xref: /openbmc/linux/include/scsi/libiscsi.h (revision 7dd65feb)
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 <linux/kfifo.h>
32 #include <scsi/iscsi_proto.h>
33 #include <scsi/iscsi_if.h>
34 #include <scsi/scsi_transport_iscsi.h>
35 
36 struct scsi_transport_template;
37 struct scsi_host_template;
38 struct scsi_device;
39 struct Scsi_Host;
40 struct scsi_target;
41 struct scsi_cmnd;
42 struct socket;
43 struct iscsi_transport;
44 struct iscsi_cls_session;
45 struct iscsi_cls_conn;
46 struct iscsi_session;
47 struct iscsi_nopin;
48 struct device;
49 
50 #define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
51 #define ISCSI_MGMT_CMDS_MAX	15
52 
53 #define ISCSI_DEF_CMD_PER_LUN	32
54 
55 /* Task Mgmt states */
56 enum {
57 	TMF_INITIAL,
58 	TMF_QUEUED,
59 	TMF_SUCCESS,
60 	TMF_FAILED,
61 	TMF_TIMEDOUT,
62 	TMF_NOT_FOUND,
63 };
64 
65 /* Connection suspend "bit" */
66 #define ISCSI_SUSPEND_BIT		1
67 
68 #define ISCSI_ITT_MASK			0x1fff
69 #define ISCSI_TOTAL_CMDS_MAX		4096
70 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
71 #define ISCSI_TOTAL_CMDS_MIN		16
72 #define ISCSI_AGE_SHIFT			28
73 #define ISCSI_AGE_MASK			0xf
74 
75 #define ISCSI_ADDRESS_BUF_LEN		64
76 
77 enum {
78 	/* this is the maximum possible storage for AHSs */
79 	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
80 				sizeof(struct iscsi_rlength_ahdr),
81 	ISCSI_DIGEST_SIZE = sizeof(__u32),
82 };
83 
84 
85 enum {
86 	ISCSI_TASK_FREE,
87 	ISCSI_TASK_COMPLETED,
88 	ISCSI_TASK_PENDING,
89 	ISCSI_TASK_RUNNING,
90 	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
91 	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
92 };
93 
94 struct iscsi_r2t_info {
95 	__be32			ttt;		/* copied from R2T */
96 	__be32			exp_statsn;	/* copied from R2T */
97 	uint32_t		data_length;	/* copied from R2T */
98 	uint32_t		data_offset;	/* copied from R2T */
99 	int			data_count;	/* DATA-Out payload progress */
100 	int			datasn;
101 	/* LLDs should set/update these values */
102 	int			sent;		/* R2T sequence progress */
103 };
104 
105 struct iscsi_task {
106 	/*
107 	 * Because LLDs allocate their hdr differently, this is a pointer
108 	 * and length to that storage. It must be setup at session
109 	 * creation time.
110 	 */
111 	struct iscsi_hdr	*hdr;
112 	unsigned short		hdr_max;
113 	unsigned short		hdr_len;	/* accumulated size of hdr used */
114 	/* copied values in case we need to send tmfs */
115 	itt_t			hdr_itt;
116 	__be32			cmdsn;
117 	uint8_t			lun[8];
118 
119 	int			itt;		/* this ITT */
120 
121 	unsigned		imm_count;	/* imm-data (bytes)   */
122 	/* offset in unsolicited stream (bytes); */
123 	struct iscsi_r2t_info	unsol_r2t;
124 	char			*data;		/* mgmt payload */
125 	unsigned		data_count;
126 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
127 	struct iscsi_conn	*conn;		/* used connection    */
128 
129 	/* data processing tracking */
130 	unsigned long		last_xfer;
131 	unsigned long		last_timeout;
132 	bool			have_checked_conn;
133 	/* state set/tested under session->lock */
134 	int			state;
135 	atomic_t		refcount;
136 	struct list_head	running;	/* running cmd list */
137 	void			*dd_data;	/* driver/transport data */
138 };
139 
140 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
141 {
142 	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
143 }
144 
145 static inline void* iscsi_next_hdr(struct iscsi_task *task)
146 {
