linux/drivers/infiniband/ulp/srpt/ib_srpt.h
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   1/*
   2 * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
   3 * Copyright (C) 2009 - 2010 Bart Van Assche <bvanassche@acm.org>.
   4 *
   5 * This software is available to you under a choice of one of two
   6 * licenses.  You may choose to be licensed under the terms of the GNU
   7 * General Public License (GPL) Version 2, available from the file
   8 * COPYING in the main directory of this source tree, or the
   9 * OpenIB.org BSD license below:
  10 *
  11 *     Redistribution and use in source and binary forms, with or
  12 *     without modification, are permitted provided that the following
  13 *     conditions are met:
  14 *
  15 *      - Redistributions of source code must retain the above
  16 *        copyright notice, this list of conditions and the following
  17 *        disclaimer.
  18 *
  19 *      - Redistributions in binary form must reproduce the above
  20 *        copyright notice, this list of conditions and the following
  21 *        disclaimer in the documentation and/or other materials
  22 *        provided with the distribution.
  23 *
  24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31 * SOFTWARE.
  32 *
  33 */
  34
  35#ifndef IB_SRPT_H
  36#define IB_SRPT_H
  37
  38#include <linux/types.h>
  39#include <linux/list.h>
  40#include <linux/wait.h>
  41
  42#include <rdma/ib_verbs.h>
  43#include <rdma/ib_sa.h>
  44#include <rdma/ib_cm.h>
  45#include <rdma/rdma_cm.h>
  46#include <rdma/rw.h>
  47
  48#include <scsi/srp.h>
  49
  50#include "ib_dm_mad.h"
  51
  52/*
  53 * The prefix the ServiceName field must start with in the device management
  54 * ServiceEntries attribute pair. See also the SRP specification.
  55 */
  56#define SRP_SERVICE_NAME_PREFIX         "SRP.T10:"
  57
  58struct srpt_nexus;
  59
  60enum {
  61        /*
  62         * SRP IOControllerProfile attributes for SRP target ports that have
  63         * not been defined in <scsi/srp.h>. Source: section B.7, table B.7
  64         * in the SRP specification.
  65         */
  66        SRP_PROTOCOL = 0x0108,
  67        SRP_PROTOCOL_VERSION = 0x0001,
  68        SRP_IO_SUBCLASS = 0x609e,
  69        SRP_SEND_TO_IOC = 0x01,
  70        SRP_SEND_FROM_IOC = 0x02,
  71        SRP_RDMA_READ_FROM_IOC = 0x08,
  72        SRP_RDMA_WRITE_FROM_IOC = 0x20,
  73
  74        /*
  75         * srp_login_cmd.req_flags bitmasks. See also table 9 in the SRP
  76         * specification.
  77         */
  78        SRP_MTCH_ACTION = 0x03, /* MULTI-CHANNEL ACTION */
  79        SRP_LOSOLNT = 0x10, /* logout solicited notification */
  80        SRP_CRSOLNT = 0x20, /* credit request solicited notification */
  81        SRP_AESOLNT = 0x40, /* asynchronous event solicited notification */
  82
  83        /*
  84         * srp_cmd.sol_nt / srp_tsk_mgmt.sol_not bitmasks. See also tables
  85         * 18 and 20 in the SRP specification.
  86         */
  87        SRP_SCSOLNT = 0x02, /* SCSOLNT = successful solicited notification */
  88        SRP_UCSOLNT = 0x04, /* UCSOLNT = unsuccessful solicited notification */
  89
  90        /*
  91         * srp_rsp.sol_not / srp_t_logout.sol_not bitmasks. See also tables
  92         * 16 and 22 in the SRP specification.
  93         */
  94        SRP_SOLNT = 0x01, /* SOLNT = solicited notification */
  95
  96        /* See also table 24 in the SRP specification. */
  97        SRP_TSK_MGMT_SUCCESS = 0x00,
  98        SRP_TSK_MGMT_FUNC_NOT_SUPP = 0x04,
  99        SRP_TSK_MGMT_FAILED = 0x05,
 100
 101        /* See also table 21 in the SRP specification. */
 102        SRP_CMD_SIMPLE_Q = 0x0,
 103        SRP_CMD_HEAD_OF_Q = 0x1,
 104        SRP_CMD_ORDERED_Q = 0x2,
 105        SRP_CMD_ACA = 0x4,
 106
 107        SRP_LOGIN_RSP_MULTICHAN_NO_CHAN = 0x0,
 108        SRP_LOGIN_RSP_MULTICHAN_TERMINATED = 0x1,
 109        SRP_LOGIN_RSP_MULTICHAN_MAINTAINED = 0x2,
 110
 111        SRPT_DEF_SG_TABLESIZE = 128,
 112        /*
 113         * An experimentally determined value that avoids that QP creation
 114         * fails due to "swiotlb buffer is full" on systems using the swiotlb.
