88 строки
2.2 KiB
C
88 строки
2.2 KiB
C
|
/*
|
||
|
|
* Simple kernel driver to link kernel Ftrace and an STM device
|
||
|
|
* Copyright (c) 2016, Linaro Ltd.
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify it
|
||
|
|
* under the terms and conditions of the GNU General Public License,
|
||
|
|
* version 2, as published by the Free Software Foundation.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope 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.
|
||
|
|
*
|
||
|
|
* STM Ftrace will be registered as a trace_export.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/stm.h>
|
||
|
|
#include <linux/trace.h>
|
||
|
|
|
||
|
|
#define STM_FTRACE_NR_CHANNELS 1
|
||
|
|
#define STM_FTRACE_CHAN 0
|
||
|
|
|
||
|
|
static int stm_ftrace_link(struct stm_source_data *data);
|
||
|
|
static void stm_ftrace_unlink(struct stm_source_data *data);
|
||
|
|
|
||
|
|
static struct stm_ftrace {
|
||
|
|
struct stm_source_data data;
|
||
|
|
struct trace_export ftrace;
|
||
|
|
} stm_ftrace = {
|
||
|
|
.data = {
|
||
|
|
.name = "ftrace",
|
||
|
|
.nr_chans = STM_FTRACE_NR_CHANNELS,
|
||
|
|
.link = stm_ftrace_link,
|
||
|
|
.unlink = stm_ftrace_unlink,
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* stm_ftrace_write() - write data to STM via 'stm_ftrace' source
|
||
|
|
* @buf: buffer containing the data packet
|
||
|
|
* @len: length of the data packet
|
||
|
|
*/
|
||
|
|
static void notrace
|
||
|
|
stm_ftrace_write(const void *buf, unsigned int len)
|
||
|
|
{
|
||
|
|
stm_source_write(&stm_ftrace.data, STM_FTRACE_CHAN, buf, len);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int stm_ftrace_link(struct stm_source_data *data)
|
||
|
|
{
|
||
|
|
struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data);
|
||
|
|
|
||
|
|
sf->ftrace.write = stm_ftrace_write;
|
||
|
|
|
||
|
|
return register_ftrace_export(&sf->ftrace);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void stm_ftrace_unlink(struct stm_source_data *data)
|
||
|
|
{
|
||
|
|
struct stm_ftrace *sf = container_of(data, struct stm_ftrace, data);
|
||
|
|
|
||
|
|
unregister_ftrace_export(&sf->ftrace);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int __init stm_ftrace_init(void)
|
||
|
|
{
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
ret = stm_source_register_device(NULL, &stm_ftrace.data);
|
||
|
|
if (ret)
|
||
|
|
pr_err("Failed to register stm_source - ftrace.\n");
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit stm_ftrace_exit(void)
|
||
|
|
{
|
||
|
|
stm_source_unregister_device(&stm_ftrace.data);
|
||
|
|
}
|
||
|
|
|
||
|
|
module_init(stm_ftrace_init);
|
||
|
|
module_exit(stm_ftrace_exit);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL v2");
|
||
|
|
MODULE_DESCRIPTION("stm_ftrace driver");
|
||
|
|
MODULE_AUTHOR("Chunyan Zhang <zhang.chunyan@linaro.org>");
|