147 	return (void*)task->hdr + task->hdr_len;
148 }
149 
150 /* Connection's states */
151 enum {
152 	ISCSI_CONN_INITIAL_STAGE,
153 	ISCSI_CONN_STARTED,
154 	ISCSI_CONN_STOPPED,
155 	ISCSI_CONN_CLEANUP_WAIT,
156 };
157 
158 struct iscsi_conn {
159 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
160 	void			*dd_data;	/* iscsi_transport data */
161 	struct iscsi_session	*session;	/* parent session */
162 	/*
163 	 * conn_stop() flag: stop to recover, stop to terminate
164 	 */
165         int			stop_stage;
166 	struct timer_list	transport_timer;
167 	unsigned long		last_recv;
168 	unsigned long		last_ping;
169 	int			ping_timeout;
170 	int			recv_timeout;
171 	struct iscsi_task 	*ping_task;
172 
173 	/* iSCSI connection-wide sequencing */
174 	uint32_t		exp_statsn;
175 
176 	/* control data */
177 	int			id;		/* CID */
178 	int			c_stage;	/* connection state */
179 	/*
180 	 * Preallocated buffer for pdus that have data but do not
181 	 * originate from scsi-ml. We never have two pdus using the
182 	 * buffer at the same time. It is only allocated to
183 	 * the default max recv size because the pdus we support
184 	 * should always fit in this buffer
185 	 */
186 	char			*data;
187 	struct iscsi_task 	*login_task;	/* mtask used for login/text */
188 	struct iscsi_task	*task;		/* xmit task in progress */
189 
190 	/* xmit */
191 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
192 	struct list_head	cmdqueue;	/* data-path cmd queue */
193 	struct list_head	requeue;	/* tasks needing another run */
194 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
195 	unsigned long		suspend_tx;	/* suspend Tx */
196 	unsigned long		suspend_rx;	/* suspend Rx */
197 
198 	/* abort */
199 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
200 	struct iscsi_tm		tmhdr;
201 	struct timer_list	tmf_timer;
202 	int			tmf_state;	/* see TMF_INITIAL, etc.*/
203 
204 	/* negotiated params */
205 	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
206 	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
207 	int			hdrdgst_en;
208 	int			datadgst_en;
209 	int			ifmarker_en;
210 	int			ofmarker_en;
211 	/* values userspace uses to id a conn */
212 	int			persistent_port;
213 	char			*persistent_address;
214 	/* remote portal currently connected to */
215 	int			portal_port;
216 	char			portal_address[ISCSI_ADDRESS_BUF_LEN];
217 
218 	/* MIB-statistics */
219 	uint64_t		txdata_octets;
220 	uint64_t		rxdata_octets;
221 	uint32_t		scsicmd_pdus_cnt;
222 	uint32_t		dataout_pdus_cnt;
223 	uint32_t		scsirsp_pdus_cnt;
224 	uint32_t		datain_pdus_cnt;
225 	uint32_t		r2t_pdus_cnt;
226 	uint32_t		tmfcmd_pdus_cnt;
227 	int32_t			tmfrsp_pdus_cnt;
228 
229 	/* custom statistics */
230 	uint32_t		eh_abort_cnt;
231 	uint32_t		fmr_unalign_cnt;
232 };
233 
234 struct iscsi_pool {
235 	struct kfifo		queue;		/* FIFO Queue */
236 	void			**pool;		/* Pool of elements */
237 	int			max;		/* Max number of elements */
238 };
239 
240 /* Session's states */
241 enum {
242 	ISCSI_STATE_FREE = 1,
243 	ISCSI_STATE_LOGGED_IN,
244 	ISCSI_STATE_FAILED,
245 	ISCSI_STATE_TERMINATE,
246 	ISCSI_STATE_IN_RECOVERY,
247 	ISCSI_STATE_RECOVERY_FAILED,
248 	ISCSI_STATE_LOGGING_OUT,
249 };
250 
251 struct iscsi_session {
252 	struct iscsi_cls_session *cls_session;
253 	/*
254 	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
255 	 * task management functions. This must be taken before the session
256 	 * and recv lock.
