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 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 #define SMC_MAX_HOSTNAME_LEN    32
  33 #define SMC_MAX_EID_LEN         32
  34
  35 extern struct proto smc_proto;
  36 extern struct proto smc_proto6;
  37
  38 #ifdef ATOMIC64_INIT
  39 #define KERNEL_HAS_ATOMIC64
  40 #endif
  41
  42 enum smc_state {                /* possible states of an SMC socket */
  43         SMC_ACTIVE      = 1,
  44         SMC_INIT        = 2,
  45         SMC_CLOSED      = 7,
  46         SMC_LISTEN      = 10,
  47         /* normal close */
  48         SMC_PEERCLOSEWAIT1      = 20,
  49         SMC_PEERCLOSEWAIT2      = 21,
  50         SMC_APPFINCLOSEWAIT     = 24,
  51         SMC_APPCLOSEWAIT1       = 22,
  52         SMC_APPCLOSEWAIT2       = 23,
  53         SMC_PEERFINCLOSEWAIT    = 25,
  54         /* abnormal close */
  55         SMC_PEERABORTWAIT       = 26,
  56         SMC_PROCESSABORT        = 27,
  57 };
  58
  59 struct smc_link_group;
  60
  61 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  62         u8                      type;
  63 } __aligned(1);
  64
  65 struct smc_cdc_conn_state_flags {
  66 #if defined(__BIG_ENDIAN_BITFIELD)
  67         u8      peer_done_writing : 1;  /* Sending done indicator */
  68         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  69         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  70         u8      reserved : 5;
  71 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  72         u8      reserved : 5;
  73         u8      peer_conn_abort : 1;
  74         u8      peer_conn_closed : 1;
  75         u8      peer_done_writing : 1;
  76 #endif
  77 };
  78
  79 struct smc_cdc_producer_flags {
  80 #if defined(__BIG_ENDIAN_BITFIELD)
  81         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  82         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  83         u8      urg_data_present : 1;   /* Urgent Data Present */
  84         u8      cons_curs_upd_req : 1;  /* cursor update requested */
  85         u8      failover_validation : 1;/* message replay due to failover */
  86         u8      reserved : 3;
  87 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  88         u8      reserved : 3;
  89         u8      failover_validation : 1;
  90         u8      cons_curs_upd_req : 1;
  91         u8      urg_data_present : 1;
  92         u8      urg_data_pending : 1;
  93         u8      write_blocked : 1;
  94 #endif
  95 };
  96
  97 /* in host byte order */
  98 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
  99         struct {
 100                 u16     reserved;
 101                 u16     wrap;           /* window wrap sequence number */
 102                 u32     count;          /* cursor (= offset) part */
 103         };
 104 #ifdef KERNEL_HAS_ATOMIC64
 105         atomic64_t              acurs;  /* for atomic processing */
 106 #else
 107         u64                     acurs;  /* for atomic processing */
 108 #endif
 109 } __aligned(8);
 110
 111 /* in host byte order, except for flag bitfields in network byte order */
 112 struct smc_host_cdc_msg {               /* Connection Data Control message */
 113         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 114         u8                              len;    /* length = 44 */
 115         u16                             seqno;  /* connection seq # */
 116         u32                             token;  /* alert_token */
 117         union smc_host_cursor           prod;           /* producer cursor */
 118         union smc_host_cursor           cons;           /* consumer cursor,
 119                                                          * piggy backed "ack"
 120                                                          */
 121         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 122         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 123         u8                              reserved[18];
 124 } __aligned(8);
 125
 126 enum smc_urg_state {
 127         SMC_URG_VALID   = 1,                    /* data present */
 128         SMC_URG_NOTYET  = 2,                    /* data pending */
 129         SMC_URG_READ    = 3,                    /* data was already read */
 130 };
 131
 132 struct smc_mark_woken {
 133         bool woken;
 134         void *key;
 135         wait_queue_entry_t wait_entry;
 136 };
 137
 138 struct smc_connection {
 139         struct rb_node          alert_node;
 140         struct smc_link_group   *lgr;           /* link group of connection */
 141         struct smc_link         *lnk;           /* assigned SMC-R link */
 142         u32                     alert_token_local; /* unique conn. id */
 143         u8                      peer_rmbe_idx;  /* from tcp handshake */
 144         int                     peer_rmbe_size; /* size of peer rx buffer */
 145         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 146                                                  * rmbe
 147                                                  */
 148         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 149
 150         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 151         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 152         int                     rmbe_size_short;/* compressed notation */
 153         int                     rmbe_update_limit;
 154                                                 /* lower limit for consumer
 155                                                  * cursor update
 156                                                  */
 157
 158         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 159                                                  * buffer for CDC msg send
 160                                                  * .prod cf. TCP snd_nxt
 161                                                  * .cons cf. TCP sends ack
 162                                                  */
 163         union smc_host_cursor   local_tx_ctrl_fin;
 164                                                 /* prod crsr - confirmed by peer
 165                                                  */
 166         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 167                                                  * snd_max..wmem_alloc
 168                                                  */
 169         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 170                                                  * snd_nxt ?
 171                                                  */
 172         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 173                                                  * snd-wnd-begin ?
