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
 26#define SMC_WR_TX_SIZE 44 /* actual size of wr_send data (<=SMC_WR_BUF_SIZE) */
 27
 28#define SMC_WR_TX_PEND_PRIV_SIZE 32
 29
 30struct smc_wr_tx_pend_priv {
 31	u8			priv[SMC_WR_TX_PEND_PRIV_SIZE];
 32};
 33
 34typedef void (*smc_wr_tx_handler)(struct smc_wr_tx_pend_priv *,
 35				  struct smc_link *,
 36				  enum ib_wc_status);
 37
 38typedef bool (*smc_wr_tx_filter)(struct smc_wr_tx_pend_priv *,
 39				 unsigned long);
 40
 41typedef void (*smc_wr_tx_dismisser)(struct smc_wr_tx_pend_priv *);
 42
 43struct smc_wr_rx_handler {
 44	struct hlist_node	list;	/* hash table collision resolution */
 45	void			(*handler)(struct ib_wc *, void *);
 46	u8			type;
 47};
 48
 49/* Only used by RDMA write WRs.
 50 * All other WRs (CDC/LLC) use smc_wr_tx_send handling WR_ID implicitly
 51 */
 52static inline long smc_wr_tx_get_next_wr_id(struct smc_link *link)
 53{
 54	return atomic_long_inc_return(&link->wr_tx_id);
 55}
 56
 57static inline void smc_wr_tx_set_wr_id(atomic_long_t *wr_tx_id, long val)
 58{
 59	atomic_long_set(wr_tx_id, val);
 60}
 61
 62static inline bool smc_wr_tx_link_hold(struct smc_link *link)
 63{
 64	if (!smc_link_sendable(link))
 65		return false;
 66	percpu_ref_get(&link->wr_tx_refs);
 67	return true;
 68}
 69
 70static inline void smc_wr_tx_link_put(struct smc_link *link)
 71{
 72	percpu_ref_put(&link->wr_tx_refs);
 73}
 74
 75static inline void smc_wr_drain_cq(struct smc_link *lnk)
 76{
 77	wait_event(lnk->wr_rx_empty_wait, lnk->wr_rx_id_compl == lnk->wr_rx_id);
 78}
 79
 80static inline void smc_wr_wakeup_tx_wait(struct smc_link *lnk)
 81{
 82	wake_up_all(&lnk->wr_tx_wait);
 83}
 84
 85static inline void smc_wr_wakeup_reg_wait(struct smc_link *lnk)
 86{
 87	wake_up(&lnk->wr_reg_wait);
 88}
 89
 90/* post a new receive work request to fill a completed old work request entry */
 91static inline int smc_wr_rx_post(struct smc_link *link)
 92{
 93	int rc;
 94	u64 wr_id, temp_wr_id;
 95	u32 index;
 96
 97	wr_id = ++link->wr_rx_id; /* tasklet context, thus not atomic */
 98	temp_wr_id = wr_id;
 99	index = do_div(temp_wr_id, link->wr_rx_cnt);
100	link->wr_rx_ibs[index].wr_id = wr_id;
101	rc = ib_post_recv(link->roce_qp, &link->wr_rx_ibs[index], NULL);
102	return rc;
103}
104
105int smc_wr_create_link(struct smc_link *lnk);
106int smc_wr_alloc_link_mem(struct smc_link *lnk);
107int smc_wr_alloc_lgr_mem(struct smc_link_group *lgr);
108void smc_wr_free_link(struct smc_link *lnk);
109void smc_wr_free_link_mem(struct smc_link *lnk);
110void smc_wr_free_lgr_mem(struct smc_link_group *lgr);
111void smc_wr_remember_qp_attr(struct smc_link *lnk);
112void smc_wr_remove_dev(struct smc_ib_device *smcibdev);
113void smc_wr_add_dev(struct smc_ib_device *smcibdev);
114
115int smc_wr_tx_get_free_slot(struct smc_link *link, smc_wr_tx_handler handler,
116			    struct smc_wr_buf **wr_buf,
117			    struct smc_rdma_wr **wrs,
118			    struct smc_wr_tx_pend_priv **wr_pend_priv);
119int smc_wr_tx_get_v2_slot(struct smc_link *link,
120			  smc_wr_tx_handler handler,
121			  struct smc_wr_v2_buf **wr_buf,
122			  struct smc_wr_tx_pend_priv **wr_pend_priv);
123int smc_wr_tx_put_slot(struct smc_link *link,
124		       struct smc_wr_tx_pend_priv *wr_pend_priv);
125int smc_wr_tx_send(struct smc_link *link,
126		   struct smc_wr_tx_pend_priv *wr_pend_priv);
127int smc_wr_tx_v2_send(struct smc_link *link,
128		      struct smc_wr_tx_pend_priv *priv, int len);
129int smc_wr_tx_send_wait(struct smc_link *link, struct smc_wr_tx_pend_priv *priv,
130			unsigned long timeout);
131void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
132void smc_wr_tx_wait_no_pending_sends(struct smc_link *link);
133
134int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
135int smc_wr_rx_post_init(struct smc_link *link);
136void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
137int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr);
138
139#endif /* SMC_WR_H */