net/smc/smc_wr.h

   1 /*
   2  * Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  * Work Requests exploiting Infiniband API
   5  *
   6  * Copyright IBM Corp. 2016
   7  *
   8  * Author(s):  Steffen Maier <maier@linux.vnet.ibm.com>
   9  */
  10
  11 #ifndef SMC_WR_H
  12 #define SMC_WR_H
  13
  14 #include <linux/atomic.h>
  15 #include <rdma/ib_verbs.h>
  16 #include <asm/div64.h>
  17
  18 #include "smc.h"
  19 #include "smc_core.h"
  20
  21 #define SMC_WR_MAX_CQE 32768    /* max. # of completion queue elements */
  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
  31 struct smc_wr_tx_pend_priv {
  32         u8                      priv[SMC_WR_TX_PEND_PRIV_SIZE];
  33 };
  34
  35 typedef void (*smc_wr_tx_handler)(struct smc_wr_tx_pend_priv *,
  36                                   struct smc_link *,
  37                                   enum ib_wc_status);
  38
  39 typedef bool (*smc_wr_tx_filter)(struct smc_wr_tx_pend_priv *,
  40                                  unsigned long);
  41
  42 typedef void (*smc_wr_tx_dismisser)(struct smc_wr_tx_pend_priv *);
  43
  44 struct 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  */
  53 static 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
  58 static 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
  63 /* post a new receive work request to fill a completed old work request entry */
  64 static inline int smc_wr_rx_post(struct smc_link *link)
  65 {
  66         struct ib_recv_wr *bad_recv_wr = NULL;
  67         int rc;
  68         u64 wr_id, temp_wr_id;
  69         u32 index;
  70
  71         wr_id = ++link->wr_rx_id; /* tasklet context, thus not atomic */
  72         temp_wr_id = wr_id;
  73         index = do_div(temp_wr_id, link->wr_rx_cnt);
  74         link->wr_rx_ibs[index].wr_id = wr_id;
  75         rc = ib_post_recv(link->roce_qp, &link->wr_rx_ibs[index], &bad_recv_wr);
  76         return rc;
  77 }
  78
  79 int smc_wr_create_link(struct smc_link *lnk);
  80 int smc_wr_alloc_link_mem(struct smc_link *lnk);
  81 void smc_wr_free_link(struct smc_link *lnk);
  82 void smc_wr_free_link_mem(struct smc_link *lnk);
  83 void smc_wr_remember_qp_attr(struct smc_link *lnk);
  84 void smc_wr_remove_dev(struct smc_ib_device *smcibdev);
  85 void smc_wr_add_dev(struct smc_ib_device *smcibdev);
  86
  87 int smc_wr_tx_get_free_slot(struct smc_link *link, smc_wr_tx_handler handler,
  88                             struct smc_wr_buf **wr_buf,
  89                             struct smc_wr_tx_pend_priv **wr_pend_priv);
  90 int smc_wr_tx_put_slot(struct smc_link *link,
  91                        struct smc_wr_tx_pend_priv *wr_pend_priv);
  92 int smc_wr_tx_send(struct smc_link *link,
  93                    struct smc_wr_tx_pend_priv *wr_pend_priv);
  94 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
  95 bool smc_wr_tx_has_pending(struct smc_link *link, u8 wr_rx_hdr_type,
  96                            smc_wr_tx_filter filter, unsigned long data);
  97 void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type,
  98                              smc_wr_tx_filter filter,
  99                              smc_wr_tx_dismisser dismisser,
 100                              unsigned long data);
 101
 102 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
 103 int smc_wr_rx_post_init(struct smc_link *link);
 104 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
 105
 106 #endif /* SMC_WR_H */