xref: /openbmc/linux/net/smc/smc_wr.h (revision e2c75e76)
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_MAX_CQE 32768	/* max. # of completion queue elements */
23 #define SMC_WR_BUF_CNT 16	/* # of ctrl buffers per link */
24 
25 #define SMC_WR_TX_WAIT_FREE_SLOT_TIME	(10 * HZ)
26 #define SMC_WR_TX_WAIT_PENDING_TIME	(5 * HZ)
27 
28 #define SMC_WR_TX_SIZE 44 /* actual size of wr_send data (<=SMC_WR_BUF_SIZE) */
29 
30 #define SMC_WR_TX_PEND_PRIV_SIZE 32
31 
32 struct smc_wr_tx_pend_priv {
33 	u8			priv[SMC_WR_TX_PEND_PRIV_SIZE];
34 };
35 
36 typedef void (*smc_wr_tx_handler)(struct smc_wr_tx_pend_priv *,
37 				  struct smc_link *,
38 				  enum ib_wc_status);
39 
40 typedef bool (*smc_wr_tx_filter)(struct smc_wr_tx_pend_priv *,
41 				 unsigned long);
42 
43 typedef void (*smc_wr_tx_dismisser)(struct smc_wr_tx_pend_priv *);
44 
45 struct smc_wr_rx_handler {
46 	struct hlist_node	list;	/* hash table collision resolution */
47 	void			(*handler)(struct ib_wc *, void *);
48 	u8			type;
49 };
50 
51 /* Only used by RDMA write WRs.
52  * All other WRs (CDC/LLC) use smc_wr_tx_send handling WR_ID implicitly
53  */
54 static inline long smc_wr_tx_get_next_wr_id(struct smc_link *link)
55 {
56 	return atomic_long_inc_return(&link->wr_tx_id);
57 }
58 
59 static inline void smc_wr_tx_set_wr_id(atomic_long_t *wr_tx_id, long val)
60 {
61 	atomic_long_set(wr_tx_id, val);
62 }
63 
64 /* post a new receive work request to fill a completed old work request entry */
65 static inline int smc_wr_rx_post(struct smc_link *link)
66 {
67 	struct ib_recv_wr *bad_recv_wr = NULL;
68 	int rc;
69 	u64 wr_id, temp_wr_id;
70 	u32 index;
71 
72 	wr_id = ++link->wr_rx_id; /* tasklet context, thus not atomic */
73 	temp_wr_id = wr_id;
74 	index = do_div(temp_wr_id, link->wr_rx_cnt);
75 	link->wr_rx_ibs[index].wr_id = wr_id;
76 	rc = ib_post_recv(link->roce_qp, &link->wr_rx_ibs[index], &bad_recv_wr);
77 	return rc;
78 }
79 
80 int smc_wr_create_link(struct smc_link *lnk);
81 int smc_wr_alloc_link_mem(struct smc_link *lnk);
82 void smc_wr_free_link(struct smc_link *lnk);
83 void smc_wr_free_link_mem(struct smc_link *lnk);
84 void smc_wr_remember_qp_attr(struct smc_link *lnk);
85 void smc_wr_remove_dev(struct smc_ib_device *smcibdev);
86 void smc_wr_add_dev(struct smc_ib_device *smcibdev);
87 
88 int smc_wr_tx_get_free_slot(struct smc_link *link, smc_wr_tx_handler handler,
89 			    struct smc_wr_buf **wr_buf,
90 			    struct smc_wr_tx_pend_priv **wr_pend_priv);
91 int smc_wr_tx_put_slot(struct smc_link *link,
92 		       struct smc_wr_tx_pend_priv *wr_pend_priv);
93 int smc_wr_tx_send(struct smc_link *link,
94 		   struct smc_wr_tx_pend_priv *wr_pend_priv);
95 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
96 void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type,
97 			     smc_wr_tx_filter filter,
98 			     smc_wr_tx_dismisser dismisser,
99 			     unsigned long data);
100 
101 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler);
102 int smc_wr_rx_post_init(struct smc_link *link);
103 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context);
104 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr);
105 
106 #endif /* SMC_WR_H */
107