xref: /linux/include/linux/sunrpc/rpc_rdma.h (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
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
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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
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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,
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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
rpcrdma_encode_buffer_size(unsigned int size)116 rpcrdma_encode_buffer_size(unsigned int size)
117 {
118 	return (size >> 10) - 1;
119 }
120 
121 static inline unsigned int
rpcrdma_decode_buffer_size(u8 val)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  */
xdr_encode_rdma_segment(__be32 * p,u32 handle,u32 length,u64 offset)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  */
xdr_encode_read_segment(__be32 * p,u32 position,u32 handle,u32 length,u64 offset)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  */
xdr_decode_rdma_segment(__be32 * p,u32 * handle,u32 * length,u64 * offset)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  */
xdr_decode_read_segment(__be32 * p,u32 * position,u32 * handle,u32 * length,u64 * offset)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 */
202