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Diffstat (limited to 'drivers/remoteproc/remoteproc_sysfs.c')
-rw-r--r--drivers/remoteproc/remoteproc_sysfs.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
new file mode 100644
index 0000000000..8c7ea89226
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Remote Processor Framework
+ */
+
+#include <linux/remoteproc.h>
+#include <linux/slab.h>
+
+#include "remoteproc_internal.h"
+
+#define to_rproc(d) container_of(d, struct rproc, dev)
+
+static ssize_t recovery_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rproc *rproc = to_rproc(dev);
+
+ return sysfs_emit(buf, "%s", rproc->recovery_disabled ? "disabled\n" : "enabled\n");
+}
+
+/*
+ * By writing to the 'recovery' sysfs entry, we control the behavior of the
+ * recovery mechanism dynamically. The default value of this entry is "enabled".
+ *
+ * The 'recovery' sysfs entry supports these commands:
+ *
+ * enabled: When enabled, the remote processor will be automatically
+ * recovered whenever it crashes. Moreover, if the remote
+ * processor crashes while recovery is disabled, it will
+ * be automatically recovered too as soon as recovery is enabled.
+ *
+ * disabled: When disabled, a remote processor will remain in a crashed
+ * state if it crashes. This is useful for debugging purposes;
+ * without it, debugging a crash is substantially harder.
+ *
+ * recover: This function will trigger an immediate recovery if the
+ * remote processor is in a crashed state, without changing
+ * or checking the recovery state (enabled/disabled).
+ * This is useful during debugging sessions, when one expects
+ * additional crashes to happen after enabling recovery. In this
+ * case, enabling recovery will make it hard to debug subsequent
+ * crashes, so it's recommended to keep recovery disabled, and
+ * instead use the "recover" command as needed.
+ */
+static ssize_t recovery_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rproc *rproc = to_rproc(dev);
+
+ if (sysfs_streq(buf, "enabled")) {
+ /* change the flag and begin the recovery process if needed */
+ rproc->recovery_disabled = false;
+ rproc_trigger_recovery(rproc);
+ } else if (sysfs_streq(buf, "disabled")) {
+ rproc->recovery_disabled = true;
+ } else if (sysfs_streq(buf, "recover")) {
+ /* begin the recovery process without changing the flag */
+ rproc_trigger_recovery(rproc);
+ } else {
+ return -EINVAL;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_RW(recovery);
+
+/*
+ * A coredump-configuration-to-string lookup table, for exposing a
+ * human readable configuration via sysfs. Always keep in sync with
+ * enum rproc_coredump_mechanism
+ */
+static const char * const rproc_coredump_str[] = {
+ [RPROC_COREDUMP_DISABLED] = "disabled",
+ [RPROC_COREDUMP_ENABLED] = "enabled",
+ [RPROC_COREDUMP_INLINE] = "inline",
+};
+
+/* Expose the current coredump configuration via debugfs */
+static ssize_t coredump_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rproc *rproc = to_rproc(dev);
+
+ return sysfs_emit(buf, "%s\n", rproc_coredump_str[rproc->dump_conf]);
+}
+
+/*
+ * By writing to the 'coredump' sysfs entry, we control the behavior of the
+ * coredump mechanism dynamically. The default value of this entry is "default".
+ *
+ * The 'coredump' sysfs entry supports these commands:
+ *
+ * disabled: This is the default coredump mechanism. Recovery will proceed
+ * without collecting any dump.
+ *
+ * default: When the remoteproc crashes the entire coredump will be
+ * copied to a separate buffer and exposed to userspace.
+ *
+ * inline: The coredump will not be copied to a separate buffer and the
+ * recovery process will have to wait until data is read by
+ * userspace. But this avoid usage of extra memory.
