![David Fries](/assets/img/avatar_default.png)
The bus_mutex needs to be taken to serialize access to a specific bus. netlink wasn't updated when bus_mutex was added and was calling without that lock held, and not all of the masters were holding the bus_mutex in a search. This was causing the ds2490 hardware to stop responding when both netlink and /sys slaves were executing bus commands at the same time. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
599 lines
14 KiB
C
599 lines
14 KiB
C
/*
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* w1_netlink.c
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*
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* Copyright (c) 2003 Evgeniy Polyakov <zbr@ioremap.net>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/slab.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/connector.h>
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#include "w1.h"
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#include "w1_log.h"
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#include "w1_netlink.h"
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#if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
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void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
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{
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char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
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struct cn_msg *m = (struct cn_msg *)buf;
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struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
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memset(buf, 0, sizeof(buf));
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m->id.idx = CN_W1_IDX;
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m->id.val = CN_W1_VAL;
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m->seq = dev->seq++;
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m->len = sizeof(struct w1_netlink_msg);
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memcpy(w, msg, sizeof(struct w1_netlink_msg));
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cn_netlink_send(m, dev->portid, 0, GFP_KERNEL);
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}
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static void w1_send_slave(struct w1_master *dev, u64 rn)
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{
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struct cn_msg *msg = dev->priv;
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struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
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struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
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int avail;
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u64 *data;
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avail = dev->priv_size - cmd->len;
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if (avail < 8) {
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msg->ack++;
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cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL);
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msg->len = sizeof(struct w1_netlink_msg) +
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sizeof(struct w1_netlink_cmd);
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hdr->len = sizeof(struct w1_netlink_cmd);
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cmd->len = 0;
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}
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data = (void *)(cmd + 1) + cmd->len;
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*data = rn;
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cmd->len += 8;
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hdr->len += 8;
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msg->len += 8;
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}
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static void w1_found_send_slave(struct w1_master *dev, u64 rn)
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{
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/* update kernel slave list */
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w1_slave_found(dev, rn);
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w1_send_slave(dev, rn);
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}
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/* Get the current slave list, or search (with or without alarm) */
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static int w1_get_slaves(struct w1_master *dev,
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struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr,
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struct w1_netlink_cmd *req_cmd)
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{
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struct cn_msg *msg;
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struct w1_netlink_msg *hdr;
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struct w1_netlink_cmd *cmd;
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struct w1_slave *sl;
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msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
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if (!msg)
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return -ENOMEM;
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msg->id = req_msg->id;
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msg->seq = req_msg->seq;
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msg->ack = 0;
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msg->len = sizeof(struct w1_netlink_msg) +
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sizeof(struct w1_netlink_cmd);
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hdr = (struct w1_netlink_msg *)(msg + 1);
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cmd = (struct w1_netlink_cmd *)(hdr + 1);
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hdr->type = W1_MASTER_CMD;
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hdr->id = req_hdr->id;
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hdr->len = sizeof(struct w1_netlink_cmd);
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cmd->cmd = req_cmd->cmd;
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cmd->len = 0;
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dev->priv = msg;
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dev->priv_size = PAGE_SIZE - msg->len - sizeof(struct cn_msg);
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if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
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__u64 rn;
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mutex_lock(&dev->list_mutex);
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list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
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memcpy(&rn, &sl->reg_num, sizeof(rn));
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w1_send_slave(dev, rn);
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}
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mutex_unlock(&dev->list_mutex);
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} else {
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w1_search_process_cb(dev, cmd->cmd == W1_CMD_ALARM_SEARCH ?
