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 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         struct svcxprt_rdma *xprt;
  83         unsigned long flags;
  84         enum dma_data_direction direction;
  85         int count;
  86         struct ib_sge sge[RPCSVC_MAXPAGES];
  87         struct page *pages[RPCSVC_MAXPAGES];
  88 };
  89
  90 /*
  91  * NFS_ requests are mapped on the client side by the chunk lists in
  92  * the RPCRDMA header. During the fetching of the RPC from the client
  93  * and the writing of the reply to the client, the memory in the
  94  * client and the memory in the server must be mapped as contiguous
  95  * vaddr/len for access by the hardware. These data strucures keep
  96  * these mappings.
  97  *
  98  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
  99  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
 100  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
 101  * mapping of the reply.
 102  */
 103 struct svc_rdma_chunk_sge {
 104         int start;              /* sge no for this chunk */
 105         int count;              /* sge count for this chunk */
 106 };
 107 struct svc_rdma_fastreg_mr {
 108         struct ib_mr *mr;
 109         void *kva;
 110         struct ib_fast_reg_page_list *page_list;
 111         int page_list_len;
 112         unsigned long access_flags;
 113         unsigned long map_len;
 114         enum dma_data_direction direction;
 115         struct list_head frmr_list;
 116 };
 117 struct svc_rdma_req_map {
 118         struct svc_rdma_fastreg_mr *frmr;
 119         unsigned long count;
 120         union {
 121                 struct kvec sge[RPCSVC_MAXPAGES];
 122                 struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
 123         };
 124 };
 125 #define RDMACTXT_F_FAST_UNREG   1
 126 #define RDMACTXT_F_LAST_CTXT    2
 127
 128 #define SVCRDMA_DEVCAP_FAST_REG         1       /* fast mr registration */
 129 #define SVCRDMA_DEVCAP_READ_W_INV       2       /* read w/ invalidate */
 130
 131 struct svcxprt_rdma {
 132         struct svc_xprt      sc_xprt;           /* SVC transport structure */
 133         struct rdma_cm_id    *sc_cm_id;         /* RDMA connection id */
 134         struct list_head     sc_accept_q;       /* Conn. waiting accept */
 135         int                  sc_ord;            /* RDMA read limit */
 136         int                  sc_max_sge;
 137
 138         int                  sc_sq_depth;       /* Depth of SQ */
 139         atomic_t             sc_sq_count;       /* Number of SQ WR on queue */
 140
 141         int                  sc_max_requests;   /* Depth of RQ */
 142         int                  sc_max_req_size;   /* Size of each RQ WR buf */
 143
 144         struct ib_pd         *sc_pd;
 145
 146         atomic_t             sc_dma_used;
 147         atomic_t             sc_ctxt_used;
 148         struct list_head     sc_rq_dto_q;
 149         spinlock_t           sc_rq_dto_lock;
 150         struct ib_qp         *sc_qp;
 151         struct ib_cq         *sc_rq_cq;
 152         struct ib_cq         *sc_sq_cq;
 153         struct ib_mr         *sc_phys_mr;       /* MR for server memory */
 154         u32                  sc_dev_caps;       /* distilled device caps */
 155         u32                  sc_dma_lkey;       /* local dma key */
 156         unsigned int         sc_frmr_pg_list_len;
 157         struct list_head     sc_frmr_q;
 158         spinlock_t           sc_frmr_q_lock;
 159
 160         spinlock_t           sc_lock;           /* transport lock */
 161
 162         wait_queue_head_t    sc_send_wait;      /* SQ exhaustion waitlist */
 163         unsigned long        sc_flags;
 164         struct list_head     sc_dto_q;          /* DTO tasklet I/O pending Q */
 165         struct list_head     sc_read_complete_q;
 166         struct work_struct   sc_work;
 167 };
 168 /* sc_flags */
 169 #define RDMAXPRT_RQ_PENDING     1
 170 #define RDMAXPRT_SQ_PENDING     2
 171 #define RDMAXPRT_CONN_PENDING   3
 172
 173 #define RPCRDMA_LISTEN_BACKLOG  10
 174 /* The default ORD value is based on two outstanding full-size writes with a
 175  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
 176 #define RPCRDMA_ORD             (64/4)
 177 #define RPCRDMA_SQ_DEPTH_MULT   8
 178 #define RPCRDMA_MAX_THREADS     16
 179 #define RPCRDMA_MAX_REQUESTS    16
 180 #define RPCRDMA_MAX_REQ_SIZE    4096
 181
 182 /* svc_rdma_marshal.c */
 183 extern void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *,
 184                                       int *, int *);
 185 extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
 186 extern int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *);
 187 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
