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 #include <asm/topology.h>
  28
  29 static u64 stream_id;
  30 static struct device suspend_dev;
  31 static DECLARE_COMPLETION(suspend_work);
  32 static struct rtas_suspend_me_data suspend_data;
  33 static atomic_t suspending;
  34
  35 /**
  36  * pseries_suspend_begin - First phase of hibernation
  37  *
  38  * Check to ensure we are in a valid state to hibernate
  39  *
  40  * Return value:
  41  *      0 on success / other on failure
  42  **/
  43 static int pseries_suspend_begin(suspend_state_t state)
  44 {
  45         long vasi_state, rc;
  46         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  47
  48         /* Make sure the state is valid */
  49         rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
  50
  51         vasi_state = retbuf[0];
  52
  53         if (rc) {
  54                 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
  55                 return rc;
  56         } else if (vasi_state == H_VASI_ENABLED) {
  57                 return -EAGAIN;
  58         } else if (vasi_state != H_VASI_SUSPENDING) {
  59                 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
  60                        vasi_state);
  61                 return -EIO;
  62         }
  63
  64         return 0;
  65 }
  66
  67 /**
  68  * pseries_suspend_cpu - Suspend a single CPU
  69  *
  70  * Makes the H_JOIN call to suspend the CPU
  71  *
  72  **/
  73 static int pseries_suspend_cpu(void)
  74 {
  75         if (atomic_read(&suspending))
  76                 return rtas_suspend_cpu(&suspend_data);
  77         return 0;
  78 }
  79
  80 /**
  81  * pseries_suspend_enter - Final phase of hibernation
  82  *
  83  * Return value:
  84  *      0 on success / other on failure
  85  **/
  86 static int pseries_suspend_enter(suspend_state_t state)
  87 {
  88         int rc = rtas_suspend_last_cpu(&suspend_data);
  89
  90         atomic_set(&suspending, 0);
  91         atomic_set(&suspend_data.done, 1);
  92         return rc;
  93 }
  94
  95 /**
  96  * pseries_prepare_late - Prepare to suspend all other CPUs
  97  *
  98  * Return value:
  99  *      0 on success / other on failure
 100  **/
 101 static int pseries_prepare_late(void)
 102 {
 103         atomic_set(&suspending, 1);
 104         atomic_set(&suspend_data.working, 0);
 105         atomic_set(&suspend_data.done, 0);
 106         atomic_set(&suspend_data.error, 0);
 107         suspend_data.complete = &suspend_work;
 108         INIT_COMPLETION(suspend_work);
 109         return 0;
 110 }
 111
 112 /**
 113  * store_hibernate - Initiate partition hibernation
 114  * @dev:                subsys root device
 115  * @attr:               device attribute struct
 116  * @buf:                buffer
 117  * @count:              buffer size
 118  *
 119  * Write the stream ID received from the HMC to this file
 120  * to trigger hibernating the partition
 121  *
 122  * Return value:
 123  *      number of bytes printed to buffer / other on failure
 124  **/
 125 static ssize_t store_hibernate(struct device *dev,
 126                                struct device_attribute *attr,
 127                                const char *buf, size_t count)
 128 {
 129         int rc;
 130
 131         if (!capable(CAP_SYS_ADMIN))
 132                 return -EPERM;
 133
 134         stream_id = simple_strtoul(buf, NULL, 16);
 135
 136         do {
 137                 rc = pseries_suspend_begin(PM_SUSPEND_MEM);
 138                 if (rc == -EAGAIN)
 139                         ssleep(1);
 140         } while (rc == -EAGAIN);
 141
 142         if (!rc) {
 143                 stop_topology_update();
 144                 rc = pm_suspend(PM_SUSPEND_MEM);
 145                 start_topology_update();
 146         }
 147
 148         stream_id = 0;
 149
 150         if (!rc)
 151                 rc = count;
 152         return rc;
 153 }
 154
 155 static DEVICE_ATTR(hibernate, S_IWUSR, NULL, store_hibernate);
 156
 157 static struct bus_type suspend_subsys = {
 158         .name = "power",
 159         .dev_name = "power",
 160 };
 161
 162 static const struct platform_suspend_ops pseries_suspend_ops = {
 163         .valid          = suspend_valid_only_mem,
 164         .begin          = pseries_suspend_begin,
 165         .prepare_late   = pseries_prepare_late,
 166         .enter          = pseries_suspend_enter,
 167 };
 168
 169 /**
 170  * pseries_suspend_sysfs_register - Register with sysfs
 171  *
 172  * Return value:
 173  *      0 on success / other on failure
 174  **/
 175 static int pseries_suspend_sysfs_register(struct device *dev)
 176 {
 177         int rc;
 178
 179         if ((rc = subsys_system_register(&suspend_subsys, NULL)))
 180                 return rc;
 181
 182         dev->id = 0;
 183         dev->bus = &suspend_subsys;
 184
 185         if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
 186                 goto subsys_unregister;
 187
 188         return 0;
 189
 190 subsys_unregister:
 191         bus_unregister(&suspend_subsys);
 192         return rc;
 193 }
 194
 195 /**
 196  * pseries_suspend_init - initcall for pSeries suspend
 197  *
 198  * Return value:
 199  *      0 on success / other on failure
 200  **/
 201 static int __init pseries_suspend_init(void)
 202 {
 203         int rc;
 204
 205         if (!machine_is(pseries) || !firmware_has_feature(FW_FEATURE_LPAR))
 206                 return 0;
 207
 208         suspend_data.token = rtas_token("ibm,suspend-me");
 209         if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
 210                 return 0;
 211
 212         if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
 213                 return rc;
 214
 215         ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
 216         suspend_set_ops(&pseries_suspend_ops);
 217         return 0;
 218 }
 219
 220 __initcall(pseries_suspend_init);