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_connection {
 133         struct rb_node          alert_node;
 134         struct smc_link_group   *lgr;           /* link group of connection */
 135         struct smc_link         *lnk;           /* assigned SMC-R link */
 136         u32                     alert_token_local; /* unique conn. id */
 137         u8                      peer_rmbe_idx;  /* from tcp handshake */
 138         int                     peer_rmbe_size; /* size of peer rx buffer */
 139         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 140                                                  * rmbe
 141                                                  */
 142         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 143
 144         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 145         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 146         int                     rmbe_size_short;/* compressed notation */
 147         int                     rmbe_update_limit;
 148                                                 /* lower limit for consumer
 149                                                  * cursor update
 150                                                  */
 151
 152         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 153                                                  * buffer for CDC msg send
 154                                                  * .prod cf. TCP snd_nxt
 155                                                  * .cons cf. TCP sends ack
 156                                                  */
 157         union smc_host_cursor   local_tx_ctrl_fin;
 158                                                 /* prod crsr - confirmed by peer
 159                                                  */
 160         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 161                                                  * snd_max..wmem_alloc
 162                                                  */
 163         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 164                                                  * snd_nxt ?
 165                                                  */
 166         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 167                                                  * snd-wnd-begin ?
 168                                                  */
 169         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 170         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 171         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 172         spinlock_t              send_lock;      /* protect wr_sends */
 173         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 174         u32                     tx_off;         /* base offset in peer rmb */
 175
 176         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 177                                                  * .prod cf. TCP rcv_nxt
 178                                                  * .cons cf. TCP snd_una
 179                                                  */
 180         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 181                                                     * source of snd_una ?
 182                                                     */
 183         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 184         enum smc_urg_state      urg_state;
 185         bool                    urg_tx_pend;    /* urgent data staged */
 186         bool                    urg_rx_skip_pend;
 187                                                 /* indicate urgent oob data
 188                                                  * read, but previous regular
 189                                                  * data still pending
 190                                                  */
 191         char                    urg_rx_byte;    /* urgent byte */
 192         atomic_t                bytes_to_rcv;   /* arrived data,
 193                                                  * not yet received
 194                                                  */
 195         atomic_t                splice_pending; /* number of spliced bytes
 196                                                  * pending processing
 197                                                  */
 198 #ifndef KERNEL_HAS_ATOMIC64
 199         spinlock_t              acurs_lock;     /* protect cursors */
 200 #endif
 201         struct work_struct      close_work;     /* peer sent some closing */
 202         struct work_struct      abort_work;     /* abort the connection */
 203         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 204         u8                      rx_off;         /* receive offset:
 205                                                  * 0 for SMC-R, 32 for SMC-D
 206                                                  */
 207         u64                     peer_token;     /* SMC-D token of peer */
 208         u8                      killed : 1;     /* abnormal termination */
 209         u8                      out_of_sync : 1; /* out of sync with peer */
 210 };
 211
 212 struct smc_sock {                               /* smc sock container */
 213         struct sock             sk;
 214         struct socket           *clcsock;       /* internal tcp socket */
 215         void                    (*clcsk_data_ready)(struct sock *sk);
 216                                                 /* original data_ready fct. **/
 217         struct smc_connection   conn;           /* smc connection */
 218         struct smc_sock         *listen_smc;    /* listen parent */
 219         struct work_struct      connect_work;   /* handle non-blocking connect*/
 220         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 221         struct work_struct      smc_listen_work;/* prepare new accept socket */
 222         struct list_head        accept_q;       /* sockets to be accepted */
 223         spinlock_t              accept_q_lock;  /* protects accept_q */
 224         bool                    use_fallback;   /* fallback to tcp */
 225         int                     fallback_rsn;   /* reason for fallback */
 226         u32                     peer_diagnosis; /* decline reason from peer */
 227         int                     sockopt_defer_accept;
 228                                                 /* sockopt TCP_DEFER_ACCEPT
 229                                                  * value
 230                                                  */
 231         u8                      wait_close_tx_prepared : 1;
 232                                                 /* shutdown wr or close
 233                                                  * started, waiting for unsent
 234                                                  * data to be sent
 235                                                  */
 236         u8                      connect_nonblock : 1;
 237                                                 /* non-blocking connect in
 238                                                  * flight
 239                                                  */
 240         struct mutex            clcsock_release_lock;
 241                                                 /* protects clcsock of a listen
 242                                                  * socket
 243                                                  * */
 244 };
 245
 246 static inline struct smc_sock *smc_sk(const struct sock *sk)
 247 {
 248         return (struct smc_sock *)sk;
 249 }
 250
 251 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 252 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 253
 254 #define SMC_SYSTEMID_LEN                8
 255
 256 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 257
 258 #define ntohll(x) be64_to_cpu(x)
 259 #define htonll(x) cpu_to_be64(x)
 260
 261 /* convert an u32 value into network byte order, store it into a 3 byte field */
 262 static inline void hton24(u8 *net, u32 host)
 263 {
 264         __be32 t;
 265
 266         t = cpu_to_be32(host);
 267         memcpy(net, ((u8 *)&t) + 1, 3);
 268 }
 269
 270 /* convert a received 3 byte field into host byte order*/
 271 static inline u32 ntoh24(u8 *net)
 272 {
 273         __be32 t = 0;
 274
 275         memcpy(((u8 *)&t) + 1, net, 3);
 276         return be32_to_cpu(t);
 277 }
 278
 279 #ifdef CONFIG_XFRM
 280 static inline bool using_ipsec(struct smc_sock *smc)
 281 {
 282         return (smc->clcsock->sk->sk_policy[0] ||
 283                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 284 }
 285 #else
 286 static inline bool using_ipsec(struct smc_sock *smc)
 287 {
 288         return false;
 289 }
 290 #endif
 291
 292 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 293 void smc_close_non_accepted(struct sock *sk);
 294
 295 #endif  /* __SMC_H */