diff options
| -rw-r--r-- | drivers/remoteproc/remoteproc_debugfs.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c index 732770e92b99..2e3b3e22e1d0 100644 --- a/drivers/remoteproc/remoteproc_debugfs.c +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -28,6 +28,94 @@ static struct dentry *rproc_dbg; /* + * A coredump-configuration-to-string lookup table, for exposing a + * human readable configuration via debugfs. Always keep in sync with + * enum rproc_coredump_mechanism + */ +static const char * const rproc_coredump_str[] = { + [RPROC_COREDUMP_DEFAULT] = "default", + [RPROC_COREDUMP_INLINE] = "inline", + [RPROC_COREDUMP_DISABLED] = "disabled", +}; + +/* Expose the current coredump configuration via debugfs */ +static ssize_t rproc_coredump_read(struct file *filp, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + char buf[20]; + int len; + + len = scnprintf(buf, sizeof(buf), "%s\n", + rproc_coredump_str[rproc->dump_conf]); + + return simple_read_from_buffer(userbuf, count, ppos, buf, len); +} + +/* + * By writing to the 'coredump' debugfs entry, we control the behavior of the + * coredump mechanism dynamically. The default value of this entry is "default". + * + * The 'coredump' debugfs entry supports these commands: + * + * default: This is the default coredump mechanism. 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. + * + * disabled: This will disable coredump. Recovery will proceed without + * collecting any dump. + */ +static ssize_t rproc_coredump_write(struct file *filp, + const char __user *user_buf, size_t count, + loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + int ret, err = 0; + char buf[20]; + + if (count > sizeof(buf)) + return -EINVAL; + + ret = copy_from_user(buf, user_buf, count); + if (ret) + return -EFAULT; + + /* remove end of line */ + if (buf[count - 1] == '\n') + buf[count - 1] = '\0'; + + if (rproc->state == RPROC_CRASHED) { + dev_err(&rproc->dev, "can't change coredump configuration\n"); + err = -EBUSY; + goto out; + } + + if (!strncmp(buf, "disable", count)) { + rproc->dump_conf = RPROC_COREDUMP_DISABLED; + } else if (!strncmp(buf, "inline", count)) { + rproc->dump_conf = RPROC_COREDUMP_INLINE; + } else if (!strncmp(buf, "default", count)) { + rproc->dump_conf = RPROC_COREDUMP_DEFAULT; + } else { + dev_err(&rproc->dev, "Invalid coredump configuration\n"); + err = -EINVAL; + } +out: + return err ? err : count; +} + +static const struct file_operations rproc_coredump_fops = { + .read = rproc_coredump_read, + .write = rproc_coredump_write, + .open = simple_open, + .llseek = generic_file_llseek, +}; + +/* * Some remote processors may support dumping trace logs into a shared * memory buffer. We expose this trace buffer using debugfs, so users * can easily tell what's going on remotely. @@ -337,6 +425,8 @@ void rproc_create_debug_dir(struct rproc *rproc) rproc, &rproc_rsc_table_fops); debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir, rproc, &rproc_carveouts_fops); + debugfs_create_file("coredump", 0600, rproc->dbg_dir, + rproc, &rproc_coredump_fops); } void __init rproc_init_debugfs(void) |