drivers/infiniband/ulp/srpt/ib_srpt.h

   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
  58 struct srpt_nexus;
  59
  60 enum {
  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         SRPT_DEF_SG_TABLESIZE = 128,
 108         /*
 109          * An experimentally determined value that avoids that QP creation
 110          * fails due to "swiotlb buffer is full" on systems using the swiotlb.
 111          */
 112         SRPT_MAX_SG_PER_WQE = 16,
 113
 114         MIN_SRPT_SQ_SIZE = 16,
 115         DEF_SRPT_SQ_SIZE = 4096,
 116         MAX_SRPT_RQ_SIZE = 128,
 117         MIN_SRPT_SRQ_SIZE = 4,
 118         DEFAULT_SRPT_SRQ_SIZE = 4095,
 119         MAX_SRPT_SRQ_SIZE = 65535,
 120         MAX_SRPT_RDMA_SIZE = 1U << 24,
 121         MAX_SRPT_RSP_SIZE = 1024,
 122
 123         SRP_MAX_ADD_CDB_LEN = 16,
 124         SRP_MAX_IMM_DATA_OFFSET = 80,
 125         SRP_MAX_IMM_DATA = 8 * 1024,
 126         MIN_MAX_REQ_SIZE = 996,
 127         DEFAULT_MAX_REQ_SIZE_1 = sizeof(struct srp_cmd)/*48*/ +
 128                                  SRP_MAX_ADD_CDB_LEN +
 129                                  sizeof(struct srp_indirect_buf)/*20*/ +
 130                                  128 * sizeof(struct srp_direct_buf)/*16*/,
 131         DEFAULT_MAX_REQ_SIZE_2 = SRP_MAX_IMM_DATA_OFFSET +
 132                                  sizeof(struct srp_imm_buf) + SRP_MAX_IMM_DATA,
 133         DEFAULT_MAX_REQ_SIZE = DEFAULT_MAX_REQ_SIZE_1 > DEFAULT_MAX_REQ_SIZE_2 ?
 134                                DEFAULT_MAX_REQ_SIZE_1 : DEFAULT_MAX_REQ_SIZE_2,
 135
 136         MIN_MAX_RSP_SIZE = sizeof(struct srp_rsp)/*36*/ + 4,
 137         DEFAULT_MAX_RSP_SIZE = 256, /* leaves 220 bytes for sense data */
 138
 139         DEFAULT_MAX_RDMA_SIZE = 65536,
 140 };
 141
 142 /**
 143  * enum srpt_command_state - SCSI command state managed by SRPT
 144  * @SRPT_STATE_NEW:           New command arrived and is being processed.
 145  * @SRPT_STATE_NEED_DATA:     Processing a write or bidir command and waiting
 146  *                            for data arrival.
 147  * @SRPT_STATE_DATA_IN:       Data for the write or bidir command arrived and is
 148  *                            being processed.
 149  * @SRPT_STATE_CMD_RSP_SENT:  SRP_RSP for SRP_CMD has been sent.
 150  * @SRPT_STATE_MGMT:          Processing a SCSI task management command.
 151  * @SRPT_STATE_MGMT_RSP_SENT: SRP_RSP for SRP_TSK_MGMT has been sent.
 152  * @SRPT_STATE_DONE:          Command processing finished successfully, command
 153  *                            processing has been aborted or command processing
 154  *                            failed.
 155  */
 156 enum srpt_command_state {
 157         SRPT_STATE_NEW           = 0,
 158         SRPT_STATE_NEED_DATA     = 1,
 159         SRPT_STATE_DATA_IN       = 2,
 160         SRPT_STATE_CMD_RSP_SENT  = 3,
 161         SRPT_STATE_MGMT          = 4,
 162         SRPT_STATE_MGMT_RSP_SENT = 5,
 163         SRPT_STATE_DONE          = 6,
 164 };
 165
 166 /**
 167  * struct srpt_ioctx - shared SRPT I/O context information
 168  * @cqe:   Completion queue element.
 169  * @buf:   Pointer to the buffer.
 170  * @dma:   DMA address of the buffer.
 171  * @offset: Offset of the first byte in @buf and @dma that is actually used.
 172  * @index: Index of the I/O context in its ioctx_ring array.
