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
 63/* post a new receive work request to fill a completed old work request entry */
 64static 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
 79int smc_wr_create_link(struct smc_link *lnk);
 80int smc_wr_alloc_link_mem(struct smc_link *lnk);
 81void smc_wr_free_link(struct smc_link *lnk);
 82void smc_wr_free_link_mem(struct smc_link *lnk);
 83void smc_wr_remember_qp_attr(struct smc_link *lnk);
 84void smc_wr_remove_dev(struct smc_ib_device *smcibdev);
 85void smc_wr_add_dev(struct smc_ib_device *smcibdev);
 86
 87int 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);
 90int smc_wr_tx_put_slot(struct smc_link *link,
 91		       struct smc_wr_tx_pend_priv *wr_pend_priv);
 92int smc_wr_tx_send(struct smc_link *link,
 93		   struct smc_wr_tx_pend_priv *wr_pend_priv);
 94void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
 95void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type,
 96			     smc_wr_tx_filter filter,
 97			     smc_wr_tx_dismisser dismisser,
 98			     unsigned long data);
 99
100int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
101int smc_wr_rx_post_init(struct smc_link *link);
102void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
103int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr);
104
105#endif /* SMC_WR_H */