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W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
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}
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msg->ack = 0;
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cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL);
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dev->priv = NULL;
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dev->priv_size = 0;
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kfree(msg);
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return 0;
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}
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static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
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struct w1_netlink_cmd *cmd, u32 portid)
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{
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void *data;
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struct w1_netlink_msg *h;
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struct w1_netlink_cmd *c;
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struct cn_msg *cm;
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int err;
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data = kzalloc(sizeof(struct cn_msg) +
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sizeof(struct w1_netlink_msg) +
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sizeof(struct w1_netlink_cmd) +
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cmd->len, GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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cm = (struct cn_msg *)(data);
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h = (struct w1_netlink_msg *)(cm + 1);
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c = (struct w1_netlink_cmd *)(h + 1);
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memcpy(cm, msg, sizeof(struct cn_msg));
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memcpy(h, hdr, sizeof(struct w1_netlink_msg));
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memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
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cm->ack = msg->seq+1;
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cm->len = sizeof(struct w1_netlink_msg) +
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sizeof(struct w1_netlink_cmd) + cmd->len;
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h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
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memcpy(c->data, cmd->data, c->len);
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err = cn_netlink_send(cm, portid, 0, GFP_KERNEL);
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kfree(data);
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return err;
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}
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static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
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struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
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{
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int err = 0;
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switch (cmd->cmd) {
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case W1_CMD_TOUCH:
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w1_touch_block(dev, cmd->data, cmd->len);
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w1_send_read_reply(msg, hdr, cmd, dev->portid);
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break;
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case W1_CMD_READ:
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w1_read_block(dev, cmd->data, cmd->len);
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w1_send_read_reply(msg, hdr, cmd, dev->portid);
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break;
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case W1_CMD_WRITE:
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w1_write_block(dev, cmd->data, cmd->len);
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break;
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default:
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err = -EINVAL;
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break;
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}
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return err;
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}
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static int w1_process_command_addremove(struct w1_master *dev,
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struct cn_msg *msg, struct w1_netlink_msg *hdr,
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struct w1_netlink_cmd *cmd)
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{
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struct w1_slave *sl;
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int err = 0;
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struct w1_reg_num *id;
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if (cmd->len != 8)
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return -EINVAL;
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id = (struct w1_reg_num *)cmd->data;
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sl = w1_slave_search_device(dev, id);
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switch (cmd->cmd) {
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case W1_CMD_SLAVE_ADD:
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if (sl)
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err = -EINVAL;
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else
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err = w1_attach_slave_device(dev, id);
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break;
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case W1_CMD_SLAVE_REMOVE:
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if (sl)
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w1_slave_detach(sl);
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else
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err = -EINVAL;
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break;
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default:
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err = -EINVAL;
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break;
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}
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return err;
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}
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static int w1_process_command_master(struct w1_master *dev,
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struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr,
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struct w1_netlink_cmd *req_cmd)
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{
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int err = -EINVAL;
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/* drop bus_mutex for search (does it's own locking), and add/remove
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* which doesn't use the bus
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*/
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switch (req_cmd->cmd) {
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case W1_CMD_SEARCH:
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case W1_CMD_ALARM_SEARCH:
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case W1_CMD_LIST_SLAVES:
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mutex_unlock(&dev->bus_mutex);
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err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
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mutex_lock(&dev->bus_mutex);
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break;
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case W1_CMD_READ:
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case W1_CMD_WRITE:
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case W1_CMD_TOUCH:
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err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd);
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break;
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case W1_CMD_RESET:
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err = w1_reset_bus(dev);
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break;
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case W1_CMD_SLAVE_ADD:
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case W1_CMD_SLAVE_REMOVE:
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mutex_unlock(&dev->bus_mutex);
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mutex_lock(&dev->mutex);
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err = w1_process_command_addremove(dev, req_msg, req_hdr,
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req_cmd);
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mutex_unlock(&dev->mutex);
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mutex_lock(&dev->bus_mutex);
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break;
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default:
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err = -EINVAL;
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break;
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}
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return err;
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}
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static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
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struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
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{
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dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
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__func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
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sl->reg_num.crc, cmd->cmd, cmd->len);
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return w1_process_command_io(sl->master, msg, hdr, cmd);
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}
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static int w1_process_command_root(struct cn_msg *msg,
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struct w1_netlink_msg *mcmd, u32 portid)
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{
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struct w1_master *m;
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struct cn_msg *cn;
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struct w1_netlink_msg *w;
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u32 *id;
