1 /* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
2 /*
3 * Copyright(c) 2018 Intel Corporation.
4 *
5 */
6 #ifndef _HFI1_OPFN_H
7 #define _HFI1_OPFN_H
8
9 /**
10 * DOC: Omni Path Feature Negotion (OPFN)
11 *
12 * OPFN is a discovery protocol for Intel Omni-Path fabric that
13 * allows two RC QPs to negotiate a common feature that both QPs
14 * can support. Currently, the only OPA feature that OPFN
15 * supports is TID RDMA.
16 *
17 * Architecture
18 *
19 * OPFN involves the communication between two QPs on the HFI
20 * level on an Omni-Path fabric, and ULPs have no knowledge of
21 * OPFN at all.
22 *
23 * Implementation
24 *
25 * OPFN extends the existing IB RC protocol with the following
26 * changes:
27 * -- Uses Bit 24 (reserved) of DWORD 1 of Base Transport
28 * Header (BTH1) to indicate that the RC QP supports OPFN;
29 * -- Uses a combination of RC COMPARE_SWAP opcode (0x13) and
30 * the address U64_MAX (0xFFFFFFFFFFFFFFFF) as an OPFN
31 * request; The 64-bit data carried with the request/response
32 * contains the parameters for negotiation and will be
33 * defined in tid_rdma.c file;
34 * -- Defines IB_WR_RESERVED3 as IB_WR_OPFN.
35 *
36 * The OPFN communication will be triggered when an RC QP
37 * receives a request with Bit 24 of BTH1 set. The responder QP
38 * will then post send an OPFN request with its local
39 * parameters, which will be sent to the requester QP once all
40 * existing requests on the responder QP side have been sent.
41 * Once the requester QP receives the OPFN request, it will
42 * keep a copy of the responder QP's parameters, and return a
43 * response packet with its own local parameters. The responder
44 * QP receives the response packet and keeps a copy of the requester
45 * QP's parameters. After this exchange, each side has the parameters
46 * for both sides and therefore can select the right parameters
47 * for future transactions
48 */
49
50 #include <linux/workqueue.h>
51 #include <rdma/ib_verbs.h>
52 #include <rdma/rdmavt_qp.h>
53
54 /* STL Verbs Extended */
55 #define IB_BTHE_E_SHIFT 24
56 #define HFI1_VERBS_E_ATOMIC_VADDR U64_MAX
57
58 enum hfi1_opfn_codes {
59 STL_VERBS_EXTD_NONE = 0,
60 STL_VERBS_EXTD_TID_RDMA,
61 STL_VERBS_EXTD_MAX
62 };
63
64 struct hfi1_opfn_data {
65 u8 extended;
66 u16 requested;
67 u16 completed;
68 enum hfi1_opfn_codes curr;
69 /* serialize opfn function calls */
70 spinlock_t lock;
71 struct work_struct opfn_work;
72 };
73
74 /* WR opcode for OPFN */
75 #define IB_WR_OPFN IB_WR_RESERVED3
76
77 void opfn_send_conn_request(struct work_struct *work);
78 void opfn_conn_response(struct rvt_qp *qp, struct rvt_ack_entry *e,
79 struct ib_atomic_eth *ateth);
80 void opfn_conn_reply(struct rvt_qp *qp, u64 data);
81 void opfn_conn_error(struct rvt_qp *qp);
82 void opfn_qp_init(struct rvt_qp *qp, struct ib_qp_attr *attr, int attr_mask);
83 void opfn_trigger_conn_request(struct rvt_qp *qp, u32 bth1);
84 int opfn_init(void);
85 void opfn_exit(void);
86
87 #endif /* _HFI1_OPFN_H */