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_MAX_ISM_DEVS        8       /* max # of proposed non-native ISM
  33                                          * devices
  34                                          */
  35 #define SMC_AUTOCORKING_DEFAULT_SIZE    0x10000 /* 64K by default */
  36
  37 extern struct proto smc_proto;
  38 extern struct proto smc_proto6;
  39
  40 #ifdef ATOMIC64_INIT
  41 #define KERNEL_HAS_ATOMIC64
  42 #endif
  43
  44 enum smc_state {                /* possible states of an SMC socket */
  45         SMC_ACTIVE      = 1,
  46         SMC_INIT        = 2,
  47         SMC_CLOSED      = 7,
  48         SMC_LISTEN      = 10,
  49         /* normal close */
  50         SMC_PEERCLOSEWAIT1      = 20,
  51         SMC_PEERCLOSEWAIT2      = 21,
  52         SMC_APPFINCLOSEWAIT     = 24,
  53         SMC_APPCLOSEWAIT1       = 22,
  54         SMC_APPCLOSEWAIT2       = 23,
  55         SMC_PEERFINCLOSEWAIT    = 25,
  56         /* abnormal close */
  57         SMC_PEERABORTWAIT       = 26,
  58         SMC_PROCESSABORT        = 27,
  59 };
  60
  61 struct smc_link_group;
  62
  63 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  64         union {
  65                 u8 type;
  66 #if defined(__BIG_ENDIAN_BITFIELD)
  67                 struct {
  68                         u8 llc_version:4,
  69                            llc_type:4;
  70                 };
  71 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  72                 struct {
  73                         u8 llc_type:4,
  74                            llc_version:4;
  75                 };
  76 #endif
  77         };
  78 } __aligned(1);
  79
  80 struct smc_cdc_conn_state_flags {
  81 #if defined(__BIG_ENDIAN_BITFIELD)
  82         u8      peer_done_writing : 1;  /* Sending done indicator */
  83         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  84         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  85         u8      reserved : 5;
  86 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  87         u8      reserved : 5;
  88         u8      peer_conn_abort : 1;
  89         u8      peer_conn_closed : 1;
  90         u8      peer_done_writing : 1;
  91 #endif
  92 };
  93
  94 struct smc_cdc_producer_flags {
  95 #if defined(__BIG_ENDIAN_BITFIELD)
  96         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  97         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  98         u8      urg_data_present : 1;   /* Urgent Data Present */
  99         u8      cons_curs_upd_req : 1;  /* cursor update requested */
 100         u8      failover_validation : 1;/* message replay due to failover */
 101         u8      reserved : 3;
 102 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 103         u8      reserved : 3;
 104         u8      failover_validation : 1;
 105         u8      cons_curs_upd_req : 1;
 106         u8      urg_data_present : 1;
 107         u8      urg_data_pending : 1;
 108         u8      write_blocked : 1;
 109 #endif
 110 };
 111
 112 /* in host byte order */
 113 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
 114         struct {
 115                 u16     reserved;
 116                 u16     wrap;           /* window wrap sequence number */
 117                 u32     count;          /* cursor (= offset) part */
 118         };
 119 #ifdef KERNEL_HAS_ATOMIC64
 120         atomic64_t              acurs;  /* for atomic processing */
 121 #else
 122         u64                     acurs;  /* for atomic processing */
 123 #endif
 124 } __aligned(8);
 125
 126 /* in host byte order, except for flag bitfields in network byte order */
 127 struct smc_host_cdc_msg {               /* Connection Data Control message */
 128         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 129         u8                              len;    /* length = 44 */
 130         u16                             seqno;  /* connection seq # */
 131         u32                             token;  /* alert_token */
 132         union smc_host_cursor           prod;           /* producer cursor */
 133         union smc_host_cursor           cons;           /* consumer cursor,
 134                                                          * piggy backed "ack"
 135                                                          */
 136         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 137         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 138         u8                              reserved[18];
 139 } __aligned(8);
 140
 141 enum smc_urg_state {
 142         SMC_URG_VALID   = 1,                    /* data present */
 143         SMC_URG_NOTYET  = 2,                    /* data pending */
 144         SMC_URG_READ    = 3,                    /* data was already read */
 145 };
 146
 147 struct smc_mark_woken {
 148         bool woken;
 149         void *key;
 150         wait_queue_entry_t wait_entry;
 151 };
 152
 153 struct smc_connection {
 154         struct rb_node          alert_node;
 155         struct smc_link_group   *lgr;           /* link group of connection */
 156         struct smc_link         *lnk;           /* assigned SMC-R link */
 157         u32                     alert_token_local; /* unique conn. id */
 158         u8                      peer_rmbe_idx;  /* from tcp handshake */
 159         int                     peer_rmbe_size; /* size of peer rx buffer */
 160         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 161                                                  * rmbe
 162                                                  */
 163         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 164
 165         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 166         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 167         int                     rmbe_size_comp; /* compressed notation */
 168         int                     rmbe_update_limit;
 169                                                 /* lower limit for consumer
 170                                                  * cursor update
 171                                                  */
 172
 173         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 174                                                  * buffer for CDC msg send
 175                                                  * .prod cf. TCP snd_nxt
 176                                                  * .cons cf. TCP sends ack
 177                                                  */
 178         union smc_host_cursor   local_tx_ctrl_fin;
 179                                                 /* prod crsr - confirmed by peer
 180                                                  */
 181         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 182                                                  * snd_max..wmem_alloc
 183                                                  */
 184         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 185                                                  * snd_nxt ?
