src/dev/pktfifo.hh

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Nathan Binkert
  29  */
  30
  31 #ifndef __DEV_PKTFIFO_HH__
  32 #define __DEV_PKTFIFO_HH__
  33
  34 #include <iosfwd>
  35 #include <list>
  36 #include <string>
  37
  38 #include "dev/etherpkt.hh"
  39 #include "sim/serialize.hh"
  40
  41 class Checkpoint;
  42
  43 struct PacketFifoEntry
  44 {
  45     EthPacketPtr packet;
  46     uint64_t number;
  47     int slack;
  48     int priv;
  49
  50     PacketFifoEntry()
  51     {
  52         clear();
  53     }
  54
  55     PacketFifoEntry(const PacketFifoEntry &s)
  56         : packet(s.packet), number(s.number), slack(s.slack), priv(s.priv)
  57     {
  58     }
  59
  60     PacketFifoEntry(EthPacketPtr p, uint64_t n)
  61         : packet(p), number(n), slack(0), priv(-1)
  62     {
  63     }
  64
  65     void clear()
  66     {
  67         packet = NULL;
  68         number = 0;
  69         slack = 0;
  70         priv = -1;
  71     }
  72
  73     void serialize(const std::string &base, std::ostream &os);
  74     void unserialize(const std::string &base, Checkpoint *cp,
  75                      const std::string &section);
  76 };
  77
  78 class PacketFifo
  79 {
  80   public:
  81
  82     typedef std::list<PacketFifoEntry> fifo_list;
  83     typedef fifo_list::iterator iterator;
  84
  85   protected:
  86     std::list<PacketFifoEntry> fifo;
  87     uint64_t _counter;
  88     int _maxsize;
  89     int _size;
  90     int _reserved;
  91
  92   public:
  93     explicit PacketFifo(int max)
  94         : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
  95     virtual ~PacketFifo() {}
  96
  97     int packets() const { return fifo.size(); }
  98     int maxsize() const { return _maxsize; }
  99     int size() const { return _size; }
 100     int reserved() const { return _reserved; }
 101     int avail() const { return _maxsize - _size - _reserved; }
 102     bool empty() const { return size() <= 0; }
 103     bool full() const { return avail() <= 0; }
 104
 105     int reserve(int len = 0)
 106     {
 107         _reserved += len;
 108         assert(avail() >= 0);
 109         return _reserved;
 110     }
 111
 112     iterator begin() { return fifo.begin(); }
 113     iterator end() { return fifo.end(); }
 114
 115     EthPacketPtr front() { return fifo.begin()->packet; }
 116
 117     bool push(EthPacketPtr ptr)
 118     {
 119         assert(ptr->length);
 120         assert(_reserved <= ptr->length);
 121         if (avail() < ptr->length - _reserved)
 122             return false;
 123
 124         _size += ptr->length;
 125
 126         PacketFifoEntry entry;
 127         entry.packet = ptr;
 128         entry.number = _counter++;
 129         fifo.push_back(entry);
 130         _reserved = 0;
 131         return true;
 132     }
 133
 134     void pop()
 135     {
 136         if (empty())
 137             return;
 138
 139         iterator entry = fifo.begin();
 140         _size -= entry->packet->length;
 141         _size -= entry->slack;
 142         entry->packet = NULL;
 143         fifo.pop_front();
 144     }
 145
 146     void clear()
 147     {
 148         for (iterator i = begin(); i != end(); ++i)
 149             i->clear();
 150         fifo.clear();
 151         _size = 0;
 152         _reserved = 0;
 153     }
 154
 155     void remove(iterator i)
 156     {
 157         if (i != fifo.begin()) {
 158             iterator prev = i;
 159             --prev;
 160             assert(prev != fifo.end());
 161             prev->slack += i->packet->length;
 162             prev->slack += i->slack;
 163         } else {
 164             _size -= i->packet->length;
 165             _size -= i->slack;
 166         }
 167
 168         i->clear();
 169         fifo.erase(i);
 170     }
 171
 172     bool copyout(void *dest, int offset, int len);
 173
 174     int countPacketsBefore(iterator i)
 175     {
 176         if (i == fifo.end())
 177             return 0;
 178         return i->number - fifo.begin()->number;
 179     }
 180
 181     int countPacketsAfter(iterator i)
 182     {
 183         iterator end = fifo.end();
 184         if (i == end)
 185             return 0;
 186         return (--end)->number - i->number;
 187     }
 188
 189     void check()
 190     {
 191         int total = 0;
 192         for (iterator i = begin(); i != end(); ++i)
 193             total += i->packet->length + i->slack;
 194
 195         if (total != _size)
 196             panic("total (%d) is not == to size (%d)\n", total, _size);
 197     }
 198
 199 /**
 200  * Serialization stuff
 201  */
 202   public:
 203     void serialize(const std::string &base, std::ostream &os);
 204     void unserialize(const std::string &base,
 205                      Checkpoint *cp, const std::string &section);
 206 };
 207
 208 #endif // __DEV_PKTFIFO_HH__