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
48struct 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 */
57struct 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 */
66struct rpcrdma_write_chunk {
67	struct rpcrdma_segment wc_target;
68};
69
70/*
71 * write chunk(s), encoded as a counted array.
72 */
73struct 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
79struct 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
106enum rpcrdma_errcode {
107	ERR_VERS = 1,
108	ERR_CHUNK = 2
109};
110
111struct rpcrdma_err_vers {
112	uint32_t rdma_vers_low;	/* Version range supported by peer */
113	uint32_t rdma_vers_high;
114};
115
116enum 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 */
131