xref: /openbmc/linux/include/scsi/libiscsi.h (revision 545e4006)
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/wait.h>
28 #include <linux/mutex.h>
29 #include <linux/timer.h>
30 #include <linux/workqueue.h>
31 #include <scsi/iscsi_proto.h>
32 #include <scsi/iscsi_if.h>
33 
34 struct scsi_transport_template;
35 struct scsi_host_template;
36 struct scsi_device;
37 struct Scsi_Host;
38 struct scsi_cmnd;
39 struct socket;
40 struct iscsi_transport;
41 struct iscsi_cls_session;
42 struct iscsi_cls_conn;
43 struct iscsi_session;
44 struct iscsi_nopin;
45 struct device;
46 
47 /* #define DEBUG_SCSI */
48 #ifdef DEBUG_SCSI
49 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
50 #else
51 #define debug_scsi(fmt...)
52 #endif
53 
54 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
55 #define ISCSI_MGMT_CMDS_MAX	15
56 
57 #define ISCSI_DEF_CMD_PER_LUN		32
58 #define ISCSI_MAX_CMD_PER_LUN		128
59 
60 /* Task Mgmt states */
61 enum {
62 	TMF_INITIAL,
63 	TMF_QUEUED,
64 	TMF_SUCCESS,
65 	TMF_FAILED,
66 	TMF_TIMEDOUT,
67 	TMF_NOT_FOUND,
68 };
69 
70 /* Connection suspend "bit" */
71 #define ISCSI_SUSPEND_BIT		1
72 
73 #define ISCSI_ITT_MASK			(0x1fff)
74 #define ISCSI_TOTAL_CMDS_MAX		4096
75 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
76 #define ISCSI_TOTAL_CMDS_MIN		16
77 #define ISCSI_AGE_SHIFT			28
78 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
79 
80 #define ISCSI_ADDRESS_BUF_LEN		64
81 
82 enum {
83 	/* this is the maximum possible storage for AHSs */
84 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
85 				sizeof(struct iscsi_rlength_ahdr),
86 	ISCSI_DIGEST_SIZE = sizeof(__u32),
87 };
88 
89 
90 enum {
91 	ISCSI_TASK_COMPLETED,
92 	ISCSI_TASK_PENDING,
93 	ISCSI_TASK_RUNNING,
94 };
95 
96 struct iscsi_task {
97 	/*
98 	 * Because LLDs allocate their hdr differently, this is a pointer
99 	 * and length to that storage. It must be setup at session
100 	 * creation time.
101 	 */
102 	struct iscsi_cmd	*hdr;
103 	unsigned short		hdr_max;
104 	unsigned short		hdr_len;	/* accumulated size of hdr used */
105 	int			itt;		/* this ITT */
106 
107 	uint32_t		unsol_datasn;
108 	unsigned		imm_count;	/* imm-data (bytes)   */
109 	unsigned		unsol_count;	/* unsolicited (bytes)*/
110 	/* offset in unsolicited stream (bytes); */
111 	unsigned		unsol_offset;
112 	unsigned		data_count;	/* remaining Data-Out */
113 	char			*data;		/* mgmt payload */
114 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
115 	struct iscsi_conn	*conn;		/* used connection    */
116 
117 	/* state set/tested under session->lock */
118 	int			state;
119 	atomic_t		refcount;
120 	struct list_head	running;	/* running cmd list */
121 	void			*dd_data;	/* driver/transport data */
122 };
123 
124 static inline void* iscsi_next_hdr(struct iscsi_task *task)
125 {
126 	return (void*)task->hdr + task->hdr_len;
127 }
128 
129 /* Connection's states */
130 enum {
131 	ISCSI_CONN_INITIAL_STAGE,
132 	ISCSI_CONN_STARTED,
133 	ISCSI_CONN_STOPPED,
134 	ISCSI_CONN_CLEANUP_WAIT,
135 };
136 
137 struct iscsi_conn {
138 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
139 	void			*dd_data;	/* iscsi_transport data */
140 	struct iscsi_session	*session;	/* parent session */
