linux/sunrpc/rpc_rdma.h

0001 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
0002 /*
0003  * Copyright (c) 2015-2017 Oracle. All rights reserved.
0004  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
0005  *
0006  * This software is available to you under a choice of one of two
0007  * licenses.  You may choose to be licensed under the terms of the GNU
0008  * General Public License (GPL) Version 2, available from the file
0009  * COPYING in the main directory of this source tree, or the BSD-type
0010  * license below:
0011  *
0012  * Redistribution and use in source and binary forms, with or without
0013  * modification, are permitted provided that the following conditions
0014  * are met:
0015  *
0016  *      Redistributions of source code must retain the above copyright
0017  *      notice, this list of conditions and the following disclaimer.
0018  *
0019  *      Redistributions in binary form must reproduce the above
0020  *      copyright notice, this list of conditions and the following
0021  *      disclaimer in the documentation and/or other materials provided
0022  *      with the distribution.
0023  *
0024  *      Neither the name of the Network Appliance, Inc. nor the names of
0025  *      its contributors may be used to endorse or promote products
0026  *      derived from this software without specific prior written
0027  *      permission.
0028  *
0029  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
0030  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
0031  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
0032  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
0033  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
0034  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
0035  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
0036  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
0037  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0038  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
0039  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0040  */
0041
0042 #ifndef _LINUX_SUNRPC_RPC_RDMA_H
0043 #define _LINUX_SUNRPC_RPC_RDMA_H
0044
0045 #include <linux/types.h>
0046 #include <linux/bitops.h>
0047
0048 #define RPCRDMA_VERSION     1
0049 #define rpcrdma_version     cpu_to_be32(RPCRDMA_VERSION)
0050
0051 enum {
0052     RPCRDMA_V1_DEF_INLINE_SIZE  = 1024,
0053 };
0054
0055 /*
0056  * XDR sizes, in quads
0057  */
0058 enum {
0059     rpcrdma_fixed_maxsz = 4,
0060     rpcrdma_segment_maxsz   = 4,
0061     rpcrdma_readseg_maxsz   = 1 + rpcrdma_segment_maxsz,
0062     rpcrdma_readchunk_maxsz = 1 + rpcrdma_readseg_maxsz,
0063 };
0064
0065 /*
0066  * Smallest RPC/RDMA header: rm_xid through rm_type, then rm_nochunks
0067  */
0068 #define RPCRDMA_HDRLEN_MIN  (sizeof(__be32) * 7)
0069 #define RPCRDMA_HDRLEN_ERR  (sizeof(__be32) * 5)
0070
0071 enum rpcrdma_errcode {
0072     ERR_VERS = 1,
0073     ERR_CHUNK = 2
0074 };
0075
0076 enum rpcrdma_proc {
0077     RDMA_MSG = 0,       /* An RPC call or reply msg */
0078     RDMA_NOMSG = 1,     /* An RPC call or reply msg - separate body */
0079     RDMA_MSGP = 2,      /* An RPC call or reply msg with padding */
0080     RDMA_DONE = 3,      /* Client signals reply completion */
0081     RDMA_ERROR = 4      /* An RPC RDMA encoding error */
0082 };
0083
0084 #define rdma_msg    cpu_to_be32(RDMA_MSG)
0085 #define rdma_nomsg  cpu_to_be32(RDMA_NOMSG)
0086 #define rdma_msgp   cpu_to_be32(RDMA_MSGP)
0087 #define rdma_done   cpu_to_be32(RDMA_DONE)
0088 #define rdma_error  cpu_to_be32(RDMA_ERROR)
0089
0090 #define err_vers    cpu_to_be32(ERR_VERS)
0091 #define err_chunk   cpu_to_be32(ERR_CHUNK)
0092
0093 /*
0094  * Private extension to RPC-over-RDMA Version One.
0095  * Message passed during RDMA-CM connection set-up.
0096  *
0097  * Add new fields at the end, and don't permute existing
0098  * fields.
