mt.hh revision 5991 
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>
48
49namespace MipsISA
50{
51
52
53template <class TC>
54inline unsigned
55getVirtProcNum(TC *tc)
56{
57    MiscReg tcbind = tc->readMiscRegNoEffect(TCBind);
58    return bits(tcbind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
59}
60
61template <class TC>
62inline unsigned
63getTargetThread(TC *tc)
64{
65    MiscReg vpec_ctrl = tc->readMiscRegNoEffect(VPEControl);
66    return bits(vpec_ctrl, VPEC_TARG_TC_HI, VPEC_TARG_TC_LO);
67}
68
69template <class TC>
70inline void
71haltThread(TC *tc)
72{
73    if (tc->status() == TC::Active) {
74        tc->halt();
75
76        // Save last known PC in TCRestart
77        // @TODO: Needs to check if this is a branch and if so, take previous instruction
78        tc->setMiscReg(TCRestart, tc->readNextPC());
79
80        warn("%i: Halting thread %i in %s @ PC %x, setting restart PC to %x", curTick, tc->threadId(), tc->getCpuPtr()->name(),
81             tc->readPC(), tc->readNextPC());
82    }
83}
84
85template <class TC>
86inline void
87restoreThread(TC *tc)
88{
89    if (tc->status() != TC::Active) {
90        // Restore PC from TCRestart
91        IntReg pc = tc->readMiscRegNoEffect(TCRestart);
92
93        // TODO: SET PC WITH AN EVENT INSTEAD OF INSTANTANEOUSLY
94        // tc->setPCEvent(pc, pc + 4, pc + 8);
95        tc->setPC(pc);
96        tc->setNextPC(pc + 4);
97        tc->setNextNPC(pc + 8);
98        tc->activate(0);
99
100        warn("%i: Restoring thread %i in %s @ PC %x", curTick, tc->threadId(), tc->getCpuPtr()->name(),
101             tc->readPC());
102    }
103}
104
105template <class TC>
106void
107forkThread(TC *tc, Fault &fault, int Rd_bits, int Rs, int Rt)
108{
109    int num_threads = bits(tc->readMiscRegNoEffect(MVPConf0), MVPC0_PTC_HI, MVPC0_PTC_LO) + 1;
110
111    int success = 0;
112    for (int tid = 0; tid < num_threads && success == 0; tid++) {
113        unsigned tid_TCBind = tc->readRegOtherThread(MipsISA::TCBind + Ctrl_Base_DepTag,
114                                                     tid);
115        unsigned tc_bind = tc->readMiscRegNoEffect(MipsISA::TCBind);
116
117        if (bits(tid_TCBind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO) ==
118            bits(tc_bind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO)) {
119
120            unsigned tid_TCStatus = tc->readRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
121                                                           tid);
122
123            unsigned tid_TCHalt = tc->readRegOtherThread(MipsISA::TCHalt + Ctrl_Base_DepTag,
124                                                         tid);
125
126            if (bits(tid_TCStatus, TCS_DA) == 1 &&
127                bits(tid_TCHalt, TCH_H) == 0    &&
128                bits(tid_TCStatus, TCS_A) == 0  &&
129                success == 0) {
130
131                tc->setRegOtherThread(MipsISA::TCRestart + Ctrl_Base_DepTag, Rs, tid);
132
133                tc->setRegOtherThread(Rd_bits, Rt, tid);
134
135                unsigned status_ksu = bits(tc->readMiscReg(MipsISA::Status),
136                                           S_KSU_HI, S_KSU_LO);
137                unsigned tc_status_asid = bits(tc->readMiscReg(MipsISA::TCStatus),
138                                          TCS_ASID_HI, TCS_ASID_LO);
139
140                // Set Run-State to Running
141                replaceBits(tid_TCStatus, TCSTATUS_RNST_HI, TCSTATUS_RNST_LO, 0);
142
143                // Set Delay-Slot to 0
144                replaceBits(tid_TCStatus, TCSTATUS_TDS, 0);
145
146                // Set Dirty TC to 1
147                replaceBits(tid_TCStatus, TCSTATUS_DT, 1);
148
149                // Set Activated to 1
150                replaceBits(tid_TCStatus, TCSTATUS_A, 1);
151
152                // Set status to previous thread's status
153                replaceBits(tid_TCStatus, TCSTATUS_TKSU_HI, TCSTATUS_TKSU_LO, status_ksu);
154
155                // Set ASID to previous thread's state
156                replaceBits(tid_TCStatus, TCSTATUS_ASID_HI, TCSTATUS_ASID_LO, tc_status_asid);
157
158                // Write Status Register
159                tc->setRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
160                                      tid_TCStatus, tid);
161
162                // Mark As Successful Fork
163                success = 1;
164            }
165        } else {
166            std::cerr << "Bad VPEs" << std::endl;
167        }
168    }
169
170    if (success == 0) {
171        unsigned vpe_control = tc->readMiscRegNoEffect(MipsISA::VPEControl);
172        tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 1));
173        fault = new ThreadFault();
174    }
175}
176
177
178template <class TC>
179int
180yieldThread(TC *tc, Fault &fault, int src_reg, uint32_t yield_mask)
181{
182    if (src_reg == 0) {
183        unsigned mvpconf0 = tc->readMiscRegNoEffect(MVPConf0);
