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/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only 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.
*
*/
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/idr.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/ipc_logging.h>
#include "ipc_logging_private.h"
static DEFINE_MUTEX(ipc_log_debugfs_init_lock);
static struct dentry *root_dent;
static int debug_log(struct ipc_log_context *ilctxt,
char *buff, int size, int cont)
{
int i = 0;
int ret;
if (size < MAX_MSG_DECODED_SIZE) {
pr_err("%s: buffer size %d < %d\n", __func__, size,
MAX_MSG_DECODED_SIZE);
return -ENOMEM;
}
do {
i = ipc_log_extract(ilctxt, buff, size - 1);
if (cont && i == 0) {
ret = wait_for_completion_interruptible(
&ilctxt->read_avail);
if (ret < 0)
return ret;
}
} while (cont && i == 0);
return i;
}
/*
* VFS Read operation helper which dispatches the call to the debugfs
* read command stored in file->private_data.
*
* @file File structure
* @buff user buffer
* @count size of user buffer
* @ppos file position to read from (only a value of 0 is accepted)
* @cont 1 = continuous mode (don't return 0 to signal end-of-file)
*
* @returns ==0 end of file
* >0 number of bytes read
* <0 error
*/
static ssize_t debug_read_helper(struct file *file, char __user *buff,
size_t count, loff_t *ppos, int cont)
{
struct ipc_log_context *ilctxt = file->private_data;
char *buffer;
int bsize;
buffer = kmalloc(count, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
bsize = debug_log(ilctxt, buffer, count, cont);
if (bsize > 0) {
if (copy_to_user(buff, buffer, bsize)) {
kfree(buffer);
return -EFAULT;
}
*ppos += bsize;
}
kfree(buffer);
return bsize;
}
static ssize_t debug_read(struct file *file, char __user *buff,
size_t count, loff_t *ppos)
{
return debug_read_helper(file, buff, count, ppos, 0);
}
static ssize_t debug_read_cont(struct file *file, char __user *buff,
size_t count, loff_t *ppos)
{
return debug_read_helper(file, buff, count, ppos, 1);
}
static int debug_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static const struct file_operations debug_ops = {
.read = debug_read,
.open = debug_open,
};
static const struct file_operations debug_ops_cont = {
.read = debug_read_cont,
.open = debug_open,
};
static void debug_create(const char *name, mode_t mode,
struct dentry *dent,
struct ipc_log_context *ilctxt,
const struct file_operations *fops)
{
debugfs_create_file(name, mode, dent, ilctxt, fops);
}
static void dfunc_string(struct encode_context *ectxt,
struct decode_context *dctxt)
{
tsv_timestamp_read(ectxt, dctxt, "");
tsv_qtimer_read(ectxt, dctxt, " ");
tsv_byte_array_read(ectxt, dctxt, "");
/* add trailing \n if necessary */
if (*(dctxt->buff - 1) != '\n') {
if (dctxt->size) {
++dctxt->buff;
--dctxt->size;
}
*(dctxt->buff - 1) = '\n';
}
}
void check_and_create_debugfs(void)
{
mutex_lock(&ipc_log_debugfs_init_lock);
if (!root_dent) {
root_dent = debugfs_create_dir("ipc_logging", 0);
if (IS_ERR(root_dent)) {
pr_err("%s: unable to create debugfs %ld\n",
__func__, PTR_ERR(root_dent));
root_dent = NULL;
}
}
mutex_unlock(&ipc_log_debugfs_init_lock);
}
EXPORT_SYMBOL(check_and_create_debugfs);
void create_ctx_debugfs(struct ipc_log_context *ctxt,
const char *mod_name)
{
if (!root_dent)
check_and_create_debugfs();
if (root_dent) {
ctxt->dent = debugfs_create_dir(mod_name, root_dent);
if (!IS_ERR(ctxt->dent)) {
debug_create("log", 0444, ctxt->dent,
ctxt, &debug_ops);
debug_create("log_cont", 0444, ctxt->dent,
ctxt, &debug_ops_cont);
}
}
add_deserialization_func((void *)ctxt,
TSV_TYPE_STRING, dfunc_string);
}
EXPORT_SYMBOL(create_ctx_debugfs);
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