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/genetlink.h>
  18 #include <net/sock.h>
  19
  20 #include "smc_ib.h"
  21
  22 #define SMC_V1          1               /* SMC version V1 */
  23 #define SMC_V2          2               /* SMC version V2 */
  24 #define SMC_RELEASE     0
  25
  26 #define SMCPROTO_SMC            0       /* SMC protocol, IPv4 */
  27 #define SMCPROTO_SMC6           1       /* SMC protocol, IPv6 */
  28
  29 #define SMC_MAX_ISM_DEVS        8       /* max # of proposed non-native ISM
  30                                          * devices
  31                                          */
  32 #define SMC_AUTOCORKING_DEFAULT_SIZE    0x10000 /* 64K by default */
  33
  34 extern struct proto smc_proto;
  35 extern struct proto smc_proto6;
  36
  37 #ifdef ATOMIC64_INIT
  38 #define KERNEL_HAS_ATOMIC64
  39 #endif
  40
  41 enum smc_state {                /* possible states of an SMC socket */
  42         SMC_ACTIVE      = 1,
  43         SMC_INIT        = 2,
  44         SMC_CLOSED      = 7,
  45         SMC_LISTEN      = 10,
  46         /* normal close */
  47         SMC_PEERCLOSEWAIT1      = 20,
  48         SMC_PEERCLOSEWAIT2      = 21,
  49         SMC_APPFINCLOSEWAIT     = 24,
  50         SMC_APPCLOSEWAIT1       = 22,
  51         SMC_APPCLOSEWAIT2       = 23,
  52         SMC_PEERFINCLOSEWAIT    = 25,
  53         /* abnormal close */
  54         SMC_PEERABORTWAIT       = 26,
  55         SMC_PROCESSABORT        = 27,
  56 };
  57
  58 struct smc_link_group;
  59
  60 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  61         union {
  62                 u8 type;
  63 #if defined(__BIG_ENDIAN_BITFIELD)
  64                 struct {
  65                         u8 llc_version:4,
  66                            llc_type:4;
  67                 };
  68 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  69                 struct {
  70                         u8 llc_type:4,
  71                            llc_version:4;
  72                 };
  73 #endif
  74         };
  75 } __aligned(1);
  76
  77 struct smc_cdc_conn_state_flags {
  78 #if defined(__BIG_ENDIAN_BITFIELD)
  79         u8      peer_done_writing : 1;  /* Sending done indicator */
  80         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  81         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  82         u8      reserved : 5;
  83 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  84         u8      reserved : 5;
  85         u8      peer_conn_abort : 1;
  86         u8      peer_conn_closed : 1;
  87         u8      peer_done_writing : 1;
  88 #endif
  89 };
  90
  91 struct smc_cdc_producer_flags {
  92 #if defined(__BIG_ENDIAN_BITFIELD)
  93         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  94         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  95         u8      urg_data_present : 1;   /* Urgent Data Present */
  96         u8      cons_curs_upd_req : 1;  /* cursor update requested */
  97         u8      failover_validation : 1;/* message replay due to failover */
  98         u8      reserved : 3;
  99 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 100         u8      reserved : 3;
 101         u8      failover_validation : 1;
 102         u8      cons_curs_upd_req : 1;
 103         u8      urg_data_present : 1;
 104         u8      urg_data_pending : 1;
 105         u8      write_blocked : 1;
 106 #endif
 107 };
 108
 109 /* in host byte order */
 110 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
 111         struct {
 112                 u16     reserved;
 113                 u16     wrap;           /* window wrap sequence number */
 114                 u32     count;          /* cursor (= offset) part */
 115         };
 116 #ifdef KERNEL_HAS_ATOMIC64
 117         atomic64_t              acurs;  /* for atomic processing */
 118 #else
 119         u64                     acurs;  /* for atomic processing */
 120 #endif
 121 } __aligned(8);
 122
 123 /* in host byte order, except for flag bitfields in network byte order */
 124 struct smc_host_cdc_msg {               /* Connection Data Control message */
 125         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 126         u8                              len;    /* length = 44 */
 127         u16                             seqno;  /* connection seq # */
 128         u32                             token;  /* alert_token */
 129         union smc_host_cursor           prod;           /* producer cursor */
 130         union smc_host_cursor           cons;           /* consumer cursor,
 131                                                          * piggy backed "ack"
 132                                                          */
 133         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 134         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 135         u8                              reserved[18];
 136 } __aligned(8);
 137
 138 enum smc_urg_state {
 139         SMC_URG_VALID   = 1,                    /* data present */
 140         SMC_URG_NOTYET  = 2,                    /* data pending */
 141         SMC_URG_READ    = 3,                    /* data was already read */
 142 };
 143
 144 struct smc_mark_woken {
 145         bool woken;
 146         void *key;
 147         wait_queue_entry_t wait_entry;
 148 };
 149
 150 struct smc_connection {
 151         struct rb_node          alert_node;
 152         struct smc_link_group   *lgr;           /* link group of connection */
 153         struct smc_link         *lnk;           /* assigned SMC-R link */
 154         u32                     alert_token_local; /* unique conn. id */
 155         u8                      peer_rmbe_idx;  /* from tcp handshake */
 156         int                     peer_rmbe_size; /* size of peer rx buffer */
