xref: /openbmc/linux/include/scsi/libiscsi.h (revision 64c70b1c)
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 
33 struct scsi_transport_template;
34 struct scsi_device;
35 struct Scsi_Host;
36 struct scsi_cmnd;
37 struct socket;
38 struct iscsi_transport;
39 struct iscsi_cls_session;
40 struct iscsi_cls_conn;
41 struct iscsi_session;
42 struct 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 
76 struct 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 
89 enum {
90 	ISCSI_TASK_COMPLETED,
91 	ISCSI_TASK_PENDING,
92 	ISCSI_TASK_RUNNING,
93 };
94 
95 struct 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 
122 struct 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 
202 struct iscsi_queue {
203 	struct kfifo		*queue;		/* FIFO Queue */
204 	void			**pool;		/* Pool of elements */
205 	int			max;		/* Max number of elements */
206 };
207 
208 struct 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  */
252 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
253 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
254 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
255 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
256 			      void (*done)(struct scsi_cmnd *));
257 
258 /*
259  * session management
260  */
261 extern struct iscsi_cls_session *
262 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
263 		    int, int, uint32_t, uint32_t *);
264 extern void iscsi_session_teardown(struct iscsi_cls_session *);
265 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
266 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
267 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
268 			   enum iscsi_param param, char *buf, int buflen);
269 extern 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  */
278 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
279 					       uint32_t);
280 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
281 extern int iscsi_conn_start(struct iscsi_cls_conn *);
282 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
283 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
284 			   int);
285 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
286 extern 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  */
292 extern int iscsi_check_assign_cmdsn(struct iscsi_session *,
293 				    struct iscsi_nopin *);
294 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
295 					struct iscsi_data *hdr);
296 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
297 				char *, uint32_t);
298 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
299 			      char *, int);
300 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
301 				char *, int);
302 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
303 			    uint32_t *);
304 
305 /*
306  * generic helpers
307  */
308 extern void iscsi_pool_free(struct iscsi_queue *, void **);
309 extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
310 
311 #endif
312