include/linux/sunrpc/svc_rdma.h

   1 /*
   2  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the BSD-type
   8  * license below:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  *      Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *
  17  *      Redistributions in binary form must reproduce the above
  18  *      copyright notice, this list of conditions and the following
  19  *      disclaimer in the documentation and/or other materials provided
  20  *      with the distribution.
  21  *
  22  *      Neither the name of the Network Appliance, Inc. nor the names of
  23  *      its contributors may be used to endorse or promote products
  24  *      derived from this software without specific prior written
  25  *      permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  *
  39  * Author: Tom Tucker <tom@opengridcomputing.com>
  40  */
  41
  42 #ifndef SVC_RDMA_H
  43 #define SVC_RDMA_H
  44 #include <linux/sunrpc/xdr.h>
  45 #include <linux/sunrpc/svcsock.h>
  46 #include <linux/sunrpc/rpc_rdma.h>
  47 #include <rdma/ib_verbs.h>
  48 #include <rdma/rdma_cm.h>
  49 #define SVCRDMA_DEBUG
  50
  51 /* RPC/RDMA parameters and stats */
  52 extern unsigned int svcrdma_ord;
  53 extern unsigned int svcrdma_max_requests;
  54 extern unsigned int svcrdma_max_req_size;
  55
  56 extern atomic_t rdma_stat_recv;
  57 extern atomic_t rdma_stat_read;
  58 extern atomic_t rdma_stat_write;
  59 extern atomic_t rdma_stat_sq_starve;
  60 extern atomic_t rdma_stat_rq_starve;
  61 extern atomic_t rdma_stat_rq_poll;
  62 extern atomic_t rdma_stat_rq_prod;
  63 extern atomic_t rdma_stat_sq_poll;
  64 extern atomic_t rdma_stat_sq_prod;
  65
  66 #define RPCRDMA_VERSION 1
  67
  68 /*
  69  * Contexts are built when an RDMA request is created and are a
  70  * record of the resources that can be recovered when the request
  71  * completes.
  72  */
  73 struct svc_rdma_op_ctxt {
  74         struct svc_rdma_op_ctxt *read_hdr;
  75         struct list_head free_list;
  76         struct xdr_buf arg;
  77         struct list_head dto_q;
  78         enum ib_wr_opcode wr_op;
  79         enum ib_wc_status wc_status;
  80         u32 byte_len;
  81         struct svcxprt_rdma *xprt;
  82         unsigned long flags;
  83         enum dma_data_direction direction;
  84         int count;
  85         struct ib_sge sge[RPCSVC_MAXPAGES];
  86         struct page *pages[RPCSVC_MAXPAGES];
  87 };
  88
  89 #define RDMACTXT_F_LAST_CTXT    2
  90
  91 struct svcxprt_rdma {
  92         struct svc_xprt      sc_xprt;           /* SVC transport structure */
  93         struct rdma_cm_id    *sc_cm_id;         /* RDMA connection id */
  94         struct list_head     sc_accept_q;       /* Conn. waiting accept */
  95         int                  sc_ord;            /* RDMA read limit */
  96         wait_queue_head_t    sc_read_wait;
  97         int                  sc_max_sge;
  98
  99         int                  sc_sq_depth;       /* Depth of SQ */
 100         atomic_t             sc_sq_count;       /* Number of SQ WR on queue */
 101
 102         int                  sc_max_requests;   /* Depth of RQ */
 103         int                  sc_max_req_size;   /* Size of each RQ WR buf */
 104
 105         struct ib_pd         *sc_pd;
 106
 107         atomic_t             sc_ctxt_used;
 108         struct list_head     sc_ctxt_free;
 109         int                  sc_ctxt_cnt;
 110         int                  sc_ctxt_bump;
 111         int                  sc_ctxt_max;
 112         spinlock_t           sc_ctxt_lock;
 113         struct list_head     sc_rq_dto_q;
 114         spinlock_t           sc_rq_dto_lock;
 115         struct ib_qp         *sc_qp;
 116         struct ib_cq         *sc_rq_cq;
 117         struct ib_cq         *sc_sq_cq;
 118         struct ib_mr         *sc_phys_mr;       /* MR for server memory */
 119
 120         spinlock_t           sc_lock;           /* transport lock */
 121
 122         wait_queue_head_t    sc_send_wait;      /* SQ exhaustion waitlist */
 123         unsigned long        sc_flags;
 124         struct list_head     sc_dto_q;          /* DTO tasklet I/O pending Q */
 125         struct list_head     sc_read_complete_q;
 126         spinlock_t           sc_read_complete_lock;
 127         struct work_struct   sc_work;
 128 };
 129 /* sc_flags */
 130 #define RDMAXPRT_RQ_PENDING     1
 131 #define RDMAXPRT_SQ_PENDING     2
 132 #define RDMAXPRT_CONN_PENDING   3
 133
 134 #define RPCRDMA_LISTEN_BACKLOG  10
 135 /* The default ORD value is based on two outstanding full-size writes with a
 136  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
 137 #define RPCRDMA_ORD             (64/4)
 138 #define RPCRDMA_SQ_DEPTH_MULT   8
 139 #define RPCRDMA_MAX_THREADS     16
 140 #define RPCRDMA_MAX_REQUESTS    16
