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 SMCPROTO_SMC            0       /* SMC protocol */
  22
  23 #define SMC_MAX_PORTS           2       /* Max # of ports */
  24
  25 extern struct proto smc_proto;
  26
  27 #ifdef ATOMIC64_INIT
  28 #define KERNEL_HAS_ATOMIC64
  29 #endif
  30
  31 enum smc_state {                /* possible states of an SMC socket */
  32         SMC_ACTIVE      = 1,
  33         SMC_INIT        = 2,
  34         SMC_CLOSED      = 7,
  35         SMC_LISTEN      = 10,
  36         /* normal close */
  37         SMC_PEERCLOSEWAIT1      = 20,
  38         SMC_PEERCLOSEWAIT2      = 21,
  39         SMC_APPFINCLOSEWAIT     = 24,
  40         SMC_APPCLOSEWAIT1       = 22,
  41         SMC_APPCLOSEWAIT2       = 23,
  42         SMC_PEERFINCLOSEWAIT    = 25,
  43         /* abnormal close */
  44         SMC_PEERABORTWAIT       = 26,
  45         SMC_PROCESSABORT        = 27,
  46 };
  47
  48 struct smc_link_group;
  49
  50 struct smc_wr_rx_hdr {  /* common prefix part of LLC and CDC to demultiplex */
  51         u8                      type;
  52 } __aligned(1);
  53
  54 struct smc_cdc_conn_state_flags {
  55 #if defined(__BIG_ENDIAN_BITFIELD)
  56         u8      peer_done_writing : 1;  /* Sending done indicator */
  57         u8      peer_conn_closed : 1;   /* Peer connection closed indicator */
  58         u8      peer_conn_abort : 1;    /* Abnormal close indicator */
  59         u8      reserved : 5;
  60 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  61         u8      reserved : 5;
  62         u8      peer_conn_abort : 1;
  63         u8      peer_conn_closed : 1;
  64         u8      peer_done_writing : 1;
  65 #endif
  66 };
  67
  68 struct smc_cdc_producer_flags {
  69 #if defined(__BIG_ENDIAN_BITFIELD)
  70         u8      write_blocked : 1;      /* Writing Blocked, no rx buf space */
  71         u8      urg_data_pending : 1;   /* Urgent Data Pending */
  72         u8      urg_data_present : 1;   /* Urgent Data Present */
  73         u8      cons_curs_upd_req : 1;  /* cursor update requested */
  74         u8      failover_validation : 1;/* message replay due to failover */
  75         u8      reserved : 3;
  76 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  77         u8      reserved : 3;
  78         u8      failover_validation : 1;
  79         u8      cons_curs_upd_req : 1;
  80         u8      urg_data_present : 1;
  81         u8      urg_data_pending : 1;
  82         u8      write_blocked : 1;
  83 #endif
  84 };
  85
  86 /* in host byte order */
  87 union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
  88         struct {
  89                 u16     reserved;
  90                 u16     wrap;           /* window wrap sequence number */
  91                 u32     count;          /* cursor (= offset) part */
  92         };
  93 #ifdef KERNEL_HAS_ATOMIC64
  94         atomic64_t              acurs;  /* for atomic processing */
  95 #else
  96         u64                     acurs;  /* for atomic processing */
  97 #endif
  98 } __aligned(8);
  99
 100 /* in host byte order, except for flag bitfields in network byte order */
 101 struct smc_host_cdc_msg {               /* Connection Data Control message */
 102         struct smc_wr_rx_hdr            common; /* .type = 0xFE */
 103         u8                              len;    /* length = 44 */
 104         u16                             seqno;  /* connection seq # */
 105         u32                             token;  /* alert_token */
 106         union smc_host_cursor           prod;           /* producer cursor */
 107         union smc_host_cursor           cons;           /* consumer cursor,
 108                                                          * piggy backed "ack"
 109                                                          */
 110         struct smc_cdc_producer_flags   prod_flags;     /* conn. tx/rx status */
 111         struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
 112         u8                              reserved[18];
 113 } __aligned(8);
 114
 115 struct smc_connection {
 116         struct rb_node          alert_node;
 117         struct smc_link_group   *lgr;           /* link group of connection */
 118         u32                     alert_token_local; /* unique conn. id */
 119         u8                      peer_conn_idx;  /* from tcp handshake */
 120         int                     peer_rmbe_size; /* size of peer rx buffer */
 121         atomic_t                peer_rmbe_space;/* remaining free bytes in peer
 122                                                  * rmbe
 123                                                  */
 124         int                     rtoken_idx;     /* idx to peer RMB rkey/addr */
 125
 126         struct smc_buf_desc     *sndbuf_desc;   /* send buffer descriptor */
 127         int                     sndbuf_size;    /* sndbuf size <== sock wmem */
 128         struct smc_buf_desc     *rmb_desc;      /* RMBE descriptor */
 129         int                     rmbe_size;      /* RMBE size <== sock rmem */
 130         int                     rmbe_size_short;/* compressed notation */
 131         int                     rmbe_update_limit;
 132                                                 /* lower limit for consumer
 133                                                  * cursor update
 134                                                  */
 135
 136         struct smc_host_cdc_msg local_tx_ctrl;  /* host byte order staging
 137                                                  * buffer for CDC msg send
 138                                                  * .prod cf. TCP snd_nxt
 139                                                  * .cons cf. TCP sends ack
 140                                                  */
 141         union smc_host_cursor   tx_curs_prep;   /* tx - prepared data
 142                                                  * snd_max..wmem_alloc
 143                                                  */
 144         union smc_host_cursor   tx_curs_sent;   /* tx - sent data
 145                                                  * snd_nxt ?
