linux/kernel/trace/trace_mmiotrace.c

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/*
* Memory mapped I/O tracing
*
* Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
*/
#define DEBUG 1
#include <linux/kernel.h>
#include <linux/mmiotrace.h>
#include "trace.h"
extern void
__trace_special(void *__tr, void *__data,
unsigned long arg1, unsigned long arg2, unsigned long arg3);
static struct trace_array *mmio_trace_array;
static void mmio_trace_init(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
mmio_trace_array = tr;
if (tr->ctrl)
enable_mmiotrace();
}
static void mmio_trace_reset(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
if (tr->ctrl)
disable_mmiotrace();
}
static void mmio_trace_ctrl_update(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
if (tr->ctrl)
enable_mmiotrace();
else
disable_mmiotrace();
}
static struct tracer mmio_tracer __read_mostly =
{
.name = "mmiotrace",
.init = mmio_trace_init,
.reset = mmio_trace_reset,
.ctrl_update = mmio_trace_ctrl_update,
};
__init static int init_mmio_trace(void)
{
int ret = init_mmiotrace();
if (ret)
return ret;
return register_tracer(&mmio_tracer);
}
device_initcall(init_mmio_trace);
void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg)
{
struct trace_array *tr = mmio_trace_array;
struct trace_array_cpu *data = tr->data[smp_processor_id()];
if (!current || current->pid == 0) {
/*
* XXX: This is a problem. We need to able to record, no
* matter what. tracing_generic_entry_update() would crash.
*/
static unsigned limit;
if (limit++ < 12)
pr_err("Error in %s: no current.\n", __func__);
return;
}
if (!tr || !data) {
static unsigned limit;
if (limit++ < 12)
pr_err("%s: no tr or data\n", __func__);
return;
}
__trace_special(tr, data, type, addr, arg);
}