linux/drivers/isdn/hardware/eicon/divamnt.c
Alison Schofield 096f6262c5 isdn: divamnt: use y2038-safe ktime_get_ts64() for trace data timestamps
divamnt stores a start_time at module init and uses it to calculate
elapsed time. The elapsed time, stored in secs and usecs, is part of
the trace data the driver maintains for the DIVA Server ISDN cards.
No change to the format of that time data is required.

To avoid overflow on 32-bit systems use ktime_get_ts64() to return
the elapsed monotonic time since system boot.

This is a change from real to monotonic time. Since the driver only
stores elapsed time, monotonic time is sufficient and more robust
against real time clock changes. These new monotonic values can be
more useful for debugging because they can be easily compared to
other monotonic timestamps.

Note elaspsed time values will now start at system boot time rather
than module load time, so they will differ slightly from previously
reported values.

Remove declaration and init of previously unused time constants:
start_sec, start_usec.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:09:30 -05:00

240 lines
5.0 KiB
C

/* $Id: divamnt.c,v 1.32.6.10 2005/02/11 19:40:25 armin Exp $
*
* Driver for Eicon DIVA Server ISDN cards.
* Maint module
*
* Copyright 2000-2003 by Armin Schindler (mac@melware.de)
* Copyright 2000-2003 Cytronics & Melware (info@melware.de)
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include "platform.h"
#include "di_defs.h"
#include "divasync.h"
#include "debug_if.h"
static DEFINE_MUTEX(maint_mutex);
static char *main_revision = "$Revision: 1.32.6.10 $";
static int major;
MODULE_DESCRIPTION("Maint driver for Eicon DIVA Server cards");
MODULE_AUTHOR("Cytronics & Melware, Eicon Networks");
MODULE_SUPPORTED_DEVICE("DIVA card driver");
MODULE_LICENSE("GPL");
static int buffer_length = 128;
module_param(buffer_length, int, 0);
static unsigned long diva_dbg_mem = 0;
module_param(diva_dbg_mem, ulong, 0);
static char *DRIVERNAME =
"Eicon DIVA - MAINT module (http://www.melware.net)";
static char *DRIVERLNAME = "diva_mnt";
static char *DEVNAME = "DivasMAINT";
char *DRIVERRELEASE_MNT = "2.0";
static wait_queue_head_t msgwaitq;
static unsigned long opened;
extern int mntfunc_init(int *, void **, unsigned long);
extern void mntfunc_finit(void);
extern int maint_read_write(void __user *buf, int count);
/*
* helper functions
*/
static char *getrev(const char *revision)
{
char *rev;
char *p;
if ((p = strchr(revision, ':'))) {
rev = p + 2;
p = strchr(rev, '$');
*--p = 0;
} else
rev = "1.0";
return rev;
}
/*
* kernel/user space copy functions
*/
int diva_os_copy_to_user(void *os_handle, void __user *dst, const void *src,
int length)
{
return (copy_to_user(dst, src, length));
}
int diva_os_copy_from_user(void *os_handle, void *dst, const void __user *src,
int length)
{
return (copy_from_user(dst, src, length));
}
/*
* get time
*/
void diva_os_get_time(dword *sec, dword *usec)
{
struct timespec64 time;
ktime_get_ts64(&time);
*sec = (dword) time.tv_sec;
*usec = (dword) (time.tv_nsec / NSEC_PER_USEC);
}
/*
* device node operations
*/
static unsigned int maint_poll(struct file *file, poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, &msgwaitq, wait);
mask = POLLOUT | POLLWRNORM;
if (file->private_data || diva_dbg_q_length()) {
mask |= POLLIN | POLLRDNORM;
}
return (mask);
}
static int maint_open(struct inode *ino, struct file *filep)
{
int ret;
mutex_lock(&maint_mutex);
/* only one open is allowed, so we test
it atomically */
if (test_and_set_bit(0, &opened))
ret = -EBUSY;
else {
filep->private_data = NULL;
ret = nonseekable_open(ino, filep);
}
mutex_unlock(&maint_mutex);
return ret;
}
static int maint_close(struct inode *ino, struct file *filep)
{
if (filep->private_data) {
diva_os_free(0, filep->private_data);
filep->private_data = NULL;
}
/* clear 'used' flag */
clear_bit(0, &opened);
return (0);
}
static ssize_t divas_maint_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return (maint_read_write((char __user *) buf, (int) count));
}
static ssize_t divas_maint_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return (maint_read_write(buf, (int) count));
}
static const struct file_operations divas_maint_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = divas_maint_read,
.write = divas_maint_write,
.poll = maint_poll,
.open = maint_open,
.release = maint_close
};
static void divas_maint_unregister_chrdev(void)
{
unregister_chrdev(major, DEVNAME);
}
static int __init divas_maint_register_chrdev(void)
{
if ((major = register_chrdev(0, DEVNAME, &divas_maint_fops)) < 0)
{
printk(KERN_ERR "%s: failed to create /dev entry.\n",
DRIVERLNAME);
return (0);
}
return (1);
}
/*
* wake up reader
*/
void diva_maint_wakeup_read(void)
{
wake_up_interruptible(&msgwaitq);
}
/*
* Driver Load
*/
static int __init maint_init(void)
{
char tmprev[50];
int ret = 0;
void *buffer = NULL;
init_waitqueue_head(&msgwaitq);
printk(KERN_INFO "%s\n", DRIVERNAME);
printk(KERN_INFO "%s: Rel:%s Rev:", DRIVERLNAME, DRIVERRELEASE_MNT);
strcpy(tmprev, main_revision);
printk("%s Build: %s \n", getrev(tmprev), DIVA_BUILD);
if (!divas_maint_register_chrdev()) {
ret = -EIO;
goto out;
}
if (!(mntfunc_init(&buffer_length, &buffer, diva_dbg_mem))) {
printk(KERN_ERR "%s: failed to connect to DIDD.\n",
DRIVERLNAME);
divas_maint_unregister_chrdev();
ret = -EIO;
goto out;
}
printk(KERN_INFO "%s: trace buffer = %p - %d kBytes, %s (Major: %d)\n",
DRIVERLNAME, buffer, (buffer_length / 1024),
(diva_dbg_mem == 0) ? "internal" : "external", major);
out:
return (ret);
}
/*
** Driver Unload
*/
static void __exit maint_exit(void)
{
divas_maint_unregister_chrdev();
mntfunc_finit();
printk(KERN_INFO "%s: module unloaded.\n", DRIVERLNAME);
}
module_init(maint_init);
module_exit(maint_exit);