 173  */
 174 struct srpt_ioctx {
 175         struct ib_cqe           cqe;
 176         void                    *buf;
 177         dma_addr_t              dma;
 178         uint32_t                offset;
 179         uint32_t                index;
 180 };
 181
 182 /**
 183  * struct srpt_recv_ioctx - SRPT receive I/O context
 184  * @ioctx:     See above.
 185  * @wait_list: Node for insertion in srpt_rdma_ch.cmd_wait_list.
 186  * @byte_len:  Number of bytes in @ioctx.buf.
 187  */
 188 struct srpt_recv_ioctx {
 189         struct srpt_ioctx       ioctx;
 190         struct list_head        wait_list;
 191         int                     byte_len;
 192 };
 193
 194 struct srpt_rw_ctx {
 195         struct rdma_rw_ctx      rw;
 196         struct scatterlist      *sg;
 197         unsigned int            nents;
 198 };
 199
 200 /**
 201  * struct srpt_send_ioctx - SRPT send I/O context
 202  * @ioctx:       See above.
 203  * @ch:          Channel pointer.
 204  * @recv_ioctx:  Receive I/O context associated with this send I/O context.
 205  *               Only used for processing immediate data.
 206  * @s_rw_ctx:    @rw_ctxs points here if only a single rw_ctx is needed.
 207  * @rw_ctxs:     RDMA read/write contexts.
 208  * @imm_sg:      Scatterlist for immediate data.
 209  * @rdma_cqe:    RDMA completion queue element.
 210  * @state:       I/O context state.
 211  * @cmd:         Target core command data structure.
 212  * @sense_data:  SCSI sense data.
 213  * @n_rdma:      Number of work requests needed to transfer this ioctx.
 214  * @n_rw_ctx:    Size of rw_ctxs array.
 215  * @queue_status_only: Send a SCSI status back to the initiator but no data.
 216  * @sense_data:  Sense data to be sent to the initiator.
 217  */
 218 struct srpt_send_ioctx {
 219         struct srpt_ioctx       ioctx;
 220         struct srpt_rdma_ch     *ch;
 221         struct srpt_recv_ioctx  *recv_ioctx;
 222
 223         struct srpt_rw_ctx      s_rw_ctx;
 224         struct srpt_rw_ctx      *rw_ctxs;
 225
 226         struct scatterlist      imm_sg;
 227
 228         struct ib_cqe           rdma_cqe;
 229         enum srpt_command_state state;
 230         struct se_cmd           cmd;
 231         u8                      n_rdma;
 232         u8                      n_rw_ctx;
 233         bool                    queue_status_only;
 234         u8                      sense_data[TRANSPORT_SENSE_BUFFER];
 235 };
 236
 237 /**
 238  * enum rdma_ch_state - SRP channel state
 239  * @CH_CONNECTING:    QP is in RTR state; waiting for RTU.
 240  * @CH_LIVE:          QP is in RTS state.
 241  * @CH_DISCONNECTING: DREQ has been sent and waiting for DREP or DREQ has
 242  *                    been received.
 243  * @CH_DRAINING:      DREP has been received or waiting for DREP timed out
 244  *                    and last work request has been queued.
 245  * @CH_DISCONNECTED:  Last completion has been received.
 246  */
 247 enum rdma_ch_state {
 248         CH_CONNECTING,
 249         CH_LIVE,
 250         CH_DISCONNECTING,
 251         CH_DRAINING,
 252         CH_DISCONNECTED,
 253 };
 254
 255 /**
 256  * struct srpt_rdma_ch - RDMA channel
 257  * @nexus:         I_T nexus this channel is associated with.
 258  * @qp:            IB queue pair used for communicating over this channel.
 259  * @ib_cm:         See below.
 260  * @ib_cm.cm_id:   IB CM ID associated with the channel.
 261  * @rdma_cm:       See below.
 262  * @rdma_cm.cm_id: RDMA CM ID associated with the channel.
 263  * @cq:            IB completion queue for this channel.
 264  * @zw_cqe:        Zero-length write CQE.
 265  * @rcu:           RCU head.
 266  * @kref:          kref for this channel.
 267  * @closed:        Completion object that will be signaled as soon as a new
 268  *                 channel object with the same identity can be created.
 269  * @rq_size:       IB receive queue size.
 270  * @max_rsp_size:  Maximum size of an RSP response message in bytes.
 271  * @sq_wr_avail:   number of work requests available in the send queue.
