release/src-rt-6.x.4708/linux/linux-2.6.36/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 <asm/firmware.h>
  22 #include <asm/hvcall.h>
  23 #include <asm/machdep.h>
  24 #include <asm/mmu.h>
  25 #include <asm/rtas.h>
  26
  27 static u64 stream_id;
  28 static struct sys_device suspend_sysdev;
  29 static DECLARE_COMPLETION(suspend_work);
  30 static struct rtas_suspend_me_data suspend_data;
  31 static atomic_t suspending;
  32
  33 /**
  34  * pseries_suspend_begin - First phase of hibernation
  35  *
  36  * Check to ensure we are in a valid state to hibernate
  37  *
  38  * Return value:
  39  *      0 on success / other on failure
  40  **/
  41 static int pseries_suspend_begin(suspend_state_t state)
  42 {
  43         long vasi_state, rc;
  44         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  45
  46         /* Make sure the state is valid */
  47         rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
  48
  49         vasi_state = retbuf[0];
  50
  51         if (rc) {
  52                 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
  53                 return rc;
  54         } else if (vasi_state == H_VASI_ENABLED) {
  55                 return -EAGAIN;
  56         } else if (vasi_state != H_VASI_SUSPENDING) {
  57                 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
  58                        vasi_state);
  59                 return -EIO;
  60         }
  61
  62         return 0;
  63 }
  64
  65 /**
  66  * pseries_suspend_cpu - Suspend a single CPU
  67  *
  68  * Makes the H_JOIN call to suspend the CPU
  69  *
  70  **/
  71 static int pseries_suspend_cpu(void)
  72 {
  73         if (atomic_read(&suspending))
  74                 return rtas_suspend_cpu(&suspend_data);
  75         return 0;
  76 }
  77
  78 /**
  79  * pseries_suspend_enter - Final phase of hibernation
  80  *
  81  * Return value:
  82  *      0 on success / other on failure
  83  **/
  84 static int pseries_suspend_enter(suspend_state_t state)
  85 {
  86         int rc = rtas_suspend_last_cpu(&suspend_data);
  87
  88         atomic_set(&suspending, 0);
  89         atomic_set(&suspend_data.done, 1);
  90         return rc;
  91 }
  92
  93 /**
  94  * pseries_prepare_late - Prepare to suspend all other CPUs
  95  *
  96  * Return value:
  97  *      0 on success / other on failure
  98  **/
  99 static int pseries_prepare_late(void)
 100 {
 101         atomic_set(&suspending, 1);
 102         atomic_set(&suspend_data.working, 0);
 103         atomic_set(&suspend_data.done, 0);
 104         atomic_set(&suspend_data.error, 0);
 105         suspend_data.complete = &suspend_work;
 106         INIT_COMPLETION(suspend_work);
 107         return 0;
 108 }
 109
 110 /**
 111  * store_hibernate - Initiate partition hibernation
 112  * @classdev:   sysdev class struct
 113  * @attr:               class device attribute struct
 114  * @buf:                buffer
 115  * @count:              buffer size
 116  *
 117  * Write the stream ID received from the HMC to this file
 118  * to trigger hibernating the partition
 119  *
 120  * Return value:
 121  *      number of bytes printed to buffer / other on failure
 122  **/
 123 static ssize_t store_hibernate(struct sysdev_class *classdev,
 124                                struct sysdev_class_attribute *attr,
 125                                const char *buf, size_t count)
 126 {
 127         int rc;
 128
 129         if (!capable(CAP_SYS_ADMIN))
 130                 return -EPERM;
 131
 132         stream_id = simple_strtoul(buf, NULL, 16);
 133
 134         do {
 135                 rc = pseries_suspend_begin(PM_SUSPEND_MEM);
 136                 if (rc == -EAGAIN)
 137                         ssleep(1);
 138         } while (rc == -EAGAIN);
 139
 140         if (!rc)
 141                 rc = pm_suspend(PM_SUSPEND_MEM);
 142
 143         stream_id = 0;
 144
 145         if (!rc)
 146                 rc = count;
 147         return rc;
 148 }
 149
 150 static SYSDEV_CLASS_ATTR(hibernate, S_IWUSR, NULL, store_hibernate);
 151
 152 static struct sysdev_class suspend_sysdev_class = {
 153         .name = "power",
 154 };
 155
 156 static struct platform_suspend_ops pseries_suspend_ops = {
 157         .valid          = suspend_valid_only_mem,
 158         .begin          = pseries_suspend_begin,
 159         .prepare_late   = pseries_prepare_late,
 160         .enter          = pseries_suspend_enter,
 161 };
 162
 163 /**
 164  * pseries_suspend_sysfs_register - Register with sysfs
 165  *
 166  * Return value:
 167  *      0 on success / other on failure
 168  **/
 169 static int pseries_suspend_sysfs_register(struct sys_device *sysdev)
 170 {
 171         int rc;
 172
 173         if ((rc = sysdev_class_register(&suspend_sysdev_class)))
 174                 return rc;
 175
 176         sysdev->id = 0;
 177         sysdev->cls = &suspend_sysdev_class;
 178
 179         if ((rc = sysdev_class_create_file(&suspend_sysdev_class, &attr_hibernate)))
 180                 goto class_unregister;
 181
 182         return 0;
 183
 184 class_unregister:
 185         sysdev_class_unregister(&suspend_sysdev_class);
 186         return rc;
 187 }
 188
 189 /**
 190  * pseries_suspend_init - initcall for pSeries suspend
 191  *
 192  * Return value:
 193  *      0 on success / other on failure
 194  **/
 195 static int __init pseries_suspend_init(void)
 196 {
 197         int rc;
 198
 199         if (!machine_is(pseries) || !firmware_has_feature(FW_FEATURE_LPAR))
 200                 return 0;
 201
 202         suspend_data.token = rtas_token("ibm,suspend-me");
 203         if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
 204                 return 0;
 205
 206         if ((rc = pseries_suspend_sysfs_register(&suspend_sysdev)))
 207                 return rc;
 208
 209         ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
 210         suspend_set_ops(&pseries_suspend_ops);
 211         return 0;
 212 }
 213
 214 __initcall(pseries_suspend_init);