ulp/srpt/ib_srpt.h

0001 /*
0002  * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
0003  * Copyright (C) 2009 - 2010 Bart Van Assche <bvanassche@acm.org>.
0004  *
0005  * This software is available to you under a choice of one of two
0006  * licenses.  You may choose to be licensed under the terms of the GNU
0007  * General Public License (GPL) Version 2, available from the file
0008  * COPYING in the main directory of this source tree, or the
0009  * OpenIB.org BSD license below:
0010  *
0011  *     Redistribution and use in source and binary forms, with or
0012  *     without modification, are permitted provided that the following
0013  *     conditions are met:
0014  *
0015  *      - Redistributions of source code must retain the above
0016  *        copyright notice, this list of conditions and the following
0017  *        disclaimer.
0018  *
0019  *      - Redistributions in binary form must reproduce the above
0020  *        copyright notice, this list of conditions and the following
0021  *        disclaimer in the documentation and/or other materials
0022  *        provided with the distribution.
0023  *
0024  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
0025  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
0026  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
0027  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
0028  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
0029  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
0030  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
0031  * SOFTWARE.
0032  *
0033  */
0034
0035 #ifndef IB_SRPT_H
0036 #define IB_SRPT_H
0037
0038 #include <linux/types.h>
0039 #include <linux/list.h>
0040 #include <linux/wait.h>
0041
0042 #include <rdma/ib_verbs.h>
0043 #include <rdma/ib_sa.h>
0044 #include <rdma/ib_cm.h>
0045 #include <rdma/rdma_cm.h>
0046 #include <rdma/rw.h>
0047
0048 #include <scsi/srp.h>
0049
0050 #include "ib_dm_mad.h"
0051
0052 /*
0053  * The prefix the ServiceName field must start with in the device management
0054  * ServiceEntries attribute pair. See also the SRP specification.
0055  */
0056 #define SRP_SERVICE_NAME_PREFIX     "SRP.T10:"
0057
0058 struct srpt_nexus;
0059
0060 enum {
0061     /*
0062      * SRP IOControllerProfile attributes for SRP target ports that have
0063      * not been defined in <scsi/srp.h>. Source: section B.7, table B.7
0064      * in the SRP specification.
0065      */
0066     SRP_PROTOCOL = 0x0108,
0067     SRP_PROTOCOL_VERSION = 0x0001,
0068     SRP_IO_SUBCLASS = 0x609e,
0069     SRP_SEND_TO_IOC = 0x01,
0070     SRP_SEND_FROM_IOC = 0x02,
0071     SRP_RDMA_READ_FROM_IOC = 0x08,
0072     SRP_RDMA_WRITE_FROM_IOC = 0x20,
0073
0074     /*
0075      * srp_login_cmd.req_flags bitmasks. See also table 9 in the SRP
0076      * specification.
0077      */
0078     SRP_MTCH_ACTION = 0x03, /* MULTI-CHANNEL ACTION */
0079     SRP_LOSOLNT = 0x10, /* logout solicited notification */
0080     SRP_CRSOLNT = 0x20, /* credit request solicited notification */
0081     SRP_AESOLNT = 0x40, /* asynchronous event solicited notification */
0082
0083     /*
0084      * srp_cmd.sol_nt / srp_tsk_mgmt.sol_not bitmasks. See also tables
0085      * 18 and 20 in the SRP specification.
0086      */
0087     SRP_SCSOLNT = 0x02, /* SCSOLNT = successful solicited notification */
0088     SRP_UCSOLNT = 0x04, /* UCSOLNT = unsuccessful solicited notification */
0089
0090     /*
0091      * srp_rsp.sol_not / srp_t_logout.sol_not bitmasks. See also tables
0092      * 16 and 22 in the SRP specification.
