rpc_rdma.h

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/*
 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the BSD-type
 * license below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *      Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 *      Neither the name of the Network Appliance, Inc. nor the names of
 *      its contributors may be used to endorse or promote products
 *      derived from this software without specific prior written
 *      permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#ifndef _LINUX_SUNRPC_RPC_RDMA_H
#define _LINUX_SUNRPC_RPC_RDMA_H

#include <linux/types.h>

struct rpcrdma_segment {
    __be32 rs_handle;   /* Registered memory handle */
    __be32 rs_length;   /* Length of the chunk in bytes */
    __be64 rs_offset;   /* Chunk virtual address or offset */
};

/*
 * read chunk(s), encoded as a linked list.
 */
struct rpcrdma_read_chunk {
    __be32 rc_discrim;  /* 1 indicates presence */
    __be32 rc_position; /* Position in XDR stream */
    struct rpcrdma_segment rc_target;
};

/*
 * write chunk, and reply chunk.
 */
struct rpcrdma_write_chunk {
    struct rpcrdma_segment wc_target;
};

/*
 * write chunk(s), encoded as a counted array.
 */
struct rpcrdma_write_array {
    __be32 wc_discrim;  /* 1 indicates presence */
    __be32 wc_nchunks;  /* Array count */
    struct rpcrdma_write_chunk wc_array[0];
};

struct rpcrdma_msg {
    __be32 rm_xid;  /* Mirrors the RPC header xid */
    __be32 rm_vers; /* Version of this protocol */
    __be32 rm_credit;   /* Buffers requested/granted */
    __be32 rm_type; /* Type of message (enum rpcrdma_proc) */
    union {

        struct {            /* no chunks */
            __be32 rm_empty[3]; /* 3 empty chunk lists */
        } rm_nochunks;

        struct {            /* no chunks and padded */
            __be32 rm_align;    /* Padding alignment */
            __be32 rm_thresh;   /* Padding threshold */
            __be32 rm_pempty[3];    /* 3 empty chunk lists */
        } rm_padded;

        __be32 rm_chunks[0];    /* read, write and reply chunks */

    } rm_body;
};

#define RPCRDMA_HDRLEN_MIN  28

enum rpcrdma_errcode {
    ERR_VERS = 1,
    ERR_CHUNK = 2
};

struct rpcrdma_err_vers {
    uint32_t rdma_vers_low; /* Version range supported by peer */
    uint32_t rdma_vers_high;
};

enum rpcrdma_proc {
    RDMA_MSG = 0,       /* An RPC call or reply msg */
    RDMA_NOMSG = 1,     /* An RPC call or reply msg - separate body */
    RDMA_MSGP = 2,      /* An RPC call or reply msg with padding */
    RDMA_DONE = 3,      /* Client signals reply completion */
    RDMA_ERROR = 4      /* An RPC RDMA encoding error */
};

#endif              /* _LINUX_SUNRPC_RPC_RDMA_H */