 157         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 158                                                  * rmbe
 159                                                  */
 160         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 161
 162         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 163         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 164         int                     rmbe_size_short;/* compressed notation */
 165         int                     rmbe_update_limit;
 166                                                 /* lower limit for consumer
 167                                                  * cursor update
 168                                                  */
 169
 170         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 171                                                  * buffer for CDC msg send
 172                                                  * .prod cf. TCP snd_nxt
 173                                                  * .cons cf. TCP sends ack
 174                                                  */
 175         union smc_host_cursor   local_tx_ctrl_fin;
 176                                                 /* prod crsr - confirmed by peer
 177                                                  */
 178         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 179                                                  * snd_max..wmem_alloc
 180                                                  */
 181         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 182                                                  * snd_nxt ?
 183                                                  */
 184         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 185                                                  * snd-wnd-begin ?
 186                                                  */
 187         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 188         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 189         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 190         spinlock_t              send_lock;      /* protect wr_sends */
 191         atomic_t                cdc_pend_tx_wr; /* number of pending tx CDC wqe
 192                                                  * - inc when post wqe,
 193                                                  * - dec on polled tx cqe
 194                                                  */
 195         wait_queue_head_t       cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
 196         atomic_t                tx_pushing;     /* nr_threads trying tx push */
 197         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 198         u32                     tx_off;         /* base offset in peer rmb */
 199
 200         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 201                                                  * .prod cf. TCP rcv_nxt
 202                                                  * .cons cf. TCP snd_una
 203                                                  */
 204         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 205                                                     * source of snd_una ?
 206                                                     */
 207         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 208         enum smc_urg_state      urg_state;
 209         bool                    urg_tx_pend;    /* urgent data staged */
 210         bool                    urg_rx_skip_pend;
 211                                                 /* indicate urgent oob data
 212                                                  * read, but previous regular
 213                                                  * data still pending
 214                                                  */
 215         char                    urg_rx_byte;    /* urgent byte */
 216         bool                    tx_in_release_sock;
 217                                                 /* flush pending tx data in
 218                                                  * sock release_cb()
 219                                                  */
 220         atomic_t                bytes_to_rcv;   /* arrived data,
 221                                                  * not yet received
 222                                                  */
 223         atomic_t                splice_pending; /* number of spliced bytes
 224                                                  * pending processing
 225                                                  */
 226 #ifndef KERNEL_HAS_ATOMIC64
 227         spinlock_t              acurs_lock;     /* protect cursors */
 228 #endif
 229         struct work_struct      close_work;     /* peer sent some closing */
 230         struct work_struct      abort_work;     /* abort the connection */
 231         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 232         u8                      rx_off;         /* receive offset:
 233                                                  * 0 for SMC-R, 32 for SMC-D
 234                                                  */
 235         u64                     peer_token;     /* SMC-D token of peer */
 236         u8                      killed : 1;     /* abnormal termination */
 237         u8                      freed : 1;      /* normal termiation */
 238         u8                      out_of_sync : 1; /* out of sync with peer */
 239 };
 240
 241 struct smc_sock {                               /* smc sock container */
 242         struct sock             sk;
 243         struct socket           *clcsock;       /* internal tcp socket */
 244         void                    (*clcsk_state_change)(struct sock *sk);
 245                                                 /* original stat_change fct. */
 246         void                    (*clcsk_data_ready)(struct sock *sk);
