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/* arch/arm/mach-msm/qdsp5/evlog.h
*
* simple event log debugging facility
*
* Copyright (C) 2008 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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/fs.h>
#include <linux/hrtimer.h>
#include <linux/debugfs.h>
#define EV_LOG_ENTRY_NAME(n) n##_entry
#define DECLARE_LOG(_name, _size, _str) \
static struct ev_entry EV_LOG_ENTRY_NAME(_name)[_size]; \
static struct ev_log _name = { \
.name = #_name, \
.strings = _str, \
.num_strings = ARRAY_SIZE(_str), \
.entry = EV_LOG_ENTRY_NAME(_name), \
.max = ARRAY_SIZE(EV_LOG_ENTRY_NAME(_name)), \
}
struct ev_entry {
ktime_t when;
uint32_t id;
uint32_t arg;
};
struct ev_log {
struct ev_entry *entry;
unsigned max;
unsigned next;
unsigned fault;
const char **strings;
unsigned num_strings;
const char *name;
};
static char ev_buf[4096];
static ssize_t ev_log_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct ev_log *log = file->private_data;
struct ev_entry *entry;
unsigned long flags;
int size = 0;
unsigned n, id, max;
ktime_t now, t;
max = log->max;
now = ktime_get();
local_irq_save(flags);
n = (log->next - 1) & (max - 1);
entry = log->entry;
while (n != log->next) {
t = ktime_sub(now, entry[n].when);
id = entry[n].id;
if (id) {
const char *str;
if (id < log->num_strings)
str = log->strings[id];
else
str = "UNKNOWN";
size += scnprintf(ev_buf + size, 4096 - size,
"%8d.%03d %08x %s\n",
t.tv.sec, t.tv.nsec / 1000000,
entry[n].arg, str);
}
n = (n - 1) & (max - 1);
}
log->fault = 0;
local_irq_restore(flags);
return simple_read_from_buffer(buf, count, ppos, ev_buf, size);
}
static void ev_log_write(struct ev_log *log, unsigned id, unsigned arg)
{
struct ev_entry *entry;
unsigned long flags;
local_irq_save(flags);
if (log->fault) {
if (log->fault == 1)
goto done;
log->fault--;
}
entry = log->entry + log->next;
entry->when = ktime_get();
entry->id = id;
entry->arg = arg;
log->next = (log->next + 1) & (log->max - 1);
done:
local_irq_restore(flags);
}
static void ev_log_freeze(struct ev_log *log, unsigned count)
{
unsigned long flags;
local_irq_save(flags);
log->fault = count;
local_irq_restore(flags);
}
static int ev_log_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static const struct file_operations ev_log_ops = {
.read = ev_log_read,
.open = ev_log_open,
};
static int ev_log_init(struct ev_log *log)
{
debugfs_create_file(log->name, 0444, 0, log, &ev_log_ops);
return 0;
}
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