+ */
+static ssize_t coredump_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rproc *rproc = to_rproc(dev);
+
+ if (rproc->state == RPROC_CRASHED) {
+ dev_err(&rproc->dev, "can't change coredump configuration\n");
+ return -EBUSY;
+ }
+
+ if (sysfs_streq(buf, "disabled")) {
+ rproc->dump_conf = RPROC_COREDUMP_DISABLED;
+ } else if (sysfs_streq(buf, "enabled")) {
+ rproc->dump_conf = RPROC_COREDUMP_ENABLED;
+ } else if (sysfs_streq(buf, "inline")) {
+ rproc->dump_conf = RPROC_COREDUMP_INLINE;
+ } else {
+ dev_err(&rproc->dev, "Invalid coredump configuration\n");
+ return -EINVAL;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_RW(coredump);
+
+/* Expose the loaded / running firmware name via sysfs */
+static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rproc *rproc = to_rproc(dev);
+ const char *firmware = rproc->firmware;
+
+ /*
+ * If the remote processor has been started by an external
+ * entity we have no idea of what image it is running. As such
+ * simply display a generic string rather then rproc->firmware.
+ */
+ if (rproc->state == RPROC_ATTACHED)
+ firmware = "unknown";
+
+ return sprintf(buf, "%s\n", firmware);
+}
+
+/* Change firmware name via sysfs */
+static ssize_t firmware_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rproc *rproc = to_rproc(dev);
+ int err;
+
+ err = rproc_set_firmware(rproc, buf);
+
+ return err ? err : count;
+}
+static DEVICE_ATTR_RW(firmware);
+
+/*
+ * A state-to-string lookup table, for exposing a human readable state
+ * via sysfs. Always keep in sync with enum rproc_state
+ */
+static const char * const rproc_state_string[] = {
+ [RPROC_OFFLINE] = "offline",
+ [RPROC_SUSPENDED] = "suspended",
+ [RPROC_RUNNING] = "running",
+ [RPROC_CRASHED] = "crashed",
+ [RPROC_DELETED] = "deleted",
+ [RPROC_ATTACHED] = "attached",
+ [RPROC_DETACHED] = "detached",
+ [RPROC_LAST] = "invalid",
+};
+
+/* Expose the state of the remote processor via sysfs */
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rproc *rproc = to_rproc(dev);
+ unsigned int state;
+
+ state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
+ return sprintf(buf, "%s\n", rproc_state_string[state]);
+}
+
+/* Change remote processor state via sysfs */
+static ssize_t state_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rproc *rproc = to_rproc(dev);
+ int ret = 0;
+
+ if (sysfs_streq(buf, "start")) {
+ ret = rproc_boot(rproc);
+ if (ret)
+ dev_err(&rproc->dev, "Boot failed: %d\n", ret);
+ } else if (sysfs_streq(buf, "stop")) {
+ ret = rproc_shutdown(rproc);
+ } else if (sysfs_streq(buf, "detach")) {
+ ret = rproc_detach(rproc);
+ } else {
+ dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
+ ret = -EINVAL;
+ }
+ return ret ? ret : count;
+}
+static DEVICE_ATTR_RW(state);
+
+/* Expose the name of the remote processor via sysfs */
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct rproc *rproc = to_rproc(dev);
+
+ return sprintf(buf, "%s\n", rproc->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct rproc *rproc = to_rproc(dev);
+ umode_t mode = attr->mode;
+
+ if (rproc->sysfs_read_only && (attr == &dev_attr_recovery.attr ||
+ attr == &dev_attr_firmware.attr ||
+ attr == &dev_attr_state.attr ||
+ attr == &dev_attr_coredump.attr))
+ mode = 0444;
+
+ return mode;
+}
+
+static struct attribute *rproc_attrs[] = {
+ &dev_attr_coredump.attr,
+ &dev_attr_recovery.attr,
+ &dev_attr_firmware.attr,
+ &dev_attr_state.attr,
+ &dev_attr_name.attr,
+ NULL
+};
+
+static const struct attribute_group rproc_devgroup = {
+ .attrs = rproc_attrs,
+ .is_visible = rproc_is_visible,
+};
+
+static const struct attribute_group *rproc_devgroups[] = {
+ &rproc_devgroup,
+ NULL
+};
+
+struct class rproc_class = {
+ .name = "remoteproc",
+ .dev_groups = rproc_devgroups,
+};
+
+int __init rproc_init_sysfs(void)
+{
+ /* create remoteproc device class for sysfs */
+ int err = class_register(&rproc_class);
+
+ if (err)
+ pr_err("remoteproc: unable to register class\n");
+ return err;
+}
+
+void __exit rproc_exit_sysfs(void)
+{
+ class_unregister(&rproc_class);
+}