0093      */
0094     SRP_SOLNT = 0x01, /* SOLNT = solicited notification */
0095
0096     /* See also table 24 in the SRP specification. */
0097     SRP_TSK_MGMT_SUCCESS = 0x00,
0098     SRP_TSK_MGMT_FUNC_NOT_SUPP = 0x04,
0099     SRP_TSK_MGMT_FAILED = 0x05,
0100
0101     /* See also table 21 in the SRP specification. */
0102     SRP_CMD_SIMPLE_Q = 0x0,
0103     SRP_CMD_HEAD_OF_Q = 0x1,
0104     SRP_CMD_ORDERED_Q = 0x2,
0105     SRP_CMD_ACA = 0x4,
0106
0107     SRPT_DEF_SG_TABLESIZE = 128,
0108
0109     MIN_SRPT_SQ_SIZE = 16,
0110     DEF_SRPT_SQ_SIZE = 4096,
0111     MAX_SRPT_RQ_SIZE = 128,
0112     MIN_SRPT_SRQ_SIZE = 4,
0113     DEFAULT_SRPT_SRQ_SIZE = 4095,
0114     MAX_SRPT_SRQ_SIZE = 65535,
0115     MAX_SRPT_RDMA_SIZE = 1U << 24,
0116     MAX_SRPT_RSP_SIZE = 1024,
0117
0118     SRP_MAX_ADD_CDB_LEN = 16,
0119     SRP_MAX_IMM_DATA_OFFSET = 80,
0120     SRP_MAX_IMM_DATA = 8 * 1024,
0121     MIN_MAX_REQ_SIZE = 996,
0122     DEFAULT_MAX_REQ_SIZE_1 = sizeof(struct srp_cmd)/*48*/ +
0123                  SRP_MAX_ADD_CDB_LEN +
0124                  sizeof(struct srp_indirect_buf)/*20*/ +
0125                  128 * sizeof(struct srp_direct_buf)/*16*/,
0126     DEFAULT_MAX_REQ_SIZE_2 = SRP_MAX_IMM_DATA_OFFSET +
0127                  sizeof(struct srp_imm_buf) + SRP_MAX_IMM_DATA,
0128     DEFAULT_MAX_REQ_SIZE = DEFAULT_MAX_REQ_SIZE_1 > DEFAULT_MAX_REQ_SIZE_2 ?
0129                    DEFAULT_MAX_REQ_SIZE_1 : DEFAULT_MAX_REQ_SIZE_2,
0130
0131     MIN_MAX_RSP_SIZE = sizeof(struct srp_rsp)/*36*/ + 4,
0132     DEFAULT_MAX_RSP_SIZE = 256, /* leaves 220 bytes for sense data */
0133
0134     DEFAULT_MAX_RDMA_SIZE = 65536,
0135 };
0136
0137 /**
0138  * enum srpt_command_state - SCSI command state managed by SRPT
0139  * @SRPT_STATE_NEW:           New command arrived and is being processed.
0140  * @SRPT_STATE_NEED_DATA:     Processing a write or bidir command and waiting
0141  *                            for data arrival.
0142  * @SRPT_STATE_DATA_IN:       Data for the write or bidir command arrived and is
0143  *                            being processed.
0144  * @SRPT_STATE_CMD_RSP_SENT:  SRP_RSP for SRP_CMD has been sent.
0145  * @SRPT_STATE_MGMT:          Processing a SCSI task management command.
0146  * @SRPT_STATE_MGMT_RSP_SENT: SRP_RSP for SRP_TSK_MGMT has been sent.
0147  * @SRPT_STATE_DONE:          Command processing finished successfully, command
0148  *                            processing has been aborted or command processing
0149  *                            failed.
0150  */
0151 enum srpt_command_state {
0152     SRPT_STATE_NEW       = 0,
0153     SRPT_STATE_NEED_DATA     = 1,
0154     SRPT_STATE_DATA_IN   = 2,
0155     SRPT_STATE_CMD_RSP_SENT  = 3,
0156     SRPT_STATE_MGMT      = 4,
0157     SRPT_STATE_MGMT_RSP_SENT = 5,
0158     SRPT_STATE_DONE      = 6,
0159 };
0160
0161 /**
0162  * struct srpt_ioctx - shared SRPT I/O context information
0163  * @cqe:   Completion queue element.
0164  * @buf:   Pointer to the buffer.
0165  * @dma:   DMA address of the buffer.
0166  * @offset: Offset of the first byte in @buf and @dma that is actually used.
0167  * @index: Index of the I/O context in its ioctx_ring array.
0168  */
0169 struct srpt_ioctx {
0170     struct ib_cqe       cqe;
0171     void            *buf;
0172     dma_addr_t      dma;
0173     uint32_t        offset;
0174     uint32_t        index;
0175 };
0176
0177 /**
0178  * struct srpt_recv_ioctx - SRPT receive I/O context
0179  * @ioctx:     See above.