 247                                                 /* original data_ready fct. */
 248         void                    (*clcsk_write_space)(struct sock *sk);
 249                                                 /* original write_space fct. */
 250         void                    (*clcsk_error_report)(struct sock *sk);
 251                                                 /* original error_report fct. */
 252         struct smc_connection   conn;           /* smc connection */
 253         struct smc_sock         *listen_smc;    /* listen parent */
 254         struct work_struct      connect_work;   /* handle non-blocking connect*/
 255         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 256         struct work_struct      smc_listen_work;/* prepare new accept socket */
 257         struct list_head        accept_q;       /* sockets to be accepted */
 258         spinlock_t              accept_q_lock;  /* protects accept_q */
 259         bool                    limit_smc_hs;   /* put constraint on handshake */
 260         bool                    use_fallback;   /* fallback to tcp */
 261         int                     fallback_rsn;   /* reason for fallback */
 262         u32                     peer_diagnosis; /* decline reason from peer */
 263         atomic_t                queued_smc_hs;  /* queued smc handshakes */
 264         struct inet_connection_sock_af_ops              af_ops;
 265         const struct inet_connection_sock_af_ops        *ori_af_ops;
 266                                                 /* original af ops */
 267         int                     sockopt_defer_accept;
 268                                                 /* sockopt TCP_DEFER_ACCEPT
 269                                                  * value
 270                                                  */
 271         u8                      wait_close_tx_prepared : 1;
 272                                                 /* shutdown wr or close
 273                                                  * started, waiting for unsent
 274                                                  * data to be sent
 275                                                  */
 276         u8                      connect_nonblock : 1;
 277                                                 /* non-blocking connect in
 278                                                  * flight
 279                                                  */
 280         struct mutex            clcsock_release_lock;
 281                                                 /* protects clcsock of a listen
 282                                                  * socket
 283                                                  * */
 284 };
 285
 286 #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
 287
 288 static inline void smc_init_saved_callbacks(struct smc_sock *smc)
 289 {
 290         smc->clcsk_state_change = NULL;
 291         smc->clcsk_data_ready   = NULL;
 292         smc->clcsk_write_space  = NULL;
 293         smc->clcsk_error_report = NULL;
 294 }
 295
 296 static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
 297 {
 298         return (struct smc_sock *)
 299                ((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
 300 }
 301
 302 /* save target_cb in saved_cb, and replace target_cb with new_cb */
 303 static inline void smc_clcsock_replace_cb(void (**target_cb)(struct sock *),
 304                                           void (*new_cb)(struct sock *),
 305                                           void (**saved_cb)(struct sock *))
 306 {
 307         /* only save once */
 308         if (!*saved_cb)
 309                 *saved_cb = *target_cb;
 310         *target_cb = new_cb;
 311 }
 312
 313 /* restore target_cb to saved_cb, and reset saved_cb to NULL */
 314 static inline void smc_clcsock_restore_cb(void (**target_cb)(struct sock *),
 315                                           void (**saved_cb)(struct sock *))
 316 {
 317         if (!*saved_cb)
 318                 return;
 319         *target_cb = *saved_cb;
 320         *saved_cb = NULL;
 321 }
 322
 323 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 324 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 325
 326 #define SMC_SYSTEMID_LEN                8
 327
 328 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 329
 330 #define ntohll(x) be64_to_cpu(x)
 331 #define htonll(x) cpu_to_be64(x)
 332
 333 /* convert an u32 value into network byte order, store it into a 3 byte field */
 334 static inline void hton24(u8 *net, u32 host)
 335 {
 336         __be32 t;
 337
 338         t = cpu_to_be32(host);
 339         memcpy(net, ((u8 *)&t) + 1, 3);
 340 }
 341
 342 /* convert a received 3 byte field into host byte order*/
 343 static inline u32 ntoh24(u8 *net)
 344 {
 345         __be32 t = 0;
 346
 347         memcpy(((u8 *)&t) + 1, net, 3);
 348         return be32_to_cpu(t);
 349 }
 350
 351 #ifdef CONFIG_XFRM
 352 static inline bool using_ipsec(struct smc_sock *smc)
 353 {
 354         return (smc->clcsock->sk->sk_policy[0] ||
 355                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 356 }
 357 #else
 358 static inline bool using_ipsec(struct smc_sock *smc)
 359 {
 360         return false;
 361 }
 362 #endif
 363
 364 struct smc_gidlist;
 365
 366 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 367 void smc_close_non_accepted(struct sock *sk);
 368 void smc_fill_gid_list(struct smc_link_group *lgr,
 369                        struct smc_gidlist *gidlist,
 370                        struct smc_ib_device *known_dev, u8 *known_gid);
 371
 372 /* smc handshake limitation interface for netlink  */
 373 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb);
 374 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 375 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 376
 377 #endif  /* __SMC_H */