packet.cc revision 4022 
1/*
2 * Copyright (c) 2006 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: Ali Saidi
29 *          Steve Reinhardt
30 */
31
32/**
33 * @file
34 * Definition of the Packet Class, a packet is a transaction occuring
35 * between a single level of the memory heirarchy (ie L1->L2).
36 */
37
38#include <iostream>
39#include <cstring>
40#include "base/misc.hh"
41#include "base/trace.hh"
42#include "mem/packet.hh"
43
44// The one downside to bitsets is that static initializers can get ugly.
45#define SET1(a1)                     (1 << (a1))
46#define SET2(a1, a2)                 (SET1(a1) | SET1(a2))
47#define SET3(a1, a2, a3)             (SET2(a1, a2) | SET1(a3))
48#define SET4(a1, a2, a3, a4)         (SET3(a1, a2, a3) | SET1(a4))
49#define SET5(a1, a2, a3, a4, a5)     (SET4(a1, a2, a3, a4) | SET1(a5))
50#define SET6(a1, a2, a3, a4, a5, a6) (SET5(a1, a2, a3, a4, a5) | SET1(a6))
51
52const MemCmd::CommandInfo
53MemCmd::commandInfo[] =
54{
55    /* InvalidCmd */
56    { 0, InvalidCmd, "InvalidCmd" },
57    /* ReadReq */
58    { SET3(IsRead, IsRequest, NeedsResponse), ReadResp, "ReadReq" },
59    /* WriteReq */
60    { SET4(IsWrite, IsRequest, NeedsResponse, HasData),
61            WriteResp, "WriteReq" },
62    /* WriteReqNoAck */
63    { SET3(IsWrite, IsRequest, HasData), InvalidCmd, "WriteReqNoAck" },
64    /* ReadResp */
65    { SET3(IsRead, IsResponse, HasData), InvalidCmd, "ReadResp" },
66    /* WriteResp */
67    { SET2(IsWrite, IsResponse), InvalidCmd, "WriteResp" },
68    /* Writeback */
69    { SET3(IsWrite, IsRequest, HasData), InvalidCmd, "Writeback" },
70    /* SoftPFReq */
71    { SET4(IsRead, IsRequest, IsSWPrefetch, NeedsResponse),
72            SoftPFResp, "SoftPFReq" },
73    /* HardPFReq */
74    { SET4(IsRead, IsRequest, IsHWPrefetch, NeedsResponse),
75            HardPFResp, "HardPFReq" },
76    /* SoftPFResp */
77    { SET4(IsRead, IsResponse, IsSWPrefetch, HasData),
78            InvalidCmd, "SoftPFResp" },
79    /* HardPFResp */
80    { SET4(IsRead, IsResponse, IsHWPrefetch, HasData),
81            InvalidCmd, "HardPFResp" },
82    /* InvalidateReq */
83    { SET2(IsInvalidate, IsRequest), InvalidCmd, "InvalidateReq" },
84    /* WriteInvalidateReq */
85    { SET5(IsWrite, IsInvalidate, IsRequest, HasData, NeedsResponse),
86            WriteInvalidateResp, "WriteInvalidateReq" },
87    /* WriteInvalidateResp */
88    { SET5(IsWrite, IsInvalidate, IsRequest, NeedsResponse, IsResponse),
89            InvalidCmd, "WriteInvalidateResp" },
90    /* UpgradeReq */
91    { SET3(IsInvalidate, IsRequest, IsUpgrade), InvalidCmd, "UpgradeReq" },
92    /* ReadExReq */
93    { SET4(IsRead, IsInvalidate, IsRequest, NeedsResponse),
94            ReadExResp, "ReadExReq" },
95    /* ReadExResp */
96    { SET4(IsRead, IsInvalidate, IsResponse, HasData),
97            InvalidCmd, "ReadExResp" }
98};
99
100
101/** delete the data pointed to in the data pointer. Ok to call to matter how
102 * data was allocted. */
103void
104Packet::deleteData()
105{
106    assert(staticData || dynamicData);
107    if (staticData)
108        return;
109
110    if (arrayData)
111        delete [] data;
112    else
113        delete data;
114}
115
116/** If there isn't data in the packet, allocate some. */
117void
118Packet::allocate()
119{
120    if (data)
121        return;
122    assert(!staticData);
123    dynamicData = true;
124    arrayData = true;
125    data = new uint8_t[getSize()];
126}
127
128/** Do the packet modify the same addresses. */
129bool
130Packet::intersect(PacketPtr p)
131{
132    Addr s1 = getAddr();
133    Addr e1 = getAddr() + getSize() - 1;
134    Addr s2 = p->getAddr();
135    Addr e2 = p->getAddr() + p->getSize() - 1;
136
137    return !(s1 > e2 || e1 < s2);
138}
139
140bool
141fixDelayedResponsePacket(PacketPtr func, PacketPtr timing)
142{
143    bool result;
144
145    if (timing->isRead() || timing->isWrite()) {
146        // Ugly hack to deal with the fact that we queue the requests
147        // and don't convert them to responses until we issue them on
148        // the bus.  I tried to avoid this by converting packets to
149        // responses right away, but this breaks during snoops where a
150        // responder may do the conversion before other caches have
151        // done the snoop.  Would work if we copied the packet instead
152        // of just hanging on to a pointer.