141 	/*
142 	 * conn_stop() flag: stop to recover, stop to terminate
143 	 */
144         int			stop_stage;
145 	struct timer_list	transport_timer;
146 	unsigned long		last_recv;
147 	unsigned long		last_ping;
148 	int			ping_timeout;
149 	int			recv_timeout;
150 	struct iscsi_task 	*ping_task;
151 
152 	/* iSCSI connection-wide sequencing */
153 	uint32_t		exp_statsn;
154 
155 	/* control data */
156 	int			id;		/* CID */
157 	int			c_stage;	/* connection state */
158 	/*
159 	 * Preallocated buffer for pdus that have data but do not
160 	 * originate from scsi-ml. We never have two pdus using the
161 	 * buffer at the same time. It is only allocated to
162 	 * the default max recv size because the pdus we support
163 	 * should always fit in this buffer
164 	 */
165 	char			*data;
166 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
167 	struct iscsi_task	*task;		/* xmit task in progress */
168 
169 	/* xmit */
170 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
171 	struct list_head	mgmt_run_list;	/* list of control tasks */
172 	struct list_head	xmitqueue;	/* data-path cmd queue */
173 	struct list_head	run_list;	/* list of cmds in progress */
174 	struct list_head	requeue;	/* tasks needing another run */
175 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
176 	unsigned long		suspend_tx;	/* suspend Tx */
177 	unsigned long		suspend_rx;	/* suspend Rx */
178 
179 	/* abort */
180 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
181 	struct iscsi_tm		tmhdr;
182 	struct timer_list	tmf_timer;
183 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
184 
185 	/* negotiated params */
186 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
187 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
188 	int			hdrdgst_en;
189 	int			datadgst_en;
190 	int			ifmarker_en;
191 	int			ofmarker_en;
192 	/* values userspace uses to id a conn */
193 	int			persistent_port;
194 	char			*persistent_address;
195 	/* remote portal currently connected to */
196 	int			portal_port;
197 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
198 
199 	/* MIB-statistics */
200 	uint64_t		txdata_octets;
201 	uint64_t		rxdata_octets;
202 	uint32_t		scsicmd_pdus_cnt;
203 	uint32_t		dataout_pdus_cnt;
204 	uint32_t		scsirsp_pdus_cnt;
205 	uint32_t		datain_pdus_cnt;
206 	uint32_t		r2t_pdus_cnt;
207 	uint32_t		tmfcmd_pdus_cnt;
208 	int32_t			tmfrsp_pdus_cnt;
209 
210 	/* custom statistics */
211 	uint32_t		eh_abort_cnt;
212 	uint32_t		fmr_unalign_cnt;
213 };
214 
215 struct iscsi_pool {
216 	struct kfifo		*queue;		/* FIFO Queue */
217 	void			**pool;		/* Pool of elements */
218 	int			max;		/* Max number of elements */
219 };
220 
221 /* Session's states */
222 enum {
223 	ISCSI_STATE_FREE = 1,
224 	ISCSI_STATE_LOGGED_IN,
225 	ISCSI_STATE_FAILED,
226 	ISCSI_STATE_TERMINATE,
227 	ISCSI_STATE_IN_RECOVERY,
228 	ISCSI_STATE_RECOVERY_FAILED,
229 	ISCSI_STATE_LOGGING_OUT,
230 };
231 
232 struct iscsi_session {
233 	struct iscsi_cls_session *cls_session;
234 	/*
235 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
236 	 * task management functions. This must be taken before the session
237 	 * and recv lock.