 115         */
 116        SRPT_MAX_SG_PER_WQE = 16,
 117
 118        MIN_SRPT_SQ_SIZE = 16,
 119        DEF_SRPT_SQ_SIZE = 4096,
 120        MAX_SRPT_RQ_SIZE = 128,
 121        MIN_SRPT_SRQ_SIZE = 4,
 122        DEFAULT_SRPT_SRQ_SIZE = 4095,
 123        MAX_SRPT_SRQ_SIZE = 65535,
 124        MAX_SRPT_RDMA_SIZE = 1U << 24,
 125        MAX_SRPT_RSP_SIZE = 1024,
 126
 127        MIN_MAX_REQ_SIZE = 996,
 128        DEFAULT_MAX_REQ_SIZE
 129                = sizeof(struct srp_cmd)/*48*/
 130                + sizeof(struct srp_indirect_buf)/*20*/
 131                + 128 * sizeof(struct srp_direct_buf)/*16*/,
 132
 133        MIN_MAX_RSP_SIZE = sizeof(struct srp_rsp)/*36*/ + 4,
 134        DEFAULT_MAX_RSP_SIZE = 256, /* leaves 220 bytes for sense data */
 135
 136        DEFAULT_MAX_RDMA_SIZE = 65536,
 137};
 138
 139/**
 140 * enum srpt_command_state - SCSI command state managed by SRPT
 141 * @SRPT_STATE_NEW:           New command arrived and is being processed.
 142 * @SRPT_STATE_NEED_DATA:     Processing a write or bidir command and waiting
 143 *                            for data arrival.
 144 * @SRPT_STATE_DATA_IN:       Data for the write or bidir command arrived and is
 145 *                            being processed.
 146 * @SRPT_STATE_CMD_RSP_SENT:  SRP_RSP for SRP_CMD has been sent.
 147 * @SRPT_STATE_MGMT:          Processing a SCSI task management command.
 148 * @SRPT_STATE_MGMT_RSP_SENT: SRP_RSP for SRP_TSK_MGMT has been sent.
 149 * @SRPT_STATE_DONE:          Command processing finished successfully, command
 150 *                            processing has been aborted or command processing
 151 *                            failed.
 152 */
 153enum srpt_command_state {
 154        SRPT_STATE_NEW           = 0,
 155        SRPT_STATE_NEED_DATA     = 1,
 156        SRPT_STATE_DATA_IN       = 2,
 157        SRPT_STATE_CMD_RSP_SENT  = 3,
 158        SRPT_STATE_MGMT          = 4,
 159        SRPT_STATE_MGMT_RSP_SENT = 5,
 160        SRPT_STATE_DONE          = 6,
 161};
 162
 163/**
 164 * struct srpt_ioctx - shared SRPT I/O context information
 165 * @cqe:   Completion queue element.
 166 * @buf:   Pointer to the buffer.
 167 * @dma:   DMA address of the buffer.
 168 * @index: Index of the I/O context in its ioctx_ring array.
 169 */
 170struct srpt_ioctx {
 171        struct ib_cqe           cqe;
 172        void                    *buf;
 173        dma_addr_t              dma;
 174        uint32_t                index;
 175};
 176
 177/**
 178 * struct srpt_recv_ioctx - SRPT receive I/O context
 179 * @ioctx:     See above.
 180 * @wait_list: Node for insertion in srpt_rdma_ch.cmd_wait_list.
 181 */
 182struct srpt_recv_ioctx {
 183        struct srpt_ioctx       ioctx;
 184        struct list_head        wait_list;
 185};
 186        
 187struct srpt_rw_ctx {
 188        struct rdma_rw_ctx      rw;
 189        struct scatterlist      *sg;
 190        unsigned int            nents;
 191};
 192
 193/**
 194 * struct srpt_send_ioctx - SRPT send I/O context
 195 * @ioctx:       See above.
 196 * @ch:          Channel pointer.
 197 * @s_rw_ctx:    @rw_ctxs points here if only a single rw_ctx is needed.
 198 * @rw_ctxs:     RDMA read/write contexts.
 199 * @rdma_cqe:    RDMA completion queue element.
 200 * @free_list:   Node in srpt_rdma_ch.free_list.
 201 * @state:       I/O context state.
 202 * @cmd:         Target core command data structure.
 203 * @sense_data:  SCSI sense data.
 204 * @n_rdma:      Number of work requests needed to transfer this ioctx.
 205 * @n_rw_ctx:    Size of rw_ctxs array.
 206 * @queue_status_only: Send a SCSI status back to the initiator but no data.
 207 * @sense_data:  Sense data to be sent to the initiator.
