1 /*******************************************************************************
2  * This file contains the iSCSI Virtual Device and Disk Transport
3  * agnostic related functions.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  ******************************************************************************/
19 
20 #include <target/target_core_base.h>
21 #include <target/target_core_fabric.h>
22 
23 #include <target/iscsi/iscsi_target_core.h>
24 #include "iscsi_target_device.h"
25 #include "iscsi_target_tpg.h"
26 #include "iscsi_target_util.h"
27 
28 void iscsit_determine_maxcmdsn(struct iscsi_session *sess)
29 {
30 	struct se_node_acl *se_nacl;
31 
32 	/*
33 	 * This is a discovery session, the single queue slot was already
34 	 * assigned in iscsi_login_zero_tsih().  Since only Logout and
35 	 * Text Opcodes are allowed during discovery we do not have to worry
36 	 * about the HBA's queue depth here.
37 	 */
38 	if (sess->sess_ops->SessionType)
39 		return;
40 
41 	se_nacl = sess->se_sess->se_node_acl;
42 
43 	/*
44 	 * This is a normal session, set the Session's CmdSN window to the
45 	 * struct se_node_acl->queue_depth.  The value in struct se_node_acl->queue_depth
46 	 * has already been validated as a legal value in
47 	 * core_set_queue_depth_for_node().
48 	 */
49 	sess->cmdsn_window = se_nacl->queue_depth;
50 	atomic_add(se_nacl->queue_depth - 1, &sess->max_cmd_sn);
51 }
52 
53 void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
54 {
55 	u32 max_cmd_sn;
56 
57 	if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
58 		return;
59 
60 	cmd->maxcmdsn_inc = 1;
61 
62 	max_cmd_sn = atomic_inc_return(&sess->max_cmd_sn);
63 	pr_debug("Updated MaxCmdSN to 0x%08x\n", max_cmd_sn);
64 }
65 EXPORT_SYMBOL(iscsit_increment_maxcmdsn);
66