238 	 */
239 	struct mutex		eh_mutex;
240 
241 	/* iSCSI session-wide sequencing */
242 	uint32_t		cmdsn;
243 	uint32_t		exp_cmdsn;
244 	uint32_t		max_cmdsn;
245 
246 	/* This tracks the reqs queued into the initiator */
247 	uint32_t		queued_cmdsn;
248 
249 	/* configuration */
250 	int			abort_timeout;
251 	int			lu_reset_timeout;
252 	int			initial_r2t_en;
253 	unsigned		max_r2t;
254 	int			imm_data_en;
255 	unsigned		first_burst;
256 	unsigned		max_burst;
257 	int			time2wait;
258 	int			time2retain;
259 	int			pdu_inorder_en;
260 	int			dataseq_inorder_en;
261 	int			erl;
262 	int			fast_abort;
263 	int			tpgt;
264 	char			*username;
265 	char			*username_in;
266 	char			*password;
267 	char			*password_in;
268 	char			*targetname;
269 	char			*ifacename;
270 	char			*initiatorname;
271 	/* control data */
272 	struct iscsi_transport	*tt;
273 	struct Scsi_Host	*host;
274 	struct iscsi_conn	*leadconn;	/* leading connection */
275 	spinlock_t		lock;		/* protects session state, *
276 						 * sequence numbers,       *
277 						 * session resources:      *
278 						 * - cmdpool,		   *
279 						 * - mgmtpool,		   *
280 						 * - r2tpool		   */
281 	int			state;		/* session state           */
282 	int			age;		/* counts session re-opens */
283 
284 	int			scsi_cmds_max; 	/* max scsi commands */
285 	int			cmds_max;	/* size of cmds array */
286 	struct iscsi_task	**cmds;		/* Original Cmds arr */
287 	struct iscsi_pool	cmdpool;	/* PDU's pool */
288 };
289 
290 struct iscsi_host {
291 	char			*initiatorname;
292 	/* hw address or netdev iscsi connection is bound to */
293 	char			*hwaddress;
294 	char			*netdev;
295 	/* local address */
296 	int			local_port;
297 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
298 };
299 
300 /*
301  * scsi host template
302  */
303 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
304 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
305 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
306 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
307 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
308 			      void (*done)(struct scsi_cmnd *));
309 
310 /*
311  * iSCSI host helpers.
312  */
313 #define iscsi_host_priv(_shost) \
314 	(shost_priv(_shost) + sizeof(struct iscsi_host))
315 
316 extern int iscsi_host_set_param(struct Scsi_Host *shost,
317 				enum iscsi_host_param param, char *buf,
318 				int buflen);
319 extern int iscsi_host_get_param(struct Scsi_Host *shost,
320 				enum iscsi_host_param param, char *buf);
321 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
322 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
323 					  int dd_data_size, uint16_t qdepth);
324 extern void iscsi_host_remove(struct Scsi_Host *shost);
325 extern void iscsi_host_free(struct Scsi_Host *shost);
326 
327 /*
328  * session management
329  */
330 extern struct iscsi_cls_session *
331 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
332 		    uint16_t, int, uint32_t, unsigned int);
333 extern void iscsi_session_teardown(struct iscsi_cls_session *);
334 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
335 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
336 			   enum iscsi_param param, char *buf, int buflen);
337 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
338 				   enum iscsi_param param, char *buf);
339 
340 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
341 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
342 
343 /*
344  * connection management
345  */
346 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
347 					       int, uint32_t);
348 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
349 extern int iscsi_conn_start(struct iscsi_cls_conn *);
350 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
351 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
352 			   int);
353 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
354 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
355 				enum iscsi_param param, char *buf);
356 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
357 
358 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
359 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
360 			      fmt, ##a)
361 
362 /*
363  * pdu and task processing
364  */
365 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
366 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
367 					struct iscsi_data *hdr);
368 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
369 				char *, uint32_t);
370 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
371 			      char *, int);
372 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
373 				char *, int);
374 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
375 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
376 extern void iscsi_requeue_task(struct iscsi_task *task);
377 extern void iscsi_put_task(struct iscsi_task *task);
378 extern void __iscsi_get_task(struct iscsi_task *task);
379 
380 /*
381  * generic helpers
382  */
383 extern void iscsi_pool_free(struct iscsi_pool *);
384 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
385 
386 /*
387  * inline functions to deal with padding.
388  */
389 static inline unsigned int
390 iscsi_padded(unsigned int len)
391 {
392 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
393 }
394 
395 static inline unsigned int
396 iscsi_padding(unsigned int len)
397 {
398 	len &= (ISCSI_PAD_LEN - 1);
399 	if (len)
400 		len = ISCSI_PAD_LEN - len;
401 	return len;
402 }
403 
404 #endif
405