net/smc/smc_core.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Definitions for SMC Connections, Link Groups and Links
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  10  */
  11
  12 #ifndef _SMC_CORE_H
  13 #define _SMC_CORE_H
  14
  15 #include <linux/atomic.h>
  16 #include <rdma/ib_verbs.h>
  17
  18 #include "smc.h"
  19 #include "smc_ib.h"
  20
  21 #define SMC_RMBS_PER_LGR_MAX    255     /* max. # of RMBs per link group */
  22
  23 struct smc_lgr_list {                   /* list of link group definition */
  24         struct list_head        list;
  25         spinlock_t              lock;   /* protects list of link groups */
  26 };
  27
  28 extern struct smc_lgr_list      smc_lgr_list; /* list of link groups */
  29
  30 enum smc_lgr_role {             /* possible roles of a link group */
  31         SMC_CLNT,       /* client */
  32         SMC_SERV        /* server */
  33 };
  34
  35 #define SMC_WR_BUF_SIZE         48      /* size of work request buffer */
  36
  37 struct smc_wr_buf {
  38         u8      raw[SMC_WR_BUF_SIZE];
  39 };
  40
  41 #define SMC_WR_REG_MR_WAIT_TIME (5 * HZ)/* wait time for ib_wr_reg_mr result */
  42
  43 enum smc_wr_reg_state {
  44         POSTED,         /* ib_wr_reg_mr request posted */
  45         CONFIRMED,      /* ib_wr_reg_mr response: successful */
  46         FAILED          /* ib_wr_reg_mr response: failure */
  47 };
  48
  49 struct smc_link {
  50         struct smc_ib_device    *smcibdev;      /* ib-device */
  51         u8                      ibport;         /* port - values 1 | 2 */
  52         struct ib_pd            *roce_pd;       /* IB protection domain,
  53                                                  * unique for every RoCE QP
  54                                                  */
  55         struct ib_qp            *roce_qp;       /* IB queue pair */
  56         struct ib_qp_attr       qp_attr;        /* IB queue pair attributes */
  57
  58         struct smc_wr_buf       *wr_tx_bufs;    /* WR send payload buffers */
  59         struct ib_send_wr       *wr_tx_ibs;     /* WR send meta data */
  60         struct ib_sge           *wr_tx_sges;    /* WR send gather meta data */
  61         struct smc_wr_tx_pend   *wr_tx_pends;   /* WR send waiting for CQE */
  62         /* above four vectors have wr_tx_cnt elements and use the same index */
  63         dma_addr_t              wr_tx_dma_addr; /* DMA address of wr_tx_bufs */
  64         atomic_long_t           wr_tx_id;       /* seq # of last sent WR */
  65         unsigned long           *wr_tx_mask;    /* bit mask of used indexes */
  66         u32                     wr_tx_cnt;      /* number of WR send buffers */
  67         wait_queue_head_t       wr_tx_wait;     /* wait for free WR send buf */
  68
  69         struct smc_wr_buf       *wr_rx_bufs;    /* WR recv payload buffers */
  70         struct ib_recv_wr       *wr_rx_ibs;     /* WR recv meta data */
  71         struct ib_sge           *wr_rx_sges;    /* WR recv scatter meta data */
  72         /* above three vectors have wr_rx_cnt elements and use the same index */
  73         dma_addr_t              wr_rx_dma_addr; /* DMA address of wr_rx_bufs */
  74         u64                     wr_rx_id;       /* seq # of last recv WR */
  75         u32                     wr_rx_cnt;      /* number of WR recv buffers */
  76
  77         struct ib_reg_wr        wr_reg;         /* WR register memory region */
  78         wait_queue_head_t       wr_reg_wait;    /* wait for wr_reg result */
  79         enum smc_wr_reg_state   wr_reg_state;   /* state of wr_reg request */
  80
  81         union ib_gid            gid;            /* gid matching used vlan id */
  82         u32                     peer_qpn;       /* QP number of peer */
  83         enum ib_mtu             path_mtu;       /* used mtu */
  84         enum ib_mtu             peer_mtu;       /* mtu size of peer */
  85         u32                     psn_initial;    /* QP tx initial packet seqno */
  86         u32                     peer_psn;       /* QP rx initial packet seqno */
  87         u8                      peer_mac[ETH_ALEN];     /* = gid[8:10||13:15] */
  88         u8                      peer_gid[sizeof(union ib_gid)]; /* gid of peer*/
  89         u8                      link_id;        /* unique # within link group */
  90         struct completion       llc_confirm;    /* wait for rx of conf link */
  91         struct completion       llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
  92 };
  93
  94 /* For now we just allow one parallel link per link group. The SMC protocol
  95  * allows more (up to 8).
