arch/powerpc/platforms/pseries/suspend.c

   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/delay.h>
  20 #include <linux/suspend.h>
  21 #include <linux/stat.h>
  22 #include <asm/firmware.h>
  23 #include <asm/hvcall.h>
  24 #include <asm/machdep.h>
  25 #include <asm/mmu.h>
  26 #include <asm/rtas.h>
  27
  28 static u64 stream_id;
  29 static struct device suspend_dev;
  30 static DECLARE_COMPLETION(suspend_work);
  31 static struct rtas_suspend_me_data suspend_data;
  32 static atomic_t suspending;
  33
  34 /**
  35  * pseries_suspend_begin - First phase of hibernation
  36  *
  37  * Check to ensure we are in a valid state to hibernate
  38  *
  39  * Return value:
  40  *      0 on success / other on failure
  41  **/
  42 static int pseries_suspend_begin(suspend_state_t state)
  43 {
  44         long vasi_state, rc;
  45         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  46
  47         /* Make sure the state is valid */
  48         rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
  49
  50         vasi_state = retbuf[0];
  51
  52         if (rc) {
  53                 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
  54                 return rc;
  55         } else if (vasi_state == H_VASI_ENABLED) {
  56                 return -EAGAIN;
  57         } else if (vasi_state != H_VASI_SUSPENDING) {
  58                 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
  59                        vasi_state);
  60                 return -EIO;
  61         }
  62
  63         return 0;
  64 }
  65
  66 /**
  67  * pseries_suspend_cpu - Suspend a single CPU
  68  *
  69  * Makes the H_JOIN call to suspend the CPU
  70  *
  71  **/
  72 static int pseries_suspend_cpu(void)
  73 {
  74         if (atomic_read(&suspending))
  75                 return rtas_suspend_cpu(&suspend_data);
  76         return 0;
  77 }
  78
  79 /**
  80  * pseries_suspend_enter - Final phase of hibernation
  81  *
  82  * Return value:
  83  *      0 on success / other on failure
  84  **/
  85 static int pseries_suspend_enter(suspend_state_t state)
  86 {
  87         int rc = rtas_suspend_last_cpu(&suspend_data);
  88
  89         atomic_set(&suspending, 0);
  90         atomic_set(&suspend_data.done, 1);
  91         return rc;
  92 }
  93
  94 /**
  95  * pseries_prepare_late - Prepare to suspend all other CPUs
  96  *
  97  * Return value:
  98  *      0 on success / other on failure
  99  **/
 100 static int pseries_prepare_late(void)
 101 {
 102         atomic_set(&suspending, 1);
 103         atomic_set(&suspend_data.working, 0);
 104         atomic_set(&suspend_data.done, 0);
 105         atomic_set(&suspend_data.error, 0);
 106         suspend_data.complete = &suspend_work;
 107         INIT_COMPLETION(suspend_work);
 108         return 0;
 109 }
 110
 111 /**
 112  * store_hibernate - Initiate partition hibernation
 113  * @dev:                subsys root device
 114  * @attr:               device attribute struct
 115  * @buf:                buffer
 116  * @count:              buffer size
 117  *
 118  * Write the stream ID received from the HMC to this file
 119  * to trigger hibernating the partition
 120  *
 121  * Return value:
 122  *      number of bytes printed to buffer / other on failure
 123  **/
 124 static ssize_t store_hibernate(struct device *dev,
 125                                struct device_attribute *attr,
 126                                const char *buf, size_t count)
 127 {
 128         int rc;
 129
 130         if (!capable(CAP_SYS_ADMIN))
 131                 return -EPERM;
 132
 133         stream_id = simple_strtoul(buf, NULL, 16);
 134
 135         do {
 136                 rc = pseries_suspend_begin(PM_SUSPEND_MEM);
 137                 if (rc == -EAGAIN)
 138                         ssleep(1);
 139         } while (rc == -EAGAIN);
 140
 141         if (!rc)
 142                 rc = pm_suspend(PM_SUSPEND_MEM);
 143
 144         stream_id = 0;
 145
 146         if (!rc)
 147                 rc = count;
 148         return rc;
 149 }
 150
 151 static DEVICE_ATTR(hibernate, S_IWUSR, NULL, store_hibernate);
 152
 153 static struct bus_type suspend_subsys = {
 154         .name = "power",
 155         .dev_name = "power",
 156 };
 157
 158 static const struct platform_suspend_ops pseries_suspend_ops = {
 159         .valid          = suspend_valid_only_mem,
 160         .begin          = pseries_suspend_begin,
 161         .prepare_late   = pseries_prepare_late,
 162         .enter          = pseries_suspend_enter,
 163 };
 164
 165 /**
 166  * pseries_suspend_sysfs_register - Register with sysfs
 167  *
 168  * Return value:
 169  *      0 on success / other on failure
 170  **/
 171 static int pseries_suspend_sysfs_register(struct device *dev)
 172 {
 173         int rc;
 174
 175         if ((rc = subsys_system_register(&suspend_subsys, NULL)))
 176                 return rc;
 177
 178         dev->id = 0;
 179         dev->bus = &suspend_subsys;
 180
 181         if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
 182                 goto subsys_unregister;
 183
 184         return 0;
 185
 186 subsys_unregister:
 187         bus_unregister(&suspend_subsys);
 188         return rc;
 189 }
 190
 191 /**
 192  * pseries_suspend_init - initcall for pSeries suspend
 193  *
 194  * Return value:
 195  *      0 on success / other on failure
 196  **/
 197 static int __init pseries_suspend_init(void)
 198 {
 199         int rc;
 200
 201         if (!machine_is(pseries) || !firmware_has_feature(FW_FEATURE_LPAR))
 202                 return 0;
 203
 204         suspend_data.token = rtas_token("ibm,suspend-me");
 205         if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
 206                 return 0;
 207
 208         if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
 209                 return rc;
 210
 211         ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
 212         suspend_set_ops(&pseries_suspend_ops);
 213         return 0;
 214 }
 215
 216 __initcall(pseries_suspend_init);