--- /dev/null
+/*
+ * 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);
+}
Code Review / kvmfornfv.git / blobdiff