0180  * @wait_list: Node for insertion in srpt_rdma_ch.cmd_wait_list.
0181  * @byte_len:  Number of bytes in @ioctx.buf.
0182  */
0183 struct srpt_recv_ioctx {
0184     struct srpt_ioctx   ioctx;
0185     struct list_head    wait_list;
0186     int         byte_len;
0187 };
0188
0189 struct srpt_rw_ctx {
0190     struct rdma_rw_ctx  rw;
0191     struct scatterlist  *sg;
0192     unsigned int        nents;
0193 };
0194
0195 /**
0196  * struct srpt_send_ioctx - SRPT send I/O context
0197  * @ioctx:       See above.
0198  * @ch:          Channel pointer.
0199  * @recv_ioctx:  Receive I/O context associated with this send I/O context.
0200  *       Only used for processing immediate data.
0201  * @s_rw_ctx:    @rw_ctxs points here if only a single rw_ctx is needed.
0202  * @rw_ctxs:     RDMA read/write contexts.
0203  * @imm_sg:      Scatterlist for immediate data.
0204  * @rdma_cqe:    RDMA completion queue element.
0205  * @state:       I/O context state.
0206  * @cmd:         Target core command data structure.
0207  * @sense_data:  SCSI sense data.
0208  * @n_rdma:      Number of work requests needed to transfer this ioctx.
0209  * @n_rw_ctx:    Size of rw_ctxs array.
0210  * @queue_status_only: Send a SCSI status back to the initiator but no data.
0211  * @sense_data:  Sense data to be sent to the initiator.
0212  */
0213 struct srpt_send_ioctx {
0214     struct srpt_ioctx   ioctx;
0215     struct srpt_rdma_ch *ch;
0216     struct srpt_recv_ioctx  *recv_ioctx;
0217
0218     struct srpt_rw_ctx  s_rw_ctx;
0219     struct srpt_rw_ctx  *rw_ctxs;
0220
0221     struct scatterlist  imm_sg;
0222
0223     struct ib_cqe       rdma_cqe;
0224     enum srpt_command_state state;
0225     struct se_cmd       cmd;
0226     u8          n_rdma;
0227     u8          n_rw_ctx;
0228     bool            queue_status_only;
0229     u8          sense_data[TRANSPORT_SENSE_BUFFER];
0230 };
0231
0232 /**
0233  * enum rdma_ch_state - SRP channel state
0234  * @CH_CONNECTING:    QP is in RTR state; waiting for RTU.
0235  * @CH_LIVE:          QP is in RTS state.
0236  * @CH_DISCONNECTING: DREQ has been sent and waiting for DREP or DREQ has
0237  *                    been received.
0238  * @CH_DRAINING:      DREP has been received or waiting for DREP timed out
0239  *                    and last work request has been queued.
0240  * @CH_DISCONNECTED:  Last completion has been received.
0241  */
0242 enum rdma_ch_state {
0243     CH_CONNECTING,
0244     CH_LIVE,
0245     CH_DISCONNECTING,
0246     CH_DRAINING,
0247     CH_DISCONNECTED,
0248 };
0249
0250 /**
0251  * struct srpt_rdma_ch - RDMA channel
0252  * @nexus:         I_T nexus this channel is associated with.
0253  * @qp:            IB queue pair used for communicating over this channel.
0254  * @ib_cm:     See below.
0255  * @ib_cm.cm_id:   IB CM ID associated with the channel.
0256  * @rdma_cm:       See below.
0257  * @rdma_cm.cm_id: RDMA CM ID associated with the channel.
0258  * @cq:            IB completion queue for this channel.
0259  * @cq_size:       Number of CQEs in @cq.
0260  * @zw_cqe:    Zero-length write CQE.
0261  * @rcu:           RCU head.
0262  * @kref:      kref for this channel.
0263  * @closed:    Completion object that will be signaled as soon as a new
0264  *         channel object with the same identity can be created.
0265  * @rq_size:       IB receive queue size.
0266  * @max_rsp_size:  Maximum size of an RSP response message in bytes.
0267  * @sq_wr_avail:   number of work requests available in the send queue.
0268  * @sport:         pointer to the information of the HCA port used by this
0269  *                 channel.
0270  * @max_ti_iu_len: maximum target-to-initiator information unit length.
0271  * @req_lim:       request limit: maximum number of requests that may be sent
0272  *                 by the initiator without having received a response.
