mt.hh revision 5561 
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/isa_traits.hh"
41#include "arch/mips/faults.hh"
42#include "arch/mips/mt_constants.hh"
43#include "base/bitfield.hh"
44#include "base/trace.hh"
45#include "base/misc.hh"
46
47#include <iostream>
48using namespace std;
49
50namespace MipsISA
51{
52
53
54template <class TC>
55inline unsigned
56getVirtProcNum(TC *tc)
57{
58    MiscReg tcbind = tc->readMiscRegNoEffect(TCBind);
59    return bits(tcbind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
60}
61
62template <class TC>
63inline unsigned
64getTargetThread(TC *tc)
65{
66    MiscReg vpec_ctrl = tc->readMiscRegNoEffect(VPEControl);
67    return bits(vpec_ctrl, VPEC_TARG_TC_HI, VPEC_TARG_TC_LO);
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, take previous instruction
79        tc->setMiscReg(TCRestart, tc->readNextPC());
80
81        warn("%i: Halting thread %i in %s @ PC %x, setting restart PC to %x", curTick, tc->getThreadNum(), tc->getCpuPtr()->name(),
82             tc->readPC(), tc->readNextPC());
83    }
84}
85
86template <class TC>
87inline void
88restoreThread(TC *tc)
89{
90    if (tc->status() != TC::Active) {
91        // Restore PC from TCRestart
92        IntReg pc = tc->readMiscRegNoEffect(TCRestart);
93
94        // TODO: SET PC WITH AN EVENT INSTEAD OF INSTANTANEOUSLY
95        // tc->setPCEvent(pc, pc + 4, pc + 8);
96        tc->setPC(pc);
97        tc->setNextPC(pc + 4);
98        tc->setNextNPC(pc + 8);
99        tc->activate(0);
100
101        warn("%i: Restoring thread %i in %s @ PC %x", curTick, tc->getThreadNum(), tc->getCpuPtr()->name(),
102             tc->readPC());
103    }
104}
105
106template <class TC>
107void
108forkThread(TC *tc, Fault &fault, int Rd_bits, int Rs, int Rt)
109{
110    int num_threads = bits(tc->readMiscRegNoEffect(MVPConf0), MVPC0_PTC_HI, MVPC0_PTC_LO) + 1;
111
112    int success = 0;
113    for (int tid = 0; tid < num_threads && success == 0; tid++) {
114        unsigned tid_TCBind = tc->readRegOtherThread(MipsISA::TCBind + Ctrl_Base_DepTag,
115                                                     tid);
116        unsigned tc_bind = tc->readMiscRegNoEffect(MipsISA::TCBind);
117
118        if (bits(tid_TCBind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO) ==
119            bits(tc_bind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO)) {
120
121            unsigned tid_TCStatus = tc->readRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
122                                                           tid);
123
124            unsigned tid_TCHalt = tc->readRegOtherThread(MipsISA::TCHalt + Ctrl_Base_DepTag,
125                                                         tid);
126
127            if (bits(tid_TCStatus, TCS_DA) == 1 &&
128                bits(tid_TCHalt, TCH_H) == 0    &&
129                bits(tid_TCStatus, TCS_A) == 0  &&
130                success == 0) {
131
132                tc->setRegOtherThread(MipsISA::TCRestart + Ctrl_Base_DepTag, Rs, tid);
133
134                tc->setRegOtherThread(Rd_bits, Rt, tid);
135
136                unsigned status_ksu = bits(tc->readMiscReg(MipsISA::Status),
137                                           S_KSU_HI, S_KSU_LO);
138                unsigned tc_status_asid = bits(tc->readMiscReg(MipsISA::TCStatus),
139                                          TCS_ASID_HI, TCS_ASID_LO);
140
141                // Set Run-State to Running
142                replaceBits(tid_TCStatus, TCSTATUS_RNST_HI, TCSTATUS_RNST_LO, 0);
143
144                // Set Delay-Slot to 0
145                replaceBits(tid_TCStatus, TCSTATUS_TDS, 0);
146
147                // Set Dirty TC to 1
148                replaceBits(tid_TCStatus, TCSTATUS_DT, 1);
149
150                // Set Activated to 1
151                replaceBits(tid_TCStatus, TCSTATUS_A, 1);
152
153                // Set status to previous thread's status
154                replaceBits(tid_TCStatus, TCSTATUS_TKSU_HI, TCSTATUS_TKSU_LO, status_ksu);
155
156                // Set ASID to previous thread's state
157                replaceBits(tid_TCStatus, TCSTATUS_ASID_HI, TCSTATUS_ASID_LO, tc_status_asid);
158
159                // Write Status Register
160                tc->setRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
161                                      tid_TCStatus, tid);
162
163                // Mark As Successful Fork
164                success = 1;
165            }
166        } else {
167            std::cerr << "Bad VPEs" << endl;
168        }
169    }
170
171    if (success == 0) {
172        unsigned vpe_control = tc->readMiscRegNoEffect(MipsISA::VPEControl);
173        tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 1));
174        fault = new ThreadFault();
175    }
176}
177
178
179template <class TC>
180int
181yieldThread(TC *tc, Fault &fault, int src_reg, uint32_t yield_mask)
182{
183    if (src_reg == 0) {
184        unsigned mvpconf0 = tc->readMiscRegNoEffect(MVPConf0);
