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