net/smc/smc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Definitions for the SMC module (socket related)
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  10  */
  11 #ifndef __SMC_H
  12 #define __SMC_H
  13
  14 #include <linux/socket.h>
  15 #include <linux/types.h>
  16 #include <linux/compiler.h> /* __aligned */
  17 #include <net/sock.h>
  18
  19 #include "smc_ib.h"
  20
  21 #define SMCPROTO_SMC            0       /* SMC protocol, IPv4 */
  22 #define SMCPROTO_SMC6           1       /* SMC protocol, IPv6 */
  23
  24 extern struct proto smc_proto;
  25 extern struct proto smc_proto6;
  26
  27 #ifdef ATOMIC64_INIT
  28 #define KERNEL_HAS_ATOMIC64
  29 #endif
  30
  31 enum smc_state {                /* possible states of an SMC socket */
  32         SMC_ACTIVE      = 1,
  33         SMC_INIT        = 2,
  34         SMC_CLOSED      = 7,
  35         SMC_LISTEN      = 10,
  36         /* normal close */
  37         SMC_PEERCLOSEWAIT1      = 20,
  38         SMC_PEERCLOSEWAIT2      = 21,
  39         SMC_APPFINCLOSEWAIT     = 24,
  40         SMC_APPCLOSEWAIT1       = 22,
  41         SMC_APPCLOSEWAIT2       = 23,
  42         SMC_PEERFINCLOSEWAIT    = 25,
  43         /* abnormal close */
  44         SMC_PEERABORTWAIT       = 26,
  45         SMC_PROCESSABORT        = 27,
  46 };
  47
  48 struct smc_link_group;
  49
  50 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  51         u8                      type;
  52 } __aligned(1);
  53
  54 struct smc_cdc_conn_state_flags {
  55 #if defined(__BIG_ENDIAN_BITFIELD)
  56         u8      peer_done_writing : 1;  /* Sending done indicator */
  57         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  58         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  59         u8      reserved : 5;
  60 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  61         u8      reserved : 5;
  62         u8      peer_conn_abort : 1;
  63         u8      peer_conn_closed : 1;
  64         u8      peer_done_writing : 1;
  65 #endif
  66 };
  67
  68 struct smc_cdc_producer_flags {
  69 #if defined(__BIG_ENDIAN_BITFIELD)
  70         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  71         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  72         u8      urg_data_present : 1;   /* Urgent Data Present */
  73         u8      cons_curs_upd_req : 1;  /* cursor update requested */
  74         u8      failover_validation : 1;/* message replay due to failover */
  75         u8      reserved : 3;
  76 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  77         u8      reserved : 3;
  78         u8      failover_validation : 1;
  79         u8      cons_curs_upd_req : 1;
  80         u8      urg_data_present : 1;
  81         u8      urg_data_pending : 1;
  82         u8      write_blocked : 1;
  83 #endif
  84 };
  85
  86 /* in host byte order */
  87 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
  88         struct {
  89                 u16     reserved;
  90                 u16     wrap;           /* window wrap sequence number */
  91                 u32     count;          /* cursor (= offset) part */
  92         };
  93 #ifdef KERNEL_HAS_ATOMIC64
  94         atomic64_t              acurs;  /* for atomic processing */
  95 #else
  96         u64                     acurs;  /* for atomic processing */
  97 #endif
  98 } __aligned(8);
  99
 100 /* in host byte order, except for flag bitfields in network byte order */
 101 struct smc_host_cdc_msg {               /* Connection Data Control message */
 102         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 103         u8                              len;    /* length = 44 */
 104         u16                             seqno;  /* connection seq # */
 105         u32                             token;  /* alert_token */
 106         union smc_host_cursor           prod;           /* producer cursor */
 107         union smc_host_cursor           cons;           /* consumer cursor,
 108                                                          * piggy backed "ack"
 109                                                          */
 110         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 111         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 112         u8                              reserved[18];
 113 } __aligned(8);
 114
 115 enum smc_urg_state {
 116         SMC_URG_VALID   = 1,                    /* data present */
 117         SMC_URG_NOTYET  = 2,                    /* data pending */
 118         SMC_URG_READ    = 3,                    /* data was already read */
 119 };
 120
 121 struct smc_connection {
 122         struct rb_node          alert_node;
 123         struct smc_link_group   *lgr;           /* link group of connection */
 124         u32                     alert_token_local; /* unique conn. id */
 125         u8                      peer_rmbe_idx;  /* from tcp handshake */
 126         int                     peer_rmbe_size; /* size of peer rx buffer */
 127         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 128                                                  * rmbe
 129                                                  */
 130         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 131
 132         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 133         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 134         int                     rmbe_size_short;/* compressed notation */
 135         int                     rmbe_update_limit;
 136                                                 /* lower limit for consumer
 137                                                  * cursor update
 138                                                  */
 139
 140         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 141                                                  * buffer for CDC msg send
 142                                                  * .prod cf. TCP snd_nxt
 143                                                  * .cons cf. TCP sends ack
 144                                                  */
 145         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 146                                                  * snd_max..wmem_alloc
 147                                                  */
 148         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 149                                                  * snd_nxt ?
