/* * Remote Processor Framework * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * * Ohad Ben-Cohen <ohad@wizery.com> * Mark Grosen <mgrosen@ti.com> * Brian Swetland <swetland@google.com> * Fernando Guzman Lugo <fernando.lugo@ti.com> * Suman Anna <s-anna@ti.com> * Robert Tivy <rtivy@ti.com> * Armando Uribe De Leon <x0095078@ti.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) "%s: " fmt, __func__ #include <linux/kernel.h> #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; /* * 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. * * We will most probably improve the rproc tracing facilities later on, * but this kind of lightweight and simple mechanism is always good to have, * as it provides very early tracing with little to no dependencies at all. */ static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf, size_t count, loff_t *ppos) { struct rproc_mem_entry *trace = filp->private_data; int len = strnlen(trace->va, trace->len); return simple_read_from_buffer(userbuf, count, ppos, trace->va, len); } static const struct file_operations trace_rproc_ops = { .read = rproc_trace_read, .open = simple_open, .llseek = generic_file_llseek, }; /* * A state-to-string lookup table, for exposing a human readable state * via debugfs. Always keep in sync with enum rproc_state */ static const char * const rproc_state_string[] = { "offline", "suspended", "running", "crashed", "invalid", }; /* expose the state of the remote processor via debugfs */ static ssize_t rproc_state_read(struct file *filp, char __user *userbuf, size_t count, loff_t *ppos) { struct rproc *rproc = filp->private_data; unsigned int state; char buf[30]; int i; state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state; i = scnprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state], rproc->state); return simple_read_from_buffer(userbuf, count, ppos, buf, i); } static const struct file_operations rproc_state_ops = { .read = rproc_state_read, .open = simple_open, .llseek = generic_file_llseek, }; /* expose the name of the remote processor via debugfs */ static ssize_t rproc_name_read(struct file *filp, char __user *userbuf, size_t count, loff_t *ppos) { struct rproc *rproc = filp->private_data; /* need room for the name, a newline and a terminating null */ char buf[100]; int i; i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name); return simple_read_from_buffer(userbuf, count, ppos, buf, i); } static const struct file_operations rproc_name_ops = { .read = rproc_name_read, .open = simple_open, .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 -EFAULT; /* 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); } struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc, struct rproc_mem_entry *trace) { struct dentry *tfile; tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace, &trace_rproc_ops); if (!tfile) { dev_err(&rproc->dev, "failed to create debugfs trace entry\n"); return NULL; } return tfile; } void rproc_delete_debug_dir(struct rproc *rproc) { if (!rproc->dbg_dir) return; debugfs_remove_recursive(rproc->dbg_dir); } void rproc_create_debug_dir(struct rproc *rproc) { struct device *dev = &rproc->dev; if (!rproc_dbg) return; rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg); if (!rproc->dbg_dir) return; debugfs_create_file("name", 0400, rproc->dbg_dir, 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) { if (debugfs_initialized()) { rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL); if (!rproc_dbg) pr_err("can't create debugfs dir\n"); } } void __exit rproc_exit_debugfs(void) { debugfs_remove(rproc_dbg); }