 208 */
 209struct srpt_send_ioctx {
 210        struct srpt_ioctx       ioctx;
 211        struct srpt_rdma_ch     *ch;
 212
 213        struct srpt_rw_ctx      s_rw_ctx;
 214        struct srpt_rw_ctx      *rw_ctxs;
 215
 216        struct ib_cqe           rdma_cqe;
 217        struct list_head        free_list;
 218        enum srpt_command_state state;
 219        struct se_cmd           cmd;
 220        u8                      n_rdma;
 221        u8                      n_rw_ctx;
 222        bool                    queue_status_only;
 223        u8                      sense_data[TRANSPORT_SENSE_BUFFER];
 224};
 225
 226/**
 227 * enum rdma_ch_state - SRP channel state
 228 * @CH_CONNECTING:    QP is in RTR state; waiting for RTU.
 229 * @CH_LIVE:          QP is in RTS state.
 230 * @CH_DISCONNECTING: DREQ has been sent and waiting for DREP or DREQ has
 231 *                    been received.
 232 * @CH_DRAINING:      DREP has been received or waiting for DREP timed out
 233 *                    and last work request has been queued.
 234 * @CH_DISCONNECTED:  Last completion has been received.
 235 */
 236enum rdma_ch_state {
 237        CH_CONNECTING,
 238        CH_LIVE,
 239        CH_DISCONNECTING,
 240        CH_DRAINING,
 241        CH_DISCONNECTED,
 242};
 243
 244/**
 245 * struct srpt_rdma_ch - RDMA channel
 246 * @nexus:         I_T nexus this channel is associated with.
 247 * @qp:            IB queue pair used for communicating over this channel.
 248 * @cm_id:         IB CM ID associated with the channel.
 249 * @cq:            IB completion queue for this channel.
 250 * @zw_cqe:        Zero-length write CQE.
 251 * @rcu:           RCU head.
 252 * @kref:          kref for this channel.
 253 * @rq_size:       IB receive queue size.
 254 * @max_rsp_size:  Maximum size of an RSP response message in bytes.
 255 * @sq_wr_avail:   number of work requests available in the send queue.
 256 * @sport:         pointer to the information of the HCA port used by this
 257 *                 channel.
 258 * @max_ti_iu_len: maximum target-to-initiator information unit length.
 259 * @req_lim:       request limit: maximum number of requests that may be sent
 260 *                 by the initiator without having received a response.
 261 * @req_lim_delta: Number of credits not yet sent back to the initiator.
 262 * @spinlock:      Protects free_list and state.
 263 * @free_list:     Head of list with free send I/O contexts.
 264 * @state:         channel state. See also enum rdma_ch_state.
 265 * @using_rdma_cm: Whether the RDMA/CM or IB/CM is used for this channel.
 266 * @processing_wait_list: Whether or not cmd_wait_list is being processed.
 267 * @ioctx_ring:    Send ring.
 268 * @ioctx_recv_ring: Receive I/O context ring.
 269 * @list:          Node in srpt_nexus.ch_list.
 270 * @cmd_wait_list: List of SCSI commands that arrived before the RTU event. This
 271 *                 list contains struct srpt_ioctx elements and is protected
 272 *                 against concurrent modification by the cm_id spinlock.
 273 * @pkey:          P_Key of the IB partition for this SRP channel.
 274 * @sess:          Session information associated with this SRP channel.
 275 * @sess_name:     Session name.
 276 * @release_work:  Allows scheduling of srpt_release_channel().
 277 */
 278struct srpt_rdma_ch {
 279        struct srpt_nexus       *nexus;
 280        struct ib_qp            *qp;
 281        union {
 282                struct {
 283                        struct ib_cm_id         *cm_id;
 284                } ib_cm;
 285                struct {
 286                        struct rdma_cm_id       *cm_id;
 287                } rdma_cm;
 288        };
 289        struct ib_cq            *cq;
 290        struct ib_cqe           zw_cqe;
 291        struct rcu_head         rcu;
 292        struct kref             kref;
 293        int                     rq_size;
 294        u32                     max_rsp_size;
 295        atomic_t                sq_wr_avail;
 296        struct srpt_port        *sport;
 297        int                     max_ti_iu_len;
 298        atomic_t                req_lim;
 299        atomic_t                req_lim_delta;
 300        spinlock_t              spinlock;
 301        struct list_head        free_list;
 302        enum rdma_ch_state      state;
 303        struct srpt_send_ioctx  **ioctx_ring;
 304        struct srpt_recv_ioctx  **ioctx_recv_ring;
 305        struct list_head        list;
 306        struct list_head        cmd_wait_list;
 307        uint16_t                pkey;
 308        bool                    using_rdma_cm;
 309        bool                    processing_wait_list;
 310        struct se_session       *sess;
 311        u8                      sess_name[40];
 312        struct work_struct      release_work;
 313};
 314
 315/**
 316 * struct srpt_nexus - I_T nexus
 317 * @rcu:       RCU head for this data structure.
