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 /* Default and maximum inline threshold sizes */
  52 enum {
  53         RPCRDMA_DEF_INLINE_THRESH = 4096,
  54         RPCRDMA_MAX_INLINE_THRESH = 65536
  55 };
  56
  57 /* RPC/RDMA parameters and stats */
  58 extern unsigned int svcrdma_ord;
  59 extern unsigned int svcrdma_max_requests;
  60 extern unsigned int svcrdma_max_bc_requests;
  61 extern unsigned int svcrdma_max_req_size;
  62
  63 extern atomic_t rdma_stat_recv;
  64 extern atomic_t rdma_stat_read;
  65 extern atomic_t rdma_stat_write;
  66 extern atomic_t rdma_stat_sq_starve;
  67 extern atomic_t rdma_stat_rq_starve;
  68 extern atomic_t rdma_stat_rq_poll;
  69 extern atomic_t rdma_stat_rq_prod;
  70 extern atomic_t rdma_stat_sq_poll;
  71 extern atomic_t rdma_stat_sq_prod;
  72
  73 /*
  74  * Contexts are built when an RDMA request is created and are a
  75  * record of the resources that can be recovered when the request
  76  * completes.
  77  */
  78 struct svc_rdma_op_ctxt {
  79         struct list_head list;
  80         struct xdr_buf arg;
  81         struct ib_cqe cqe;
  82         u32 byte_len;
  83         struct svcxprt_rdma *xprt;
  84         enum dma_data_direction direction;
  85         int count;
  86         unsigned int mapped_sges;
  87         int hdr_count;
  88         struct ib_send_wr send_wr;
  89         struct ib_sge sge[1 + RPCRDMA_MAX_INLINE_THRESH / PAGE_SIZE];
  90         struct page *pages[RPCSVC_MAXPAGES];
  91 };
  92
  93 struct svcxprt_rdma {
  94         struct svc_xprt      sc_xprt;           /* SVC transport structure */
  95         struct rdma_cm_id    *sc_cm_id;         /* RDMA connection id */
  96         struct list_head     sc_accept_q;       /* Conn. waiting accept */
  97         int                  sc_ord;            /* RDMA read limit */
  98         int                  sc_max_sge;
  99         bool                 sc_snd_w_inv;      /* OK to use Send With Invalidate */
 100
 101         atomic_t             sc_sq_avail;       /* SQEs ready to be consumed */
 102         unsigned int         sc_sq_depth;       /* Depth of SQ */
 103         unsigned int         sc_rq_depth;       /* Depth of RQ */
 104         __be32               sc_fc_credits;     /* Forward credits */
 105         u32                  sc_max_requests;   /* Max requests */
 106         u32                  sc_max_bc_requests;/* Backward credits */
 107         int                  sc_max_req_size;   /* Size of each RQ WR buf */
 108         u8                   sc_port_num;
 109
 110         struct ib_pd         *sc_pd;
 111
 112         spinlock_t           sc_ctxt_lock;
 113         struct list_head     sc_ctxts;
 114         int                  sc_ctxt_used;
 115         spinlock_t           sc_rw_ctxt_lock;
 116         struct list_head     sc_rw_ctxts;
 117
 118         struct list_head     sc_rq_dto_q;
 119         spinlock_t           sc_rq_dto_lock;
 120         struct ib_qp         *sc_qp;
 121         struct ib_cq         *sc_rq_cq;
 122         struct ib_cq         *sc_sq_cq;
 123
 124         spinlock_t           sc_lock;           /* transport lock */
 125
 126         wait_queue_head_t    sc_send_wait;      /* SQ exhaustion waitlist */
 127         unsigned long        sc_flags;
 128         struct list_head     sc_read_complete_q;
 129         struct work_struct   sc_work;
 130 };
 131 /* sc_flags */
 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_MAX_REQUESTS    32
 139
 140 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
 141  * current NFSv4.1 implementation supports one backchannel slot.
 142  */
 143 #define RPCRDMA_MAX_BC_REQUESTS 2
 144
 145 #define RPCSVC_MAXPAYLOAD_RDMA  RPCSVC_MAXPAYLOAD
 146
 147 /* Track DMA maps for this transport and context */
 148 static inline void svc_rdma_count_mappings(struct svcxprt_rdma *rdma,
 149                                            struct svc_rdma_op_ctxt *ctxt)
 150 {
 151         ctxt->mapped_sges++;
 152 }
 153
 154 /* svc_rdma_backchannel.c */
 155 extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
 156                                     __be32 *rdma_resp,
 157                                     struct xdr_buf *rcvbuf);
 158
 159 /* svc_rdma_recvfrom.c */
 160 extern int svc_rdma_recvfrom(struct svc_rqst *);
 161
 162 /* svc_rdma_rw.c */
 163 extern void svc_rdma_destroy_rw_ctxts(struct svcxprt_rdma *rdma);
 164 extern int svc_rdma_recv_read_chunk(struct svcxprt_rdma *rdma,
 165                                     struct svc_rqst *rqstp,
 166                                     struct svc_rdma_op_ctxt *head, __be32 *p);
 167 extern int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma,
 168                                      __be32 *wr_ch, struct xdr_buf *xdr);
 169 extern int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma,
 170                                      __be32 *rp_ch, bool writelist,
 171                                      struct xdr_buf *xdr);
 172
 173 /* svc_rdma_sendto.c */
 174 extern int svc_rdma_map_reply_hdr(struct svcxprt_rdma *rdma,
 175                                   struct svc_rdma_op_ctxt *ctxt,
 176                                   __be32 *rdma_resp, unsigned int len);
 177 extern int svc_rdma_post_send_wr(struct svcxprt_rdma *rdma,
 178                                  struct svc_rdma_op_ctxt *ctxt,
 179                                  int num_sge, u32 inv_rkey);
 180 extern int svc_rdma_sendto(struct svc_rqst *);
 181
 182 /* svc_rdma_transport.c */
 183 extern void svc_rdma_wc_send(struct ib_cq *, struct ib_wc *);
 184 extern void svc_rdma_wc_reg(struct ib_cq *, struct ib_wc *);
 185 extern void svc_rdma_wc_read(struct ib_cq *, struct ib_wc *);
 186 extern void svc_rdma_wc_inv(struct ib_cq *, struct ib_wc *);
 187 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
 188 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
 189 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
 190 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
 191 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
 192 extern void svc_sq_reap(struct svcxprt_rdma *);
 193 extern void svc_rq_reap(struct svcxprt_rdma *);
 194 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
 195
 196 extern struct svc_xprt_class svc_rdma_class;
 197 #ifdef CONFIG_SUNRPC_BACKCHANNEL
 198 extern struct svc_xprt_class svc_rdma_bc_class;
 199 #endif
 200
 201 /* svc_rdma.c */
 202 extern struct workqueue_struct *svc_rdma_wq;
 203 extern int svc_rdma_init(void);
 204 extern void svc_rdma_cleanup(void);
 205
 206 #endif