  96  */
  97 #define SMC_LINKS_PER_LGR_MAX   1
  98 #define SMC_SINGLE_LINK         0
  99
 100 #define SMC_FIRST_CONTACT       1               /* first contact to a peer */
 101 #define SMC_REUSE_CONTACT       0               /* follow-on contact to a peer*/
 102
 103 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
 104 struct smc_buf_desc {
 105         struct list_head        list;
 106         void                    *cpu_addr;      /* virtual address of buffer */
 107         struct sg_table         sgt[SMC_LINKS_PER_LGR_MAX];/* virtual buffer */
 108         struct ib_mr            *mr_rx[SMC_LINKS_PER_LGR_MAX];
 109                                                 /* for rmb only: memory region
 110                                                  * incl. rkey provided to peer
 111                                                  */
 112         u32                     order;          /* allocation order */
 113         u32                     used;           /* currently used / unused */
 114         bool                    reused;         /* new created / reused */
 115 };
 116
 117 struct smc_rtoken {                             /* address/key of remote RMB */
 118         u64                     dma_addr;
 119         u32                     rkey;
 120 };
 121
 122 #define SMC_LGR_ID_SIZE         4
 123
 124 struct smc_link_group {
 125         struct list_head        list;
 126         enum smc_lgr_role       role;           /* client or server */
 127         __be32                  daddr;          /* destination ip address */
 128         struct smc_link         lnk[SMC_LINKS_PER_LGR_MAX];     /* smc link */
 129         char                    peer_systemid[SMC_SYSTEMID_LEN];
 130                                                 /* unique system_id of peer */
 131         struct rb_root          conns_all;      /* connection tree */
 132         rwlock_t                conns_lock;     /* protects conns_all */
 133         unsigned int            conns_num;      /* current # of connections */
 134         unsigned short          vlan_id;        /* vlan id of link group */
 135
 136         struct list_head        sndbufs[SMC_RMBE_SIZES];/* tx buffers */
 137         rwlock_t                sndbufs_lock;   /* protects tx buffers */
 138         struct list_head        rmbs[SMC_RMBE_SIZES];   /* rx buffers */
 139         rwlock_t                rmbs_lock;      /* protects rx buffers */
 140         struct smc_rtoken       rtokens[SMC_RMBS_PER_LGR_MAX]
 141                                        [SMC_LINKS_PER_LGR_MAX];
 142                                                 /* remote addr/key pairs */
 143         unsigned long           rtokens_used_mask[BITS_TO_LONGS(
 144                                                         SMC_RMBS_PER_LGR_MAX)];
 145                                                 /* used rtoken elements */
 146
 147         u8                      id[SMC_LGR_ID_SIZE];    /* unique lgr id */
 148         struct delayed_work     free_work;      /* delayed freeing of an lgr */
 149         bool                    sync_err;       /* lgr no longer fits to peer */
 150 };
 151
 152 /* Find the connection associated with the given alert token in the link group.
 153  * To use rbtrees we have to implement our own search core.
 154  * Requires @conns_lock
 155  * @token       alert token to search for
 156  * @lgr          link group to search in
 157  * Returns connection associated with token if found, NULL otherwise.
 158  */
 159 static inline struct smc_connection *smc_lgr_find_conn(
 160         u32 token, struct smc_link_group *lgr)
 161 {
 162         struct smc_connection *res = NULL;
 163         struct rb_node *node;
 164
 165         node = lgr->conns_all.rb_node;
 166         while (node) {
 167                 struct smc_connection *cur = rb_entry(node,
 168                                         struct smc_connection, alert_node);
 169
 170                 if (cur->alert_token_local > token) {
 171                         node = node->rb_left;
 172                 } else {
 173                         if (cur->alert_token_local < token) {
 174                                 node = node->rb_right;
 175                         } else {
 176                                 res = cur;
 177                                 break;
 178                         }
 179                 }
 180         }
 181
 182         return res;
 183 }
 184
 185 struct smc_sock;
 186 struct smc_clc_msg_accept_confirm;
 187
 188 void smc_lgr_free(struct smc_link_group *lgr);
 189 void smc_lgr_terminate(struct smc_link_group *lgr);
 190 int smc_buf_create(struct smc_sock *smc);
 191 int smc_rmb_rtoken_handling(struct smc_connection *conn,
 192                             struct smc_clc_msg_accept_confirm *clc);
 193 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
 194 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
 195 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
 196 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
 197 #endif