185        int num_threads = bits(mvpconf0, MVPC0_PTC_HI, MVPC0_PTC_LO) + 1;
186
187        int ok = 0;
188
189        // Get Current VPE & TC numbers from calling thread
190        unsigned tcbind = tc->readMiscRegNoEffect(TCBind);
191        unsigned cur_vpe = bits(tcbind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
192        unsigned cur_tc = bits(tcbind, TCB_CUR_TC_HI, TCB_CUR_TC_LO);
193
194        for (int tid = 0; tid < num_threads; tid++) {
195            unsigned tid_TCStatus = tc->readRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
196                                                           tid);
197            unsigned tid_TCHalt = tc->readRegOtherThread(MipsISA::TCHalt + Ctrl_Base_DepTag,
198                                                         tid);
199            unsigned tid_TCBind = tc->readRegOtherThread(MipsISA::TCBind + Ctrl_Base_DepTag,
200                                                         tid);
201
202            unsigned tid_vpe = bits(tid_TCBind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
203            unsigned tid_tc = bits(tid_TCBind, TCB_CUR_TC_HI, TCB_CUR_TC_LO);
204            unsigned tid_tcstatus_da = bits(tid_TCStatus, TCS_DA);
205            unsigned tid_tcstatus_a = bits(tid_TCStatus, TCS_A);
206            unsigned tid_tchalt_h = bits(tid_TCHalt, TCH_H);
207
208            if (tid_vpe == cur_vpe &&
209                tid_tc == cur_tc &&
210                tid_tcstatus_da == 1 &&
211                tid_tchalt_h == 0    &&
212                tid_tcstatus_a == 1) {
213                ok = 1;
214            }
215        }
216
217        if (ok == 1) {
218            unsigned tcstatus = tc->readMiscRegNoEffect(TCStatus);
219            tc->setMiscReg(TCStatus, insertBits(tcstatus, TCS_A, TCS_A, 0));
220            warn("%i: Deactivating Hardware Thread Context #%i", curTick, tc->getThreadNum());
221        }
222    } else if (src_reg > 0) {
223        if (src_reg && !yield_mask != 0) {
224            unsigned vpe_control = tc->readMiscReg(VPEControl);
225            tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 2));
226            fault = new ThreadFault();
227        } else {
228            //tc->setThreadRescheduleCondition(src_reg & yield_mask);
229        }
230    } else if (src_reg != -2) {
231        unsigned tcstatus = tc->readMiscRegNoEffect(TCStatus);
232        unsigned vpe_control = tc->readMiscRegNoEffect(VPEControl);
233        unsigned tcstatus_dt = bits(tcstatus, TCS_DT);
234        unsigned vpe_control_ysi = bits(vpe_control, VPEC_YSI);
235
236        if (vpe_control_ysi == 1 && tcstatus_dt == 1 ) {
237            tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 4));
238            fault = new ThreadFault();
239        } else {
240            //tc->ScheduleOtherThreads();
241            //std::cerr << "T" << tc->getThreadNum() << "YIELD: Schedule Other Threads.\n" << std::endl;
242            //tc->suspend();
243            // Save last known PC in TCRestart
244            // @TODO: Needs to check if this is a branch and if so, take previous instruction
245            //tc->setMiscRegWithEffect(TCRestart, tc->readNextPC());
246        }
247    }
248
249    return src_reg & yield_mask;
250}
251
252
253// TC will usually be a object derived from ThreadContext
254// (src/cpu/thread_context.hh)
255template <class TC>
256inline void
257updateStatusView(TC *tc)
258{
259    // TCStatus' register view must be the same as
260    // Status register view for CU, MX, KSU bits
261    MiscReg tc_status = tc->readMiscRegNoEffect(TCStatus);
262    MiscReg status = tc->readMiscRegNoEffect(Status);
263
264    unsigned cu_bits = bits(tc_status, TCS_TCU_HI, TCS_TCU_LO);
265    replaceBits(status, S_CU_HI, S_CU_LO, cu_bits);
266
267    unsigned mx_bits = bits(tc_status, TCS_TMX);
268    replaceBits(status, S_MX, S_MX, mx_bits);
269
270    unsigned ksu_bits = bits(tc_status, TCS_TKSU_HI, TCS_TKSU_LO);
271    replaceBits(status, S_KSU_HI, S_KSU_LO, ksu_bits);
272
273    tc->setMiscRegNoEffect(Status, status);
274}
275
276// TC will usually be a object derived from ThreadContext
277// (src/cpu/thread_context.hh)
278template <class TC>
279inline void
280updateTCStatusView(TC *tc)
281{
282    // TCStatus' register view must be the same as
283    // Status register view for CU, MX, KSU bits
284    MiscReg tc_status = tc->readMiscRegNoEffect(TCStatus);
285    MiscReg status = tc->readMiscRegNoEffect(Status);
286
287    unsigned cu_bits = bits(status, S_CU_HI, S_CU_LO);
288    replaceBits(tc_status, TCS_TCU_HI, TCS_TCU_LO, cu_bits);
289
290    unsigned mx_bits = bits(status, S_MX, S_MX);
291    replaceBits(tc_status, TCS_TMX, mx_bits);
292
293    unsigned ksu_bits = bits(status, S_KSU_HI, S_KSU_LO);
294    replaceBits(tc_status, TCS_TKSU_HI, TCS_TKSU_LO, ksu_bits);
295
296    tc->setMiscRegNoEffect(TCStatus, tc_status);
297}
298
299} // namespace MipsISA
300
301
302#endif
303