0273  * @req_lim_delta: Number of credits not yet sent back to the initiator.
0274  * @imm_data_offset: Offset from start of SRP_CMD for immediate data.
0275  * @spinlock:      Protects free_list and state.
0276  * @state:         channel state. See also enum rdma_ch_state.
0277  * @using_rdma_cm: Whether the RDMA/CM or IB/CM is used for this channel.
0278  * @processing_wait_list: Whether or not cmd_wait_list is being processed.
0279  * @rsp_buf_cache: kmem_cache for @ioctx_ring.
0280  * @ioctx_ring:    Send ring.
0281  * @req_buf_cache: kmem_cache for @ioctx_recv_ring.
0282  * @ioctx_recv_ring: Receive I/O context ring.
0283  * @list:          Node in srpt_nexus.ch_list.
0284  * @cmd_wait_list: List of SCSI commands that arrived before the RTU event. This
0285  *                 list contains struct srpt_ioctx elements and is protected
0286  *                 against concurrent modification by the cm_id spinlock.
0287  * @pkey:          P_Key of the IB partition for this SRP channel.
0288  * @sess:          Session information associated with this SRP channel.
0289  * @sess_name:     Session name.
0290  * @release_work:  Allows scheduling of srpt_release_channel().
0291  */
0292 struct srpt_rdma_ch {
0293     struct srpt_nexus   *nexus;
0294     struct ib_qp        *qp;
0295     union {
0296         struct {
0297             struct ib_cm_id     *cm_id;
0298         } ib_cm;
0299         struct {
0300             struct rdma_cm_id   *cm_id;
0301         } rdma_cm;
0302     };
0303     struct ib_cq        *cq;
0304     u32         cq_size;
0305     struct ib_cqe       zw_cqe;
0306     struct rcu_head     rcu;
0307     struct kref     kref;
0308     struct completion   *closed;
0309     int         rq_size;
0310     u32         max_rsp_size;
0311     atomic_t        sq_wr_avail;
0312     struct srpt_port    *sport;
0313     int         max_ti_iu_len;
0314     atomic_t        req_lim;
0315     atomic_t        req_lim_delta;
0316     u16         imm_data_offset;
0317     spinlock_t      spinlock;
0318     enum rdma_ch_state  state;
0319     struct kmem_cache   *rsp_buf_cache;
0320     struct srpt_send_ioctx  **ioctx_ring;
0321     struct kmem_cache   *req_buf_cache;
0322     struct srpt_recv_ioctx  **ioctx_recv_ring;
0323     struct list_head    list;
0324     struct list_head    cmd_wait_list;
0325     uint16_t        pkey;
0326     bool            using_rdma_cm;
0327     bool            processing_wait_list;
0328     struct se_session   *sess;
0329     u8          sess_name[40];
0330     struct work_struct  release_work;
0331 };
0332
0333 /**
0334  * struct srpt_nexus - I_T nexus
0335  * @rcu:       RCU head for this data structure.
0336  * @entry:     srpt_port.nexus_list list node.
0337  * @ch_list:   struct srpt_rdma_ch list. Protected by srpt_port.mutex.
0338  * @i_port_id: 128-bit initiator port identifier copied from SRP_LOGIN_REQ.
0339  * @t_port_id: 128-bit target port identifier copied from SRP_LOGIN_REQ.
0340  */
0341 struct srpt_nexus {
0342     struct rcu_head     rcu;
0343     struct list_head    entry;
0344     struct list_head    ch_list;
0345     u8          i_port_id[16];
0346     u8          t_port_id[16];
0347 };
0348
0349 /**
0350  * struct srpt_port_attrib - attributes for SRPT port
0351  * @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
0352  * @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
0353  * @srp_sq_size: Shared receive queue (SRQ) size.
0354  * @use_srq: Whether or not to use SRQ.
0355  */
0356 struct srpt_port_attrib {
0357     u32         srp_max_rdma_size;
0358     u32         srp_max_rsp_size;
0359     u32         srp_sq_size;
0360     bool            use_srq;
0361 };
0362
0363 /**
0364  * struct srpt_tpg - information about a single "target portal group"
0365  * @entry:  Entry in @sport_id->tpg_list.
0366  * @sport_id:   Port name this TPG is associated with.
0367  * @tpg:    LIO TPG data structure.