257 	 */
258 	struct mutex		eh_mutex;
259 
260 	/* iSCSI session-wide sequencing */
261 	uint32_t		cmdsn;
262 	uint32_t		exp_cmdsn;
263 	uint32_t		max_cmdsn;
264 
265 	/* This tracks the reqs queued into the initiator */
266 	uint32_t		queued_cmdsn;
267 
268 	/* configuration */
269 	int			abort_timeout;
270 	int			lu_reset_timeout;
271 	int			tgt_reset_timeout;
272 	int			initial_r2t_en;
273 	unsigned		max_r2t;
274 	int			imm_data_en;
275 	unsigned		first_burst;
276 	unsigned		max_burst;
277 	int			time2wait;
278 	int			time2retain;
279 	int			pdu_inorder_en;
280 	int			dataseq_inorder_en;
281 	int			erl;
282 	int			fast_abort;
283 	int			tpgt;
284 	char			*username;
285 	char			*username_in;
286 	char			*password;
287 	char			*password_in;
288 	char			*targetname;
289 	char			*ifacename;
290 	char			*initiatorname;
291 	/* control data */
292 	struct iscsi_transport	*tt;
293 	struct Scsi_Host	*host;
294 	struct iscsi_conn	*leadconn;	/* leading connection */
295 	spinlock_t		lock;		/* protects session state, *
296 						 * sequence numbers,       *
297 						 * session resources:      *
298 						 * - cmdpool,		   *
299 						 * - mgmtpool,		   *
300 						 * - r2tpool		   */
301 	int			state;		/* session state           */
302 	int			age;		/* counts session re-opens */
303 
304 	int			scsi_cmds_max; 	/* max scsi commands */
305 	int			cmds_max;	/* size of cmds array */
306 	struct iscsi_task	**cmds;		/* Original Cmds arr */
307 	struct iscsi_pool	cmdpool;	/* PDU's pool */
308 	void			*dd_data;	/* LLD private data */
309 };
310 
311 enum {
312 	ISCSI_HOST_SETUP,
313 	ISCSI_HOST_REMOVED,
314 };
315 
316 struct iscsi_host {
317 	char			*initiatorname;
318 	/* hw address or netdev iscsi connection is bound to */
319 	char			*hwaddress;
320 	char			*netdev;
321 	/* local address */
322 	int			local_port;
323 	char			local_address[ISCSI_ADDRESS_BUF_LEN];
324 
325 	wait_queue_head_t	session_removal_wq;
326 	/* protects sessions and state */
327 	spinlock_t		lock;
328 	int			num_sessions;
329 	int			state;
330 
331 	struct workqueue_struct	*workq;
332 	char			workq_name[20];
333 };
334 
335 /*
336  * scsi host template
337  */
338 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth,
339 				    int reason);
340 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
341 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
342 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
343 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
344 			      void (*done)(struct scsi_cmnd *));
345 
346 /*
347  * iSCSI host helpers.
348  */
349 #define iscsi_host_priv(_shost) \
350 	(shost_priv(_shost) + sizeof(struct iscsi_host))
351 
352 extern int iscsi_host_set_param(struct Scsi_Host *shost,
353 				enum iscsi_host_param param, char *buf,
354 				int buflen);
355 extern int iscsi_host_get_param(struct Scsi_Host *shost,
356 				enum iscsi_host_param param, char *buf);
357 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
358 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
359 					  int dd_data_size,
360 					  bool xmit_can_sleep);
361 extern void iscsi_host_remove(struct Scsi_Host *shost);
362 extern void iscsi_host_free(struct Scsi_Host *shost);
363 extern int iscsi_target_alloc(struct scsi_target *starget);
364 
365 /*
366  * session management
367  */
368 extern struct iscsi_cls_session *
369 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
370 		    uint16_t, int, int, uint32_t, unsigned int);
371 extern void iscsi_session_teardown(struct iscsi_cls_session *);
372 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
373 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
374 			   enum iscsi_param param, char *buf, int buflen);
375 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
376 				   enum iscsi_param param, char *buf);
377 
378 #define iscsi_session_printk(prefix, _sess, fmt, a...)	\
379 	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
380 
381 /*
382  * connection management
383  */
384 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
385 					       int, uint32_t);
386 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
387 extern int iscsi_conn_start(struct iscsi_cls_conn *);
388 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
389 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
390 			   int);
391 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
392 extern void iscsi_session_failure(struct iscsi_session *session,
393 				  enum iscsi_err err);
394 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
395 				enum iscsi_param param, char *buf);
396 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
397 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
398 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
399 
400 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
401 	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
402 			      fmt, ##a)
403 
404 /*
405  * pdu and task processing
406  */
407 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
408 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
409 				    struct iscsi_r2t_info *r2t,
410 				    struct iscsi_data *hdr);
411 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
412 				char *, uint32_t);
413 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
414 			      char *, int);
415 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
416 				char *, int);
417 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
418 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
419 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
420 extern void iscsi_requeue_task(struct iscsi_task *task);
421 extern void iscsi_put_task(struct iscsi_task *task);
422 extern void __iscsi_get_task(struct iscsi_task *task);
423 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
424 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
425 
426 /*
427  * generic helpers
428  */
429 extern void iscsi_pool_free(struct iscsi_pool *);
430 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
431 
432 /*
433  * inline functions to deal with padding.
434  */
435 static inline unsigned int
436 iscsi_padded(unsigned int len)
437 {
438 	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
439 }
440 
441 static inline unsigned int
442 iscsi_padding(unsigned int len)
443 {
444 	len &= (ISCSI_PAD_LEN - 1);
445 	if (len)
446 		len = ISCSI_PAD_LEN - len;
447 	return len;
448 }
449 
450 #endif
451