From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/remoteproc/remoteproc_debugfs.c | 252 ++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 drivers/remoteproc/remoteproc_debugfs.c (limited to 'drivers/remoteproc/remoteproc_debugfs.c') diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c new file mode 100644 index 000000000..9d30809bb --- /dev/null +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -0,0 +1,252 @@ +/* + * Remote Processor Framework + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen + * Mark Grosen + * Brian Swetland + * Fernando Guzman Lugo + * Suman Anna + * Robert Tivy + * Armando Uribe De Leon + * + * 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 +#include +#include +#include +#include + +#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); +} -- cgit v1.2.3-54-g00ecf