ceph/src/spdk/dpdk/examples/netmap_compat/netmap/netmap_user.h

   1 /*
   2  * Copyright (C) 2011 Matteo Landi, Luigi Rizzo. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *   1. Redistributions of source code must retain the above copyright
   9  *      notice, this list of conditions and the following disclaimer.
  10  *
  11  *   2. Redistributions in binary form must reproduce the above copyright
  12  *      notice, this list of conditions and the following disclaimer in the
  13  *      documentation and/or other materials provided with the
  14  *      distribution.
  15  *
  16  *   3. Neither the name of the authors nor the names of their contributors
  17  *      may be used to endorse or promote products derived from this
  18  *      software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY MATTEO LANDI AND CONTRIBUTORS "AS IS" AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  23  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTEO LANDI OR CONTRIBUTORS
  24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  30  * THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * $FreeBSD: head/sys/net/netmap_user.h 231198 2012-02-08 11:43:29Z luigi $
  35  * $Id: netmap_user.h 10879 2012-04-12 22:48:59Z luigi $
  36  *
  37  * This header contains the macros used to manipulate netmap structures
  38  * and packets in userspace. See netmap(4) for more information.
  39  *
  40  * The address of the struct netmap_if, say nifp, is computed from the
  41  * value returned from ioctl(.., NIOCREG, ...) and the mmap region:
  42  *      ioctl(fd, NIOCREG, &req);
  43  *      mem = mmap(0, ... );
  44  *      nifp = NETMAP_IF(mem, req.nr_nifp);
  45  *              (so simple, we could just do it manually)
  46  *
  47  * From there:
  48  *      struct netmap_ring *NETMAP_TXRING(nifp, index)
  49  *      struct netmap_ring *NETMAP_RXRING(nifp, index)
  50  *              we can access ring->nr_cur, ring->nr_avail, ring->nr_flags
  51  *
  52  *      ring->slot[i] gives us the i-th slot (we can access
  53  *              directly plen, flags, bufindex)
  54  *
  55  *      char *buf = NETMAP_BUF(ring, index) returns a pointer to
  56  *              the i-th buffer
  57  *
  58  * Since rings are circular, we have macros to compute the next index
  59  *      i = NETMAP_RING_NEXT(ring, i);
  60  */
  61
  62 #ifndef _NET_NETMAP_USER_H_
  63 #define _NET_NETMAP_USER_H_
  64
  65 #define NETMAP_IF(b, o) (struct netmap_if *)((char *)(b) + (o))
  66
  67 #define NETMAP_TXRING(nifp, index)                      \
  68         ((struct netmap_ring *)((char *)(nifp) +        \
  69                 (nifp)->ring_ofs[index] ) )
  70
  71 #define NETMAP_RXRING(nifp, index)                      \
  72         ((struct netmap_ring *)((char *)(nifp) +        \
  73             (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 1] ) )
  74
  75 #define NETMAP_BUF(ring, index)                         \
  76         ((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size))
  77
  78 #define NETMAP_BUF_IDX(ring, buf)                       \
  79         ( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \
  80                 (ring)->nr_buf_size )
  81
  82 #define NETMAP_RING_NEXT(r, i)                          \
  83         ((i)+1 == (r)->num_slots ? 0 : (i) + 1 )
  84
  85 #define NETMAP_RING_FIRST_RESERVED(r)                   \
  86         ( (r)->cur < (r)->reserved ?                    \
  87           (r)->cur + (r)->num_slots - (r)->reserved :   \
  88           (r)->cur - (r)->reserved )
  89
  90 /*
  91  * Return 1 if the given tx ring is empty.
  92  */
  93 #define NETMAP_TX_RING_EMPTY(r) ((r)->avail >= (r)->num_slots - 1)
  94
  95 #endif /* _NET_NETMAP_USER_H_ */