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
  25 #define SMC_RELEASE_0 0
  26 #define SMC_RELEASE_1 1
  27 #define SMC_RELEASE     SMC_RELEASE_1 /* the latest release version */
  28
  29 #define SMCPROTO_SMC            0       /* SMC protocol, IPv4 */
  30 #define SMCPROTO_SMC6           1       /* SMC protocol, IPv6 */
  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 enum smc_supplemental_features {
  59         SMC_SPF_EMULATED_ISM_DEV        = 0,
  60 };
  61
  62 #define SMC_FEATURE_MASK \
  63         (BIT(SMC_SPF_EMULATED_ISM_DEV))
  64
  65 struct smc_link_group;
  66
  67 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  68         union {
  69                 u8 type;
  70 #if defined(__BIG_ENDIAN_BITFIELD)
  71                 struct {
  72                         u8 llc_version:4,
  73                            llc_type:4;
  74                 };
  75 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  76                 struct {
  77                         u8 llc_type:4,
  78                            llc_version:4;
  79                 };
  80 #endif
  81         };
  82 } __aligned(1);
  83
  84 struct smc_cdc_conn_state_flags {
  85 #if defined(__BIG_ENDIAN_BITFIELD)
  86         u8      peer_done_writing : 1;  /* Sending done indicator */
  87         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  88         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  89         u8      reserved : 5;
  90 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  91         u8      reserved : 5;
  92         u8      peer_conn_abort : 1;
  93         u8      peer_conn_closed : 1;
  94         u8      peer_done_writing : 1;
  95 #endif
  96 };
  97
  98 struct smc_cdc_producer_flags {
  99 #if defined(__BIG_ENDIAN_BITFIELD)
 100         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
 101         u8      urg_data_pending : 1;   /* Urgent Data Pending */
 102         u8      urg_data_present : 1;   /* Urgent Data Present */
 103         u8      cons_curs_upd_req : 1;  /* cursor update requested */
 104         u8      failover_validation : 1;/* message replay due to failover */
 105         u8      reserved : 3;
 106 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 107         u8      reserved : 3;
 108         u8      failover_validation : 1;
 109         u8      cons_curs_upd_req : 1;
 110         u8      urg_data_present : 1;
 111         u8      urg_data_pending : 1;
 112         u8      write_blocked : 1;
 113 #endif
 114 };
 115
 116 /* in host byte order */
 117 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
 118         struct {
 119                 u16     reserved;
 120                 u16     wrap;           /* window wrap sequence number */
 121                 u32     count;          /* cursor (= offset) part */
 122         };
 123 #ifdef KERNEL_HAS_ATOMIC64
 124         atomic64_t              acurs;  /* for atomic processing */
 125 #else
 126         u64                     acurs;  /* for atomic processing */
 127 #endif
 128 } __aligned(8);
 129
 130 /* in host byte order, except for flag bitfields in network byte order */
 131 struct smc_host_cdc_msg {               /* Connection Data Control message */
 132         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 133         u8                              len;    /* length = 44 */
 134         u16                             seqno;  /* connection seq # */
 135         u32                             token;  /* alert_token */
 136         union smc_host_cursor           prod;           /* producer cursor */
 137         union smc_host_cursor           cons;           /* consumer cursor,
 138                                                          * piggy backed "ack"
 139                                                          */
 140         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 141         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 142         u8                              reserved[18];
 143 } __aligned(8);
 144
 145 enum smc_urg_state {
 146         SMC_URG_VALID   = 1,                    /* data present */
 147         SMC_URG_NOTYET  = 2,                    /* data pending */
 148         SMC_URG_READ    = 3,                    /* data was already read */
 149 };
 150
 151 struct smc_mark_woken {
 152         bool woken;
 153         void *key;
 154         wait_queue_entry_t wait_entry;
 155 };
 156
 157 struct smc_connection {
 158         struct rb_node          alert_node;
 159         struct smc_link_group   *lgr;           /* link group of connection */
 160         struct smc_link         *lnk;           /* assigned SMC-R link */
 161         u32                     alert_token_local; /* unique conn. id */
 162         u8                      peer_rmbe_idx;  /* from tcp handshake */
 163         int                     peer_rmbe_size; /* size of peer rx buffer */
 164         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 165                                                  * rmbe
 166                                                  */
 167         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 168
 169         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 170         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 171         int                     rmbe_size_comp; /* compressed notation */
 172         int                     rmbe_update_limit;
 173                                                 /* lower limit for consumer
 174                                                  * cursor update
 175                                                  */
 176
 177         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 178                                                  * buffer for CDC msg send
 179                                                  * .prod cf. TCP snd_nxt
 180                                                  * .cons cf. TCP sends ack
 181                                                  */
 182         union smc_host_cursor   local_tx_ctrl_fin;
 183                                                 /* prod crsr - confirmed by peer
 184                                                  */
 185         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 186                                                  * snd_max..wmem_alloc
 187                                                  */
 188         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 189                                                  * snd_nxt ?