0368  *
0369  * Zero or more target portal groups are associated with each port name
0370  * (srpt_port_id). With each TPG an ACL list is associated.
0371  */
0372 struct srpt_tpg {
0373     struct list_head    entry;
0374     struct srpt_port_id *sport_id;
0375     struct se_portal_group  tpg;
0376 };
0377
0378 /**
0379  * struct srpt_port_id - LIO RDMA port information
0380  * @mutex:  Protects @tpg_list changes.
0381  * @tpg_list:   TPGs associated with the RDMA port name.
0382  * @wwn:    WWN associated with the RDMA port name.
0383  * @name:   ASCII representation of the port name.
0384  *
0385  * Multiple sysfs directories can be associated with a single RDMA port. This
0386  * data structure represents a single (port, name) pair.
0387  */
0388 struct srpt_port_id {
0389     struct mutex        mutex;
0390     struct list_head    tpg_list;
0391     struct se_wwn       wwn;
0392     char            name[64];
0393 };
0394
0395 /**
0396  * struct srpt_port - SRPT RDMA port information
0397  * @sdev:      backpointer to the HCA information.
0398  * @mad_agent: per-port management datagram processing information.
0399  * @enabled:   Whether or not this target port is enabled.
0400  * @port:      one-based port number.
0401  * @sm_lid:    cached value of the port's sm_lid.
0402  * @lid:       cached value of the port's lid.
0403  * @gid:       cached value of the port's gid.
0404  * @work:      work structure for refreshing the aforementioned cached values.
0405  * @guid_name: port name in GUID format.
0406  * @guid_id:   LIO target port information for the port name in GUID format.
0407  * @gid_name:  port name in GID format.
0408  * @gid_id:    LIO target port information for the port name in GID format.
0409  * @port_attrib:   Port attributes that can be accessed through configfs.
0410  * @refcount:      Number of objects associated with this port.
0411  * @freed_channels: Completion that will be signaled once @refcount becomes 0.
0412  * @mutex:     Protects nexus_list.
0413  * @nexus_list:    Nexus list. See also srpt_nexus.entry.
0414  */
0415 struct srpt_port {
0416     struct srpt_device  *sdev;
0417     struct ib_mad_agent *mad_agent;
0418     bool            enabled;
0419     u8          port;
0420     u32         sm_lid;
0421     u32         lid;
0422     union ib_gid        gid;
0423     struct work_struct  work;
0424     char            guid_name[64];
0425     struct srpt_port_id *guid_id;
0426     char            gid_name[64];
0427     struct srpt_port_id *gid_id;
0428     struct srpt_port_attrib port_attrib;
0429     atomic_t        refcount;
0430     struct completion   *freed_channels;
0431     struct mutex        mutex;
0432     struct list_head    nexus_list;
0433 };
0434
0435 /**
0436  * struct srpt_device - information associated by SRPT with a single HCA
0437  * @refcnt:    Reference count for this device.
0438  * @device:        Backpointer to the struct ib_device managed by the IB core.
0439  * @pd:            IB protection domain.
0440  * @lkey:          L_Key (local key) with write access to all local memory.
0441  * @srq:           Per-HCA SRQ (shared receive queue).
0442  * @cm_id:         Connection identifier.
0443  * @srq_size:      SRQ size.
0444  * @sdev_mutex:    Serializes use_srq changes.
0445  * @use_srq:       Whether or not to use SRQ.
0446  * @req_buf_cache: kmem_cache for @ioctx_ring buffers.
0447  * @ioctx_ring:    Per-HCA SRQ.
0448  * @event_handler: Per-HCA asynchronous IB event handler.
0449  * @list:          Node in srpt_dev_list.
0450  * @port:          Information about the ports owned by this HCA.
0451  */
0452 struct srpt_device {
0453     struct kref     refcnt;
0454     struct ib_device    *device;
0455     struct ib_pd        *pd;
0456     u32         lkey;
0457     struct ib_srq       *srq;
0458     struct ib_cm_id     *cm_id;
0459     int         srq_size;
0460     struct mutex        sdev_mutex;
0461     bool            use_srq;
0462     struct kmem_cache   *req_buf_cache;
0463     struct srpt_recv_ioctx  **ioctx_ring;
0464     struct ib_event_handler event_handler;
0465     struct list_head    list;
0466     struct srpt_port        port[];
0467 };
0468
0469 #endif              /* IB_SRPT_H */