xref: /openbmc/linux/include/scsi/libiscsi.h (revision 643d1f7f)
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_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
52 #define ISCSI_MGMT_CMDS_MAX	16	/* must be power of 2 */
53 
54 #define ISCSI_MGMT_ITT_OFFSET	0xa00
55 
56 #define ISCSI_DEF_CMD_PER_LUN		32
57 #define ISCSI_MAX_CMD_PER_LUN		128
58 
59 /* Task Mgmt states */
60 enum {
61 	TMF_INITIAL,
62 	TMF_QUEUED,
63 	TMF_SUCCESS,
64 	TMF_FAILED,
65 	TMF_TIMEDOUT,
66 	TMF_NOT_FOUND,
67 };
68 
69 /* Connection suspend "bit" */
70 #define ISCSI_SUSPEND_BIT		1
71 
72 #define ISCSI_ITT_MASK			(0xfff)
73 #define ISCSI_CID_SHIFT			12
74 #define ISCSI_CID_MASK			(0xffff << ISCSI_CID_SHIFT)
75 #define ISCSI_AGE_SHIFT			28
76 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
77 
78 #define ISCSI_ADDRESS_BUF_LEN		64
79 
80 enum {
81 	/* this is the maximum possible storage for AHSs */
82 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
83 				sizeof(struct iscsi_rlength_ahdr),
84 	ISCSI_DIGEST_SIZE = sizeof(__u32),
85 };
86 
87 struct iscsi_mgmt_task {
88 	/*
89 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
90 	 * that storage. It must be setup at session creation time.
91 	 */
92 	struct iscsi_hdr	*hdr;
93 	char			*data;		/* mgmt payload */
94 	unsigned		data_count;	/* counts data to be sent */
95 	uint32_t		itt;		/* this ITT */
96 	void			*dd_data;	/* driver/transport data */
97 	struct list_head	running;
98 };
99 
100 enum {
101 	ISCSI_TASK_COMPLETED,
102 	ISCSI_TASK_PENDING,
103 	ISCSI_TASK_RUNNING,
104 };
105 
106 struct iscsi_cmd_task {
107 	/*
108 	 * Because LLDs allocate their hdr differently, this is a pointer
109 	 * and length to that storage. It must be setup at session
110 	 * creation time.
111 	 */
112 	struct iscsi_cmd	*hdr;
113 	unsigned short		hdr_max;
114 	unsigned short		hdr_len;	/* accumulated size of hdr used */
115 	int			itt;		/* this ITT */
116 
117 	uint32_t		unsol_datasn;
118 	unsigned		imm_count;	/* imm-data (bytes)   */
119 	unsigned		unsol_count;	/* unsolicited (bytes)*/
120 	/* offset in unsolicited stream (bytes); */
121 	unsigned		unsol_offset;
122 	unsigned		data_count;	/* remaining Data-Out */
123 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
124 	struct iscsi_conn	*conn;		/* used connection    */
125 
126 	/* state set/tested under session->lock */
127 	int			state;
128 	atomic_t		refcount;
129 	struct list_head	running;	/* running cmd list */
130 	void			*dd_data;	/* driver/transport data */
131 };
132 
133 static inline void* iscsi_next_hdr(struct iscsi_cmd_task *ctask)
134 {
135 	return (void*)ctask->hdr + ctask->hdr_len;
136 }
137 
138 struct iscsi_conn {
139 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
140 	void			*dd_data;	/* iscsi_transport data */
141 	struct iscsi_session	*session;	/* parent session */
142 	/*
143 	 * LLDs should set this lock. It protects the transport recv
144 	 * code
145 	 */
146 	rwlock_t		*recv_lock;
147 	/*
148 	 * conn_stop() flag: stop to recover, stop to terminate
149 	 */
150         int			stop_stage;
151 	struct timer_list	transport_timer;
152 	unsigned long		last_recv;
153 	unsigned long		last_ping;
154 	int			ping_timeout;
155 	int			recv_timeout;
156 	struct iscsi_mgmt_task	*ping_mtask;
157 
158 	/* iSCSI connection-wide sequencing */
159 	uint32_t		exp_statsn;
160 
161 	/* control data */
162 	int			id;		/* CID */
163 	int			c_stage;	/* connection state */
164 	/*
165 	 * Preallocated buffer for pdus that have data but do not
166 	 * originate from scsi-ml. We never have two pdus using the
167 	 * buffer at the same time. It is only allocated to
168 	 * the default max recv size because the pdus we support
169 	 * should always fit in this buffer
170 	 */
171 	char			*data;
172 	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
173 	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
174 	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
175 
176 	/* xmit */
177 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
178 	struct list_head	mgmt_run_list;	/* list of control tasks */
179 	struct list_head	xmitqueue;	/* data-path cmd queue */
180 	struct list_head	run_list;	/* list of cmds in progress */
181 	struct list_head	requeue;	/* tasks needing another run */
182 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
183 	unsigned long		suspend_tx;	/* suspend Tx */
184 	unsigned long		suspend_rx;	/* suspend Rx */
185 
186 	/* abort */
187 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
188 	struct iscsi_tm		tmhdr;
189 	struct timer_list	tmf_timer;
190 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
191 
192 	/* negotiated params */
193 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
194 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
195 	int			hdrdgst_en;
196 	int			datadgst_en;
197 	int			ifmarker_en;
198 	int			ofmarker_en;
199 	/* values userspace uses to id a conn */
200 	int			persistent_port;
201 	char			*persistent_address;
202 	/* remote portal currently connected to */
203 	int			portal_port;
204 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
205 	/* local address */
206 	int			local_port;
207 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
208 
209 	/* MIB-statistics */
210 	uint64_t		txdata_octets;
211 	uint64_t		rxdata_octets;
212 	uint32_t		scsicmd_pdus_cnt;
213 	uint32_t		dataout_pdus_cnt;
214 	uint32_t		scsirsp_pdus_cnt;
215 	uint32_t		datain_pdus_cnt;
216 	uint32_t		r2t_pdus_cnt;
217 	uint32_t		tmfcmd_pdus_cnt;
218 	int32_t			tmfrsp_pdus_cnt;
219 
220 	/* custom statistics */
221 	uint32_t		eh_abort_cnt;
222 };
223 
224 struct iscsi_pool {
225 	struct kfifo		*queue;		/* FIFO Queue */
226 	void			**pool;		/* Pool of elements */
227 	int			max;		/* Max number of elements */
228 };
229 
230 struct iscsi_session {
231 	/*
232 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
233 	 * task management functions. This must be taken before the session
234 	 * and recv lock.