 190                                                  */
 191         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 192                                                  * snd-wnd-begin ?
 193                                                  */
 194         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 195         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 196         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 197         spinlock_t              send_lock;      /* protect wr_sends */
 198         atomic_t                cdc_pend_tx_wr; /* number of pending tx CDC wqe
 199                                                  * - inc when post wqe,
 200                                                  * - dec on polled tx cqe
 201                                                  */
 202         wait_queue_head_t       cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
 203         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 204         u32                     tx_off;         /* base offset in peer rmb */
 205
 206         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 207                                                  * .prod cf. TCP rcv_nxt
 208                                                  * .cons cf. TCP snd_una
 209                                                  */
 210         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 211                                                     * source of snd_una ?
 212                                                     */
 213         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 214         enum smc_urg_state      urg_state;
 215         bool                    urg_tx_pend;    /* urgent data staged */
 216         bool                    urg_rx_skip_pend;
 217                                                 /* indicate urgent oob data
 218                                                  * read, but previous regular
 219                                                  * data still pending
 220                                                  */
 221         char                    urg_rx_byte;    /* urgent byte */
 222         bool                    tx_in_release_sock;
 223                                                 /* flush pending tx data in
 224                                                  * sock release_cb()
 225                                                  */
 226         atomic_t                bytes_to_rcv;   /* arrived data,
 227                                                  * not yet received
 228                                                  */
 229         atomic_t                splice_pending; /* number of spliced bytes
 230                                                  * pending processing
 231                                                  */
 232 #ifndef KERNEL_HAS_ATOMIC64
 233         spinlock_t              acurs_lock;     /* protect cursors */
 234 #endif
 235         struct work_struct      close_work;     /* peer sent some closing */
 236         struct work_struct      abort_work;     /* abort the connection */
 237         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 238         u8                      rx_off;         /* receive offset:
 239                                                  * 0 for SMC-R, 32 for SMC-D
 240                                                  */
 241         u64                     peer_token;     /* SMC-D token of peer */
 242         u8                      killed : 1;     /* abnormal termination */
 243         u8                      freed : 1;      /* normal termiation */
 244         u8                      out_of_sync : 1; /* out of sync with peer */
 245 };
 246
 247 struct smc_sock {                               /* smc sock container */
 248         struct sock             sk;
 249         struct socket           *clcsock;       /* internal tcp socket */
 250         void                    (*clcsk_state_change)(struct sock *sk);
 251                                                 /* original stat_change fct. */
 252         void                    (*clcsk_data_ready)(struct sock *sk);
 253                                                 /* original data_ready fct. */
 254         void                    (*clcsk_write_space)(struct sock *sk);
 255                                                 /* original write_space fct. */
 256         void                    (*clcsk_error_report)(struct sock *sk);
 257                                                 /* original error_report fct. */
 258         struct smc_connection   conn;           /* smc connection */
 259         struct smc_sock         *listen_smc;    /* listen parent */
 260         struct work_struct      connect_work;   /* handle non-blocking connect*/
 261         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 262         struct work_struct      smc_listen_work;/* prepare new accept socket */
 263         struct list_head        accept_q;       /* sockets to be accepted */
 264         spinlock_t              accept_q_lock;  /* protects accept_q */
