xref: /linux-6.15/include/linux/sunrpc/rpc_rdma.h (revision 2cef30d7)
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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
116 rpcrdma_encode_buffer_size(unsigned int size)
117 {
118 	return (size >> 10) - 1;
119 }
120 
121 static inline unsigned int
122 rpcrdma_decode_buffer_size(u8 val)
123 {
124 	return ((unsigned int)val + 1) << 10;
125 }
126 
127 #endif				/* _LINUX_SUNRPC_RPC_RDMA_H */
128