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_bc_requests;
  55 extern unsigned int svcrdma_max_req_size;
  56
  57 extern atomic_t rdma_stat_recv;
  58 extern atomic_t rdma_stat_read;
  59 extern atomic_t rdma_stat_write;
  60 extern atomic_t rdma_stat_sq_starve;
  61 extern atomic_t rdma_stat_rq_starve;
  62 extern atomic_t rdma_stat_rq_poll;
  63 extern atomic_t rdma_stat_rq_prod;
  64 extern atomic_t rdma_stat_sq_poll;
  65 extern atomic_t rdma_stat_sq_prod;
  66
  67 /*
  68  * Contexts are built when an RDMA request is created and are a
  69  * record of the resources that can be recovered when the request
  70  * completes.
  71  */
  72 struct svc_rdma_op_ctxt {
  73         struct list_head free;
  74         struct svc_rdma_op_ctxt *read_hdr;
  75         struct svc_rdma_fastreg_mr *frmr;
  76         int hdr_count;
  77         struct xdr_buf arg;
  78         struct list_head dto_q;
  79         enum ib_wr_opcode wr_op;
  80         enum ib_wc_status wc_status;
  81         u32 byte_len;
  82         u32 position;
  83         struct svcxprt_rdma *xprt;
  84         unsigned long flags;
  85         enum dma_data_direction direction;
  86         int count;
  87         struct ib_sge sge[RPCSVC_MAXPAGES];
  88         struct page *pages[RPCSVC_MAXPAGES];
  89 };
  90
  91 /*
  92  * NFS_ requests are mapped on the client side by the chunk lists in
  93  * the RPCRDMA header. During the fetching of the RPC from the client
  94  * and the writing of the reply to the client, the memory in the
  95  * client and the memory in the server must be mapped as contiguous
  96  * vaddr/len for access by the hardware. These data strucures keep
  97  * these mappings.
  98  *
  99  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
 100  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
 101  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
 102  * mapping of the reply.
 103  */
 104 struct svc_rdma_chunk_sge {
 105         int start;              /* sge no for this chunk */
 106         int count;              /* sge count for this chunk */
 107 };
 108 struct svc_rdma_fastreg_mr {
 109         struct ib_mr *mr;
 110         struct scatterlist *sg;
 111         int sg_nents;
 112         unsigned long access_flags;
 113         enum dma_data_direction direction;
 114         struct list_head frmr_list;
 115 };
 116 struct svc_rdma_req_map {
 117         struct list_head free;
 118         unsigned long count;
 119         union {
 120                 struct kvec sge[RPCSVC_MAXPAGES];
 121                 struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
 122                 unsigned long lkey[RPCSVC_MAXPAGES];
 123         };
 124 };
 125 #define RDMACTXT_F_LAST_CTXT    2
 126
 127 #define SVCRDMA_DEVCAP_FAST_REG         1       /* fast mr registration */
 128 #define SVCRDMA_DEVCAP_READ_W_INV       2       /* read w/ invalidate */
 129
 130 struct svcxprt_rdma {
 131         struct svc_xprt      sc_xprt;           /* SVC transport structure */
 132         struct rdma_cm_id    *sc_cm_id;         /* RDMA connection id */
 133         struct list_head     sc_accept_q;       /* Conn. waiting accept */
 134         int                  sc_ord;            /* RDMA read limit */
 135         int                  sc_max_sge;
 136         int                  sc_max_sge_rd;     /* max sge for read target */
 137
 138         atomic_t             sc_sq_count;       /* Number of SQ WR on queue */
 139         unsigned int         sc_sq_depth;       /* Depth of SQ */
 140         unsigned int         sc_rq_depth;       /* Depth of RQ */
 141         u32                  sc_max_requests;   /* Forward credits */
 142         u32                  sc_max_bc_requests;/* Backward credits */
 143         int                  sc_max_req_size;   /* Size of each RQ WR buf */
 144
 145         struct ib_pd         *sc_pd;
 146
 147         atomic_t             sc_dma_used;
 148         spinlock_t           sc_ctxt_lock;
 149         struct list_head     sc_ctxts;
 150         int                  sc_ctxt_used;
 151         spinlock_t           sc_map_lock;
 152         struct list_head     sc_maps;
 153
 154         struct list_head     sc_rq_dto_q;
 155         spinlock_t           sc_rq_dto_lock;
 156         struct ib_qp         *sc_qp;
 157         struct ib_cq         *sc_rq_cq;
 158         struct ib_cq         *sc_sq_cq;
 159         int                  (*sc_reader)(struct svcxprt_rdma *,
 160                                           struct svc_rqst *,
 161                                           struct svc_rdma_op_ctxt *,
 162                                           int *, u32 *, u32, u32, u64, bool);
