/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2016 HGST, a Western Digital Company.
 */
#ifndef _RDMA_RW_H
#define _RDMA_RW_H

#include <linux/bvec.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <rdma/mr_pool.h>

struct rdma_rw_ctx {
        /* number of RDMA READ/WRITE WRs (not counting MR WRs) */
        u32                     nr_ops;

        /* tag for the union below: */
        u8                      type;

        union {
                /* for mapping a single SGE: */
                struct {
                        struct ib_sge           sge;
                        struct ib_rdma_wr       wr;
                } single;

                /* for mapping of multiple SGEs: */
                struct {
                        struct ib_sge           *sges;
                        struct ib_rdma_wr       *wrs;
                } map;

                /* for IOVA-based mapping of bvecs into contiguous DMA range: */
                struct {
                        struct dma_iova_state   state;
                        struct ib_sge           sge;
                        struct ib_rdma_wr       wr;
                        size_t                  mapped_len;
                } iova;

                /* for registering multiple WRs: */
                struct rdma_rw_reg_ctx {
                        struct ib_sge           sge;
                        struct ib_rdma_wr       wr;
                        struct ib_reg_wr        reg_wr;
                        struct ib_send_wr       inv_wr;
                        struct ib_mr            *mr;
                        struct sg_table         sgt;
                } *reg;
        };
};

int rdma_rw_ctx_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u32 port_num,
                struct scatterlist *sg, u32 sg_cnt, u32 sg_offset,
                u64 remote_addr, u32 rkey, enum dma_data_direction dir);
void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                         u32 port_num, struct scatterlist *sg, u32 sg_cnt,
                         enum dma_data_direction dir);

struct bio_vec;

int rdma_rw_ctx_init_bvec(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u32 port_num, const struct bio_vec *bvecs, u32 nr_bvec,
                struct bvec_iter iter, u64 remote_addr, u32 rkey,
                enum dma_data_direction dir);
void rdma_rw_ctx_destroy_bvec(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u32 port_num, const struct bio_vec *bvecs, u32 nr_bvec,
                enum dma_data_direction dir);

int rdma_rw_ctx_signature_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u32 port_num, struct scatterlist *sg, u32 sg_cnt,
                struct scatterlist *prot_sg, u32 prot_sg_cnt,
                struct ib_sig_attrs *sig_attrs, u64 remote_addr, u32 rkey,
                enum dma_data_direction dir);
void rdma_rw_ctx_destroy_signature(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u32 port_num, struct scatterlist *sg, u32 sg_cnt,
                struct scatterlist *prot_sg, u32 prot_sg_cnt,
                enum dma_data_direction dir);

struct ib_send_wr *rdma_rw_ctx_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u32 port_num, struct ib_cqe *cqe, struct ib_send_wr *chain_wr);
int rdma_rw_ctx_post(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u32 port_num,
                struct ib_cqe *cqe, struct ib_send_wr *chain_wr);

unsigned int rdma_rw_mr_factor(struct ib_device *device, u32 port_num,
                unsigned int maxpages);
unsigned int rdma_rw_max_send_wr(struct ib_device *dev, u32 port_num,
                unsigned int max_rdma_ctxs, u32 create_flags);
void rdma_rw_init_qp(struct ib_device *dev, struct ib_qp_init_attr *attr);
int rdma_rw_init_mrs(struct ib_qp *qp, struct ib_qp_init_attr *attr);
void rdma_rw_cleanup_mrs(struct ib_qp *qp);

#endif /* _RDMA_RW_H */