mt.hh revision 6383 
1/*
2 * Copyright (c) 2007 MIPS Technologies, Inc.
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: Korey Sewell
29 */
30
31#ifndef __ARCH_MIPS_MT_HH__
32#define __ARCH_MIPS_MT_HH__
33
34/**
35 * @file
36 *
37 * ISA-specific helper functions for multithreaded execution.
38 */
39
40#include "arch/mips/faults.hh"
41#include "arch/mips/isa_traits.hh"
42#include "arch/mips/mt_constants.hh"
43#include "arch/mips/pra_constants.hh"
44#include "arch/mips/registers.hh"
45#include "base/bitfield.hh"
46#include "base/trace.hh"
47#include "base/misc.hh"
48
49#include <iostream>
50
51namespace MipsISA
52{
53
54template <class TC>
55inline unsigned
56getVirtProcNum(TC *tc)
57{
58    TCBindReg tcbind = tc->readMiscRegNoEffect(MISCREG_TC_BIND);
59    return tcbind.curVPE;
60}
61
62template <class TC>
63inline unsigned
64getTargetThread(TC *tc)
65{
66    VPEControlReg vpeCtrl = tc->readMiscRegNoEffect(MISCREG_VPE_CONTROL);
67    return vpeCtrl.targTC;
68}
69
70template <class TC>
71inline void
72haltThread(TC *tc)
73{
74    if (tc->status() == TC::Active) {
75        tc->halt();
76
77        // Save last known PC in TCRestart
78        // @TODO: Needs to check if this is a branch and if so,
79        // take previous instruction
80        tc->setMiscReg(MISCREG_TC_RESTART, tc->readNextPC());
81
82        warn("%i: Halting thread %i in %s @ PC %x, setting restart PC to %x",
83                curTick, tc->threadId(), tc->getCpuPtr()->name(),
84                tc->readPC(), tc->readNextPC());
85    }
86}
87
88template <class TC>
89inline void
90restoreThread(TC *tc)
91{
92    if (tc->status() != TC::Active) {
93        // Restore PC from TCRestart
94        IntReg pc = tc->readMiscRegNoEffect(MISCREG_TC_RESTART);
95
96        // TODO: SET PC WITH AN EVENT INSTEAD OF INSTANTANEOUSLY
97        tc->setPC(pc);
98        tc->setNextPC(pc + 4);
99        tc->setNextNPC(pc + 8);
100        tc->activate(0);
101
102        warn("%i: Restoring thread %i in %s @ PC %x",
103                curTick, tc->threadId(), tc->getCpuPtr()->name(),
104                tc->readPC());
105    }
106}
107
108template <class TC>
109void
110forkThread(TC *tc, Fault &fault, int Rd_bits, int Rs, int Rt)
111{
112    MVPConf0Reg mvpConf = tc->readMiscRegNoEffect(MISCREG_MVP_CONF0);
113    int num_threads = mvpConf.ptc + 1;
114
115    int success = 0;
116    for (ThreadID tid = 0; tid < num_threads && success == 0; tid++) {
117        TCBindReg tidTCBind =
118            tc->readRegOtherThread(MISCREG_TC_BIND + Ctrl_Base_DepTag, tid);
119        TCBindReg tcBind = tc->readMiscRegNoEffect(MISCREG_TC_BIND);
120
121        if (tidTCBind.curVPE = tcBind.curVPE) {
122
123            TCStatusReg tidTCStatus =
124                tc->readRegOtherThread(MISCREG_TC_STATUS +
125                                       Ctrl_Base_DepTag,tid);
126
127            TCHaltReg tidTCHalt =
128                tc->readRegOtherThread(MISCREG_TC_HALT + Ctrl_Base_DepTag,tid);
129
130            if (tidTCStatus.da == 1 && tidTCHalt.h == 0 &&
131                tidTCStatus.a == 0 && success == 0) {
132
133                tc->setRegOtherThread(MISCREG_TC_RESTART +
134                                      Ctrl_Base_DepTag, Rs, tid);
135                tc->setRegOtherThread(Rd_bits, Rt, tid);
136
137                StatusReg status = tc->readMiscReg(MISCREG_STATUS);
138                TCStatusReg tcStatus = tc->readMiscReg(MISCREG_TC_STATUS);
139
140                // Set Run-State to Running
141                tidTCStatus.rnst = 0;
142                // Set Delay-Slot to 0
143                tidTCStatus.tds = 0;
144                // Set Dirty TC to 1
145                tidTCStatus.dt = 1;
146                // Set Activated to 1
147                tidTCStatus.a = 1;
148                // Set status to previous thread's status
149                tidTCStatus.tksu = status.ksu;
150                // Set ASID to previous thread's state
151                tidTCStatus.asid = tcStatus.asid;
152
153                // Write Status Register
154                tc->setRegOtherThread(MISCREG_TC_STATUS + Ctrl_Base_DepTag,
