include/scsi/libiscsi.h

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