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 #include <linux/bitops.h>
  45
  46 #define RPCRDMA_VERSION         1
  47 #define rpcrdma_version         cpu_to_be32(RPCRDMA_VERSION)
  48
  49 enum {
  50         RPCRDMA_V1_DEF_INLINE_SIZE      = 1024,
  51 };
  52
  53 struct rpcrdma_segment {
  54         __be32 rs_handle;       /* Registered memory handle */
  55         __be32 rs_length;       /* Length of the chunk in bytes */
  56         __be64 rs_offset;       /* Chunk virtual address or offset */
  57 };
  58
  59 /*
  60  * read chunk(s), encoded as a linked list.
  61  */
  62 struct rpcrdma_read_chunk {
  63         __be32 rc_discrim;      /* 1 indicates presence */
  64         __be32 rc_position;     /* Position in XDR stream */
  65         struct rpcrdma_segment rc_target;
  66 };
  67
  68 /*
  69  * write chunk, and reply chunk.
  70  */
  71 struct rpcrdma_write_chunk {
  72         struct rpcrdma_segment wc_target;
  73 };
  74
  75 /*
  76  * write chunk(s), encoded as a counted array.
  77  */
  78 struct rpcrdma_write_array {
  79         __be32 wc_discrim;      /* 1 indicates presence */
  80         __be32 wc_nchunks;      /* Array count */
  81         struct rpcrdma_write_chunk wc_array[0];
  82 };
  83
  84 struct rpcrdma_msg {
  85         __be32 rm_xid;  /* Mirrors the RPC header xid */
  86         __be32 rm_vers; /* Version of this protocol */
  87         __be32 rm_credit;       /* Buffers requested/granted */
  88         __be32 rm_type; /* Type of message (enum rpcrdma_proc) */
  89         union {
  90
  91                 struct {                        /* no chunks */
  92                         __be32 rm_empty[3];     /* 3 empty chunk lists */
  93                 } rm_nochunks;
  94
  95                 struct {                        /* no chunks and padded */
  96                         __be32 rm_align;        /* Padding alignment */
  97                         __be32 rm_thresh;       /* Padding threshold */
  98                         __be32 rm_pempty[3];    /* 3 empty chunk lists */
  99                 } rm_padded;
 100
 101                 struct {
 102                         __be32 rm_err;
 103                         __be32 rm_vers_low;
 104                         __be32 rm_vers_high;
 105                 } rm_error;
 106
 107                 __be32 rm_chunks[0];    /* read, write and reply chunks */
 108
 109         } rm_body;
 110 };
 111
 112 /*
 113  * XDR sizes, in quads
 114  */
 115 enum {
 116         rpcrdma_fixed_maxsz     = 4,
 117         rpcrdma_segment_maxsz   = 4,
 118         rpcrdma_readchunk_maxsz = 2 + rpcrdma_segment_maxsz,
 119 };
 120
 121 /*
 122  * Smallest RPC/RDMA header: rm_xid through rm_type, then rm_nochunks
 123  */
 124 #define RPCRDMA_HDRLEN_MIN      (sizeof(__be32) * 7)
 125 #define RPCRDMA_HDRLEN_ERR      (sizeof(__be32) * 5)
 126
 127 enum rpcrdma_errcode {
 128         ERR_VERS = 1,
 129         ERR_CHUNK = 2
 130 };
 131
 132 enum rpcrdma_proc {
 133         RDMA_MSG = 0,           /* An RPC call or reply msg */
 134         RDMA_NOMSG = 1,         /* An RPC call or reply msg - separate body */
 135         RDMA_MSGP = 2,          /* An RPC call or reply msg with padding */
 136         RDMA_DONE = 3,          /* Client signals reply completion */
 137         RDMA_ERROR = 4          /* An RPC RDMA encoding error */
 138 };
 139
 140 #define rdma_msg        cpu_to_be32(RDMA_MSG)
 141 #define rdma_nomsg      cpu_to_be32(RDMA_NOMSG)
 142 #define rdma_msgp       cpu_to_be32(RDMA_MSGP)
 143 #define rdma_done       cpu_to_be32(RDMA_DONE)
 144 #define rdma_error      cpu_to_be32(RDMA_ERROR)
 145
 146 #define err_vers        cpu_to_be32(ERR_VERS)
 147 #define err_chunk       cpu_to_be32(ERR_CHUNK)
 148
 149 /*
 150  * Private extension to RPC-over-RDMA Version One.
 151  * Message passed during RDMA-CM connection set-up.
 152  *
 153  * Add new fields at the end, and don't permute existing
 154  * fields.
 155  */
 156 struct rpcrdma_connect_private {
 157         __be32                  cp_magic;
 158         u8                      cp_version;
 159         u8                      cp_flags;
 160         u8                      cp_send_size;
 161         u8                      cp_recv_size;
 162 } __packed;
 163
 164 #define rpcrdma_cmp_magic       __cpu_to_be32(0xf6ab0e18)
 165
 166 enum {
 167         RPCRDMA_CMP_VERSION             = 1,
 168         RPCRDMA_CMP_F_SND_W_INV_OK      = BIT(0),
 169 };
 170
 171 static inline u8
 172 rpcrdma_encode_buffer_size(unsigned int size)
 173 {
 174         return (size >> 10) - 1;
 175 }
 176
 177 static inline unsigned int
 178 rpcrdma_decode_buffer_size(u8 val)
 179 {
 180         return ((unsigned int)val + 1) << 10;
 181 }
 182
 183 #endif                          /* _LINUX_SUNRPC_RPC_RDMA_H */