mt.hh revision 10474 
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 <iostream>
41
42#include "arch/mips/faults.hh"
43#include "arch/mips/isa_traits.hh"
44#include "arch/mips/mt_constants.hh"
45#include "arch/mips/pra_constants.hh"
46#include "arch/mips/registers.hh"
47#include "base/bitfield.hh"
48#include "base/misc.hh"
49#include "base/trace.hh"
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        PCState pc = tc->pcState();
81        tc->setMiscReg(MISCREG_TC_RESTART, pc.npc());
82
83        warn("%i: Halting thread %i in %s @ PC %x, setting restart PC to %x",
84                curTick(), tc->threadId(), tc->getCpuPtr()->name(),
85                pc.pc(), pc.npc());
86    }
87}
88
89template <class TC>
90inline void
91restoreThread(TC *tc)
92{
93    if (tc->status() != TC::Active) {
94        // Restore PC from TCRestart
95        Addr restartPC = tc->readMiscRegNoEffect(MISCREG_TC_RESTART);
96
97        // TODO: SET PC WITH AN EVENT INSTEAD OF INSTANTANEOUSLY
98        tc->pcState(restartPC);
99        tc->activate();
100
101        warn("%i: Restoring thread %i in %s @ PC %x",
102                curTick(), tc->threadId(), tc->getCpuPtr()->name(), restartPC);
103    }
104}
105
106template <class TC>
107void
108forkThread(TC *tc, Fault &fault, int Rd_bits, int Rs, int Rt)
109{
110    MVPConf0Reg mvpConf = tc->readMiscRegNoEffect(MISCREG_MVP_CONF0);
111    int num_threads = mvpConf.ptc + 1;
112
113    int success = 0;
114    for (ThreadID tid = 0; tid < num_threads && success == 0; tid++) {
115        TCBindReg tidTCBind =
116            tc->readRegOtherThread(MISCREG_TC_BIND + Misc_Reg_Base, tid);
117        TCBindReg tcBind = tc->readMiscRegNoEffect(MISCREG_TC_BIND);
118
119        if (tidTCBind.curVPE == tcBind.curVPE) {
120
121            TCStatusReg tidTCStatus =
122                tc->readRegOtherThread(MISCREG_TC_STATUS +
123                                       Misc_Reg_Base,tid);
124
125            TCHaltReg tidTCHalt =
126                tc->readRegOtherThread(MISCREG_TC_HALT + Misc_Reg_Base,tid);
127
128            if (tidTCStatus.da == 1 && tidTCHalt.h == 0 &&
129                tidTCStatus.a == 0 && success == 0) {
130
131                tc->setRegOtherThread(MISCREG_TC_RESTART +
132                                      Misc_Reg_Base, Rs, tid);
133                tc->setRegOtherThread(Rd_bits, Rt, tid);
134
135                StatusReg status = tc->readMiscReg(MISCREG_STATUS);
136                TCStatusReg tcStatus = tc->readMiscReg(MISCREG_TC_STATUS);
137
138                // Set Run-State to Running
139                tidTCStatus.rnst = 0;
140                // Set Delay-Slot to 0
141                tidTCStatus.tds = 0;
142                // Set Dirty TC to 1
143                tidTCStatus.dt = 1;
144                // Set Activated to 1
145                tidTCStatus.a = 1;
146                // Set status to previous thread's status
147                tidTCStatus.tksu = status.ksu;
148                // Set ASID to previous thread's state
149                tidTCStatus.asid = tcStatus.asid;
150
151                // Write Status Register
152                tc->setRegOtherThread(MISCREG_TC_STATUS + Misc_Reg_Base,
153                                      tidTCStatus, tid);
154
155                // Mark As Successful Fork
156                success = 1;
157            }
158        } else {
159            std::cerr << "Bad VPEs" << std::endl;
160        }
161    }
162
163    if (success == 0) {
164        VPEControlReg vpeControl =
165            tc->readMiscRegNoEffect(MISCREG_VPE_CONTROL);
166        vpeControl.excpt = 1;
167        tc->setMiscReg(MISCREG_VPE_CONTROL, vpeControl);