 150                                                  */
 151         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 152                                                  * snd-wnd-begin ?
 153                                                  */
 154         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 155         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 156         spinlock_t              send_lock;      /* protect wr_sends */
 157         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 158         u32                     tx_off;         /* base offset in peer rmb */
 159
 160         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 161                                                  * .prod cf. TCP rcv_nxt
 162                                                  * .cons cf. TCP snd_una
 163                                                  */
 164         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 165                                                     * source of snd_una ?
 166                                                     */
 167         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 168         enum smc_urg_state      urg_state;
 169         bool                    urg_tx_pend;    /* urgent data staged */
 170         bool                    urg_rx_skip_pend;
 171                                                 /* indicate urgent oob data
 172                                                  * read, but previous regular
 173                                                  * data still pending
 174                                                  */
 175         char                    urg_rx_byte;    /* urgent byte */
 176         atomic_t                bytes_to_rcv;   /* arrived data,
 177                                                  * not yet received
 178                                                  */
 179         atomic_t                splice_pending; /* number of spliced bytes
 180                                                  * pending processing
 181                                                  */
 182 #ifndef KERNEL_HAS_ATOMIC64
 183         spinlock_t              acurs_lock;     /* protect cursors */
 184 #endif
 185         struct work_struct      close_work;     /* peer sent some closing */
 186         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 187         u8                      rx_off;         /* receive offset:
 188                                                  * 0 for SMC-R, 32 for SMC-D
 189                                                  */
 190         u64                     peer_token;     /* SMC-D token of peer */
 191 };
 192
 193 struct smc_sock {                               /* smc sock container */
 194         struct sock             sk;
 195         struct socket           *clcsock;       /* internal tcp socket */
 196         struct smc_connection   conn;           /* smc connection */
 197         struct smc_sock         *listen_smc;    /* listen parent */
 198         struct work_struct      connect_work;   /* handle non-blocking connect*/
 199         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 200         struct work_struct      smc_listen_work;/* prepare new accept socket */
 201         struct list_head        accept_q;       /* sockets to be accepted */
 202         spinlock_t              accept_q_lock;  /* protects accept_q */
 203         bool                    use_fallback;   /* fallback to tcp */
 204         int                     fallback_rsn;   /* reason for fallback */
 205         u32                     peer_diagnosis; /* decline reason from peer */
 206         int                     sockopt_defer_accept;
 207                                                 /* sockopt TCP_DEFER_ACCEPT
 208                                                  * value
 209                                                  */
 210         u8                      wait_close_tx_prepared : 1;
 211                                                 /* shutdown wr or close
 212                                                  * started, waiting for unsent
 213                                                  * data to be sent
 214                                                  */
 215         u8                      connect_nonblock : 1;
 216                                                 /* non-blocking connect in
 217                                                  * flight
 218                                                  */
 219         struct mutex            clcsock_release_lock;
 220                                                 /* protects clcsock of a listen
 221                                                  * socket
 222                                                  * */
 223 };
 224
 225 static inline struct smc_sock *smc_sk(const struct sock *sk)
 226 {
 227         return (struct smc_sock *)sk;
 228 }
 229
 230 #define SMC_SYSTEMID_LEN                8
 231
 232 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 233
 234 /* convert an u32 value into network byte order, store it into a 3 byte field */
 235 static inline void hton24(u8 *net, u32 host)
 236 {
 237         __be32 t;
 238
 239         t = cpu_to_be32(host);
 240         memcpy(net, ((u8 *)&t) + 1, 3);
 241 }
 242
 243 /* convert a received 3 byte field into host byte order*/
 244 static inline u32 ntoh24(u8 *net)
 245 {
 246         __be32 t = 0;
 247
 248         memcpy(((u8 *)&t) + 1, net, 3);
 249         return be32_to_cpu(t);
 250 }
 251
 252 #ifdef CONFIG_XFRM
 253 static inline bool using_ipsec(struct smc_sock *smc)
 254 {
 255         return (smc->clcsock->sk->sk_policy[0] ||
 256                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 257 }
 258 #else
 259 static inline bool using_ipsec(struct smc_sock *smc)
 260 {
 261         return false;
 262 }
 263 #endif
 264
 265 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 266 void smc_close_non_accepted(struct sock *sk);
 267
 268 #endif  /* __SMC_H */