LXR linux/net/smc/smc

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
   4 *
   5 * Work Requests exploiting Infiniband API
   6 *
   7 * Copyright IBM Corp. 2016
   8 *
   9 * Author(s):  Steffen Maier <maier@linux.vnet.ibm.com>
  10 */
  11
  12#ifndef SMC_WR_H
  13#define SMC_WR_H
  14
  15#include <linux/atomic.h>
  16#include <rdma/ib_verbs.h>
  17#include <asm/div64.h>
  18
  19#include "smc.h"
  20#include "smc_core.h"
  21
  22#define SMC_WR_BUF_CNT 16       /* # of ctrl buffers per link */
  23
  24#define SMC_WR_TX_WAIT_FREE_SLOT_TIME   (10 * HZ)
  25#define SMC_WR_TX_WAIT_PENDING_TIME     (5 * HZ)
  26
  27#define SMC_WR_TX_SIZE 44 /* actual size of wr_send data (<=SMC_WR_BUF_SIZE) */
  28
  29#define SMC_WR_TX_PEND_PRIV_SIZE 32
  30
  31struct smc_wr_tx_pend_priv {
  32        u8                      priv[SMC_WR_TX_PEND_PRIV_SIZE];
  33};
  34
  35typedef void (*smc_wr_tx_handler)(struct smc_wr_tx_pend_priv *,
  36                                  struct smc_link *,
  37                                  enum ib_wc_status);
  38
  39typedef bool (*smc_wr_tx_filter)(struct smc_wr_tx_pend_priv *,
  40                                 unsigned long);
  41
  42typedef void (*smc_wr_tx_dismisser)(struct smc_wr_tx_pend_priv *);
  43
  44struct smc_wr_rx_handler {
  45        struct hlist_node       list;   /* hash table collision resolution */
  46        void                    (*handler)(struct ib_wc *, void *);
  47        u8                      type;
  48};
  49
  50/* Only used by RDMA write WRs.
  51 * All other WRs (CDC/LLC) use smc_wr_tx_send handling WR_ID implicitly
  52 */
  53static inline long smc_wr_tx_get_next_wr_id(struct smc_link *link)
  54{
  55        return atomic_long_inc_return(&link->wr_tx_id);
  56}
  57
  58static inline void smc_wr_tx_set_wr_id(atomic_long_t *wr_tx_id, long val)
  59{
  60        atomic_long_set(wr_tx_id, val);
  61}
  62
  63static inline bool smc_wr_tx_link_hold(struct smc_link *link)
  64{
  65        if (!smc_link_usable(link))
  66                return false;
  67        atomic_inc(&link->wr_tx_refcnt);
  68        return true;
  69}
  70
  71static inline void smc_wr_tx_link_put(struct smc_link *link)
  72{
  73        if (atomic_dec_and_test(&link->wr_tx_refcnt))
  74                wake_up_all(&link->wr_tx_wait);
  75}
  76
  77static inline void smc_wr_wakeup_tx_wait(struct smc_link *lnk)
  78{
  79        wake_up_all(&lnk->wr_tx_wait);
  80}
  81
  82static inline void smc_wr_wakeup_reg_wait(struct smc_link *lnk)
  83{
  84        wake_up(&lnk->wr_reg_wait);
  85}
  86
  87/* post a new receive work request to fill a completed old work request entry */
  88static inline int smc_wr_rx_post(struct smc_link *link)
  89{
  90        int rc;
  91        u64 wr_id, temp_wr_id;
  92        u32 index;
  93
  94        wr_id = ++link->wr_rx_id; /* tasklet context, thus not atomic */
  95        temp_wr_id = wr_id;
  96        index = do_div(temp_wr_id, link->wr_rx_cnt);
  97        link->wr_rx_ibs[index].wr_id = wr_id;
  98        rc = ib_post_recv(link->roce_qp, &link->wr_rx_ibs[index], NULL);
  99        return rc;
 100}
 101
 102int smc_wr_create_link(struct smc_link *lnk);
 103int smc_wr_alloc_link_mem(struct smc_link *lnk);
 104void smc_wr_free_link(struct smc_link *lnk);
 105void smc_wr_free_link_mem(struct smc_link *lnk);
 106void smc_wr_remember_qp_attr(struct smc_link *lnk);
 107void smc_wr_remove_dev(struct smc_ib_device *smcibdev);
 108void smc_wr_add_dev(struct smc_ib_device *smcibdev);
 109
 110int smc_wr_tx_get_free_slot(struct smc_link *link, smc_wr_tx_handler handler,
 111                            struct smc_wr_buf **wr_buf,
 112                            struct smc_rdma_wr **wrs,
 113                            struct smc_wr_tx_pend_priv **wr_pend_priv);
 114int smc_wr_tx_put_slot(struct smc_link *link,
 115                       struct smc_wr_tx_pend_priv *wr_pend_priv);
 116int smc_wr_tx_send(struct smc_link *link,
 117                   struct smc_wr_tx_pend_priv *wr_pend_priv);
 118int smc_wr_tx_send_wait(struct smc_link *link, struct smc_wr_tx_pend_priv *priv,
 119                        unsigned long timeout);
 120void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
 121void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type,
 122                             smc_wr_tx_filter filter,
 123                             smc_wr_tx_dismisser dismisser,
 124                             unsigned long data);
 125int smc_wr_tx_wait_no_pending_sends(struct smc_link *link);
 126
 127int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
 128int smc_wr_rx_post_init(struct smc_link *link);
 129void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
 130int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr);
 131
 132#endif /* SMC_WR_H */
 133