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if (mcmd->type != W1_LIST_MASTERS) {
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printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
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__func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
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return -EPROTO;
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}
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cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
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if (!cn)
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return -ENOMEM;
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cn->id.idx = CN_W1_IDX;
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cn->id.val = CN_W1_VAL;
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cn->seq = msg->seq;
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cn->ack = 1;
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cn->len = sizeof(struct w1_netlink_msg);
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w = (struct w1_netlink_msg *)(cn + 1);
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w->type = W1_LIST_MASTERS;
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w->status = 0;
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w->len = 0;
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id = (u32 *)(w + 1);
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mutex_lock(&w1_mlock);
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list_for_each_entry(m, &w1_masters, w1_master_entry) {
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if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
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cn_netlink_send(cn, portid, 0, GFP_KERNEL);
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cn->ack++;
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cn->len = sizeof(struct w1_netlink_msg);
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w->len = 0;
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id = (u32 *)(w + 1);
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}
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*id = m->id;
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w->len += sizeof(*id);
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cn->len += sizeof(*id);
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id++;
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}
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cn->ack = 0;
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cn_netlink_send(cn, portid, 0, GFP_KERNEL);
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mutex_unlock(&w1_mlock);
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kfree(cn);
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return 0;
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}
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static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
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struct w1_netlink_cmd *rcmd, int portid, int error)
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{
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struct cn_msg *cmsg;
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struct w1_netlink_msg *msg;
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struct w1_netlink_cmd *cmd;
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cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL);
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if (!cmsg)
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return -ENOMEM;
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msg = (struct w1_netlink_msg *)(cmsg + 1);
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cmd = (struct w1_netlink_cmd *)(msg + 1);
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memcpy(cmsg, rcmsg, sizeof(*cmsg));
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cmsg->len = sizeof(*msg);
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memcpy(msg, rmsg, sizeof(*msg));
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msg->len = 0;
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msg->status = (short)-error;
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if (rcmd) {
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memcpy(cmd, rcmd, sizeof(*cmd));
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cmd->len = 0;
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msg->len += sizeof(*cmd);
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cmsg->len += sizeof(*cmd);
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}
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error = cn_netlink_send(cmsg, portid, 0, GFP_KERNEL);
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kfree(cmsg);
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return error;
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}
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/* Bundle together a reference count, the full message, and broken out
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* commands to be executed on each w1 master kthread in one memory allocation.
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*/
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struct w1_cb_block {
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atomic_t refcnt;
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u32 portid; /* Sending process port ID */
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struct cn_msg msg;
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/* cn_msg data */
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/* one or more variable length struct w1_cb_node */
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};
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struct w1_cb_node {
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struct w1_async_cmd async;
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/* pointers within w1_cb_block and msg data */
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struct w1_cb_block *block;
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struct w1_netlink_msg *m;
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struct w1_slave *sl;
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struct w1_master *dev;
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};
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static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
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{
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struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
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async);
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u16 mlen = node->m->len;
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u8 *cmd_data = node->m->data;
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int err = 0;
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struct w1_slave *sl = node->sl;
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struct w1_netlink_cmd *cmd = NULL;
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mutex_lock(&dev->bus_mutex);
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dev->portid = node->block->portid;
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if (sl && w1_reset_select_slave(sl))
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err = -ENODEV;
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while (mlen && !err) {
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cmd = (struct w1_netlink_cmd *)cmd_data;
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if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
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err = -E2BIG;
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break;
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}
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if (sl)
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err = w1_process_command_slave(sl, &node->block->msg,
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node->m, cmd);
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else
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err = w1_process_command_master(dev, &node->block->msg,
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node->m, cmd);
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w1_netlink_send_error(&node->block->msg, node->m, cmd,
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node->block->portid, err);
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err = 0;
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cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
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mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
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}
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if (!cmd || err)
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w1_netlink_send_error(&node->block->msg, node->m, cmd,
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node->block->portid, err);
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if (sl)
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w1_unref_slave(sl);
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else
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atomic_dec(&dev->refcnt);
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dev->portid = 0;
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mutex_unlock(&dev->bus_mutex);
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mutex_lock(&dev->list_mutex);
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list_del(&async_cmd->async_entry);
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mutex_unlock(&dev->list_mutex);
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if (atomic_sub_return(1, &node->block->refcnt) == 0)
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kfree(node->block);
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}
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static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
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{
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struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
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struct w1_slave *sl;
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struct w1_master *dev;
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u16 msg_len;
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int err = 0;
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struct w1_cb_block *block = NULL;
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struct w1_cb_node *node = NULL;
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int node_count = 0;
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/* Count the number of master or slave commands there are to allocate
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* space for one cb_node each.
