include/linux/sunrpc/rpc_rdma.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
   2 /*
   3  * Copyright (c) 2015-2017 Oracle. All rights reserved.
   4  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the BSD-type
  10  * license below:
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  *
  16  *      Redistributions of source code must retain the above copyright
  17  *      notice, this list of conditions and the following disclaimer.
  18  *
  19  *      Redistributions in binary form must reproduce the above
  20  *      copyright notice, this list of conditions and the following
  21  *      disclaimer in the documentation and/or other materials provided
  22  *      with the distribution.
  23  *
  24  *      Neither the name of the Network Appliance, Inc. nor the names of
  25  *      its contributors may be used to endorse or promote products
  26  *      derived from this software without specific prior written
  27  *      permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 #ifndef _LINUX_SUNRPC_RPC_RDMA_H
  43 #define _LINUX_SUNRPC_RPC_RDMA_H
  44
  45 #include <linux/types.h>
  46 #include <linux/bitops.h>
  47
  48 #define RPCRDMA_VERSION         1
  49 #define rpcrdma_version         cpu_to_be32(RPCRDMA_VERSION)
  50
  51 enum {
  52         RPCRDMA_V1_DEF_INLINE_SIZE      = 1024,
  53 };
  54
  55 /*
  56  * XDR sizes, in quads
  57  */
  58 enum {
  59         rpcrdma_fixed_maxsz     = 4,
  60         rpcrdma_segment_maxsz   = 4,
  61         rpcrdma_readseg_maxsz   = 1 + rpcrdma_segment_maxsz,
  62         rpcrdma_readchunk_maxsz = 1 + rpcrdma_readseg_maxsz,
  63 };
  64
  65 /*
  66  * Smallest RPC/RDMA header: rm_xid through rm_type, then rm_nochunks
  67  */
  68 #define RPCRDMA_HDRLEN_MIN      (sizeof(__be32) * 7)
  69 #define RPCRDMA_HDRLEN_ERR      (sizeof(__be32) * 5)
  70
  71 enum rpcrdma_errcode {
  72         ERR_VERS = 1,
  73         ERR_CHUNK = 2
  74 };
  75
  76 enum rpcrdma_proc {
  77         RDMA_MSG = 0,           /* An RPC call or reply msg */
  78         RDMA_NOMSG = 1,         /* An RPC call or reply msg - separate body */
  79         RDMA_MSGP = 2,          /* An RPC call or reply msg with padding */
  80         RDMA_DONE = 3,          /* Client signals reply completion */
  81         RDMA_ERROR = 4          /* An RPC RDMA encoding error */
  82 };
  83
  84 #define rdma_msg        cpu_to_be32(RDMA_MSG)
  85 #define rdma_nomsg      cpu_to_be32(RDMA_NOMSG)
  86 #define rdma_msgp       cpu_to_be32(RDMA_MSGP)
  87 #define rdma_done       cpu_to_be32(RDMA_DONE)
  88 #define rdma_error      cpu_to_be32(RDMA_ERROR)
  89
  90 #define err_vers        cpu_to_be32(ERR_VERS)
  91 #define err_chunk       cpu_to_be32(ERR_CHUNK)
  92
  93 /*
  94  * Private extension to RPC-over-RDMA Version One.
  95  * Message passed during RDMA-CM connection set-up.
  96  *
  97  * Add new fields at the end, and don't permute existing
  98  * fields.
  99  */
 100 struct rpcrdma_connect_private {
 101         __be32                  cp_magic;
 102         u8                      cp_version;
 103         u8                      cp_flags;
 104         u8                      cp_send_size;
 105         u8                      cp_recv_size;
 106 } __packed;
 107
 108 #define rpcrdma_cmp_magic       __cpu_to_be32(0xf6ab0e18)
 109
 110 enum {
 111         RPCRDMA_CMP_VERSION             = 1,
 112         RPCRDMA_CMP_F_SND_W_INV_OK      = BIT(0),
 113 };
 114
 115 static inline u8
 116 rpcrdma_encode_buffer_size(unsigned int size)
 117 {
 118         return (size >> 10) - 1;
 119 }
 120
 121 static inline unsigned int
 122 rpcrdma_decode_buffer_size(u8 val)
 123 {
 124         return ((unsigned int)val + 1) << 10;
 125 }
 126
 127 /**
 128  * xdr_encode_rdma_segment - Encode contents of an RDMA segment
 129  * @p: Pointer into a send buffer
 130  * @handle: The RDMA handle to encode
 131  * @length: The RDMA length to encode
 132  * @offset: The RDMA offset to encode
 133  *
 134  * Return value:
 135  *   Pointer to the XDR position that follows the encoded RDMA segment
 136  */
 137 static inline __be32 *xdr_encode_rdma_segment(__be32 *p, u32 handle,
 138                                               u32 length, u64 offset)
 139 {
 140         *p++ = cpu_to_be32(handle);
 141         *p++ = cpu_to_be32(length);
 142         return xdr_encode_hyper(p, offset);
 143 }
 144
 145 /**
 146  * xdr_encode_read_segment - Encode contents of a Read segment
 147  * @p: Pointer into a send buffer
 148  * @position: The position to encode
 149  * @handle: The RDMA handle to encode
 150  * @length: The RDMA length to encode
 151  * @offset: The RDMA offset to encode
 152  *
 153  * Return value:
 154  *   Pointer to the XDR position that follows the encoded Read segment
 155  */
 156 static inline __be32 *xdr_encode_read_segment(__be32 *p, u32 position,
 157                                               u32 handle, u32 length,
 158                                               u64 offset)
 159 {
 160         *p++ = cpu_to_be32(position);
 161         return xdr_encode_rdma_segment(p, handle, length, offset);
 162 }
 163
 164 /**
 165  * xdr_decode_rdma_segment - Decode contents of an RDMA segment
 166  * @p: Pointer to the undecoded RDMA segment
 167  * @handle: Upon return, the RDMA handle
 168  * @length: Upon return, the RDMA length
 169  * @offset: Upon return, the RDMA offset
 170  *
 171  * Return value:
 172  *   Pointer to the XDR item that follows the RDMA segment
 173  */
 174 static inline __be32 *xdr_decode_rdma_segment(__be32 *p, u32 *handle,
 175                                               u32 *length, u64 *offset)
 176 {
 177         *handle = be32_to_cpup(p++);
 178         *length = be32_to_cpup(p++);
 179         return xdr_decode_hyper(p, offset);
 180 }
 181
 182 /**
 183  * xdr_decode_read_segment - Decode contents of a Read segment
 184  * @p: Pointer to the undecoded Read segment
 185  * @position: Upon return, the segment's position
 186  * @handle: Upon return, the RDMA handle
 187  * @length: Upon return, the RDMA length
 188  * @offset: Upon return, the RDMA offset
 189  *
 190  * Return value:
 191  *   Pointer to the XDR item that follows the Read segment
 192  */
 193 static inline __be32 *xdr_decode_read_segment(__be32 *p, u32 *position,
 194                                               u32 *handle, u32 *length,
 195                                               u64 *offset)
 196 {
 197         *position = be32_to_cpup(p++);
 198         return xdr_decode_rdma_segment(p, handle, length, offset);
 199 }
 200
 201 #endif                          /* _LINUX_SUNRPC_RPC_RDMA_H */