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/*
* w1_int.c
*
* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/delay.h>
#include "w1.h"
#include "w1_log.h"
#include "w1_netlink.h"
static u32 w1_ids = 1;
extern struct device_driver w1_master_driver;
extern struct bus_type w1_bus_type;
extern struct device w1_master_device;
extern int w1_max_slave_count;
extern int w1_max_slave_ttl;
extern struct list_head w1_masters;
extern spinlock_t w1_mlock;
extern int w1_process(void *);
static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
struct device_driver *driver,
struct device *device)
{
struct w1_master *dev;
int err;
/*
* We are in process context(kernel thread), so can sleep.
*/
dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
if (!dev) {
printk(KERN_ERR
"Failed to allocate %zd bytes for new w1 device.\n",
sizeof(struct w1_master));
return NULL;
}
memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
dev->bus_master = (struct w1_bus_master *)(dev + 1);
dev->owner = THIS_MODULE;
dev->max_slave_count = slave_count;
dev->slave_count = 0;
dev->attempts = 0;
dev->kpid = -1;
dev->initialized = 0;
dev->id = id;
dev->slave_ttl = slave_ttl;
dev->search_count = -1; /* continual scan */
atomic_set(&dev->refcnt, 2);
INIT_LIST_HEAD(&dev->slist);
init_MUTEX(&dev->mutex);
init_completion(&dev->dev_exited);
memcpy(&dev->dev, device, sizeof(struct device));
snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
"w1_bus_master%u", dev->id);
snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
dev->driver = driver;
dev->groups = 1;
dev->seq = 1;
dev_init_netlink(dev);
err = device_register(&dev->dev);
if (err) {
printk(KERN_ERR "Failed to register master device. err=%d\n", err);
dev_fini_netlink(dev);
memset(dev, 0, sizeof(struct w1_master));
kfree(dev);
dev = NULL;
}
return dev;
}
void w1_free_dev(struct w1_master *dev)
{
device_unregister(&dev->dev);
}
int w1_add_master_device(struct w1_bus_master *master)
{
struct w1_master *dev;
int retval = 0;
struct w1_netlink_msg msg;
/* validate minimum functionality */
if (!(master->touch_bit && master->reset_bus) &&
!(master->write_bit && master->read_bit)) {
printk(KERN_ERR "w1_add_master_device: invalid function set\n");
return(-EINVAL);
}
dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
if (!dev)
return -ENOMEM;
dev->kpid = kernel_thread(&w1_process, dev, 0);
if (dev->kpid < 0) {
dev_err(&dev->dev,
"Failed to create new kernel thread. err=%d\n",
dev->kpid);
retval = dev->kpid;
goto err_out_free_dev;
}
retval = w1_create_master_attributes(dev);
if (retval)
goto err_out_kill_thread;
memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
dev->initialized = 1;
spin_lock(&w1_mlock);
list_add(&dev->w1_master_entry, &w1_masters);
spin_unlock(&w1_mlock);
msg.id.mst.id = dev->id;
msg.id.mst.pid = dev->kpid;
msg.type = W1_MASTER_ADD;
w1_netlink_send(dev, &msg);
return 0;
err_out_kill_thread:
set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
if (kill_proc(dev->kpid, SIGTERM, 1))
dev_err(&dev->dev,
"Failed to send signal to w1 kernel thread %d.\n",
dev->kpid);
wait_for_completion(&dev->dev_exited);
err_out_free_dev:
w1_free_dev(dev);
return retval;
}
void __w1_remove_master_device(struct w1_master *dev)
{
int err;
struct w1_netlink_msg msg;
set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
err = kill_proc(dev->kpid, SIGTERM, 1);
if (err)
dev_err(&dev->dev,
"%s: Failed to send signal to w1 kernel thread %d.\n",
__func__, dev->kpid);
while (atomic_read(&dev->refcnt)) {
dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
dev->name, atomic_read(&dev->refcnt));
if (msleep_interruptible(1000))
flush_signals(current);
}
msg.id.mst.id = dev->id;
msg.id.mst.pid = dev->kpid;
msg.type = W1_MASTER_REMOVE;
w1_netlink_send(dev, &msg);
w1_free_dev(dev);
}
void w1_remove_master_device(struct w1_bus_master *bm)
{
struct w1_master *dev = NULL;
list_for_each_entry(dev, &w1_masters, w1_master_entry) {
if (!dev->initialized)
continue;
if (dev->bus_master->data == bm->data)
break;
}
if (!dev) {
printk(KERN_ERR "Device doesn't exist.\n");
return;
}
__w1_remove_master_device(dev);
}
EXPORT_SYMBOL(w1_add_master_device);
EXPORT_SYMBOL(w1_remove_master_device);
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_W1);
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