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*/
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msg_len = msg->len;
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while (msg_len && !err) {
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if (m->len + sizeof(struct w1_netlink_msg) > msg_len) {
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err = -E2BIG;
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break;
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}
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if (m->type == W1_MASTER_CMD || m->type == W1_SLAVE_CMD)
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++node_count;
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msg_len -= sizeof(struct w1_netlink_msg) + m->len;
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m = (struct w1_netlink_msg *)(((u8 *)m) +
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sizeof(struct w1_netlink_msg) + m->len);
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}
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m = (struct w1_netlink_msg *)(msg + 1);
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if (node_count) {
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/* msg->len doesn't include itself */
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long size = sizeof(struct w1_cb_block) + msg->len +
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node_count*sizeof(struct w1_cb_node);
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|
block = kmalloc(size, GFP_KERNEL);
|
|
if (!block) {
|
|
w1_netlink_send_error(msg, m, NULL, nsp->portid,
|
|
-ENOMEM);
|
|
return;
|
|
}
|
|
atomic_set(&block->refcnt, 1);
|
|
block->portid = nsp->portid;
|
|
memcpy(&block->msg, msg, sizeof(*msg) + msg->len);
|
|
node = (struct w1_cb_node *)((u8 *)block->msg.data + msg->len);
|
|
}
|
|
|
|
msg_len = msg->len;
|
|
while (msg_len && !err) {
|
|
struct w1_reg_num id;
|
|
u16 mlen = m->len;
|
|
|
|
dev = NULL;
|
|
sl = NULL;
|
|
|
|
memcpy(&id, m->id.id, sizeof(id));
|
|
#if 0
|
|
printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
|
|
__func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
|
|
#endif
|
|
if (m->len + sizeof(struct w1_netlink_msg) > msg_len) {
|
|
err = -E2BIG;
|
|
break;
|
|
}
|
|
|
|
if (m->type == W1_MASTER_CMD) {
|
|
dev = w1_search_master_id(m->id.mst.id);
|
|
} else if (m->type == W1_SLAVE_CMD) {
|
|
sl = w1_search_slave(&id);
|
|
if (sl)
|
|
dev = sl->master;
|
|
} else {
|
|
err = w1_process_command_root(msg, m, nsp->portid);
|
|
goto out_cont;
|
|
}
|
|
|
|
if (!dev) {
|
|
err = -ENODEV;
|
|
goto out_cont;
|
|
}
|
|
|
|
err = 0;
|
|
if (!mlen)
|
|
goto out_cont;
|
|
|
|
atomic_inc(&block->refcnt);
|
|
node->async.cb = w1_process_cb;
|
|
node->block = block;
|
|
node->m = (struct w1_netlink_msg *)((u8 *)&block->msg +
|
|
(size_t)((u8 *)m - (u8 *)msg));
|
|
node->sl = sl;
|
|
node->dev = dev;
|
|
|
|
mutex_lock(&dev->list_mutex);
|
|
list_add_tail(&node->async.async_entry, &dev->async_list);
|
|
wake_up_process(dev->thread);
|
|
mutex_unlock(&dev->list_mutex);
|
|
++node;
|
|
|
|
out_cont:
|
|
if (err)
|
|
w1_netlink_send_error(msg, m, NULL, nsp->portid, err);
|
|
msg_len -= sizeof(struct w1_netlink_msg) + m->len;
|
|
m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
|
|
|
|
/*
|
|
* Let's allow requests for nonexisting devices.
|
|
*/
|
|
if (err == -ENODEV)
|
|
err = 0;
|
|
}
|
|
if (block && atomic_sub_return(1, &block->refcnt) == 0)
|
|
kfree(block);
|
|
}
|
|
|
|
int w1_init_netlink(void)
|
|
{
|
|
struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
|
|
|
|
return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
|
|
}
|
|
|
|
void w1_fini_netlink(void)
|
|
{
|
|
struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
|
|
|
|
cn_del_callback(&w1_id);
|
|
}
|
|
#else
|
|
void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
|
|
{
|
|
}
|
|
|
|
int w1_init_netlink(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void w1_fini_netlink(void)
|
|
{
|
|
}
|
|
#endif
|