 186                                                  */
 187         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 188                                                  * snd-wnd-begin ?
 189                                                  */
 190         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 191         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 192         u16                     tx_cdc_seq_fin; /* sequence # - tx completed */
 193         spinlock_t              send_lock;      /* protect wr_sends */
 194         atomic_t                cdc_pend_tx_wr; /* number of pending tx CDC wqe
 195                                                  * - inc when post wqe,
 196                                                  * - dec on polled tx cqe
 197                                                  */
 198         wait_queue_head_t       cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
 199         atomic_t                tx_pushing;     /* nr_threads trying tx push */
 200         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 201         u32                     tx_off;         /* base offset in peer rmb */
 202
 203         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 204                                                  * .prod cf. TCP rcv_nxt
 205                                                  * .cons cf. TCP snd_una
 206                                                  */
 207         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 208                                                     * source of snd_una ?
 209                                                     */
 210         union smc_host_cursor   urg_curs;       /* points at urgent byte */
 211         enum smc_urg_state      urg_state;
 212         bool                    urg_tx_pend;    /* urgent data staged */
 213         bool                    urg_rx_skip_pend;
 214                                                 /* indicate urgent oob data
 215                                                  * read, but previous regular
 216                                                  * data still pending
 217                                                  */
 218         char                    urg_rx_byte;    /* urgent byte */
 219         bool                    tx_in_release_sock;
 220                                                 /* flush pending tx data in
 221                                                  * sock release_cb()
 222                                                  */
 223         atomic_t                bytes_to_rcv;   /* arrived data,
 224                                                  * not yet received
 225                                                  */
 226         atomic_t                splice_pending; /* number of spliced bytes
 227                                                  * pending processing
 228                                                  */
 229 #ifndef KERNEL_HAS_ATOMIC64
 230         spinlock_t              acurs_lock;     /* protect cursors */
 231 #endif
 232         struct work_struct      close_work;     /* peer sent some closing */
 233         struct work_struct      abort_work;     /* abort the connection */
 234         struct tasklet_struct   rx_tsklet;      /* Receiver tasklet for SMC-D */
 235         u8                      rx_off;         /* receive offset:
 236                                                  * 0 for SMC-R, 32 for SMC-D
 237                                                  */
 238         u64                     peer_token;     /* SMC-D token of peer */
 239         u8                      killed : 1;     /* abnormal termination */
 240         u8                      freed : 1;      /* normal termiation */
 241         u8                      out_of_sync : 1; /* out of sync with peer */
 242 };
 243
 244 struct smc_sock {                               /* smc sock container */
 245         struct sock             sk;
 246         struct socket           *clcsock;       /* internal tcp socket */
 247         void                    (*clcsk_state_change)(struct sock *sk);
 248                                                 /* original stat_change fct. */
 249         void                    (*clcsk_data_ready)(struct sock *sk);
 250                                                 /* original data_ready fct. */
 251         void                    (*clcsk_write_space)(struct sock *sk);
 252                                                 /* original write_space fct. */
 253         void                    (*clcsk_error_report)(struct sock *sk);
 254                                                 /* original error_report fct. */
 255         struct smc_connection   conn;           /* smc connection */
 256         struct smc_sock         *listen_smc;    /* listen parent */
 257         struct work_struct      connect_work;   /* handle non-blocking connect*/
 258         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 259         struct work_struct      smc_listen_work;/* prepare new accept socket */
