/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2009 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
 * Copyright (c) 2009      Cisco Systems, Inc.  All rights reserved.
 * Copyright (c) 2011-2015 Los Alamos National Security, LLC. All rights
 *                         reserved.
 * Copyright (c) 2019      Google, Inc. All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#ifndef MCA_BTL_VADER_SEND_FRAG_H
#define MCA_BTL_VADER_SEND_FRAG_H

#include "opal_config.h"

enum {
    MCA_BTL_VADER_FLAG_INLINE      = 0,
    MCA_BTL_VADER_FLAG_SINGLE_COPY = 1,
    MCA_BTL_VADER_FLAG_COMPLETE    = 2,
    MCA_BTL_VADER_FLAG_SETUP_FBOX  = 4,
};

struct mca_btl_vader_frag_t;
struct mca_btl_vader_fbox_t;

enum mca_btl_vader_sc_emu_type_t {
    MCA_BTL_VADER_OP_PUT,
    MCA_BTL_VADER_OP_GET,
    MCA_BTL_VADER_OP_ATOMIC,
    MCA_BTL_VADER_OP_CSWAP,
};
typedef enum mca_btl_vader_sc_emu_type_t mca_btl_vader_sc_emu_type_t;

struct mca_btl_vader_sc_emu_hdr_t {
    mca_btl_vader_sc_emu_type_t type;
    uint64_t addr;
    mca_btl_base_atomic_op_t op;
    int flags;
    int64_t operand[2];
};
typedef struct mca_btl_vader_sc_emu_hdr_t mca_btl_vader_sc_emu_hdr_t;

/**
 * FIFO fragment header
 */
struct mca_btl_vader_hdr_t {
    /** next item in fifo. many peers may touch this */
    volatile intptr_t next;
    /** pointer back the the fragment */
    struct mca_btl_vader_frag_t *frag;
    /** tag associated with this fragment (used to lookup callback) */
    mca_btl_base_tag_t tag;
    /** vader send flags (inline, complete, setup fbox, etc) */
    uint8_t flags;
    /** length of data following this header */
    int32_t len;
    /** io vector containing pointer to single-copy data */
    struct iovec sc_iov;
    /** if the fragment indicates to setup a fast box the base is stored here */
    intptr_t fbox_base;
};
typedef struct mca_btl_vader_hdr_t mca_btl_vader_hdr_t;

/**
 * shared memory send fragment derived type.
 */
struct mca_btl_vader_frag_t {
    /** base object */
    mca_btl_base_descriptor_t base;
    /** storage for segment data (max 2) */
    mca_btl_base_segment_t segments[2];
    /** endpoint this fragment is active on */
    struct mca_btl_base_endpoint_t *endpoint;
    /** fragment header (in the shared memory region) */
    mca_btl_vader_hdr_t *hdr;
    /** free list this fragment was allocated within */
    opal_free_list_t *my_list;
    /** rdma callback data */
    struct mca_btl_vader_rdma_cbdata_t {
        void *local_address;
        uint64_t remote_address;
        mca_btl_base_rdma_completion_fn_t cbfunc;
        void *context;
        void *cbdata;
        size_t remaining;
        size_t sent;
    } rdma;
};

typedef struct mca_btl_vader_frag_t mca_btl_vader_frag_t;

static inline int mca_btl_vader_frag_alloc (mca_btl_vader_frag_t **frag, opal_free_list_t *list,
                                            struct mca_btl_base_endpoint_t *endpoint) {
    *frag = (mca_btl_vader_frag_t *) opal_free_list_get (list);
    if (OPAL_LIKELY(NULL != *frag)) {
        (*frag)->endpoint = endpoint;
    }

    return OPAL_SUCCESS;
}

static inline void mca_btl_vader_frag_return (mca_btl_vader_frag_t *frag)
{
    if (frag->hdr) {
        frag->hdr->flags = 0;
    }

    frag->segments[0].seg_addr.pval = (char *)(frag->hdr + 1);
    frag->base.des_segment_count = 1;

    opal_free_list_return (frag->my_list, (opal_free_list_item_t *)frag);
}

OBJ_CLASS_DECLARATION(mca_btl_vader_frag_t);

#define MCA_BTL_VADER_FRAG_ALLOC_EAGER(frag, endpoint)                  \
    mca_btl_vader_frag_alloc (&(frag), &mca_btl_vader_component.vader_frags_eager, endpoint)

#define MCA_BTL_VADER_FRAG_ALLOC_MAX(frag, endpoint)                    \
    mca_btl_vader_frag_alloc (&(frag), &mca_btl_vader_component.vader_frags_max_send, endpoint)

#define MCA_BTL_VADER_FRAG_ALLOC_USER(frag, endpoint)                   \
    mca_btl_vader_frag_alloc (&(frag), &mca_btl_vader_component.vader_frags_user, endpoint)

