drivers/remoteproc/remoteproc_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Remote Processor Framework
   4  */
   5
   6 #include <linux/remoteproc.h>
   7 #include <linux/slab.h>
   8
   9 #include "remoteproc_internal.h"
  10
  11 #define to_rproc(d) container_of(d, struct rproc, dev)
  12
  13 static ssize_t recovery_show(struct device *dev,
  14                              struct device_attribute *attr, char *buf)
  15 {
  16         struct rproc *rproc = to_rproc(dev);
  17
  18         return sprintf(buf, "%s", rproc->recovery_disabled ? "disabled\n" : "enabled\n");
  19 }
  20
  21 /*
  22  * By writing to the 'recovery' sysfs entry, we control the behavior of the
  23  * recovery mechanism dynamically. The default value of this entry is "enabled".
  24  *
  25  * The 'recovery' sysfs entry supports these commands:
  26  *
  27  * enabled:     When enabled, the remote processor will be automatically
  28  *              recovered whenever it crashes. Moreover, if the remote
  29  *              processor crashes while recovery is disabled, it will
  30  *              be automatically recovered too as soon as recovery is enabled.
  31  *
  32  * disabled:    When disabled, a remote processor will remain in a crashed
  33  *              state if it crashes. This is useful for debugging purposes;
  34  *              without it, debugging a crash is substantially harder.
  35  *
  36  * recover:     This function will trigger an immediate recovery if the
  37  *              remote processor is in a crashed state, without changing
  38  *              or checking the recovery state (enabled/disabled).
  39  *              This is useful during debugging sessions, when one expects
  40  *              additional crashes to happen after enabling recovery. In this
  41  *              case, enabling recovery will make it hard to debug subsequent
  42  *              crashes, so it's recommended to keep recovery disabled, and
  43  *              instead use the "recover" command as needed.
  44  */
  45 static ssize_t recovery_store(struct device *dev,
  46                               struct device_attribute *attr,
  47                               const char *buf, size_t count)
  48 {
  49         struct rproc *rproc = to_rproc(dev);
  50
  51         if (sysfs_streq(buf, "enabled")) {
  52                 /* change the flag and begin the recovery process if needed */
  53                 rproc->recovery_disabled = false;
  54                 rproc_trigger_recovery(rproc);
  55         } else if (sysfs_streq(buf, "disabled")) {
  56                 rproc->recovery_disabled = true;
  57         } else if (sysfs_streq(buf, "recover")) {
  58                 /* begin the recovery process without changing the flag */
  59                 rproc_trigger_recovery(rproc);
  60         } else {
  61                 return -EINVAL;
  62         }
  63
  64         return count;
  65 }
  66 static DEVICE_ATTR_RW(recovery);
  67
  68 /*
  69  * A coredump-configuration-to-string lookup table, for exposing a
  70  * human readable configuration via sysfs. Always keep in sync with
  71  * enum rproc_coredump_mechanism
  72  */
  73 static const char * const rproc_coredump_str[] = {
  74         [RPROC_COREDUMP_DISABLED]       = "disabled",
  75         [RPROC_COREDUMP_ENABLED]        = "enabled",
  76         [RPROC_COREDUMP_INLINE]         = "inline",
  77 };
  78
  79 /* Expose the current coredump configuration via debugfs */
  80 static ssize_t coredump_show(struct device *dev,
  81                              struct device_attribute *attr, char *buf)
  82 {
  83         struct rproc *rproc = to_rproc(dev);
  84
  85         return sprintf(buf, "%s\n", rproc_coredump_str[rproc->dump_conf]);
  86 }
  87
  88 /*
  89  * By writing to the 'coredump' sysfs entry, we control the behavior of the
  90  * coredump mechanism dynamically. The default value of this entry is "default".
  91  *
  92  * The 'coredump' sysfs entry supports these commands:
  93  *
  94  * disabled:    This is the default coredump mechanism. Recovery will proceed
  95  *              without collecting any dump.
  96  *
  97  * default:     When the remoteproc crashes the entire coredump will be
  98  *              copied to a separate buffer and exposed to userspace.
  99  *
 100  * inline:      The coredump will not be copied to a separate buffer and the
 101  *              recovery process will have to wait until data is read by
 102  *              userspace. But this avoid usage of extra memory.
