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 <[email protected]>
  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 SMC_V1          1               /* SMC version V1 */
  22 #define SMC_V2          2               /* SMC version V2 */
  23 #define SMC_RELEASE     0
  24
  25 #define SMCPROTO_SMC            0       /* SMC protocol, IPv4 */
  26 #define SMCPROTO_SMC6           1       /* SMC protocol, IPv6 */
  27
  28 #define SMC_MAX_ISM_DEVS        8       /* max # of proposed non-native ISM
  29                                          * devices
  30                                          */
  31
  32 extern struct proto smc_proto;
  33 extern struct proto smc_proto6;
  34
  35 #ifdef ATOMIC64_INIT
  36 #define KERNEL_HAS_ATOMIC64
  37 #endif
  38
  39 enum smc_state {                /* possible states of an SMC socket */
  40         SMC_ACTIVE      = 1,
  41         SMC_INIT        = 2,
  42         SMC_CLOSED      = 7,
  43         SMC_LISTEN      = 10,
  44         /* normal close */
  45         SMC_PEERCLOSEWAIT1      = 20,
  46         SMC_PEERCLOSEWAIT2      = 21,
  47         SMC_APPFINCLOSEWAIT     = 24,
  48         SMC_APPCLOSEWAIT1       = 22,
  49         SMC_APPCLOSEWAIT2       = 23,
  50         SMC_PEERFINCLOSEWAIT    = 25,
  51         /* abnormal close */
  52         SMC_PEERABORTWAIT       = 26,
  53         SMC_PROCESSABORT        = 27,
  54 };
  55
  56 struct smc_link_group;
  57
  58 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  59         u8                      type;
  60 } __aligned(1);
  61
  62 struct smc_cdc_conn_state_flags {
  63 #if defined(__BIG_ENDIAN_BITFIELD)
  64         u8      peer_done_writing : 1;  /* Sending done indicator */
  65         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  66         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  67         u8      reserved : 5;
  68 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  69         u8      reserved : 5;
  70         u8      peer_conn_abort : 1;
  71         u8      peer_conn_closed : 1;
  72         u8      peer_done_writing : 1;
  73 #endif
  74 };
  75
  76 struct smc_cdc_producer_flags {
  77 #if defined(__BIG_ENDIAN_BITFIELD)
  78         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  79         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  80         u8      urg_data_present : 1;   /* Urgent Data Present */
  81         u8      cons_curs_upd_req : 1;  /* cursor update requested */
  82         u8      failover_validation : 1;/* message replay due to failover */
  83         u8      reserved : 3;
  84 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  85         u8      reserved : 3;
  86         u8      failover_validation : 1;
  87         u8      cons_curs_upd_req : 1;
  88         u8      urg_data_present : 1;
  89         u8      urg_data_pending : 1;
  90         u8      write_blocked : 1;
  91 #endif
  92 };
  93
  94 /* in host byte order */
  95 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
  96         struct {
  97                 u16     reserved;
  98                 u16     wrap;           /* window wrap sequence number */
  99                 u32     count;          /* cursor (= offset) part */
 100         };
 101 #ifdef KERNEL_HAS_ATOMIC64
 102         atomic64_t              acurs;  /* for atomic processing */
 103 #else
 104         u64                     acurs;  /* for atomic processing */
 105 #endif
 106 } __aligned(8);
 107
 108 /* in host byte order, except for flag bitfields in network byte order */
 109 struct smc_host_cdc_msg {               /* Connection Data Control message */
 110         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 111         u8                              len;    /* length = 44 */
 112         u16                             seqno;  /* connection seq # */
 113         u32                             token;  /* alert_token */
 114         union smc_host_cursor           prod;           /* producer cursor */
 115         union smc_host_cursor           cons;           /* consumer cursor,
 116                                                          * piggy backed "ack"
 117                                                          */
 118         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 119         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 120         u8                              reserved[18];
 121 } __aligned(8);
 122
 123 enum smc_urg_state {
 124         SMC_URG_VALID   = 1,                    /* data present */
 125         SMC_URG_NOTYET  = 2,                    /* data pending */
 126         SMC_URG_READ    = 3,                    /* data was already read */
 127 };
 128
 129 struct smc_connection {
 130         struct rb_node          alert_node;
 131         struct smc_link_group   *lgr;           /* link group of connection */
 132         struct smc_link         *lnk;           /* assigned SMC-R link */
 133         u32                     alert_token_local; /* unique conn. id */
 134         u8                      peer_rmbe_idx;  /* from tcp handshake */
 135         int                     peer_rmbe_size; /* size of peer rx buffer */
 136         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 137                                                  * rmbe
 138                                                  */
 139         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 140
 141         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 142         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 143         int                     rmbe_size_short;/* compressed notation */
 144         int                     rmbe_update_limit;
 145                                                 /* lower limit for consumer
 146                                                  * cursor update
 147                                                  */
 148
 149         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 150                                                  * buffer for CDC msg send
 151                                                  * .prod cf. TCP snd_nxt
 152                                                  * .cons cf. TCP sends ack
 153                                                  */
 154         union smc_host_cursor   local_tx_ctrl_fin;
 155                                                 /* prod crsr - confirmed by peer
 156                                                  */
 157         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 158                                                  * snd_max..wmem_alloc
 159                                                  */
 160         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 161                                                  * snd_nxt ?