153        MemCmd oldCmd = timing->cmd;
154        timing->cmd = timing->cmd.responseCommand();
155        result = fixPacket(func, timing);
156        timing->cmd = oldCmd;
157    }
158    else {
159        //Don't toggle if it isn't a read/write response
160        result = fixPacket(func, timing);
161    }
162
163    return result;
164}
165
166bool
167fixPacket(PacketPtr func, PacketPtr timing)
168{
169    Addr funcStart      = func->getAddr();
170    Addr funcEnd        = func->getAddr() + func->getSize() - 1;
171    Addr timingStart    = timing->getAddr();
172    Addr timingEnd      = timing->getAddr() + timing->getSize() - 1;
173
174    assert(!(funcStart > timingEnd || timingStart > funcEnd));
175
176    // this packet can't solve our problem, continue on
177    if (!timing->hasData())
178        return true;
179
180    if (func->isRead()) {
181        if (funcStart >= timingStart && funcEnd <= timingEnd) {
182            func->allocate();
183            std::memcpy(func->getPtr<uint8_t>(), timing->getPtr<uint8_t>() +
184                    funcStart - timingStart, func->getSize());
185            func->result = Packet::Success;
186            func->flags |= SATISFIED;
187            return false;
188        } else {
189            // In this case the timing packet only partially satisfies the
190            // requset, so we would need more information to make this work.
191            // Like bytes valid in the packet or something, so the request could
192            // continue and get this bit of possibly newer data along with the
193            // older data not written to yet.
194            panic("Timing packet only partially satisfies the functional"
195                    "request. Now what?");
196        }
197    } else if (func->isWrite()) {
198        if (funcStart >= timingStart) {
199            std::memcpy(timing->getPtr<uint8_t>() + (funcStart - timingStart),
200                   func->getPtr<uint8_t>(),
201                   (std::min(funcEnd, timingEnd) - funcStart) + 1);
202        } else { // timingStart > funcStart
203            std::memcpy(timing->getPtr<uint8_t>(),
204                   func->getPtr<uint8_t>() + (timingStart - funcStart),
205                   (std::min(funcEnd, timingEnd) - timingStart) + 1);
206        }
207        // we always want to keep going with a write
208        return true;
209    } else
210        panic("Don't know how to handle command type %#x\n",
211                func->cmdToIndex());
212
213}
214
215
216std::ostream &
217operator<<(std::ostream &o, const Packet &p)
218{
219
220    o << "[0x";
221    o.setf(std::ios_base::hex, std::ios_base::showbase);
222    o <<  p.getAddr();
223    o.unsetf(std::ios_base::hex| std::ios_base::showbase);
224    o <<  ":";
225    o.setf(std::ios_base::hex, std::ios_base::showbase);
226    o <<  p.getAddr() + p.getSize() - 1 << "] ";
227    o.unsetf(std::ios_base::hex| std::ios_base::showbase);
228
229    if (p.result == Packet::Success)
230        o << "Successful ";
231    if (p.result == Packet::BadAddress)
232        o << "BadAddress ";
233    if (p.result == Packet::Nacked)
234        o << "Nacked ";
235    if (p.result == Packet::Unknown)
236        o << "Inflight ";
237
238    if (p.isRead())
239        o << "Read ";
240    if (p.isWrite())
241        o << "Read ";
242    if (p.isInvalidate())
243        o << "Read ";
244    if (p.isRequest())
245        o << "Request ";
246    if (p.isResponse())
247        o << "Response ";
248    if (p.hasData())
249        o << "w/Data ";
250
251    o << std::endl;
252    return o;
253}
254
255