xref: /openbmc/linux/net/smc/smc_clc.h (revision 71844fac)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  CLC (connection layer control) handshake over initial TCP socket to
6  *  prepare for RDMA traffic
7  *
8  *  Copyright IBM Corp. 2016
9  *
10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
11  */
12 
13 #ifndef _SMC_CLC_H
14 #define _SMC_CLC_H
15 
16 #include <rdma/ib_verbs.h>
17 
18 #include "smc.h"
19 
20 #define SMC_CLC_PROPOSAL	0x01
21 #define SMC_CLC_ACCEPT		0x02
22 #define SMC_CLC_CONFIRM		0x03
23 #define SMC_CLC_DECLINE		0x04
24 
25 #define SMC_CLC_V1		0x1		/* SMC version                */
26 #define SMC_TYPE_R		0		/* SMC-R only		      */
27 #define SMC_TYPE_D		1		/* SMC-D only		      */
28 #define SMC_TYPE_B		3		/* SMC-R and SMC-D	      */
29 #define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
30 #define CLC_WAIT_TIME_SHORT	HZ		/* short wait time on clcsock */
31 #define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
32 #define SMC_CLC_DECL_TIMEOUT_CL	0x02010000  /* timeout w4 QP confirm link     */
33 #define SMC_CLC_DECL_TIMEOUT_AL	0x02020000  /* timeout w4 QP add link	      */
34 #define SMC_CLC_DECL_CNFERR	0x03000000  /* configuration error            */
35 #define SMC_CLC_DECL_PEERNOSMC	0x03010000  /* peer did not indicate SMC      */
36 #define SMC_CLC_DECL_IPSEC	0x03020000  /* IPsec usage		      */
37 #define SMC_CLC_DECL_NOSMCDEV	0x03030000  /* no SMC device found	      */
38 #define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
39 #define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
40 #define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
41 #define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
42 #define SMC_CLC_DECL_PEERDECL	0x05000000  /* peer declined during handshake */
43 #define SMC_CLC_DECL_INTERR	0x99990000  /* internal error                 */
44 #define SMC_CLC_DECL_ERR_RTOK	0x99990001  /*	 rtoken handling failed       */
45 #define SMC_CLC_DECL_ERR_RDYLNK	0x99990002  /*	 ib ready link failed	      */
46 #define SMC_CLC_DECL_ERR_REGRMB	0x99990003  /*	 reg rmb failed		      */
47 
48 struct smc_clc_msg_hdr {	/* header1 of clc messages */
49 	u8 eyecatcher[4];	/* eye catcher */
50 	u8 type;		/* proposal / accept / confirm / decline */
51 	__be16 length;
52 #if defined(__BIG_ENDIAN_BITFIELD)
53 	u8 version : 4,
54 	   flag    : 1,
55 	   rsvd	   : 1,
56 	   path	   : 2;
57 #elif defined(__LITTLE_ENDIAN_BITFIELD)
58 	u8 path    : 2,
59 	   rsvd    : 1,
60 	   flag    : 1,
61 	   version : 4;
62 #endif
63 } __packed;			/* format defined in RFC7609 */
64 
65 struct smc_clc_msg_trail {	/* trailer of clc messages */
66 	u8 eyecatcher[4];
67 };
68 
69 struct smc_clc_msg_local {	/* header2 of clc messages */
70 	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
71 	u8 gid[16];		/* gid of ib_device port */
72 	u8 mac[6];		/* mac of ib_device port */
73 };
74 
75 #define SMC_CLC_MAX_V6_PREFIX	8
76 
77 /* Struct would be 4 byte aligned, but it is used in an array that is sent
78  * to peers and must conform to RFC7609, hence we need to use packed here.