 260         struct list_head        accept_q;       /* sockets to be accepted */
 261         spinlock_t              accept_q_lock;  /* protects accept_q */
 262         bool                    limit_smc_hs;   /* put constraint on handshake */
 263         bool                    use_fallback;   /* fallback to tcp */
 264         int                     fallback_rsn;   /* reason for fallback */
 265         u32                     peer_diagnosis; /* decline reason from peer */
 266         atomic_t                queued_smc_hs;  /* queued smc handshakes */
 267         struct inet_connection_sock_af_ops              af_ops;
 268         const struct inet_connection_sock_af_ops        *ori_af_ops;
 269                                                 /* original af ops */
 270         int                     sockopt_defer_accept;
 271                                                 /* sockopt TCP_DEFER_ACCEPT
 272                                                  * value
 273                                                  */
 274         u8                      wait_close_tx_prepared : 1;
 275                                                 /* shutdown wr or close
 276                                                  * started, waiting for unsent
 277                                                  * data to be sent
 278                                                  */
 279         u8                      connect_nonblock : 1;
 280                                                 /* non-blocking connect in
 281                                                  * flight
 282                                                  */
 283         struct mutex            clcsock_release_lock;
 284                                                 /* protects clcsock of a listen
 285                                                  * socket
 286                                                  * */
 287 };
 288
 289 #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
 290
 291 static inline void smc_init_saved_callbacks(struct smc_sock *smc)
 292 {
 293         smc->clcsk_state_change = NULL;
 294         smc->clcsk_data_ready   = NULL;
 295         smc->clcsk_write_space  = NULL;
 296         smc->clcsk_error_report = NULL;
 297 }
 298
 299 static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
 300 {
 301         return (struct smc_sock *)
 302                ((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
 303 }
 304
 305 /* save target_cb in saved_cb, and replace target_cb with new_cb */
 306 static inline void smc_clcsock_replace_cb(void (**target_cb)(struct sock *),
 307                                           void (*new_cb)(struct sock *),
 308                                           void (**saved_cb)(struct sock *))
 309 {
 310         /* only save once */
 311         if (!*saved_cb)
 312                 *saved_cb = *target_cb;
 313         *target_cb = new_cb;
 314 }
 315
 316 /* restore target_cb to saved_cb, and reset saved_cb to NULL */
 317 static inline void smc_clcsock_restore_cb(void (**target_cb)(struct sock *),
 318                                           void (**saved_cb)(struct sock *))
 319 {
 320         if (!*saved_cb)
 321                 return;
 322         *target_cb = *saved_cb;
 323         *saved_cb = NULL;
 324 }
 325
 326 extern struct workqueue_struct  *smc_hs_wq;     /* wq for handshake work */
 327 extern struct workqueue_struct  *smc_close_wq;  /* wq for close work */
 328
 329 #define SMC_SYSTEMID_LEN                8
 330
 331 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 332
 333 #define ntohll(x) be64_to_cpu(x)
 334 #define htonll(x) cpu_to_be64(x)
 335
 336 /* convert an u32 value into network byte order, store it into a 3 byte field */
 337 static inline void hton24(u8 *net, u32 host)
 338 {
 339         __be32 t;
 340
 341         t = cpu_to_be32(host);
 342         memcpy(net, ((u8 *)&t) + 1, 3);
 343 }
 344
 345 /* convert a received 3 byte field into host byte order*/
 346 static inline u32 ntoh24(u8 *net)
 347 {
 348         __be32 t = 0;
 349
 350         memcpy(((u8 *)&t) + 1, net, 3);
 351         return be32_to_cpu(t);
 352 }
 353
 354 #ifdef CONFIG_XFRM
 355 static inline bool using_ipsec(struct smc_sock *smc)
 356 {
 357         return (smc->clcsock->sk->sk_policy[0] ||
 358                 smc->clcsock->sk->sk_policy[1]) ? true : false;
 359 }
 360 #else
 361 static inline bool using_ipsec(struct smc_sock *smc)
 362 {
 363         return false;
 364 }
 365 #endif
 366
 367 struct smc_gidlist;
 368
 369 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 370 void smc_close_non_accepted(struct sock *sk);
 371 void smc_fill_gid_list(struct smc_link_group *lgr,
 372                        struct smc_gidlist *gidlist,
 373                        struct smc_ib_device *known_dev, u8 *known_gid);
 374
 375 /* smc handshake limitation interface for netlink  */
 376 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb);
 377 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 378 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
 379
 380 #endif  /* __SMC_H */