 163         u32                  sc_dev_caps;       /* distilled device caps */
 164         unsigned int         sc_frmr_pg_list_len;
 165         struct list_head     sc_frmr_q;
 166         spinlock_t           sc_frmr_q_lock;
 167
 168         spinlock_t           sc_lock;           /* transport lock */
 169
 170         wait_queue_head_t    sc_send_wait;      /* SQ exhaustion waitlist */
 171         unsigned long        sc_flags;
 172         struct list_head     sc_dto_q;          /* DTO tasklet I/O pending Q */
 173         struct list_head     sc_read_complete_q;
 174         struct work_struct   sc_work;
 175 };
 176 /* sc_flags */
 177 #define RDMAXPRT_RQ_PENDING     1
 178 #define RDMAXPRT_SQ_PENDING     2
 179 #define RDMAXPRT_CONN_PENDING   3
 180
 181 #define RPCRDMA_LISTEN_BACKLOG  10
 182 /* The default ORD value is based on two outstanding full-size writes with a
 183  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
 184 #define RPCRDMA_ORD             (64/4)
 185 #define RPCRDMA_SQ_DEPTH_MULT   8
 186 #define RPCRDMA_MAX_REQUESTS    32
 187 #define RPCRDMA_MAX_REQ_SIZE    4096
 188
 189 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
 190  * current NFSv4.1 implementation supports one backchannel slot.
 191  */
 192 #define RPCRDMA_MAX_BC_REQUESTS 2
 193
 194 #define RPCSVC_MAXPAYLOAD_RDMA  RPCSVC_MAXPAYLOAD
 195
 196 /* svc_rdma_backchannel.c */
 197 extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
 198                                     struct rpcrdma_msg *rmsgp,
 199                                     struct xdr_buf *rcvbuf);
 200
 201 /* svc_rdma_marshal.c */
 202 extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
 203 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
 204                                      struct rpcrdma_msg *,
 205                                      enum rpcrdma_errcode, __be32 *);
 206 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
 207 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
 208 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
 209                                             __be32, __be64, u32);
 210 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
 211                                              struct rpcrdma_msg *,
 212                                              struct rpcrdma_msg *,
 213                                              enum rpcrdma_proc);
 214 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
 215
 216 /* svc_rdma_recvfrom.c */
 217 extern int svc_rdma_recvfrom(struct svc_rqst *);
 218 extern int rdma_read_chunk_lcl(struct svcxprt_rdma *, struct svc_rqst *,
 219                                struct svc_rdma_op_ctxt *, int *, u32 *,
 220                                u32, u32, u64, bool);
 221 extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *,
 222                                 struct svc_rdma_op_ctxt *, int *, u32 *,
 223                                 u32, u32, u64, bool);
 224
 225 /* svc_rdma_sendto.c */
 226 extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *,
 227                             struct svc_rdma_req_map *, bool);
 228 extern int svc_rdma_sendto(struct svc_rqst *);
 229 extern struct rpcrdma_read_chunk *
 230         svc_rdma_get_read_chunk(struct rpcrdma_msg *);
 231 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
 232                                 int);
 233
 234 /* svc_rdma_transport.c */
 235 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
 236 extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t);
 237 extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t);
 238 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
 239 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
 240 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
 241 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
 242 extern struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *);
 243 extern void svc_rdma_put_req_map(struct svcxprt_rdma *,
 244                                  struct svc_rdma_req_map *);
 245 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
 246 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
 247                               struct svc_rdma_fastreg_mr *);
 248 extern void svc_sq_reap(struct svcxprt_rdma *);
 249 extern void svc_rq_reap(struct svcxprt_rdma *);
 250 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
 251
 252 extern struct svc_xprt_class svc_rdma_class;
 253 #ifdef CONFIG_SUNRPC_BACKCHANNEL
 254 extern struct svc_xprt_class svc_rdma_bc_class;
 255 #endif
 256
 257 /* svc_rdma.c */
 258 extern struct workqueue_struct *svc_rdma_wq;
 259 extern int svc_rdma_init(void);
 260 extern void svc_rdma_cleanup(void);
 261
 262 #endif