1 /* arch/arm/mach-msm/qdsp5/evlog.h
3 * simple event log debugging facility
5 * Copyright (C) 2008 Google, Inc.
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
19 #include <linux/hrtimer.h>
20 #include <linux/debugfs.h>
22 #define EV_LOG_ENTRY_NAME(n) n##_entry
24 #define DECLARE_LOG(_name, _size, _str) \
25 static struct ev_entry EV_LOG_ENTRY_NAME(_name)[_size]; \
26 static struct ev_log _name = { \
29 .num_strings = ARRAY_SIZE(_str), \
30 .entry = EV_LOG_ENTRY_NAME(_name), \
31 .max = ARRAY_SIZE(EV_LOG_ENTRY_NAME(_name)), \
41 struct ev_entry *entry;
50 static char ev_buf[4096];
52 static ssize_t ev_log_read(struct file *file, char __user *buf,
53 size_t count, loff_t *ppos)
55 struct ev_log *log = file->private_data;
56 struct ev_entry *entry;
64 local_irq_save(flags);
65 n = (log->next - 1) & (max - 1);
67 while (n != log->next) {
68 t = ktime_sub(now, entry[n].when);
72 if (id < log->num_strings)
73 str = log->strings[id];
76 size += scnprintf(ev_buf + size, 4096 - size,
78 t.tv.sec, t.tv.nsec / 1000000,
81 n = (n - 1) & (max - 1);
84 local_irq_restore(flags);
85 return simple_read_from_buffer(buf, count, ppos, ev_buf, size);
88 static void ev_log_write(struct ev_log *log, unsigned id, unsigned arg)
90 struct ev_entry *entry;
92 local_irq_save(flags);
100 entry = log->entry + log->next;
101 entry->when = ktime_get();
104 log->next = (log->next + 1) & (log->max - 1);
106 local_irq_restore(flags);
109 static void ev_log_freeze(struct ev_log *log, unsigned count)
112 local_irq_save(flags);
114 local_irq_restore(flags);
117 static int ev_log_open(struct inode *inode, struct file *file)
119 file->private_data = inode->i_private;
123 static const struct file_operations ev_log_ops = {
126 .llseek = default_llseek,
129 static int ev_log_init(struct ev_log *log)
131 debugfs_create_file(log->name, 0444, 0, log, &ev_log_ops);