, rc;
48	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
49
50	/* Make sure the state is valid */
51	rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
52
53	vasi_state = retbuf[0];
54
55	if (rc) {
56		pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
57		return rc;
58	} else if (vasi_state == H_VASI_ENABLED) {
59		return -EAGAIN;
60	} else if (vasi_state != H_VASI_SUSPENDING) {
61		pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
62		       vasi_state);
63		return -EIO;
64	}
65
66	return 0;
67}
68
69/**
70 * pseries_suspend_cpu - Suspend a single CPU
71 *
72 * Makes the H_JOIN call to suspend the CPU
73 *
74 **/
75static int pseries_suspend_cpu(void)
76{
77	if (atomic_read(&suspending))
78		return rtas_suspend_cpu(&suspend_data);
79	return 0;
80}
81
82/**
83 * pseries_suspend_enable_irqs
84 *
85 * Post suspend configuration updates
86 *
87 **/
88static void pseries_suspend_enable_irqs(void)
89{
90	/*
91	 * Update configuration which can be modified based on device tree
92	 * changes during resume.
93	 */
94	cacheinfo_cpu_offline(smp_processor_id());
95	post_mobility_fixup();
96	cacheinfo_cpu_online(smp_processor_id());
97}
98
99/**
100 * pseries_suspend_enter - Final phase of hibernation
101 *
102 * Return value:
103 * 	0 on success / other on failure
104 **/
105static int pseries_suspend_enter(suspend_state_t state)
106{
107	int rc = rtas_suspend_last_cpu(&suspend_data);
108
109	atomic_set(&suspending, 0);
110	atomic_set(&suspend_data.done, 1);
111	return rc;
112}
113
114/**
115 * pseries_prepare_late - Prepare to suspend all other CPUs
116 *
117 * Return value:
118 * 	0 on success / other on failure
119 **/
120static int pseries_prepare_late(void)
121{
122	atomic_set(&suspending, 1);
123	atomic_set(&suspend_data.working, 0);
124	atomic_set(&suspend_data.done, 0);
125	atomic_set(&suspend_data.error, 0);
126	suspend_data.complete = &suspend_work;
127	reinit_completion(&suspend_work);
128	return 0;
129}
130
131/**
132 * store_hibernate - Initiate partition hibernation
133 * @dev:		subsys root device
134 * @attr:		device attribute struct
135 * @buf:		buffer
136 * @count:		buffer size
137 *
138 * Write the stream ID received from the HMC to this file
139 * to trigger hibernating the partition
140 *
141 * Return value:
142 * 	number of bytes printed to buffer / other on failure
143 **/
144static ssize_t store_hibernate(struct device *dev,
145			       struct device_attribute *attr,
146			       const char *buf, size_t count)
147{
148	cpumask_var_t offline_mask;
149	int rc;
150
151	if (!capable(CAP_SYS_ADMIN))
152		return -EPERM;
153
154	if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
155		return -ENOMEM;
156
157	stream_id = simple_strtoul(buf, NULL, 16);
158
159	do {
160		rc = pseries_suspend_begin(PM_SUSPEND_MEM);
161		if (rc == -EAGAIN)
162			ssleep(1);
163	} while (rc == -EAGAIN);
164
165	if (!rc) {
166		/* All present CPUs must be online */
167		cpumask_andnot(offline_mask, cpu_present_mask,
168				cpu_online_mask);
169		rc = rtas_online_cpus_mask(offline_mask);
170		if (rc) {
171			pr_err("%s: Could not bring present CPUs online.\n",
172					__func__);
173			goto out;
174		}
175
176		stop_topology_update();
177		rc = pm_suspend(PM_SUSPEND_MEM);
178		start_topology_update();
179
180		/* Take down CPUs not online prior to suspend */
181		if (!rtas_offline_cpus_mask(offline_mask))
182			pr_warn("%s: Could not restore CPUs to offline "
183					"state.\n", __func__);
184	}
185
186	stream_id = 0;
187
188	if (!rc)
189		rc = count;
190out:
191	free_cpumask_var(offline_mask);
192	return rc;
193}
194
195#define USER_DT_UPDATE	0
196#define KERN_DT_UPDATE	1
197
198/**
199 * show_hibernate - Report device tree update responsibilty
200 * @dev:		subsys root device
201 * @attr:		device attribute struct
202 * @buf:		buffer
203 *
204 * Report whether a device tree update is performed by the kernel after a
205 * resume, or if drmgr must coordinate the update from user space.
206 *
207 * Return value:
208 *	0 if drmgr is to initiate update, and 1 otherwise
209 **/
210static ssize_t show_hibernate(struct device *dev,
211			      struct device_attribute *attr,
212			      char *buf)
213{
214	return sprintf(buf, "%d\n", KERN_DT_UPDATE);
215}
216
217static DEVICE_ATTR(hibernate, S_IWUSR | S_IRUGO,
218		   show_hibernate, store_hibernate);
219
220static struct bus_type suspend_subsys = {
221	.name = "power",
222	.dev_name = "power",
223};
224
225static const struct platform_suspend_ops pseries_suspend_ops = {
226	.valid		= suspend_valid_only_mem,
227	.begin		= pseries_suspend_begin,
228	.prepare_late	= pseries_prepare_late,
229	.enter		= pseries_suspend_enter,
230};
231
232/**
233 * pseries_suspend_sysfs_register - Register with sysfs
234 *
235 * Return value:
236 * 	0 on success / other on failure
237 **/
238static int pseries_suspend_sysfs_register(struct device *dev)
239{
240	int rc;
241
242	if ((rc = subsys_system_register(&suspend_subsys, NULL)))
243		return rc;
244
245	dev->id = 0;
246	dev->bus = &suspend_subsys;
247
248	if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
249		goto subsys_unregister;
250
251	return 0;
252
253subsys_unregister:
254	bus_unregister(&suspend_subsys);
255	return rc;
256}
257
258/**
259 * pseries_suspend_init - initcall for pSeries suspend
260 *
261 * Return value:
262 * 	0 on success / other on failure
263 **/
264static int __init pseries_suspend_init(void)
265{
266	int rc;
267
268	if (!firmware_has_feature(FW_FEATURE_LPAR))
269		return 0;
270
271	suspend_data.token = rtas_token("ibm,suspend-me");
272	if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
273		return 0;
274
275	if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
276		return rc;
277
278	ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
279	ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs;
280	suspend_set_ops(&pseries_suspend_ops);
281	return 0;
282}
283machine_device_initcall(pseries, pseries_suspend_init);
284