 162                                                  */
 163         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 164                                                  * snd-wnd-begin ?
 165                                                  */
 166         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 167         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 168         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 169         spinlock_t              send_lock;      /* protect wr_sends */
 170         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 171         u32                     tx_off;         /* base offset in peer rmb */
 172
 173         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 174                                                  * .prod cf. TCP rcv_nxt
 175                                                  * .cons cf. TCP snd_una
 176                                                  */
 177         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 178                                                     * source of snd_una ?
 179                                                     */
 180         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 181         enum smc_urg_state      urg_state;
 182         bool                    urg_tx_pend;    /* urgent data staged */
 183         bool                    urg_rx_skip_pend;
 184                                                 /* indicate urgent oob data
 185                                                  * read, but previous regular
 186                                                  * data still pending
 187                                                  */
 188         char                    urg_rx_byte;    /* urgent byte */
 189         atomic_t                bytes_to_rcv;   /* arrived data,
 190                                                  * not yet received
 191                                                  */
 192         atomic_t                splice_pending; /* number of spliced bytes
 193                                                  * pending processing
 194                                                  */
 195 #ifndef KERNEL_HAS_ATOMIC64
 196         spinlock_t              acurs_lock;     /* protect cursors */
 197 #endif
 198         struct work_struct      close_work;     /* peer sent some closing */
 199         struct work_struct      abort_work;     /* abort the connection */
 200         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 201         u8                      rx_off;         /* receive offset:
 202                                                  * 0 for SMC-R, 32 for SMC-D
 203                                                  */
 204         u64                     peer_token;     /* SMC-D token of peer */
 205         u8                      killed : 1;     /* abnormal termination */
 206         u8                      out_of_sync : 1; /* out of sync with peer */
 207 };
 208
 209 struct smc_sock {                               /* smc sock container */
 210         struct sock             sk;
 211         struct socket           *clcsock;       /* internal tcp socket */
 212         void                    (*clcsk_data_ready)(struct sock *sk);
 213                                                 /* original data_ready fct. **/
 214         struct smc_connection   conn;           /* smc connection */
 215         struct smc_sock         *listen_smc;    /* listen parent */
 216         struct work_struct      connect_work;   /* handle non-blocking connect*/
 217         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 218         struct work_struct      smc_listen_work;/* prepare new accept socket */
 219         struct list_head        accept_q;       /* sockets to be accepted */
 220         spinlock_t              accept_q_lock;  /* protects accept_q */
 221         bool                    use_fallback;   /* fallback to tcp */
 222         int                     fallback_rsn;   /* reason for fallback */
 223         u32                     peer_diagnosis; /* decline reason from peer */
 224         int                     sockopt_defer_accept;
 225                                                 /* sockopt TCP_DEFER_ACCEPT
 226                                                  * value
 227                                                  */
 228         u8                      wait_close_tx_prepared : 1;
 229                                                 /* shutdown wr or close
 230                                                  * started, waiting for unsent
 231                                                  * data to be sent
 232                                                  */
 233         u8                      connect_nonblock : 1;
 234                                                 /* non-blocking connect in
 235                                                  * flight
 236                                                  */
 237         struct mutex            clcsock_release_lock;
 238                                                 /* protects clcsock of a listen
 239                                                  * socket
 240                                                  * */
 241 };
 242
 243 static inline struct smc_sock *smc_sk(const struct sock *sk)
 244 {
 245         return (struct smc_sock *)sk;
 246 }
 247
 248 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 249 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 250
 251 #define SMC_SYSTEMID_LEN                8
 252
 253 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 254
 255 #define ntohll(x) be64_to_cpu(x)
 256 #define htonll(x) cpu_to_be64(x)
 257
 258 /* convert an u32 value into network byte order, store it into a 3 byte field */
 259 static inline void hton24(u8 *net, u32 host)
 260 {
 261         __be32 t;
 262
 263         t = cpu_to_be32(host);
 264         memcpy(net, ((u8 *)&t) + 1, 3);
 265 }
 266
 267 /* convert a received 3 byte field into host byte order*/
 268 static inline u32 ntoh24(u8 *net)
 269 {
 270         __be32 t = 0;
 271
 272         memcpy(((u8 *)&t) + 1, net, 3);
 273         return be32_to_cpu(t);
 274 }
 275
 276 #ifdef CONFIG_XFRM
 277 static inline bool using_ipsec(struct smc_sock *smc)
 278 {
 279         return (smc->clcsock->sk->sk_policy[0] ||
 280                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 281 }
 282 #else
 283 static inline bool using_ipsec(struct smc_sock *smc)
 284 {
 285         return false;
 286 }
 287 #endif
 288
 289 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 290 void smc_close_non_accepted(struct sock *sk);
 291
 292 #endif  /* __SMC_H */