155                                      tidTCStatus, tid);
156
157                // Mark As Successful Fork
158                success = 1;
159            }
160        } else {
161            std::cerr << "Bad VPEs" << std::endl;
162        }
163    }
164
165    if (success == 0) {
166        VPEControlReg vpeControl =
167            tc->readMiscRegNoEffect(MISCREG_VPE_CONTROL);
168        vpeControl.excpt = 1;
169        tc->setMiscReg(MISCREG_VPE_CONTROL, vpeControl);
170        fault = new ThreadFault();
171    }
172}
173
174
175template <class TC>
176int
177yieldThread(TC *tc, Fault &fault, int src_reg, uint32_t yield_mask)
178{
179    if (src_reg == 0) {
180        MVPConf0Reg mvpConf0 = tc->readMiscRegNoEffect(MISCREG_MVP_CONF0);
181        ThreadID num_threads = mvpConf0.ptc + 1;
182
183        int ok = 0;
184
185        // Get Current VPE & TC numbers from calling thread
186        TCBindReg tcBind = tc->readMiscRegNoEffect(MISCREG_TC_BIND);
187
188        for (ThreadID tid = 0; tid < num_threads; tid++) {
189            TCStatusReg tidTCStatus =
190                tc->readRegOtherThread(MISCREG_TC_STATUS + Ctrl_Base_DepTag,
191                                       tid);
192            TCHaltReg tidTCHalt =
193                tc->readRegOtherThread(MISCREG_TC_HALT + Ctrl_Base_DepTag,
194                                       tid);
195            TCBindReg tidTCBind =
196                tc->readRegOtherThread(MISCREG_TC_BIND + Ctrl_Base_DepTag,
197                                       tid);
198
199            if (tidTCBind.curVPE == tcBind.curVPE &&
200                tidTCBind.curTC == tcBind.curTC &&
201                tidTCStatus.da == 1 &&
202                tidTCHalt.h == 0    &&
203                tidTCStatus.a == 1) {
204                ok = 1;
205            }
206        }
207
208        if (ok == 1) {
209            TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
210            tcStatus.a = 0;
211            tc->setMiscReg(MISCREG_TC_STATUS, tcStatus);
212            warn("%i: Deactivating Hardware Thread Context #%i",
213                    curTick, tc->threadId());
214        }
215    } else if (src_reg > 0) {
216        if (src_reg && !yield_mask != 0) {
217            VPEControlReg vpeControl = tc->readMiscReg(MISCREG_VPE_CONTROL);
218            vpeControl.excpt = 2;
219            tc->setMiscReg(MISCREG_VPE_CONTROL, vpeControl);
220            fault = new ThreadFault();
221        } else {
222        }
223    } else if (src_reg != -2) {
224        TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
225        VPEControlReg vpeControl =
226            tc->readMiscRegNoEffect(MISCREG_VPE_CONTROL);
227
228        if (vpeControl.ysi == 1 && tcStatus.dt == 1 ) {
229            vpeControl.excpt = 4;
230            fault = new ThreadFault();
231        } else {
232        }
233    }
234
235    return src_reg & yield_mask;
236}
237
238
239// TC will usually be a object derived from ThreadContext
240// (src/cpu/thread_context.hh)
241template <class TC>
242inline void
243updateStatusView(TC *tc)
244{
245    // TCStatus' register view must be the same as
246    // Status register view for CU, MX, KSU bits
247    TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
248    StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
249
250    status.cu = tcStatus.tcu;
251    status.mx = tcStatus.tmx;
252    status.ksu = tcStatus.tksu;
253
254    tc->setMiscRegNoEffect(MISCREG_STATUS, status);
255}
256
257// TC will usually be a object derived from ThreadContext
258// (src/cpu/thread_context.hh)
259template <class TC>
260inline void
261updateTCStatusView(TC *tc)
262{
263    // TCStatus' register view must be the same as
264    // Status register view for CU, MX, KSU bits
265    TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
266    StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
267
268    tcStatus.tcu = status.cu;
269    tcStatus.tmx = status.mx;
270    tcStatus.tksu = status.ksu;
271
272    tc->setMiscRegNoEffect(MISCREG_TC_STATUS, tcStatus);
273}
274
275} // namespace MipsISA
276
277
278#endif
279