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
  64 /* Connection suspend "bit" */
  65 #define ISCSI_SUSPEND_BIT               1
  66
  67 #define ISCSI_ITT_MASK                  (0xfff)
  68 #define ISCSI_CID_SHIFT                 12
  69 #define ISCSI_CID_MASK                  (0xffff << ISCSI_CID_SHIFT)
  70 #define ISCSI_AGE_SHIFT                 28
  71 #define ISCSI_AGE_MASK                  (0xf << ISCSI_AGE_SHIFT)
  72
  73 struct iscsi_mgmt_task {
  74         /*
  75          * Becuae LLDs allocate their hdr differently, this is a pointer to
  76          * that storage. It must be setup at session creation time.
  77          */
  78         struct iscsi_hdr        *hdr;
  79         char                    *data;          /* mgmt payload */
  80         int                     data_count;     /* counts data to be sent */
  81         uint32_t                itt;            /* this ITT */
  82         void                    *dd_data;       /* driver/transport data */
  83         struct list_head        running;
  84 };
  85
  86 struct iscsi_cmd_task {
  87         /*
  88          * Becuae LLDs allocate their hdr differently, this is a pointer to
  89          * that storage. It must be setup at session creation time.
  90          */
  91         struct iscsi_cmd        *hdr;
  92         int                     itt;            /* this ITT */
  93         int                     datasn;         /* DataSN */
  94
  95         uint32_t                unsol_datasn;
  96         int                     imm_count;      /* imm-data (bytes)   */
  97         int                     unsol_count;    /* unsolicited (bytes)*/
  98         int                     data_count;     /* remaining Data-Out */
  99         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 100         int                     total_length;
 101         struct iscsi_conn       *conn;          /* used connection    */
 102         struct iscsi_mgmt_task  *mtask;         /* tmf mtask in progr */
 103
 104         struct list_head        running;        /* running cmd list */
 105         void                    *dd_data;       /* driver/transport data */
 106 };
 107
 108 struct iscsi_conn {
 109         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 110         void                    *dd_data;       /* iscsi_transport data */
 111         struct iscsi_session    *session;       /* parent session */
 112         /*
 113          * LLDs should set this lock. It protects the transport recv
 114          * code
 115          */
 116         rwlock_t                *recv_lock;
 117         /*
 118          * conn_stop() flag: stop to recover, stop to terminate
 119          */
 120         int                     stop_stage;
 121
 122         /* iSCSI connection-wide sequencing */
 123         uint32_t                exp_statsn;
 124
 125         /* control data */
 126         int                     id;             /* CID */
 127         struct list_head        item;           /* maintains list of conns */
 128         int                     c_stage;        /* connection state */
 129         struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
 130         struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
 131         struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
 132
 133         /* xmit */
 134         struct kfifo            *immqueue;      /* immediate xmit queue */
 135         struct kfifo            *mgmtqueue;     /* mgmt (control) xmit queue */
 136         struct list_head        mgmt_run_list;  /* list of control tasks */
 137         struct kfifo            *xmitqueue;     /* data-path cmd queue */
 138         struct list_head        run_list;       /* list of cmds in progress */
 139         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 140         /*
 141          * serializes connection xmit, access to kfifos:
 142          * xmitqueue, immqueue, mgmtqueue
 143          */
 144         struct mutex            xmitmutex;
 145
 146         unsigned long           suspend_tx;     /* suspend Tx */
 147         unsigned long           suspend_rx;     /* suspend Rx */
 148
 149         /* abort */
 150         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 151         struct iscsi_tm         tmhdr;
 152         struct timer_list       tmabort_timer;
 153         int                     tmabort_state;  /* see TMABORT_INITIAL, etc.*/
 154
 155         /* negotiated params */
 156         int                     max_recv_dlength; /* initiator_max_recv_dsl*/
 157         int                     max_xmit_dlength; /* target_max_recv_dsl */
 158         int                     hdrdgst_en;
 159         int                     datadgst_en;
 160
 161         /* MIB-statistics */
 162         uint64_t                txdata_octets;
 163         uint64_t                rxdata_octets;
 164         uint32_t                scsicmd_pdus_cnt;
 165         uint32_t                dataout_pdus_cnt;
 166         uint32_t                scsirsp_pdus_cnt;
 167         uint32_t                datain_pdus_cnt;
 168         uint32_t                r2t_pdus_cnt;
 169         uint32_t                tmfcmd_pdus_cnt;
 170         int32_t                 tmfrsp_pdus_cnt;
 171
 172         /* custom statistics */
 173         uint32_t                eh_abort_cnt;
 174 };
 175
 176 struct iscsi_queue {
 177         struct kfifo            *queue;         /* FIFO Queue */
 178         void                    **pool;         /* Pool of elements */
 179         int                     max;            /* Max number of elements */
 180 };
 181
 182 struct iscsi_session {
 183         /* iSCSI session-wide sequencing */
 184         uint32_t                cmdsn;
 185         uint32_t                exp_cmdsn;
 186         uint32_t                max_cmdsn;
 187
 188         /* configuration */
 189         int                     initial_r2t_en;
 190         int                     max_r2t;
 191         int                     imm_data_en;
 192         int                     first_burst;
 193         int                     max_burst;
 194         int                     time2wait;
 195         int                     time2retain;
 196         int                     pdu_inorder_en;
 197         int                     dataseq_inorder_en;
 198         int                     erl;
 199         int                     ifmarker_en;
 200         int                     ofmarker_en;
 201
 202         /* control data */
 203         struct iscsi_transport  *tt;
 204         struct Scsi_Host        *host;
 205         struct iscsi_conn       *leadconn;      /* leading connection */
 206         spinlock_t              lock;           /* protects session state, *
 207                                                  * sequence numbers,       *
 208                                                  * session resources:      *
 209                                                  * - cmdpool,              *
 210                                                  * - mgmtpool,             *
 211                                                  * - r2tpool               */
 212         int                     state;          /* session state           */
 213         struct list_head        item;
 214         int                     age;            /* counts session re-opens */
 215
 216         struct list_head        connections;    /* list of connections */
 217         int                     cmds_max;       /* size of cmds array */
 218         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
 219         struct iscsi_queue      cmdpool;        /* PDU's pool */
 220         int                     mgmtpool_max;   /* size of mgmt array */
 221         struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
 222         struct iscsi_queue      mgmtpool;       /* Mgmt PDU's pool */
 223 };
 224
 225 /*
 226  * scsi host template
 227  */
 228 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 229 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 230 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
 231 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 232                               void (*done)(struct scsi_cmnd *));
 233
 234 /*
 235  * session management
 236  */
 237 extern struct iscsi_cls_session *
 238 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
 239                     int, int, uint32_t, uint32_t *);
 240 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 241 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
 242 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 243
 244 #define session_to_cls(_sess) \
 245         hostdata_session(_sess->host->hostdata)
 246
 247 /*
 248  * connection management
 249  */
 250 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 251                                                uint32_t);
 252 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 253 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 254 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 255 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 256                            int);
 257 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 258
 259 /*
 260  * pdu and task processing
 261  */
 262 extern int iscsi_check_assign_cmdsn(struct iscsi_session *,
 263                                     struct iscsi_nopin *);
 264 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
 265                                         struct iscsi_data *hdr,
 266                                         int transport_data_cnt);
 267 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 268                                 char *, uint32_t);
 269 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 270                               char *, int);
 271 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 272                                 char *, int);
 273 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
 274                             uint32_t *);
 275
 276 /*
 277  * generic helpers
 278  */
 279 extern void iscsi_pool_free(struct iscsi_queue *, void **);
 280 extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
 281
 282 #endif