 265         bool                    limit_smc_hs;   /* put constraint on handshake */
 266         bool                    use_fallback;   /* fallback to tcp */
 267         int                     fallback_rsn;   /* reason for fallback */
 268         u32                     peer_diagnosis; /* decline reason from peer */
 269         atomic_t                queued_smc_hs;  /* queued smc handshakes */
 270         struct inet_connection_sock_af_ops              af_ops;
 271         const struct inet_connection_sock_af_ops        *ori_af_ops;
 272                                                 /* original af ops */
 273         int                     sockopt_defer_accept;
 274                                                 /* sockopt TCP_DEFER_ACCEPT
 275                                                  * value
 276                                                  */
 277         u8                      wait_close_tx_prepared : 1;
 278                                                 /* shutdown wr or close
 279                                                  * started, waiting for unsent
 280                                                  * data to be sent
 281                                                  */
 282         u8                      connect_nonblock : 1;
 283                                                 /* non-blocking connect in
 284                                                  * flight
 285                                                  */
 286         struct mutex            clcsock_release_lock;
 287                                                 /* protects clcsock of a listen
 288                                                  * socket
 289                                                  * */
 290 };
 291
 292 #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
 293
 294 static inline void smc_init_saved_callbacks(struct smc_sock *smc)
 295 {
 296         smc->clcsk_state_change = NULL;
 297         smc->clcsk_data_ready   = NULL;
 298         smc->clcsk_write_space  = NULL;
 299         smc->clcsk_error_report = NULL;
 300 }
 301
 302 static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
 303 {
 304         return (struct smc_sock *)
 305                ((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
 306 }
 307
 308 /* save target_cb in saved_cb, and replace target_cb with new_cb */
 309 static inline void smc_clcsock_replace_cb(void (**target_cb)(struct sock *),
 310                                           void (*new_cb)(struct sock *),
 311                                           void (**saved_cb)(struct sock *))
 312 {
 313         /* only save once */
 314         if (!*saved_cb)
 315                 *saved_cb = *target_cb;
 316         *target_cb = new_cb;
 317 }
 318
 319 /* restore target_cb to saved_cb, and reset saved_cb to NULL */
 320 static inline void smc_clcsock_restore_cb(void (**target_cb)(struct sock *),
 321                                           void (**saved_cb)(struct sock *))
 322 {
 323         if (!*saved_cb)
 324                 return;
 325         *target_cb = *saved_cb;
 326         *saved_cb = NULL;
 327 }
 328
 329 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 330 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 331
 332 #define SMC_SYSTEMID_LEN                8
 333
 334 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 335
 336 #define ntohll(x) be64_to_cpu(x)
 337 #define htonll(x) cpu_to_be64(x)
 338
 339 /* convert an u32 value into network byte order, store it into a 3 byte field */
 340 static inline void hton24(u8 *net, u32 host)
 341 {
 342         __be32 t;
 343
 344         t = cpu_to_be32(host);
 345         memcpy(net, ((u8 *)&t) + 1, 3);
 346 }
 347
 348 /* convert a received 3 byte field into host byte order*/
 349 static inline u32 ntoh24(u8 *net)
 350 {
 351         __be32 t = 0;
 352
 353         memcpy(((u8 *)&t) + 1, net, 3);
 354         return be32_to_cpu(t);
 355 }
 356
 357 #ifdef CONFIG_XFRM
 358 static inline bool using_ipsec(struct smc_sock *smc)
 359 {
 360         return (smc->clcsock->sk->sk_policy[0] ||
 361                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 362 }
 363 #else
 364 static inline bool using_ipsec(struct smc_sock *smc)
 365 {
 366         return false;
 367 }
 368 #endif
 369
 370 struct smc_gidlist;
 371
 372 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 373 void smc_close_non_accepted(struct sock *sk);
 374 void smc_fill_gid_list(struct smc_link_group *lgr,
 375                        struct smc_gidlist *gidlist,
 376                        struct smc_ib_device *known_dev, u8 *known_gid);
 377
 378 /* smc handshake limitation interface for netlink  */
 379 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb);
 380 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 381 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 382
 383 static inline void smc_sock_set_flag(struct sock *sk, enum sock_flags flag)
 384 {
 385         set_bit(flag, &sk->sk_flags);
 386 }
 387
 388 #endif  /* __SMC_H */