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 */