184        int num_threads = bits(mvpconf0, MVPC0_PTC_HI, MVPC0_PTC_LO) + 1;
185
186        int ok = 0;
187
188        // Get Current VPE & TC numbers from calling thread
189        unsigned tcbind = tc->readMiscRegNoEffect(TCBind);
190        unsigned cur_vpe = bits(tcbind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
191        unsigned cur_tc = bits(tcbind, TCB_CUR_TC_HI, TCB_CUR_TC_LO);
192
193        for (int tid = 0; tid < num_threads; tid++) {
194            unsigned tid_TCStatus = tc->readRegOtherThread(MipsISA::TCStatus + Ctrl_Base_DepTag,
195                                                           tid);
196            unsigned tid_TCHalt = tc->readRegOtherThread(MipsISA::TCHalt + Ctrl_Base_DepTag,
197                                                         tid);
198            unsigned tid_TCBind = tc->readRegOtherThread(MipsISA::TCBind + Ctrl_Base_DepTag,
199                                                         tid);
200
201            unsigned tid_vpe = bits(tid_TCBind, TCB_CUR_VPE_HI, TCB_CUR_VPE_LO);
202            unsigned tid_tc = bits(tid_TCBind, TCB_CUR_TC_HI, TCB_CUR_TC_LO);
203            unsigned tid_tcstatus_da = bits(tid_TCStatus, TCS_DA);
204            unsigned tid_tcstatus_a = bits(tid_TCStatus, TCS_A);
205            unsigned tid_tchalt_h = bits(tid_TCHalt, TCH_H);
206
207            if (tid_vpe == cur_vpe &&
208                tid_tc == cur_tc &&
209                tid_tcstatus_da == 1 &&
210                tid_tchalt_h == 0    &&
211                tid_tcstatus_a == 1) {
212                ok = 1;
213            }
214        }
215
216        if (ok == 1) {
217            unsigned tcstatus = tc->readMiscRegNoEffect(TCStatus);
218            tc->setMiscReg(TCStatus, insertBits(tcstatus, TCS_A, TCS_A, 0));
219            warn("%i: Deactivating Hardware Thread Context #%i", curTick, tc->threadId());
220        }
221    } else if (src_reg > 0) {
222        if (src_reg && !yield_mask != 0) {
223            unsigned vpe_control = tc->readMiscReg(VPEControl);
224            tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 2));
225            fault = new ThreadFault();
226        } else {
227            //tc->setThreadRescheduleCondition(src_reg & yield_mask);
228        }
229    } else if (src_reg != -2) {
230        unsigned tcstatus = tc->readMiscRegNoEffect(TCStatus);
231        unsigned vpe_control = tc->readMiscRegNoEffect(VPEControl);
232        unsigned tcstatus_dt = bits(tcstatus, TCS_DT);
233        unsigned vpe_control_ysi = bits(vpe_control, VPEC_YSI);
234
235        if (vpe_control_ysi == 1 && tcstatus_dt == 1 ) {
236            tc->setMiscReg(VPEControl, insertBits(vpe_control, VPEC_EXCPT_HI, VPEC_EXCPT_LO, 4));
237            fault = new ThreadFault();
238        } else {
239            //tc->ScheduleOtherThreads();
240            //std::cerr << "T" << tc->threadId() << "YIELD: Schedule Other Threads.\n" << std::endl;
241            //tc->suspend();
242            // Save last known PC in TCRestart
243            // @TODO: Needs to check if this is a branch and if so, take previous instruction
244            //tc->setMiscRegWithEffect(TCRestart, tc->readNextPC());
245        }
246    }
247
248    return src_reg & yield_mask;
249}
250
251
252// TC will usually be a object derived from ThreadContext
253// (src/cpu/thread_context.hh)
254template <class TC>
255inline void
256updateStatusView(TC *tc)
257{
258    // TCStatus' register view must be the same as
259    // Status register view for CU, MX, KSU bits
260    MiscReg tc_status = tc->readMiscRegNoEffect(TCStatus);
261    MiscReg status = tc->readMiscRegNoEffect(Status);
262
263    unsigned cu_bits = bits(tc_status, TCS_TCU_HI, TCS_TCU_LO);
264    replaceBits(status, S_CU_HI, S_CU_LO, cu_bits);
265
266    unsigned mx_bits = bits(tc_status, TCS_TMX);
267    replaceBits(status, S_MX, S_MX, mx_bits);
268
269    unsigned ksu_bits = bits(tc_status, TCS_TKSU_HI, TCS_TKSU_LO);
270    replaceBits(status, S_KSU_HI, S_KSU_LO, ksu_bits);
271
272    tc->setMiscRegNoEffect(Status, status);
273}
274
275// TC will usually be a object derived from ThreadContext
276// (src/cpu/thread_context.hh)
277template <class TC>
278inline void
279updateTCStatusView(TC *tc)
280{
281    // TCStatus' register view must be the same as
282    // Status register view for CU, MX, KSU bits
283    MiscReg tc_status = tc->readMiscRegNoEffect(TCStatus);
284    MiscReg status = tc->readMiscRegNoEffect(Status);
285
286    unsigned cu_bits = bits(status, S_CU_HI, S_CU_LO);
287    replaceBits(tc_status, TCS_TCU_HI, TCS_TCU_LO, cu_bits);
288
289    unsigned mx_bits = bits(status, S_MX, S_MX);
290    replaceBits(tc_status, TCS_TMX, mx_bits);
291
292    unsigned ksu_bits = bits(status, S_KSU_HI, S_KSU_LO);
293    replaceBits(tc_status, TCS_TKSU_HI, TCS_TKSU_LO, ksu_bits);
294
295    tc->setMiscRegNoEffect(TCStatus, tc_status);
296}
297
298} // namespace MipsISA
299
300
301#endif
302