include/linux/sunrpc/rpc_rdma.h

   1 /*
   2  * Copyright (c) 2003-2007 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
  40 #ifndef _LINUX_SUNRPC_RPC_RDMA_H
  41 #define _LINUX_SUNRPC_RPC_RDMA_H
  42
  43 #include <linux/types.h>
  44
  45 #define RPCRDMA_VERSION         1
  46 #define rpcrdma_version         cpu_to_be32(RPCRDMA_VERSION)
  47
  48 struct rpcrdma_segment {
  49         __be32 rs_handle;       /* Registered memory handle */
  50         __be32 rs_length;       /* Length of the chunk in bytes */
  51         __be64 rs_offset;       /* Chunk virtual address or offset */
  52 };
  53
  54 /*
  55  * read chunk(s), encoded as a linked list.
  56  */
  57 struct rpcrdma_read_chunk {
  58         __be32 rc_discrim;      /* 1 indicates presence */
  59         __be32 rc_position;     /* Position in XDR stream */
  60         struct rpcrdma_segment rc_target;
  61 };
  62
  63 /*
  64  * write chunk, and reply chunk.
  65  */
  66 struct rpcrdma_write_chunk {
  67         struct rpcrdma_segment wc_target;
  68 };
  69
  70 /*
  71  * write chunk(s), encoded as a counted array.
  72  */
  73 struct rpcrdma_write_array {
  74         __be32 wc_discrim;      /* 1 indicates presence */
  75         __be32 wc_nchunks;      /* Array count */
  76         struct rpcrdma_write_chunk wc_array[0];
  77 };
  78
  79 struct rpcrdma_msg {
  80         __be32 rm_xid;  /* Mirrors the RPC header xid */
  81         __be32 rm_vers; /* Version of this protocol */
  82         __be32 rm_credit;       /* Buffers requested/granted */
  83         __be32 rm_type; /* Type of message (enum rpcrdma_proc) */
  84         union {
  85
  86                 struct {                        /* no chunks */
  87                         __be32 rm_empty[3];     /* 3 empty chunk lists */
  88                 } rm_nochunks;
  89
  90                 struct {                        /* no chunks and padded */
  91                         __be32 rm_align;        /* Padding alignment */
  92                         __be32 rm_thresh;       /* Padding threshold */
  93                         __be32 rm_pempty[3];    /* 3 empty chunk lists */
  94                 } rm_padded;
  95
  96                 __be32 rm_chunks[0];    /* read, write and reply chunks */
  97
  98         } rm_body;
  99 };
 100
 101 /*
 102  * Smallest RPC/RDMA header: rm_xid through rm_type, then rm_nochunks
 103  */
 104 #define RPCRDMA_HDRLEN_MIN      (sizeof(__be32) * 7)
 105
 106 enum rpcrdma_errcode {
 107         ERR_VERS = 1,
 108         ERR_CHUNK = 2
 109 };
 110
 111 struct rpcrdma_err_vers {
 112         uint32_t rdma_vers_low; /* Version range supported by peer */
 113         uint32_t rdma_vers_high;
 114 };
 115
 116 enum rpcrdma_proc {
 117         RDMA_MSG = 0,           /* An RPC call or reply msg */
 118         RDMA_NOMSG = 1,         /* An RPC call or reply msg - separate body */
 119         RDMA_MSGP = 2,          /* An RPC call or reply msg with padding */
 120         RDMA_DONE = 3,          /* Client signals reply completion */
 121         RDMA_ERROR = 4          /* An RPC RDMA encoding error */
 122 };
 123
 124 #define rdma_msg        cpu_to_be32(RDMA_MSG)
 125 #define rdma_nomsg      cpu_to_be32(RDMA_NOMSG)
 126 #define rdma_msgp       cpu_to_be32(RDMA_MSGP)
 127 #define rdma_done       cpu_to_be32(RDMA_DONE)
 128 #define rdma_error      cpu_to_be32(RDMA_ERROR)
 129
 130 #endif                          /* _LINUX_SUNRPC_RPC_RDMA_H */