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
 51enum {
 52	RPCRDMA_V1_DEF_INLINE_SIZE	= 1024,
 53};
 54
 55/*
 56 * XDR sizes, in quads
 57 */
 58enum {
 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
 71enum rpcrdma_errcode {
 72	ERR_VERS = 1,
 73	ERR_CHUNK = 2
 74};
 75
 76enum 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 */
100struct 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
110enum {
111	RPCRDMA_CMP_VERSION		= 1,
112	RPCRDMA_CMP_F_SND_W_INV_OK	= BIT(0),
113};
114
115static inline u8
116rpcrdma_encode_buffer_size(unsigned int size)
117{
118	return (size >> 10) - 1;
119}
120
121static inline unsigned int
122rpcrdma_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 */
137static 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 */
156static 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 */
174static 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 */
193static 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 */