 174                                                  */
 175         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 176         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 177         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 178         spinlock_t              send_lock;      /* protect wr_sends */
 179         atomic_t                cdc_pend_tx_wr; /* number of pending tx CDC wqe
 180                                                  * - inc when post wqe,
 181                                                  * - dec on polled tx cqe
 182                                                  */
 183         wait_queue_head_t       cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
 184         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 185         u32                     tx_off;         /* base offset in peer rmb */
 186
 187         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 188                                                  * .prod cf. TCP rcv_nxt
 189                                                  * .cons cf. TCP snd_una
 190                                                  */
 191         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 192                                                     * source of snd_una ?
 193                                                     */
 194         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 195         enum smc_urg_state      urg_state;
 196         bool                    urg_tx_pend;    /* urgent data staged */
 197         bool                    urg_rx_skip_pend;
 198                                                 /* indicate urgent oob data
 199                                                  * read, but previous regular
 200                                                  * data still pending
 201                                                  */
 202         char                    urg_rx_byte;    /* urgent byte */
 203         atomic_t                bytes_to_rcv;   /* arrived data,
 204                                                  * not yet received
 205                                                  */
 206         atomic_t                splice_pending; /* number of spliced bytes
 207                                                  * pending processing
 208                                                  */
 209 #ifndef KERNEL_HAS_ATOMIC64
 210         spinlock_t              acurs_lock;     /* protect cursors */
 211 #endif
 212         struct work_struct      close_work;     /* peer sent some closing */
 213         struct work_struct      abort_work;     /* abort the connection */
 214         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 215         u8                      rx_off;         /* receive offset:
 216                                                  * 0 for SMC-R, 32 for SMC-D
 217                                                  */
 218         u64                     peer_token;     /* SMC-D token of peer */
 219         u8                      killed : 1;     /* abnormal termination */
 220         u8                      out_of_sync : 1; /* out of sync with peer */
 221 };
 222
 223 struct smc_sock {                               /* smc sock container */
 224         struct sock             sk;
 225         struct socket           *clcsock;       /* internal tcp socket */
 226         void                    (*clcsk_state_change)(struct sock *sk);
 227                                                 /* original stat_change fct. */
 228         void                    (*clcsk_data_ready)(struct sock *sk);
 229                                                 /* original data_ready fct. */
 230         void                    (*clcsk_write_space)(struct sock *sk);
 231                                                 /* original write_space fct. */
 232         void                    (*clcsk_error_report)(struct sock *sk);
 233                                                 /* original error_report fct. */
 234         struct smc_connection   conn;           /* smc connection */
 235         struct smc_sock         *listen_smc;    /* listen parent */
 236         struct work_struct      connect_work;   /* handle non-blocking connect*/
 237         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 238         struct work_struct      smc_listen_work;/* prepare new accept socket */
 239         struct list_head        accept_q;       /* sockets to be accepted */
 240         spinlock_t              accept_q_lock;  /* protects accept_q */
 241         bool                    use_fallback;   /* fallback to tcp */
 242         int                     fallback_rsn;   /* reason for fallback */
 243         u32                     peer_diagnosis; /* decline reason from peer */
 244         int                     sockopt_defer_accept;
 245                                                 /* sockopt TCP_DEFER_ACCEPT
 246                                                  * value
 247                                                  */
 248         u8                      wait_close_tx_prepared : 1;
 249                                                 /* shutdown wr or close
 250                                                  * started, waiting for unsent
 251                                                  * data to be sent
 252                                                  */
 253         u8                      connect_nonblock : 1;
 254                                                 /* non-blocking connect in
 255                                                  * flight
 256                                                  */
 257         struct mutex            clcsock_release_lock;
 258                                                 /* protects clcsock of a listen
 259                                                  * socket
 260                                                  * */
 261 };
 262
 263 static inline struct smc_sock *smc_sk(const struct sock *sk)
 264 {
 265         return (struct smc_sock *)sk;
 266 }
 267
 268 static inline struct smc_sock *smc_clcsock_user_data(struct sock *clcsk)
 269 {
 270         return (struct smc_sock *)
 271                ((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
 272 }
 273
 274 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 275 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 276
 277 #define SMC_SYSTEMID_LEN                8
 278
 279 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 280
 281 #define ntohll(x) be64_to_cpu(x)
 282 #define htonll(x) cpu_to_be64(x)
 283
 284 /* convert an u32 value into network byte order, store it into a 3 byte field */
 285 static inline void hton24(u8 *net, u32 host)
 286 {
 287         __be32 t;
 288
 289         t = cpu_to_be32(host);
 290         memcpy(net, ((u8 *)&t) + 1, 3);
 291 }
 292
 293 /* convert a received 3 byte field into host byte order*/
 294 static inline u32 ntoh24(u8 *net)
 295 {
 296         __be32 t = 0;
 297
 298         memcpy(((u8 *)&t) + 1, net, 3);
 299         return be32_to_cpu(t);
 300 }
 301
 302 #ifdef CONFIG_XFRM
 303 static inline bool using_ipsec(struct smc_sock *smc)
 304 {
 305         return (smc->clcsock->sk->sk_policy[0] ||
 306                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 307 }
 308 #else
 309 static inline bool using_ipsec(struct smc_sock *smc)
 310 {
 311         return false;
 312 }
 313 #endif
 314
 315 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 316 void smc_close_non_accepted(struct sock *sk);
 317
 318 #endif  /* __SMC_H */