11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * w1_int.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4SLinus Torvalds * it under the terms of the GNU General Public License as published by 91da177e4SLinus Torvalds * the Free Software Foundation; either version 2 of the License, or 101da177e4SLinus Torvalds * (at your option) any later version. 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * This program is distributed in the hope that it will be useful, 131da177e4SLinus Torvalds * but WITHOUT ANY WARRANTY; without even the implied warranty of 141da177e4SLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 151da177e4SLinus Torvalds * GNU General Public License for more details. 161da177e4SLinus Torvalds * 171da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License 181da177e4SLinus Torvalds * along with this program; if not, write to the Free Software 191da177e4SLinus Torvalds * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 201da177e4SLinus Torvalds */ 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds #include <linux/kernel.h> 231da177e4SLinus Torvalds #include <linux/list.h> 241da177e4SLinus Torvalds #include <linux/delay.h> 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds #include "w1.h" 271da177e4SLinus Torvalds #include "w1_log.h" 281da177e4SLinus Torvalds #include "w1_netlink.h" 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds static u32 w1_ids = 1; 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds extern struct device_driver w1_driver; 331da177e4SLinus Torvalds extern struct bus_type w1_bus_type; 341da177e4SLinus Torvalds extern struct device w1_device; 351da177e4SLinus Torvalds extern int w1_max_slave_count; 361da177e4SLinus Torvalds extern int w1_max_slave_ttl; 371da177e4SLinus Torvalds extern struct list_head w1_masters; 381da177e4SLinus Torvalds extern spinlock_t w1_mlock; 391da177e4SLinus Torvalds 401da177e4SLinus Torvalds extern int w1_process(void *); 411da177e4SLinus Torvalds 427785925dSEvgeniy Polyakov static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, 437785925dSEvgeniy Polyakov struct device_driver *driver, 447785925dSEvgeniy Polyakov struct device *device) 451da177e4SLinus Torvalds { 461da177e4SLinus Torvalds struct w1_master *dev; 471da177e4SLinus Torvalds int err; 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds /* 501da177e4SLinus Torvalds * We are in process context(kernel thread), so can sleep. 511da177e4SLinus Torvalds */ 521da177e4SLinus Torvalds dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); 531da177e4SLinus Torvalds if (!dev) { 541da177e4SLinus Torvalds printk(KERN_ERR 551da177e4SLinus Torvalds "Failed to allocate %zd bytes for new w1 device.\n", 561da177e4SLinus Torvalds sizeof(struct w1_master)); 571da177e4SLinus Torvalds return NULL; 581da177e4SLinus Torvalds } 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds dev->bus_master = (struct w1_bus_master *)(dev + 1); 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds dev->owner = THIS_MODULE; 651da177e4SLinus Torvalds dev->max_slave_count = slave_count; 661da177e4SLinus Torvalds dev->slave_count = 0; 671da177e4SLinus Torvalds dev->attempts = 0; 681da177e4SLinus Torvalds dev->kpid = -1; 691da177e4SLinus Torvalds dev->initialized = 0; 701da177e4SLinus Torvalds dev->id = id; 711da177e4SLinus Torvalds dev->slave_ttl = slave_ttl; 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds atomic_set(&dev->refcnt, 2); 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds INIT_LIST_HEAD(&dev->slist); 761da177e4SLinus Torvalds init_MUTEX(&dev->mutex); 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds init_completion(&dev->dev_released); 791da177e4SLinus Torvalds init_completion(&dev->dev_exited); 801da177e4SLinus Torvalds 811da177e4SLinus Torvalds memcpy(&dev->dev, device, sizeof(struct device)); 821da177e4SLinus Torvalds snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id), 831da177e4SLinus Torvalds "w1_bus_master%u", dev->id); 841da177e4SLinus Torvalds snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); 851da177e4SLinus Torvalds 861da177e4SLinus Torvalds dev->driver = driver; 871da177e4SLinus Torvalds 881da177e4SLinus Torvalds dev->groups = 23; 891da177e4SLinus Torvalds dev->seq = 1; 901da177e4SLinus Torvalds dev->nls = netlink_kernel_create(NETLINK_NFLOG, NULL); 911da177e4SLinus Torvalds if (!dev->nls) { 921da177e4SLinus Torvalds printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n", 931da177e4SLinus Torvalds NETLINK_NFLOG, dev->dev.bus_id); 941da177e4SLinus Torvalds } 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds err = device_register(&dev->dev); 971da177e4SLinus Torvalds if (err) { 981da177e4SLinus Torvalds printk(KERN_ERR "Failed to register master device. err=%d\n", err); 991da177e4SLinus Torvalds if (dev->nls && dev->nls->sk_socket) 1001da177e4SLinus Torvalds sock_release(dev->nls->sk_socket); 1011da177e4SLinus Torvalds memset(dev, 0, sizeof(struct w1_master)); 1021da177e4SLinus Torvalds kfree(dev); 1031da177e4SLinus Torvalds dev = NULL; 1041da177e4SLinus Torvalds } 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds return dev; 1071da177e4SLinus Torvalds } 1081da177e4SLinus