arch/powerpc/platforms/pseries/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
  17 static struct device suspend_dev;
  18
  19 /**
  20  * pseries_suspend_begin - First phase of hibernation
  21  *
  22  * Check to ensure we are in a valid state to hibernate
  23  *
  24  * Return value:
  25  *      0 on success / other on failure
  26  **/
  27 static int pseries_suspend_begin(u64 stream_id)
  28 {
  29         long vasi_state, rc;
  30         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  31
  32         /* Make sure the state is valid */
  33         rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
  34
  35         vasi_state = retbuf[0];
  36
  37         if (rc) {
  38                 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
  39                 return rc;
  40         } else if (vasi_state == H_VASI_ENABLED) {
  41                 return -EAGAIN;
  42         } else if (vasi_state != H_VASI_SUSPENDING) {
  43                 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
  44                        vasi_state);
  45                 return -EIO;
  46         }
  47         return 0;
  48 }
  49
  50 /**
  51  * pseries_suspend_enter - Final phase of hibernation
  52  *
  53  * Return value:
  54  *      0 on success / other on failure
  55  **/
  56 static int pseries_suspend_enter(suspend_state_t state)
  57 {
  58         return rtas_ibm_suspend_me(NULL);
  59 }
  60
  61 /**
  62  * store_hibernate - Initiate partition hibernation
  63  * @dev:                subsys root device
  64  * @attr:               device attribute struct
  65  * @buf:                buffer
  66  * @count:              buffer size
  67  *
  68  * Write the stream ID received from the HMC to this file
  69  * to trigger hibernating the partition
  70  *
  71  * Return value:
  72  *      number of bytes printed to buffer / other on failure
  73  **/
  74 static ssize_t store_hibernate(struct device *dev,
  75                                struct device_attribute *attr,
  76                                const char *buf, size_t count)
  77 {
  78         u64 stream_id;
  79         int rc;
  80
  81         if (!capable(CAP_SYS_ADMIN))
  82                 return -EPERM;
  83
  84         stream_id = simple_strtoul(buf, NULL, 16);
  85
  86         do {
  87                 rc = pseries_suspend_begin(stream_id);
  88                 if (rc == -EAGAIN)
  89                         ssleep(1);
  90         } while (rc == -EAGAIN);
  91
  92         if (!rc)
  93                 rc = pm_suspend(PM_SUSPEND_MEM);
  94
  95         if (!rc) {
  96                 rc = count;
  97                 post_mobility_fixup();
  98         }
  99
 100
 101         return rc;
 102 }
 103
 104 #define USER_DT_UPDATE  0
 105 #define KERN_DT_UPDATE  1
 106
 107 /**
 108  * show_hibernate - Report device tree update responsibilty
 109  * @dev:                subsys root device
 110  * @attr:               device attribute struct
 111  * @buf:                buffer
 112  *
 113  * Report whether a device tree update is performed by the kernel after a
 114  * resume, or if drmgr must coordinate the update from user space.
 115  *
 116  * Return value:
 117  *      0 if drmgr is to initiate update, and 1 otherwise
 118  **/
 119 static ssize_t show_hibernate(struct device *dev,
 120                               struct device_attribute *attr,
 121                               char *buf)
 122 {
 123         return sprintf(buf, "%d\n", KERN_DT_UPDATE);
 124 }
 125
 126 static DEVICE_ATTR(hibernate, 0644, show_hibernate, store_hibernate);
 127
 128 static struct bus_type suspend_subsys = {
 129         .name = "power",
 130         .dev_name = "power",
 131 };
 132
 133 static const struct platform_suspend_ops pseries_suspend_ops = {
 134         .valid          = suspend_valid_only_mem,
 135         .enter          = pseries_suspend_enter,
 136 };
 137
 138 /**
 139  * pseries_suspend_sysfs_register - Register with sysfs
 140  *
 141  * Return value:
 142  *      0 on success / other on failure
 143  **/
 144 static int pseries_suspend_sysfs_register(struct device *dev)
 145 {
 146         int rc;
 147
 148         if ((rc = subsys_system_register(&suspend_subsys, NULL)))
 149                 return rc;
 150
 151         dev->id = 0;
 152         dev->bus = &suspend_subsys;
 153
 154         if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
 155                 goto subsys_unregister;
 156
 157         return 0;
 158
 159 subsys_unregister:
 160         bus_unregister(&suspend_subsys);
 161         return rc;
 162 }
 163
 164 /**
 165  * pseries_suspend_init - initcall for pSeries suspend
 166  *
 167  * Return value:
 168  *      0 on success / other on failure
 169  **/
 170 static int __init pseries_suspend_init(void)
 171 {
 172         int rc;
 173
 174         if (!firmware_has_feature(FW_FEATURE_LPAR))
 175                 return 0;
 176
 177         if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
 178                 return rc;
 179
 180         suspend_set_ops(&pseries_suspend_ops);
 181         return 0;
 182 }
 183 machine_device_initcall(pseries, pseries_suspend_init);