diff options
Diffstat (limited to 'drivers/remoteproc/remoteproc_debugfs.c')
| -rw-r--r-- | drivers/remoteproc/remoteproc_debugfs.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c index 03833850f21..10a38258e31 100644 --- a/drivers/remoteproc/remoteproc_debugfs.c +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -28,6 +28,9 @@ #include <linux/debugfs.h> #include <linux/remoteproc.h> #include <linux/device.h> +#include <linux/uaccess.h> + +#include "remoteproc_internal.h" /* remoteproc debugfs parent dir */ static struct dentry *rproc_dbg; @@ -111,6 +114,82 @@ static const struct file_operations rproc_name_ops = { .llseek = generic_file_llseek, }; +/* expose recovery flag via debugfs */ +static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n"; + + return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf)); +} + +/* + * By writing to the 'recovery' debugfs entry, we control the behavior of the + * recovery mechanism dynamically. The default value of this entry is "enabled". + * + * The 'recovery' debugfs 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 +rproc_recovery_write(struct file *filp, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + char buf[10]; + int ret; + + if (count > sizeof(buf)) + return count; + + ret = copy_from_user(buf, user_buf, count); + if (ret) + return ret; + + /* remove end of line */ + if (buf[count - 1] == '\n') + buf[count - 1] = '\0'; + + if (!strncmp(buf, "enabled", count)) { + rproc->recovery_disabled = false; + /* if rproc has crashed, trigger recovery */ + if (rproc->state == RPROC_CRASHED) + rproc_trigger_recovery(rproc); + } else if (!strncmp(buf, "disabled", count)) { + rproc->recovery_disabled = true; + } else if (!strncmp(buf, "recover", count)) { + /* if rproc has crashed, trigger recovery */ + if (rproc->state == RPROC_CRASHED) + rproc_trigger_recovery(rproc); + } + + return count; +} + +static const struct file_operations rproc_recovery_ops = { + .read = rproc_recovery_read, + .write = rproc_recovery_write, + .open = simple_open, + .llseek = generic_file_llseek, +}; + void rproc_remove_trace_file(struct dentry *tfile) { debugfs_remove(tfile); @@ -154,6 +233,8 @@ void rproc_create_debug_dir(struct rproc *rproc) rproc, &rproc_name_ops); debugfs_create_file("state", 0400, rproc->dbg_dir, rproc, &rproc_state_ops); + debugfs_create_file("recovery", 0400, rproc->dbg_dir, + rproc, &rproc_recovery_ops); } void __init rproc_init_debugfs(void) |