LXR linux/drivers/infiniband/hw/hfi1/opfn.h

   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
  58enum hfi1_opfn_codes {
  59        STL_VERBS_EXTD_NONE = 0,
  60        STL_VERBS_EXTD_TID_RDMA,
  61        STL_VERBS_EXTD_MAX
  62};
  63
  64struct 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
  77void opfn_send_conn_request(struct work_struct *work);
  78void opfn_conn_response(struct rvt_qp *qp, struct rvt_ack_entry *e,
  79                        struct ib_atomic_eth *ateth);
  80void opfn_conn_reply(struct rvt_qp *qp, u64 data);
  81void opfn_conn_error(struct rvt_qp *qp);
  82void opfn_qp_init(struct rvt_qp *qp, struct ib_qp_attr *attr, int attr_mask);
  83void opfn_trigger_conn_request(struct rvt_qp *qp, u32 bth1);
  84int opfn_init(void);
  85void opfn_exit(void);
  86
  87#endif /* _HFI1_OPFN_H */
  88