79  */
80 struct smc_clc_ipv6_prefix {
81 	struct in6_addr prefix;
82 	u8 prefix_len;
83 } __packed;			/* format defined in RFC7609 */
84 
85 struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
86 	__be32 outgoing_subnet;	/* subnet mask */
87 	u8 prefix_len;		/* number of significant bits in mask */
88 	u8 reserved[2];
89 	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
90 } __aligned(4);
91 
92 struct smc_clc_msg_smcd {	/* SMC-D GID information */
93 	u64 gid;		/* ISM GID of requestor */
94 	u8 res[32];
95 };
96 
97 struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
98 	struct smc_clc_msg_hdr hdr;
99 	struct smc_clc_msg_local lcl;
100 	__be16 iparea_offset;	/* offset to IP address information area */
101 } __aligned(4);
102 
103 #define SMC_CLC_PROPOSAL_MAX_OFFSET	0x28
104 #define SMC_CLC_PROPOSAL_MAX_PREFIX	(SMC_CLC_MAX_V6_PREFIX * \
105 					 sizeof(struct smc_clc_ipv6_prefix))
106 #define SMC_CLC_MAX_LEN		(sizeof(struct smc_clc_msg_proposal) + \
107 				 SMC_CLC_PROPOSAL_MAX_OFFSET + \
108 				 sizeof(struct smc_clc_msg_proposal_prefix) + \
109 				 SMC_CLC_PROPOSAL_MAX_PREFIX + \
110 				 sizeof(struct smc_clc_msg_trail))
111 
112 struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
113 	struct smc_clc_msg_hdr hdr;
114 	union {
115 		struct { /* SMC-R */
116 			struct smc_clc_msg_local lcl;
117 			u8 qpn[3];		/* QP number */
118 			__be32 rmb_rkey;	/* RMB rkey */
119 			u8 rmbe_idx;		/* Index of RMBE in RMB */
120 			__be32 rmbe_alert_token;/* unique connection id */
121 #if defined(__BIG_ENDIAN_BITFIELD)
122 			u8 rmbe_size : 4,	/* buf size (compressed) */
123 			   qp_mtu   : 4;	/* QP mtu */
124 #elif defined(__LITTLE_ENDIAN_BITFIELD)
125 			u8 qp_mtu   : 4,
126 			   rmbe_size : 4;
127 #endif
128 			u8 reserved;
129 			__be64 rmb_dma_addr;	/* RMB virtual address */
130 			u8 reserved2;
131 			u8 psn[3];		/* packet sequence number */
132 			struct smc_clc_msg_trail smcr_trl;
133 						/* eye catcher "SMCR" EBCDIC */
134 		} __packed;
135 		struct { /* SMC-D */
136 			u64 gid;		/* Sender GID */
137 			u64 token;		/* DMB token */
138 			u8 dmbe_idx;		/* DMBE index */
139 #if defined(__BIG_ENDIAN_BITFIELD)
140 			u8 dmbe_size : 4,	/* buf size (compressed) */
141 			   reserved3 : 4;
142 #elif defined(__LITTLE_ENDIAN_BITFIELD)
143 			u8 reserved3 : 4,
144 			   dmbe_size : 4;
145 #endif
146 			u16 reserved4;
147 			u32 linkid;		/* Link identifier */
148 			u32 reserved5[3];
149 			struct smc_clc_msg_trail smcd_trl;
150 						/* eye catcher "SMCD" EBCDIC */
151 		} __packed;
152 	};
153 } __packed;			/* format defined in RFC7609 */
154 
155 struct smc_clc_msg_decline {	/* clc decline message */
156 	struct smc_clc_msg_hdr hdr;
157 	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
158 	__be32 peer_diagnosis;	/* diagnosis information */
159 	u8 reserved2[4];
160 	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
161 } __aligned(4);
162 
163 /* determine start of the prefix area within the proposal message */
164 static inline struct smc_clc_msg_proposal_prefix *
165 smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
166 {
167 	return (struct smc_clc_msg_proposal_prefix *)
168 	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
169 }
170 
171 /* get SMC-D info from proposal message */
172 static inline struct smc_clc_msg_smcd *
173 smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
174 {
175 	if (ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
176 		return NULL;
177 
178 	return (struct smc_clc_msg_smcd *)(prop + 1);
179 }
180 
181 struct smcd_dev;
182 
183 int smc_clc_prfx_match(struct socket *clcsock,
184 		       struct smc_clc_msg_proposal_prefix *prop);
185 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
186 		     u8 expected_type, unsigned long timeout);
187 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
188 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
189 			  struct smc_ib_device *smcibdev, u8 ibport, u8 gid[],
190 			  struct smcd_dev *ismdev);
191 int smc_clc_send_confirm(struct smc_sock *smc);
192 int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
193 
194 #endif
195