 141 #define RPCRDMA_MAX_REQ_SIZE    4096
 142
 143 /* svc_rdma_marshal.c */
 144 extern void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *,
 145                                       int *, int *);
 146 extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
 147 extern int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *);
 148 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
 149                                      struct rpcrdma_msg *,
 150                                      enum rpcrdma_errcode, u32 *);
 151 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
 152 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
 153 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
 154                                             u32, u64, u32);
 155 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
 156                                              struct rpcrdma_msg *,
 157                                              struct rpcrdma_msg *,
 158                                              enum rpcrdma_proc);
 159 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
 160
 161 /* svc_rdma_recvfrom.c */
 162 extern int svc_rdma_recvfrom(struct svc_rqst *);
 163
 164 /* svc_rdma_sendto.c */
 165 extern int svc_rdma_sendto(struct svc_rqst *);
 166
 167 /* svc_rdma_transport.c */
 168 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
 169 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
 170                                 enum rpcrdma_errcode);
 171 struct page *svc_rdma_get_page(void);
 172 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
 173 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
 174 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
 175 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
 176 extern void svc_sq_reap(struct svcxprt_rdma *);
 177 extern void svc_rq_reap(struct svcxprt_rdma *);
 178 extern struct svc_xprt_class svc_rdma_class;
 179 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
 180
 181 /* svc_rdma.c */
 182 extern int svc_rdma_init(void);
 183 extern void svc_rdma_cleanup(void);
 184
 185 /*
 186  * Returns the address of the first read chunk or <nul> if no read chunk is
 187  * present
 188  */
 189 static inline struct rpcrdma_read_chunk *
 190 svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)
 191 {
 192         struct rpcrdma_read_chunk *ch =
 193                 (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
 194
 195         if (ch->rc_discrim == 0)
 196                 return NULL;
 197
 198         return ch;
 199 }
 200
 201 /*
 202  * Returns the address of the first read write array element or <nul> if no
 203  * write array list is present
 204  */
 205 static inline struct rpcrdma_write_array *
 206 svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)
 207 {
 208         if (rmsgp->rm_body.rm_chunks[0] != 0
 209             || rmsgp->rm_body.rm_chunks[1] == 0)
 210                 return NULL;
 211
 212         return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];
 213 }
 214
 215 /*
 216  * Returns the address of the first reply array element or <nul> if no
 217  * reply array is present
 218  */
 219 static inline struct rpcrdma_write_array *
 220 svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)
 221 {
 222         struct rpcrdma_read_chunk *rch;
 223         struct rpcrdma_write_array *wr_ary;
 224         struct rpcrdma_write_array *rp_ary;
 225
 226         /* XXX: Need to fix when reply list may occur with read-list and/or
 227          * write list */
 228         if (rmsgp->rm_body.rm_chunks[0] != 0 ||
 229             rmsgp->rm_body.rm_chunks[1] != 0)
 230                 return NULL;
 231
 232         rch = svc_rdma_get_read_chunk(rmsgp);
 233         if (rch) {
 234                 while (rch->rc_discrim)
 235                         rch++;
 236
 237                 /* The reply list follows an empty write array located
 238                  * at 'rc_position' here. The reply array is at rc_target.
 239                  */
 240                 rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;
 241
 242                 goto found_it;
 243         }
 244
 245         wr_ary = svc_rdma_get_write_array(rmsgp);
 246         if (wr_ary) {
 247                 rp_ary = (struct rpcrdma_write_array *)
 248                         &wr_ary->
 249                         wc_array[wr_ary->wc_nchunks].wc_target.rs_length;
 250
 251                 goto found_it;
 252         }
 253
 254         /* No read list, no write list */
 255         rp_ary = (struct rpcrdma_write_array *)
 256                 &rmsgp->rm_body.rm_chunks[2];
 257
 258  found_it:
 259         if (rp_ary->wc_discrim == 0)
 260                 return NULL;
 261
 262         return rp_ary;
 263 }
 264 #endif