 146                                                  */
 147         union smc_host_cursor   tx_curs_fin;    /* tx - confirmed by peer
 148                                                  * snd-wnd-begin ?
 149                                                  */
 150         atomic_t                sndbuf_space;   /* remaining space in sndbuf */
 151         u16                     tx_cdc_seq;     /* sequence # for CDC send */
 152         spinlock_t              send_lock;      /* protect wr_sends */
 153         struct delayed_work     tx_work;        /* retry of smc_cdc_msg_send */
 154
 155         struct smc_host_cdc_msg local_rx_ctrl;  /* filled during event_handl.
 156                                                  * .prod cf. TCP rcv_nxt
 157                                                  * .cons cf. TCP snd_una
 158                                                  */
 159         union smc_host_cursor   rx_curs_confirmed; /* confirmed to peer
 160                                                     * source of snd_una ?
 161                                                     */
 162         atomic_t                bytes_to_rcv;   /* arrived data,
 163                                                  * not yet received
 164                                                  */
 165 #ifndef KERNEL_HAS_ATOMIC64
 166         spinlock_t              acurs_lock;     /* protect cursors */
 167 #endif
 168         struct work_struct      close_work;     /* peer sent some closing */
 169 };
 170
 171 struct smc_sock {                               /* smc sock container */
 172         struct sock             sk;
 173         struct socket           *clcsock;       /* internal tcp socket */
 174         struct smc_connection   conn;           /* smc connection */
 175         struct sockaddr         *addr;          /* inet connect address */
 176         struct smc_sock         *listen_smc;    /* listen parent */
 177         struct work_struct      tcp_listen_work;/* handle tcp socket accepts */
 178         struct work_struct      smc_listen_work;/* prepare new accept socket */
 179         struct list_head        accept_q;       /* sockets to be accepted */
 180         spinlock_t              accept_q_lock;  /* protects accept_q */
 181         struct delayed_work     sock_put_work;  /* final socket freeing */
 182         bool                    use_fallback;   /* fallback to tcp */
 183         u8                      wait_close_tx_prepared : 1;
 184                                                 /* shutdown wr or close
 185                                                  * started, waiting for unsent
 186                                                  * data to be sent
 187                                                  */
 188 };
 189
 190 static inline struct smc_sock *smc_sk(const struct sock *sk)
 191 {
 192         return (struct smc_sock *)sk;
 193 }
 194
 195 #define SMC_SYSTEMID_LEN                8
 196
 197 extern u8       local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
 198
 199 /* convert an u32 value into network byte order, store it into a 3 byte field */
 200 static inline void hton24(u8 *net, u32 host)
 201 {
 202         __be32 t;
 203
 204         t = cpu_to_be32(host);
 205         memcpy(net, ((u8 *)&t) + 1, 3);
 206 }
 207
 208 /* convert a received 3 byte field into host byte order*/
 209 static inline u32 ntoh24(u8 *net)
 210 {
 211         __be32 t = 0;
 212
 213         memcpy(((u8 *)&t) + 1, net, 3);
 214         return be32_to_cpu(t);
 215 }
 216
 217 #define SMC_BUF_MIN_SIZE 16384          /* minimum size of an RMB */
 218
 219 #define SMC_RMBE_SIZES  16      /* number of distinct sizes for an RMBE */
 220 /* theoretically, the RFC states that largest size would be 512K,
 221  * i.e. compressed 5 and thus 6 sizes (0..5), despite
 222  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
 223  */
 224
 225 /* convert the RMB size into the compressed notation - minimum 16K.
 226  * In contrast to plain ilog2, this rounds towards the next power of 2,
 227  * so the socket application gets at least its desired sndbuf / rcvbuf size.
 228  */
 229 static inline u8 smc_compress_bufsize(int size)
 230 {
 231         u8 compressed;
 232
 233         if (size <= SMC_BUF_MIN_SIZE)
 234                 return 0;
 235
 236         size = (size - 1) >> 14;
 237         compressed = ilog2(size) + 1;
 238         if (compressed >= SMC_RMBE_SIZES)
 239                 compressed = SMC_RMBE_SIZES - 1;
 240         return compressed;
 241 }
 242
 243 /* convert the RMB size from compressed notation into integer */
 244 static inline int smc_uncompress_bufsize(u8 compressed)
 245 {
 246         u32 size;
 247
 248         size = 0x00000001 << (((int)compressed) + 14);
 249         return (int)size;
 250 }
 251
 252 #ifdef CONFIG_XFRM
 253 static inline bool using_ipsec(struct smc_sock *smc)
 254 {
 255         return (smc->clcsock->sk->sk_policy[0] ||
 256                 smc->clcsock->sk->sk_policy[1]) ? 1 : 0;
 257 }
 258 #else
 259 static inline bool using_ipsec(struct smc_sock *smc)
 260 {
 261         return 0;
 262 }
 263 #endif
 264
 265 struct smc_clc_msg_local;
 266
 267 int smc_netinfo_by_tcpsk(struct socket *clcsock, __be32 *subnet,
 268                          u8 *prefix_len);
 269 void smc_conn_free(struct smc_connection *conn);
 270 int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr,
 271                     struct smc_ib_device *smcibdev, u8 ibport,
 272                     struct smc_clc_msg_local *lcl, int srv_first_contact);
 273 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
 274 void smc_close_non_accepted(struct sock *sk);
 275
 276 #endif  /* __SMC_H */