1/*
2 * iSCSI lib definitions
3 *
4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5 * Copyright (C) 2004 - 2006 Mike Christie
6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
7 * Copyright (C) 2004 - 2005 Alex Aizman
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 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 */
23#ifndef LIBISCSI_H
24#define LIBISCSI_H
25
26#include <linux/types.h>
27#include <linux/mutex.h>
28#include <linux/timer.h>
29#include <linux/workqueue.h>
30#include <scsi/iscsi_proto.h>
31#include <scsi/iscsi_if.h>
32
33struct scsi_transport_template;
34struct scsi_device;
35struct Scsi_Host;
36struct scsi_cmnd;
37struct socket;
38struct iscsi_transport;
39struct iscsi_cls_session;
40struct iscsi_cls_conn;
41struct iscsi_session;
42struct iscsi_nopin;
43
44/* #define DEBUG_SCSI */
45#ifdef DEBUG_SCSI
46#define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
47#else
48#define debug_scsi(fmt...)
49#endif
50
51#define ISCSI_XMIT_CMDS_MAX	128	/* must be power of 2 */
52#define ISCSI_MGMT_CMDS_MAX	32	/* must be power of 2 */
53#define ISCSI_CONN_MAX			1
54
55#define ISCSI_MGMT_ITT_OFFSET	0xa00
56
57#define ISCSI_DEF_CMD_PER_LUN		32
58#define ISCSI_MAX_CMD_PER_LUN		128
59
60/* Task Mgmt states */
61#define TMABORT_INITIAL			0x0
62#define TMABORT_SUCCESS			0x1
63#define TMABORT_FAILED			0x2
64#define TMABORT_TIMEDOUT		0x3
65#define TMABORT_NOT_FOUND		0x4
66
67/* Connection suspend "bit" */
68#define ISCSI_SUSPEND_BIT		1
69
70#define ISCSI_ITT_MASK			(0xfff)
71#define ISCSI_CID_SHIFT			12
72#define ISCSI_CID_MASK			(0xffff << ISCSI_CID_SHIFT)
73#define ISCSI_AGE_SHIFT			28
74#define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
75
76struct iscsi_mgmt_task {
77	/*
78	 * Becuae LLDs allocate their hdr differently, this is a pointer to
79	 * that storage. It must be setup at session creation time.
80	 */
81	struct iscsi_hdr	*hdr;
82	char			*data;		/* mgmt payload */
83	int			data_count;	/* counts data to be sent */
84	uint32_t		itt;		/* this ITT */
85	void			*dd_data;	/* driver/transport data */
86	struct list_head	running;
87};
88
89enum {
90	ISCSI_TASK_COMPLETED,
91	ISCSI_TASK_PENDING,
92	ISCSI_TASK_RUNNING,
93};
94
95struct iscsi_cmd_task {
96	/*
97	 * Becuae LLDs allocate their hdr differently, this is a pointer to
98	 * that storage. It must be setup at session creation time.
99	 */
100	struct iscsi_cmd	*hdr;
101	int			itt;		/* this ITT */
102	int			datasn;		/* DataSN */
103
104	uint32_t		unsol_datasn;
105	int			imm_count;	/* imm-data (bytes)   */
106	int			unsol_count;	/* unsolicited (bytes)*/
107	/* offset in unsolicited stream (bytes); */
108	int			unsol_offset;
109	int			data_count;	/* remaining Data-Out */
110	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
111	int			total_length;
112	struct iscsi_conn	*conn;		/* used connection    */
113	struct iscsi_mgmt_task	*mtask;		/* tmf mtask in progr */
114
115	/* state set/tested under session->lock */
116	int			state;
117	atomic_t		refcount;
118	struct list_head	running;	/* running cmd list */
119	void			*dd_data;	/* driver/transport data */
120};
121
122struct iscsi_conn {
123	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
124	void			*dd_data;	/* iscsi_transport data */
125	struct iscsi_session	*session;	/* parent session */
126	/*
127	 * LLDs should set this lock. It protects the transport recv
128	 * code
129	 */
130	rwlock_t		*recv_lock;
131	/*
132	 * conn_stop() flag: stop to recover, stop to terminate
133	 */
134        int			stop_stage;
135
136	/* iSCSI connection-wide sequencing */
137	uint32_t		exp_statsn;
138
139	/* control data */
140	int			id;		/* CID */
141	int			c_stage;	/* connection state */
142	/*
143	 * Preallocated buffer for pdus that have data but do not
144	 * originate from scsi-ml. We never have two pdus using the
145	 * buffer at the same time. It is only allocated to
146	 * the default max recv size because the pdus we support
147	 * should always fit in this buffer
148	 */
149	char			*data;
150	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
151	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
152	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
153
154	/* xmit */
155	struct kfifo		*immqueue;	/* immediate xmit queue */
156	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */
157	struct list_head	mgmt_run_list;	/* list of control tasks */
158	struct list_head	xmitqueue;	/* data-path cmd queue */
159	struct list_head	run_list;	/* list of cmds in progress */
160	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
161	/*
162	 * serializes connection xmit, access to kfifos:
163	 * xmitqueue, immqueue, mgmtqueue
164	 */
165	struct mutex		xmitmutex;
