xref: /linux/net/smc/smc_wr.h (revision af1fd391a5118449aecda26792e40f9e8ab24123)
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 */
107