168        fault = std::make_shared<ThreadFault>();
169    }
170}
171
172
173template <class TC>
174int
175yieldThread(TC *tc, Fault &fault, int src_reg, uint32_t yield_mask)
176{
177    if (src_reg == 0) {
178        MVPConf0Reg mvpConf0 = tc->readMiscRegNoEffect(MISCREG_MVP_CONF0);
179        ThreadID num_threads = mvpConf0.ptc + 1;
180
181        int ok = 0;
182
183        // Get Current VPE & TC numbers from calling thread
184        TCBindReg tcBind = tc->readMiscRegNoEffect(MISCREG_TC_BIND);
185
186        for (ThreadID tid = 0; tid < num_threads; tid++) {
187            TCStatusReg tidTCStatus =
188                tc->readRegOtherThread(MISCREG_TC_STATUS + Misc_Reg_Base,
189                                       tid);
190            TCHaltReg tidTCHalt =
191                tc->readRegOtherThread(MISCREG_TC_HALT + Misc_Reg_Base,
192                                       tid);
193            TCBindReg tidTCBind =
194                tc->readRegOtherThread(MISCREG_TC_BIND + Misc_Reg_Base,
195                                       tid);
196
197            if (tidTCBind.curVPE == tcBind.curVPE &&
198                tidTCBind.curTC == tcBind.curTC &&
199                tidTCStatus.da == 1 &&
200                tidTCHalt.h == 0    &&
201                tidTCStatus.a == 1) {
202                ok = 1;
203            }
204        }
205
206        if (ok == 1) {
207            TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
208            tcStatus.a = 0;
209            tc->setMiscReg(MISCREG_TC_STATUS, tcStatus);
210            warn("%i: Deactivating Hardware Thread Context #%i",
211                    curTick(), tc->threadId());
212        }
213    } else if (src_reg > 0) {
214        if (src_reg && !yield_mask != 0) {
215            VPEControlReg vpeControl = tc->readMiscReg(MISCREG_VPE_CONTROL);
216            vpeControl.excpt = 2;
217            tc->setMiscReg(MISCREG_VPE_CONTROL, vpeControl);
218            fault = std::make_shared<ThreadFault>();
219        } else {
220        }
221    } else if (src_reg != -2) {
222        TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
223        VPEControlReg vpeControl =
224            tc->readMiscRegNoEffect(MISCREG_VPE_CONTROL);
225
226        if (vpeControl.ysi == 1 && tcStatus.dt == 1 ) {
227            vpeControl.excpt = 4;
228            fault = std::make_shared<ThreadFault>();
229        } else {
230        }
231    }
232
233    return src_reg & yield_mask;
234}
235
236
237// TC will usually be a object derived from ThreadContext
238// (src/cpu/thread_context.hh)
239template <class TC>
240inline void
241updateStatusView(TC *tc)
242{
243    // TCStatus' register view must be the same as
244    // Status register view for CU, MX, KSU bits
245    TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
246    StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
247
248    status.cu = tcStatus.tcu;
249    status.mx = tcStatus.tmx;
250    status.ksu = tcStatus.tksu;
251
252    tc->setMiscRegNoEffect(MISCREG_STATUS, status);
253}
254
255// TC will usually be a object derived from ThreadContext
256// (src/cpu/thread_context.hh)
257template <class TC>
258inline void
259updateTCStatusView(TC *tc)
260{
261    // TCStatus' register view must be the same as
262    // Status register view for CU, MX, KSU bits
263    TCStatusReg tcStatus = tc->readMiscRegNoEffect(MISCREG_TC_STATUS);
264    StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
265
266    tcStatus.tcu = status.cu;
267    tcStatus.tmx = status.mx;
268    tcStatus.tksu = status.ksu;
269
270    tc->setMiscRegNoEffect(MISCREG_TC_STATUS, tcStatus);
271}
272
273} // namespace MipsISA
274
275
276#endif
277