166
167	unsigned long		suspend_tx;	/* suspend Tx */
168	unsigned long		suspend_rx;	/* suspend Rx */
169
170	/* abort */
171	wait_queue_head_t	ehwait;		/* used in eh_abort() */
172	struct iscsi_tm		tmhdr;
173	struct timer_list	tmabort_timer;
174	int			tmabort_state;	/* see TMABORT_INITIAL, etc.*/
175
176	/* negotiated params */
177	int			max_recv_dlength; /* initiator_max_recv_dsl*/
178	int			max_xmit_dlength; /* target_max_recv_dsl */
179	int			hdrdgst_en;
180	int			datadgst_en;
181	int			ifmarker_en;
182	int			ofmarker_en;
183	/* values userspace uses to id a conn */
184	int			persistent_port;
185	char			*persistent_address;
186
187	/* MIB-statistics */
188	uint64_t		txdata_octets;
189	uint64_t		rxdata_octets;
190	uint32_t		scsicmd_pdus_cnt;
191	uint32_t		dataout_pdus_cnt;
192	uint32_t		scsirsp_pdus_cnt;
193	uint32_t		datain_pdus_cnt;
194	uint32_t		r2t_pdus_cnt;
195	uint32_t		tmfcmd_pdus_cnt;
196	int32_t			tmfrsp_pdus_cnt;
197
198	/* custom statistics */
199	uint32_t		eh_abort_cnt;
200};
201
202struct iscsi_queue {
203	struct kfifo		*queue;		/* FIFO Queue */
204	void			**pool;		/* Pool of elements */
205	int			max;		/* Max number of elements */
206};
207
208struct iscsi_session {
209	/* iSCSI session-wide sequencing */
210	uint32_t		cmdsn;
211	uint32_t		exp_cmdsn;
212	uint32_t		max_cmdsn;
213
214	/* configuration */
215	int			initial_r2t_en;
216	int			max_r2t;
217	int			imm_data_en;
218	int			first_burst;
219	int			max_burst;
220	int			time2wait;
221	int			time2retain;
222	int			pdu_inorder_en;
223	int			dataseq_inorder_en;
224	int			erl;
225	int			tpgt;
226	char			*targetname;
227
228	/* control data */
229	struct iscsi_transport	*tt;
230	struct Scsi_Host	*host;
231	struct iscsi_conn	*leadconn;	/* leading connection */
232	spinlock_t		lock;		/* protects session state, *
233						 * sequence numbers,       *
234						 * session resources:      *
235						 * - cmdpool,		   *
236						 * - mgmtpool,		   *
237						 * - r2tpool		   */
238	int			state;		/* session state           */
239	int			age;		/* counts session re-opens */
240
241	int			cmds_max;	/* size of cmds array */
242	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
243	struct iscsi_queue	cmdpool;	/* PDU's pool */
244	int			mgmtpool_max;	/* size of mgmt array */
245	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
246	struct iscsi_queue	mgmtpool;	/* Mgmt PDU's pool */
247};
248
249/*
250 * scsi host template
251 */
252extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
253extern int iscsi_eh_abort(struct scsi_cmnd *sc);
254extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
255extern int iscsi_queuecommand(struct scsi_cmnd *sc,
256			      void (*done)(struct scsi_cmnd *));
257
258/*
259 * session management
260 */
261extern struct iscsi_cls_session *
262iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
263		    int, int, uint32_t, uint32_t *);
264extern void iscsi_session_teardown(struct iscsi_cls_session *);
265extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
266extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
267extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
268			   enum iscsi_param param, char *buf, int buflen);
269extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
270				   enum iscsi_param param, char *buf);
271
272#define session_to_cls(_sess) \
273	hostdata_session(_sess->host->hostdata)
274
275/*
276 * connection management
277 */
278extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
279					       uint32_t);
280extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
281extern int iscsi_conn_start(struct iscsi_cls_conn *);
282extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
283extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
284			   int);
285extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
286extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
287				enum iscsi_param param, char *buf);
288
289/*
290 * pdu and task processing
291 */
292extern int iscsi_check_assign_cmdsn(struct iscsi_session *,
293				    struct iscsi_nopin *);
294extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
295					struct iscsi_data *hdr);
296extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
297				char *, uint32_t);
298extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
299			      char *, int);
300extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
301				char *, int);
302extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
303			    uint32_t *);
304
305/*
306 * generic helpers
307 */
308extern void iscsi_pool_free(struct iscsi_queue *, void **);
309extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
310
311#endif
312