0099  */
0100 struct rpcrdma_connect_private {
0101     __be32          cp_magic;
0102     u8          cp_version;
0103     u8          cp_flags;
0104     u8          cp_send_size;
0105     u8          cp_recv_size;
0106 } __packed;
0107
0108 #define rpcrdma_cmp_magic   __cpu_to_be32(0xf6ab0e18)
0109
0110 enum {
0111     RPCRDMA_CMP_VERSION     = 1,
0112     RPCRDMA_CMP_F_SND_W_INV_OK  = BIT(0),
0113 };
0114
0115 static inline u8
0116 rpcrdma_encode_buffer_size(unsigned int size)
0117 {
0118     return (size >> 10) - 1;
0119 }
0120
0121 static inline unsigned int
0122 rpcrdma_decode_buffer_size(u8 val)
0123 {
0124     return ((unsigned int)val + 1) << 10;
0125 }
0126
0127 /**
0128  * xdr_encode_rdma_segment - Encode contents of an RDMA segment
0129  * @p: Pointer into a send buffer
0130  * @handle: The RDMA handle to encode
0131  * @length: The RDMA length to encode
0132  * @offset: The RDMA offset to encode
0133  *
0134  * Return value:
0135  *   Pointer to the XDR position that follows the encoded RDMA segment
0136  */
0137 static inline __be32 *xdr_encode_rdma_segment(__be32 *p, u32 handle,
0138                           u32 length, u64 offset)
0139 {
0140     *p++ = cpu_to_be32(handle);
0141     *p++ = cpu_to_be32(length);
0142     return xdr_encode_hyper(p, offset);
0143 }
0144
0145 /**
0146  * xdr_encode_read_segment - Encode contents of a Read segment
0147  * @p: Pointer into a send buffer
0148  * @position: The position to encode
0149  * @handle: The RDMA handle to encode
0150  * @length: The RDMA length to encode
0151  * @offset: The RDMA offset to encode
0152  *
0153  * Return value:
0154  *   Pointer to the XDR position that follows the encoded Read segment
0155  */
0156 static inline __be32 *xdr_encode_read_segment(__be32 *p, u32 position,
0157                           u32 handle, u32 length,
0158                           u64 offset)
0159 {
0160     *p++ = cpu_to_be32(position);
0161     return xdr_encode_rdma_segment(p, handle, length, offset);
0162 }
0163
0164 /**
0165  * xdr_decode_rdma_segment - Decode contents of an RDMA segment
0166  * @p: Pointer to the undecoded RDMA segment
0167  * @handle: Upon return, the RDMA handle
0168  * @length: Upon return, the RDMA length
0169  * @offset: Upon return, the RDMA offset
0170  *
0171  * Return value:
0172  *   Pointer to the XDR item that follows the RDMA segment
0173  */
0174 static inline __be32 *xdr_decode_rdma_segment(__be32 *p, u32 *handle,
0175                           u32 *length, u64 *offset)
0176 {
0177     *handle = be32_to_cpup(p++);
0178     *length = be32_to_cpup(p++);
0179     return xdr_decode_hyper(p, offset);
0180 }
0181
0182 /**
0183  * xdr_decode_read_segment - Decode contents of a Read segment
0184  * @p: Pointer to the undecoded Read segment
0185  * @position: Upon return, the segment's position
0186  * @handle: Upon return, the RDMA handle
0187  * @length: Upon return, the RDMA length
0188  * @offset: Upon return, the RDMA offset
0189  *
0190  * Return value:
0191  *   Pointer to the XDR item that follows the Read segment
0192  */
0193 static inline __be32 *xdr_decode_read_segment(__be32 *p, u32 *position,
0194                           u32 *handle, u32 *length,
0195                           u64 *offset)
0196 {
0197     *position = be32_to_cpup(p++);
0198     return xdr_decode_rdma_segment(p, handle, length, offset);
0199 }
0200
0201 #endif              /* _LINUX_SUNRPC_RPC_RDMA_H */