235 	 */
236 	struct mutex		eh_mutex;
237 
238 	/* iSCSI session-wide sequencing */
239 	uint32_t		cmdsn;
240 	uint32_t		exp_cmdsn;
241 	uint32_t		max_cmdsn;
242 
243 	/* This tracks the reqs queued into the initiator */
244 	uint32_t		queued_cmdsn;
245 
246 	/* configuration */
247 	int			abort_timeout;
248 	int			lu_reset_timeout;
249 	int			initial_r2t_en;
250 	unsigned		max_r2t;
251 	int			imm_data_en;
252 	unsigned		first_burst;
253 	unsigned		max_burst;
254 	int			time2wait;
255 	int			time2retain;
256 	int			pdu_inorder_en;
257 	int			dataseq_inorder_en;
258 	int			erl;
259 	int			fast_abort;
260 	int			tpgt;
261 	char			*username;
262 	char			*username_in;
263 	char			*password;
264 	char			*password_in;
265 	char			*targetname;
266 	char			*initiatorname;
267 	/* hw address or netdev iscsi connection is bound to */
268 	char			*hwaddress;
269 	char			*netdev;
270 	/* control data */
271 	struct iscsi_transport	*tt;
272 	struct Scsi_Host	*host;
273 	struct iscsi_conn	*leadconn;	/* leading connection */
274 	spinlock_t		lock;		/* protects session state, *
275 						 * sequence numbers,       *
276 						 * session resources:      *
277 						 * - cmdpool,		   *
278 						 * - mgmtpool,		   *
279 						 * - r2tpool		   */
280 	int			state;		/* session state           */
281 	int			age;		/* counts session re-opens */
282 
283 	int			cmds_max;	/* size of cmds array */
284 	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
285 	struct iscsi_pool	cmdpool;	/* PDU's pool */
286 	int			mgmtpool_max;	/* size of mgmt array */
287 	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
288 	struct iscsi_pool	mgmtpool;	/* Mgmt PDU's pool */
289 };
290 
291 /*
292  * scsi host template
293  */
294 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
295 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
296 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
297 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
298 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
299 			      void (*done)(struct scsi_cmnd *));
300 
301 
302 /*
303  * iSCSI host helpers.
304  */
305 extern int iscsi_host_set_param(struct Scsi_Host *shost,
306 				enum iscsi_host_param param, char *buf,
307 				int buflen);
308 extern int iscsi_host_get_param(struct Scsi_Host *shost,
309 				enum iscsi_host_param param, char *buf);
310 
311 /*
312  * session management
313  */
314 extern struct iscsi_cls_session *
315 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
316 		    uint16_t, uint16_t, int, int, uint32_t, uint32_t *);
317 extern void iscsi_session_teardown(struct iscsi_cls_session *);
318 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
319 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
320 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
321 			   enum iscsi_param param, char *buf, int buflen);
322 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
323 				   enum iscsi_param param, char *buf);
324 
325 #define session_to_cls(_sess) \
326 	hostdata_session(_sess->host->hostdata)
327 
328 /*
329  * connection management
330  */
331 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
332 					       uint32_t);
333 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
334 extern int iscsi_conn_start(struct iscsi_cls_conn *);
335 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
336 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
337 			   int);
338 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
339 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
340 				enum iscsi_param param, char *buf);
341 
342 /*
343  * pdu and task processing
344  */
345 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
346 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
347 					struct iscsi_data *hdr);
348 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
349 				char *, uint32_t);
350 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
351 			      char *, int);
352 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
353 				char *, int);
354 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
355 			    uint32_t *);
356 extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
357 extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
358 				 struct iscsi_mgmt_task *mtask);
359 
360 /*
361  * generic helpers
362  */
363 extern void iscsi_pool_free(struct iscsi_pool *);
364 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
365 
366 /*
367  * inline functions to deal with padding.
368  */
369 static inline unsigned int
370 iscsi_padded(unsigned int len)
371 {
372 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
373 }
374 
375 static inline unsigned int
376 iscsi_padding(unsigned int len)
377 {
378 	len &= (ISCSI_PAD_LEN - 1);
379 	if (len)
380 		len = ISCSI_PAD_LEN - len;
381 	return len;
382 }
383 
384 #endif
385