 318 * @entry:     srpt_port.nexus_list list node.
 319 * @ch_list:   struct srpt_rdma_ch list. Protected by srpt_port.mutex.
 320 * @i_port_id: 128-bit initiator port identifier copied from SRP_LOGIN_REQ.
 321 * @t_port_id: 128-bit target port identifier copied from SRP_LOGIN_REQ.
 322 */
 323struct srpt_nexus {
 324        struct rcu_head         rcu;
 325        struct list_head        entry;
 326        struct list_head        ch_list;
 327        u8                      i_port_id[16];
 328        u8                      t_port_id[16];
 329};
 330
 331/**
 332 * struct srpt_port_attib - attributes for SRPT port
 333 * @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
 334 * @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
 335 * @srp_sq_size: Shared receive queue (SRQ) size.
 336 * @use_srq: Whether or not to use SRQ.
 337 */
 338struct srpt_port_attrib {
 339        u32                     srp_max_rdma_size;
 340        u32                     srp_max_rsp_size;
 341        u32                     srp_sq_size;
 342        bool                    use_srq;
 343};
 344
 345/**
 346 * struct srpt_port - information associated by SRPT with a single IB port
 347 * @sdev:      backpointer to the HCA information.
 348 * @mad_agent: per-port management datagram processing information.
 349 * @enabled:   Whether or not this target port is enabled.
 350 * @port_guid: ASCII representation of Port GUID
 351 * @port_gid:  ASCII representation of Port GID
 352 * @port:      one-based port number.
 353 * @sm_lid:    cached value of the port's sm_lid.
 354 * @lid:       cached value of the port's lid.
 355 * @gid:       cached value of the port's gid.
 356 * @port_acl_lock spinlock for port_acl_list:
 357 * @work:      work structure for refreshing the aforementioned cached values.
 358 * @port_guid_tpg: TPG associated with target port GUID.
 359 * @port_guid_wwn: WWN associated with target port GUID.
 360 * @port_gid_tpg:  TPG associated with target port GID.
 361 * @port_gid_wwn:  WWN associated with target port GID.
 362 * @port_attrib:   Port attributes that can be accessed through configfs.
 363 * @ch_releaseQ:   Enables waiting for removal from nexus_list.
 364 * @mutex:         Protects nexus_list.
 365 * @nexus_list:    Nexus list. See also srpt_nexus.entry.
 366 */
 367struct srpt_port {
 368        struct srpt_device      *sdev;
 369        struct ib_mad_agent     *mad_agent;
 370        bool                    enabled;
 371        u8                      port_guid[24];
 372        u8                      port_gid[64];
 373        u8                      port;
 374        u32                     sm_lid;
 375        u32                     lid;
 376        union ib_gid            gid;
 377        struct work_struct      work;
 378        struct se_portal_group  port_guid_tpg;
 379        struct se_wwn           port_guid_wwn;
 380        struct se_portal_group  port_gid_tpg;
 381        struct se_wwn           port_gid_wwn;
 382        struct srpt_port_attrib port_attrib;
 383        wait_queue_head_t       ch_releaseQ;
 384        struct mutex            mutex;
 385        struct list_head        nexus_list;
 386};
 387
 388/**
 389 * struct srpt_device - information associated by SRPT with a single HCA
 390 * @device:        Backpointer to the struct ib_device managed by the IB core.
 391 * @pd:            IB protection domain.
 392 * @lkey:          L_Key (local key) with write access to all local memory.
 393 * @srq:           Per-HCA SRQ (shared receive queue).
 394 * @cm_id:         Connection identifier.
 395 * @srq_size:      SRQ size.
 396 * @sdev_mutex:    Serializes use_srq changes.
 397 * @use_srq:       Whether or not to use SRQ.
 398 * @ioctx_ring:    Per-HCA SRQ.
 399 * @port:          Information about the ports owned by this HCA.
 400 * @event_handler: Per-HCA asynchronous IB event handler.
 401 * @list:          Node in srpt_dev_list.
 402 */
 403struct srpt_device {
 404        struct ib_device        *device;
 405        struct ib_pd            *pd;
 406        u32                     lkey;
 407        struct ib_srq           *srq;
 408        struct ib_cm_id         *cm_id;
 409        int                     srq_size;
 410        struct mutex            sdev_mutex;
 411        bool                    use_srq;
 412        struct srpt_recv_ioctx  **ioctx_ring;
 413        struct srpt_port        port[2];
 414        struct ib_event_handler event_handler;
 415        struct list_head        list;
 416};
 417
 418#endif                          /* IB_SRPT_H */
 419