 103  */
 104 static ssize_t coredump_store(struct device *dev,
 105                               struct device_attribute *attr,
 106                               const char *buf, size_t count)
 107 {
 108         struct rproc *rproc = to_rproc(dev);
 109
 110         if (rproc->state == RPROC_CRASHED) {
 111                 dev_err(&rproc->dev, "can't change coredump configuration\n");
 112                 return -EBUSY;
 113         }
 114
 115         if (sysfs_streq(buf, "disabled")) {
 116                 rproc->dump_conf = RPROC_COREDUMP_DISABLED;
 117         } else if (sysfs_streq(buf, "enabled")) {
 118                 rproc->dump_conf = RPROC_COREDUMP_ENABLED;
 119         } else if (sysfs_streq(buf, "inline")) {
 120                 rproc->dump_conf = RPROC_COREDUMP_INLINE;
 121         } else {
 122                 dev_err(&rproc->dev, "Invalid coredump configuration\n");
 123                 return -EINVAL;
 124         }
 125
 126         return count;
 127 }
 128 static DEVICE_ATTR_RW(coredump);
 129
 130 /* Expose the loaded / running firmware name via sysfs */
 131 static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
 132                           char *buf)
 133 {
 134         struct rproc *rproc = to_rproc(dev);
 135         const char *firmware = rproc->firmware;
 136
 137         /*
 138          * If the remote processor has been started by an external
 139          * entity we have no idea of what image it is running.  As such
 140          * simply display a generic string rather then rproc->firmware.
 141          *
 142          * Here we rely on the autonomous flag because a remote processor
 143          * may have been attached to and currently in a running state.
 144          */
 145         if (rproc->autonomous)
 146                 firmware = "unknown";
 147
 148         return sprintf(buf, "%s\n", firmware);
 149 }
 150
 151 /* Change firmware name via sysfs */
 152 static ssize_t firmware_store(struct device *dev,
 153                               struct device_attribute *attr,
 154                               const char *buf, size_t count)
 155 {
 156         struct rproc *rproc = to_rproc(dev);
 157         int err;
 158
 159         err = rproc_set_firmware(rproc, buf);
 160
 161         return err ? err : count;
 162 }
 163 static DEVICE_ATTR_RW(firmware);
 164
 165 /*
 166  * A state-to-string lookup table, for exposing a human readable state
 167  * via sysfs. Always keep in sync with enum rproc_state
 168  */
 169 static const char * const rproc_state_string[] = {
 170         [RPROC_OFFLINE]         = "offline",
 171         [RPROC_SUSPENDED]       = "suspended",
 172         [RPROC_RUNNING]         = "running",
 173         [RPROC_CRASHED]         = "crashed",
 174         [RPROC_DELETED]         = "deleted",
 175         [RPROC_DETACHED]        = "detached",
 176         [RPROC_LAST]            = "invalid",
 177 };
 178
 179 /* Expose the state of the remote processor via sysfs */
 180 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 181                           char *buf)
 182 {
 183         struct rproc *rproc = to_rproc(dev);
 184         unsigned int state;
 185
 186         state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
 187         return sprintf(buf, "%s\n", rproc_state_string[state]);
 188 }
 189
 190 /* Change remote processor state via sysfs */
 191 static ssize_t state_store(struct device *dev,
 192                               struct device_attribute *attr,
 193                               const char *buf, size_t count)
 194 {
 195         struct rproc *rproc = to_rproc(dev);
 196         int ret = 0;
 197
 198         if (sysfs_streq(buf, "start")) {
 199                 if (rproc->state == RPROC_RUNNING)
 200                         return -EBUSY;
 201
 202                 ret = rproc_boot(rproc);
 203                 if (ret)
 204                         dev_err(&rproc->dev, "Boot failed: %d\n", ret);
 205         } else if (sysfs_streq(buf, "stop")) {
 206                 if (rproc->state != RPROC_RUNNING)
 207                         return -EINVAL;
 208
 209                 rproc_shutdown(rproc);
 210         } else {
 211                 dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
 212                 ret = -EINVAL;
 213         }
 214         return ret ? ret : count;
 215 }
 216 static DEVICE_ATTR_RW(state);
 217
 218 /* Expose the name of the remote processor via sysfs */
 219 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 220                          char *buf)
 221 {
 222         struct rproc *rproc = to_rproc(dev);
 223
 224         return sprintf(buf, "%s\n", rproc->name);
 225 }
 226 static DEVICE_ATTR_RO(name);
 227
 228 static struct attribute *rproc_attrs[] = {
 229         &dev_attr_coredump.attr,
 230         &dev_attr_recovery.attr,
 231         &dev_attr_firmware.attr,
 232         &dev_attr_state.attr,
 233         &dev_attr_name.attr,
 234         NULL
 235 };
 236
 237 static const struct attribute_group rproc_devgroup = {
 238         .attrs = rproc_attrs
 239 };
 240
 241 static const struct attribute_group *rproc_devgroups[] = {
 242         &rproc_devgroup,
 243         NULL
 244 };
 245
 246 struct class rproc_class = {
 247         .name           = "remoteproc",
 248         .dev_groups     = rproc_devgroups,
 249 };
 250
 251 int __init rproc_init_sysfs(void)
 252 {
 253         /* create remoteproc device class for sysfs */
 254         int err = class_register(&rproc_class);
 255
 256         if (err)
 257                 pr_err("remoteproc: unable to register class\n");
 258         return err;
 259 }
 260
 261 void __exit rproc_exit_sysfs(void)
 262 {
 263         class_unregister(&rproc_class);
 264 }