#define MCA_BTL_VADER_FRAG_RETURN(frag) mca_btl_vader_frag_return(frag)


static inline void mca_btl_vader_frag_complete (mca_btl_vader_frag_t *frag) {
    /* save the descriptor flags since the callback is allowed to free the frag */
    int des_flags = frag->base.des_flags;

    if (OPAL_UNLIKELY(MCA_BTL_DES_SEND_ALWAYS_CALLBACK & des_flags)) {
        /* completion callback */
        frag->base.des_cbfunc (&mca_btl_vader.super, frag->endpoint, &frag->base, OPAL_SUCCESS);
    }

    if (OPAL_LIKELY(des_flags & MCA_BTL_DES_FLAGS_BTL_OWNERSHIP)) {
        MCA_BTL_VADER_FRAG_RETURN(frag);
    }
}

int mca_btl_vader_frag_init (opal_free_list_item_t *item, void *ctx);

static inline void mca_btl_vader_rdma_frag_advance (mca_btl_base_module_t *btl, mca_btl_base_endpoint_t *endpoint,
                                                    mca_btl_vader_frag_t *frag, int status)
{
    mca_btl_vader_sc_emu_hdr_t *hdr = (mca_btl_vader_sc_emu_hdr_t *) frag->segments[0].seg_addr.pval;
    mca_btl_base_rdma_completion_fn_t cbfunc = frag->rdma.cbfunc;
    size_t hdr_size = sizeof (*hdr);
    size_t len = frag->rdma.sent ? frag->segments[0].seg_len - hdr_size : 0;
    void *context = frag->rdma.context;
    void *cbdata = frag->rdma.cbdata;
    void *data = (void *) (hdr + 1);

    if (frag->rdma.sent) {
        if (MCA_BTL_VADER_OP_GET == hdr->type) {
            memcpy (frag->rdma.local_address, data, len);
        } else if ((MCA_BTL_VADER_OP_ATOMIC == hdr->type || MCA_BTL_VADER_OP_CSWAP == hdr->type) &&
                   frag->rdma.local_address) {
            if (8 == len) {
                *((int64_t *) frag->rdma.local_address) = hdr->operand[0];
            } else {
                *((int32_t *) frag->rdma.local_address) = (int32_t) hdr->operand[0];
            }
        }
    }

    if (frag->rdma.remaining) {
        size_t packet_size = (frag->rdma.remaining + hdr_size) <= mca_btl_vader.super.btl_max_send_size ?
            frag->rdma.remaining : mca_btl_vader.super.btl_max_send_size - hdr_size;

        /* advance the local and remote pointers */
        frag->rdma.local_address = (void *)((uintptr_t) frag->rdma.local_address + len);
        frag->rdma.remote_address += len;

        if (MCA_BTL_VADER_OP_PUT == hdr->type) {
            /* copy the next block into the fragment buffer */
            memcpy ((void *) (hdr + 1), frag->rdma.local_address, packet_size);
        }

        hdr->addr = frag->rdma.remote_address;
        /* clear out the complete flag before sending the fragment again */
        frag->hdr->flags &= ~MCA_BTL_VADER_FLAG_COMPLETE;
        frag->segments[0].seg_len = packet_size + sizeof (*hdr);
        frag->rdma.sent += packet_size;
        frag->rdma.remaining -= packet_size;

        /* send is always successful */
        (void) mca_btl_vader_send (btl, endpoint, &frag->base, MCA_BTL_TAG_VADER);
        return;
    }

    /* return the fragment before calling the callback */
    MCA_BTL_VADER_FRAG_RETURN(frag);
    cbfunc (btl, endpoint, (void *)((uintptr_t) frag->rdma.local_address - frag->rdma.sent), NULL,
            context, cbdata, status);
}

static inline int
mca_btl_vader_rdma_frag_start (mca_btl_base_module_t *btl, mca_btl_base_endpoint_t *endpoint, int type,
                               uint64_t operand1, uint64_t operand2, mca_btl_base_atomic_op_t op, int order,
                               int flags, size_t size, void *local_address, int64_t remote_address,
                               mca_btl_base_rdma_completion_fn_t cbfunc, void *cbcontext, void *cbdata)
{
    mca_btl_vader_sc_emu_hdr_t *hdr;
    size_t hdr_size = sizeof (*hdr);
    size_t packet_size = (size + hdr_size) <= mca_btl_vader.super.btl_max_send_size ? size :
        mca_btl_vader.super.btl_max_send_size - hdr_size;
    mca_btl_vader_frag_t *frag;

    frag = (mca_btl_vader_frag_t *) mca_btl_vader_alloc (btl, endpoint, order, packet_size + hdr_size,
                                                         MCA_BTL_DES_SEND_ALWAYS_CALLBACK);
    if (OPAL_UNLIKELY(NULL == frag)) {
        return OPAL_ERR_OUT_OF_RESOURCE;
    }

    frag->base.des_cbfunc = (mca_btl_base_completion_fn_t) mca_btl_vader_rdma_frag_advance;
    frag->rdma.local_address = local_address;
    frag->rdma.remote_address = remote_address;
    frag->rdma.cbfunc = cbfunc;
    frag->rdma.context = cbcontext;
    frag->rdma.cbdata = cbdata;
    frag->rdma.remaining = size;
    frag->rdma.sent = 0;

    hdr = (mca_btl_vader_sc_emu_hdr_t *) frag->segments[0].seg_addr.pval;

    hdr->type = type;
    hdr->addr = remote_address;
    hdr->op = op;
    hdr->flags = flags;
    hdr->operand[0] = operand1;
    hdr->operand[1] = operand2;

    mca_btl_vader_rdma_frag_advance (btl, endpoint, frag, OPAL_SUCCESS);
    return OPAL_SUCCESS;
}

#endif /* MCA_BTL_VADER_SEND_FRAG_H */