Torvalds 1097785925dSEvgeniy Polyakov static void w1_free_dev(struct w1_master *dev) 1101da177e4SLinus Torvalds { 1111da177e4SLinus Torvalds device_unregister(&dev->dev); 1121da177e4SLinus Torvalds if (dev->nls && dev->nls->sk_socket) 1131da177e4SLinus Torvalds sock_release(dev->nls->sk_socket); 1141da177e4SLinus Torvalds memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); 1151da177e4SLinus Torvalds kfree(dev); 1161da177e4SLinus Torvalds } 1171da177e4SLinus Torvalds 1181da177e4SLinus Torvalds int w1_add_master_device(struct w1_bus_master *master) 1191da177e4SLinus Torvalds { 1201da177e4SLinus Torvalds struct w1_master *dev; 1211da177e4SLinus Torvalds int retval = 0; 1221da177e4SLinus Torvalds struct w1_netlink_msg msg; 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device); 1251da177e4SLinus Torvalds if (!dev) 1261da177e4SLinus Torvalds return -ENOMEM; 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds dev->kpid = kernel_thread(&w1_process, dev, 0); 1291da177e4SLinus Torvalds if (dev->kpid < 0) { 1301da177e4SLinus Torvalds dev_err(&dev->dev, 1311da177e4SLinus Torvalds "Failed to create new kernel thread. err=%d\n", 1321da177e4SLinus Torvalds dev->kpid); 1331da177e4SLinus Torvalds retval = dev->kpid; 1341da177e4SLinus Torvalds goto err_out_free_dev; 1351da177e4SLinus Torvalds } 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds retval = w1_create_master_attributes(dev); 1381da177e4SLinus Torvalds if (retval) 1391da177e4SLinus Torvalds goto err_out_kill_thread; 1401da177e4SLinus Torvalds 1411da177e4SLinus Torvalds memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds dev->initialized = 1; 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvalds spin_lock(&w1_mlock); 1461da177e4SLinus Torvalds list_add(&dev->w1_master_entry, &w1_masters); 1471da177e4SLinus Torvalds spin_unlock(&w1_mlock); 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds msg.id.mst.id = dev->id; 1501da177e4SLinus Torvalds msg.id.mst.pid = dev->kpid; 1511da177e4SLinus Torvalds msg.type = W1_MASTER_ADD; 1521da177e4SLinus Torvalds w1_netlink_send(dev, &msg); 1531da177e4SLinus Torvalds 1541da177e4SLinus Torvalds return 0; 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds err_out_kill_thread: 1571da177e4SLinus Torvalds dev->need_exit = 1; 1581da177e4SLinus Torvalds if (kill_proc(dev->kpid, SIGTERM, 1)) 1591da177e4SLinus Torvalds dev_err(&dev->dev, 1601da177e4SLinus Torvalds "Failed to send signal to w1 kernel thread %d.\n", 1611da177e4SLinus Torvalds dev->kpid); 1621da177e4SLinus Torvalds wait_for_completion(&dev->dev_exited); 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds err_out_free_dev: 1651da177e4SLinus Torvalds w1_free_dev(dev); 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds return retval; 1681da177e4SLinus Torvalds } 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds void __w1_remove_master_device(struct w1_master *dev) 1711da177e4SLinus Torvalds { 1721da177e4SLinus Torvalds int err; 1731da177e4SLinus Torvalds struct w1_netlink_msg msg; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds dev->need_exit = 1; 1761da177e4SLinus Torvalds err = kill_proc(dev->kpid, SIGTERM, 1); 1771da177e4SLinus Torvalds if (err) 1781da177e4SLinus Torvalds dev_err(&dev->dev, 1791da177e4SLinus Torvalds "%s: Failed to send signal to w1 kernel thread %d.\n", 1801da177e4SLinus Torvalds __func__, dev->kpid); 1811da177e4SLinus Torvalds 1821da177e4SLinus Torvalds while (atomic_read(&dev->refcnt)) { 1831da177e4SLinus Torvalds printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", 1841da177e4SLinus Torvalds dev->name, atomic_read(&dev->refcnt)); 1851da177e4SLinus Torvalds 1861da177e4SLinus Torvalds if (msleep_interruptible(1000)) 1871da177e4SLinus Torvalds flush_signals(current); 1881da177e4SLinus Torvalds } 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds msg.id.mst.id = dev->id; 1911da177e4SLinus Torvalds msg.id.mst.pid = dev->kpid; 1921da177e4SLinus Torvalds msg.type = W1_MASTER_REMOVE; 1931da177e4SLinus Torvalds w1_netlink_send(dev, &msg); 1941da177e4SLinus Torvalds 1951da177e4SLinus Torvalds w1_free_dev(dev); 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds 1981da177e4SLinus Torvalds void w1_remove_master_device(struct w1_bus_master *bm) 1991da177e4SLinus Torvalds { 2001da177e4SLinus Torvalds struct w1_master *dev = NULL; 2011da177e4SLinus Torvalds 2027785925dSEvgeniy Polyakov list_for_each_entry(dev, &w1_masters, w1_master_entry) { 2031da177e4SLinus Torvalds if (!dev->initialized) 2041da177e4SLinus Torvalds continue; 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds if (dev->bus_master->data == bm->data) 2071da177e4SLinus Torvalds break; 2081da177e4SLinus Torvalds } 2091da177e4SLinus Torvalds 2101da177e4SLinus Torvalds if (!dev) { 2111da177e4SLinus Torvalds printk(KERN_ERR "Device doesn't exist.\n"); 2121da177e4SLinus Torvalds return; 2131da177e4SLinus Torvalds } 2141da177e4SLinus Torvalds 2151da177e4SLinus Torvalds __w1_remove_master_device(dev); 2161da177e4SLinus Torvalds } 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds EXPORT_SYMBOL(w1_add_master_device); 2191da177e4SLinus Torvalds EXPORT_SYMBOL(w1_remove_master_device); 220