 272  * @sport:         pointer to the information of the HCA port used by this
 273  *                 channel.
 274  * @max_ti_iu_len: maximum target-to-initiator information unit length.
 275  * @req_lim:       request limit: maximum number of requests that may be sent
 276  *                 by the initiator without having received a response.
 277  * @req_lim_delta: Number of credits not yet sent back to the initiator.
 278  * @imm_data_offset: Offset from start of SRP_CMD for immediate data.
 279  * @spinlock:      Protects free_list and state.
 280  * @state:         channel state. See also enum rdma_ch_state.
 281  * @using_rdma_cm: Whether the RDMA/CM or IB/CM is used for this channel.
 282  * @processing_wait_list: Whether or not cmd_wait_list is being processed.
 283  * @rsp_buf_cache: kmem_cache for @ioctx_ring.
 284  * @ioctx_ring:    Send ring.
 285  * @req_buf_cache: kmem_cache for @ioctx_recv_ring.
 286  * @ioctx_recv_ring: Receive I/O context ring.
 287  * @list:          Node in srpt_nexus.ch_list.
 288  * @cmd_wait_list: List of SCSI commands that arrived before the RTU event. This
 289  *                 list contains struct srpt_ioctx elements and is protected
 290  *                 against concurrent modification by the cm_id spinlock.
 291  * @pkey:          P_Key of the IB partition for this SRP channel.
 292  * @sess:          Session information associated with this SRP channel.
 293  * @sess_name:     Session name.
 294  * @release_work:  Allows scheduling of srpt_release_channel().
 295  */
 296 struct srpt_rdma_ch {
 297         struct srpt_nexus       *nexus;
 298         struct ib_qp            *qp;
 299         union {
 300                 struct {
 301                         struct ib_cm_id         *cm_id;
 302                 } ib_cm;
 303                 struct {
 304                         struct rdma_cm_id       *cm_id;
 305                 } rdma_cm;
 306         };
 307         struct ib_cq            *cq;
 308         struct ib_cqe           zw_cqe;
 309         struct rcu_head         rcu;
 310         struct kref             kref;
 311         struct completion       *closed;
 312         int                     rq_size;
 313         u32                     max_rsp_size;
 314         atomic_t                sq_wr_avail;
 315         struct srpt_port        *sport;
 316         int                     max_ti_iu_len;
 317         atomic_t                req_lim;
 318         atomic_t                req_lim_delta;
 319         u16                     imm_data_offset;
 320         spinlock_t              spinlock;
 321         enum rdma_ch_state      state;
 322         struct kmem_cache       *rsp_buf_cache;
 323         struct srpt_send_ioctx  **ioctx_ring;
 324         struct kmem_cache       *req_buf_cache;
 325         struct srpt_recv_ioctx  **ioctx_recv_ring;
 326         struct list_head        list;
 327         struct list_head        cmd_wait_list;
 328         uint16_t                pkey;
 329         bool                    using_rdma_cm;
 330         bool                    processing_wait_list;
 331         struct se_session       *sess;
 332         u8                      sess_name[40];
 333         struct work_struct      release_work;
 334 };
 335
 336 /**
 337  * struct srpt_nexus - I_T nexus
 338  * @rcu:       RCU head for this data structure.
 339  * @entry:     srpt_port.nexus_list list node.
 340  * @ch_list:   struct srpt_rdma_ch list. Protected by srpt_port.mutex.
 341  * @i_port_id: 128-bit initiator port identifier copied from SRP_LOGIN_REQ.
 342  * @t_port_id: 128-bit target port identifier copied from SRP_LOGIN_REQ.
 343  */
 344 struct srpt_nexus {
 345         struct rcu_head         rcu;
 346         struct list_head        entry;
 347         struct list_head        ch_list;
 348         u8                      i_port_id[16];
 349         u8                      t_port_id[16];
 350 };
 351
 352 /**
 353  * struct srpt_port_attib - attributes for SRPT port
 354  * @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
 355  * @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
 356  * @srp_sq_size: Shared receive queue (SRQ) size.
 357  * @use_srq: Whether or not to use SRQ.
 358  */
 359 struct srpt_port_attrib {
 360         u32                     srp_max_rdma_size;
 361         u32                     srp_max_rsp_size;
 362         u32                     srp_sq_size;
 363         bool                    use_srq;
 364 };
 365
 366 /**
 367  * struct srpt_tpg - information about a single "target portal group"
 368  * @entry:      Entry in @sport_id->tpg_list.