 188                                      struct rpcrdma_msg *,
 189                                      enum rpcrdma_errcode, u32 *);
 190 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
 191 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
 192 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
 193                                             u32, u64, u32);
 194 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
 195                                              struct rpcrdma_msg *,
 196                                              struct rpcrdma_msg *,
 197                                              enum rpcrdma_proc);
 198 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
 199
 200 /* svc_rdma_recvfrom.c */
 201 extern int svc_rdma_recvfrom(struct svc_rqst *);
 202
 203 /* svc_rdma_sendto.c */
 204 extern int svc_rdma_sendto(struct svc_rqst *);
 205
 206 /* svc_rdma_transport.c */
 207 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
 208 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
 209                                 enum rpcrdma_errcode);
 210 struct page *svc_rdma_get_page(void);
 211 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
 212 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
 213 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
 214 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
 215 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
 216 extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
 217 extern void svc_rdma_put_req_map(struct svc_rdma_req_map *);
 218 extern int svc_rdma_fastreg(struct svcxprt_rdma *, struct svc_rdma_fastreg_mr *);
 219 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
 220 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
 221                               struct svc_rdma_fastreg_mr *);
 222 extern void svc_sq_reap(struct svcxprt_rdma *);
 223 extern void svc_rq_reap(struct svcxprt_rdma *);
 224 extern struct svc_xprt_class svc_rdma_class;
 225 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
 226
 227 /* svc_rdma.c */
 228 extern int svc_rdma_init(void);
 229 extern void svc_rdma_cleanup(void);
 230
 231 /*
 232  * Returns the address of the first read chunk or <nul> if no read chunk is
 233  * present
 234  */
 235 static inline struct rpcrdma_read_chunk *
 236 svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)
 237 {
 238         struct rpcrdma_read_chunk *ch =
 239                 (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
 240
 241         if (ch->rc_discrim == 0)
 242                 return NULL;
 243
 244         return ch;
 245 }
 246
 247 /*
 248  * Returns the address of the first read write array element or <nul> if no
 249  * write array list is present
 250  */
 251 static inline struct rpcrdma_write_array *
 252 svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)
 253 {
 254         if (rmsgp->rm_body.rm_chunks[0] != 0
 255             || rmsgp->rm_body.rm_chunks[1] == 0)
 256                 return NULL;
 257
 258         return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];
 259 }
 260
 261 /*
 262  * Returns the address of the first reply array element or <nul> if no
 263  * reply array is present
 264  */
 265 static inline struct rpcrdma_write_array *
 266 svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)
 267 {
 268         struct rpcrdma_read_chunk *rch;
 269         struct rpcrdma_write_array *wr_ary;
 270         struct rpcrdma_write_array *rp_ary;
 271
 272         /* XXX: Need to fix when reply list may occur with read-list and/or
 273          * write list */
 274         if (rmsgp->rm_body.rm_chunks[0] != 0 ||
 275             rmsgp->rm_body.rm_chunks[1] != 0)
 276                 return NULL;
 277
 278         rch = svc_rdma_get_read_chunk(rmsgp);
 279         if (rch) {
 280                 while (rch->rc_discrim)
 281                         rch++;
 282
 283                 /* The reply list follows an empty write array located
 284                  * at 'rc_position' here. The reply array is at rc_target.
 285                  */
 286                 rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;
 287
 288                 goto found_it;
 289         }
 290
 291         wr_ary = svc_rdma_get_write_array(rmsgp);
 292         if (wr_ary) {
 293                 rp_ary = (struct rpcrdma_write_array *)
 294                         &wr_ary->
 295                         wc_array[wr_ary->wc_nchunks].wc_target.rs_length;
 296
 297                 goto found_it;
 298         }
 299
 300         /* No read list, no write list */
 301         rp_ary = (struct rpcrdma_write_array *)
 302                 &rmsgp->rm_body.rm_chunks[2];
 303
 304  found_it:
 305         if (rp_ary->wc_discrim == 0)
 306                 return NULL;
 307
 308         return rp_ary;
 309 }
 310 #endif