 369  * @sport_id:   Port name this TPG is associated with.
 370  * @tpg:        LIO TPG data structure.
 371  *
 372  * Zero or more target portal groups are associated with each port name
 373  * (srpt_port_id). With each TPG an ACL list is associated.
 374  */
 375 struct srpt_tpg {
 376         struct list_head        entry;
 377         struct srpt_port_id     *sport_id;
 378         struct se_portal_group  tpg;
 379 };
 380
 381 /**
 382  * struct srpt_port_id - information about an RDMA port name
 383  * @mutex:      Protects @tpg_list changes.
 384  * @tpg_list:   TPGs associated with the RDMA port name.
 385  * @wwn:        WWN associated with the RDMA port name.
 386  * @name:       ASCII representation of the port name.
 387  *
 388  * Multiple sysfs directories can be associated with a single RDMA port. This
 389  * data structure represents a single (port, name) pair.
 390  */
 391 struct srpt_port_id {
 392         struct mutex            mutex;
 393         struct list_head        tpg_list;
 394         struct se_wwn           wwn;
 395         char                    name[64];
 396 };
 397
 398 /**
 399  * struct srpt_port - information associated by SRPT with a single IB port
 400  * @sdev:      backpointer to the HCA information.
 401  * @mad_agent: per-port management datagram processing information.
 402  * @enabled:   Whether or not this target port is enabled.
 403  * @port:      one-based port number.
 404  * @sm_lid:    cached value of the port's sm_lid.
 405  * @lid:       cached value of the port's lid.
 406  * @gid:       cached value of the port's gid.
 407  * @work:      work structure for refreshing the aforementioned cached values.
 408  * @port_guid_id: target port GUID
 409  * @port_gid_id: target port GID
 410  * @port_attrib:   Port attributes that can be accessed through configfs.
 411  * @refcount:      Number of objects associated with this port.
 412  * @freed_channels: Completion that will be signaled once @refcount becomes 0.
 413  * @mutex:         Protects nexus_list.
 414  * @nexus_list:    Nexus list. See also srpt_nexus.entry.
 415  */
 416 struct srpt_port {
 417         struct srpt_device      *sdev;
 418         struct ib_mad_agent     *mad_agent;
 419         bool                    enabled;
 420         u8                      port;
 421         u32                     sm_lid;
 422         u32                     lid;
 423         union ib_gid            gid;
 424         struct work_struct      work;
 425         struct srpt_port_id     port_guid_id;
 426         struct srpt_port_id     port_gid_id;
 427         struct srpt_port_attrib port_attrib;
 428         atomic_t                refcount;
 429         struct completion       *freed_channels;
 430         struct mutex            mutex;
 431         struct list_head        nexus_list;
 432 };
 433
 434 /**
 435  * struct srpt_device - information associated by SRPT with a single HCA
 436  * @device:        Backpointer to the struct ib_device managed by the IB core.
 437  * @pd:            IB protection domain.
 438  * @lkey:          L_Key (local key) with write access to all local memory.
 439  * @srq:           Per-HCA SRQ (shared receive queue).
 440  * @cm_id:         Connection identifier.
 441  * @srq_size:      SRQ size.
 442  * @sdev_mutex:    Serializes use_srq changes.
 443  * @use_srq:       Whether or not to use SRQ.
 444  * @req_buf_cache: kmem_cache for @ioctx_ring buffers.
 445  * @ioctx_ring:    Per-HCA SRQ.
 446  * @event_handler: Per-HCA asynchronous IB event handler.
 447  * @list:          Node in srpt_dev_list.
 448  * @port:          Information about the ports owned by this HCA.
 449  */
 450 struct srpt_device {
 451         struct ib_device        *device;
 452         struct ib_pd            *pd;
 453         u32                     lkey;
 454         struct ib_srq           *srq;
 455         struct ib_cm_id         *cm_id;
 456         int                     srq_size;
 457         struct mutex            sdev_mutex;
 458         bool                    use_srq;
 459         struct kmem_cache       *req_buf_cache;
 460         struct srpt_recv_ioctx  **ioctx_ring;
 461         struct ib_event_handler event_handler;
 462         struct list_head        list;
 463         struct srpt_port        port[];
 464 };
 465
 466 #endif                          /* IB_SRPT_H */