isa.cc revision 11574 
1/*
2 * Copyright (c) 2009 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: Gabe Black
29 */
30
31#include "arch/x86/decoder.hh"
32#include "arch/x86/isa.hh"
33#include "arch/x86/tlb.hh"
34#include "cpu/base.hh"
35#include "cpu/thread_context.hh"
36#include "params/X86ISA.hh"
37#include "sim/serialize.hh"
38
39namespace X86ISA
40{
41
42void
43ISA::updateHandyM5Reg(Efer efer, CR0 cr0,
44                      SegAttr csAttr, SegAttr ssAttr, RFLAGS rflags,
45                      ThreadContext *tc)
46{
47    HandyM5Reg m5reg = 0;
48    if (efer.lma) {
49        m5reg.mode = LongMode;
50        if (csAttr.longMode)
51            m5reg.submode = SixtyFourBitMode;
52        else
53            m5reg.submode = CompatabilityMode;
54    } else {
55        m5reg.mode = LegacyMode;
56        if (cr0.pe) {
57            if (rflags.vm)
58                m5reg.submode = Virtual8086Mode;
59            else
60                m5reg.submode = ProtectedMode;
61        } else {
62            m5reg.submode = RealMode;
63        }
64    }
65    m5reg.cpl = csAttr.dpl;
66    m5reg.paging = cr0.pg;
67    m5reg.prot = cr0.pe;
68
69    // Compute the default and alternate operand size.
70    if (m5reg.submode == SixtyFourBitMode || csAttr.defaultSize) {
71        m5reg.defOp = 2;
72        m5reg.altOp = 1;
73    } else {
74        m5reg.defOp = 1;
75        m5reg.altOp = 2;
76    }
77
78    // Compute the default and alternate address size.
79    if (m5reg.submode == SixtyFourBitMode) {
80        m5reg.defAddr = 3;
81        m5reg.altAddr = 2;
82    } else if (csAttr.defaultSize) {
83        m5reg.defAddr = 2;
84        m5reg.altAddr = 1;
85    } else {
86        m5reg.defAddr = 1;
87        m5reg.altAddr = 2;
88    }
89
90    // Compute the stack size
91    if (m5reg.submode == SixtyFourBitMode) {
92        m5reg.stack = 3;
93    } else if (ssAttr.defaultSize) {
94        m5reg.stack = 2;
95    } else {
96        m5reg.stack = 1;
97    }
98
99    regVal[MISCREG_M5_REG] = m5reg;
100    if (tc)
101        tc->getDecoderPtr()->setM5Reg(m5reg);
102}
103
104void
105ISA::clear()
106{
107    // Blank everything. 0 might not be an appropriate value for some things,
108    // but it is for most.
109    memset(regVal, 0, NumMiscRegs * sizeof(MiscReg));
110    regVal[MISCREG_DR6] = (mask(8) << 4) | (mask(16) << 16);
111    regVal[MISCREG_DR7] = 1 << 10;
112}
113
114ISA::ISA(Params *p)
115    : SimObject(p)
116{
117    clear();
118}
119
120const X86ISAParams *
121ISA::params() const
122{
123    return dynamic_cast<const Params *>(_params);
124}
125
126MiscReg
127ISA::readMiscRegNoEffect(int miscReg) const
128{
129    // Make sure we're not dealing with an illegal control register.
130    // Instructions should filter out these indexes, and nothing else should
131    // attempt to read them directly.
132    assert(isValidMiscReg(miscReg));
133
134    return regVal[miscReg];
135}
136
137MiscReg
138ISA::readMiscReg(int miscReg, ThreadContext * tc)
139{
140    if (miscReg == MISCREG_TSC) {
141        return regVal[MISCREG_TSC] + tc->getCpuPtr()->curCycle();
142    }
143
144    if (miscReg == MISCREG_FSW) {
145        MiscReg fsw = regVal[MISCREG_FSW];
146        MiscReg top = regVal[MISCREG_X87_TOP];
147        return (fsw & (~(7ULL << 11))) + (top << 11);
148    }
149
150    return readMiscRegNoEffect(miscReg);
151}
152
153void
154ISA::setMiscRegNoEffect(int miscReg, MiscReg val)
155{
156    // Make sure we're not dealing with an illegal control register.
157    // Instructions should filter out these indexes, and nothing else should
158    // attempt to write to them directly.
159    assert(isValidMiscReg(miscReg));
160
161    HandyM5Reg m5Reg = readMiscRegNoEffect(MISCREG_M5_REG);
162    switch (miscReg) {
163      case MISCREG_FSW:
164        val &= (1ULL << 16) - 1;
165        regVal[miscReg] = val;
166        miscReg = MISCREG_X87_TOP;
167        val <<= 11;
168      case MISCREG_X87_TOP:
169        val &= (1ULL << 3) - 1;
170        break;
171      case MISCREG_FTW:
172        val &= (1ULL << 8) - 1;
173        break;
174      case MISCREG_FCW:
175      case MISCREG_FOP:
176        val &= (1ULL << 16) - 1;
177        break;
178      case MISCREG_MXCSR:
179        val &= (1ULL << 32) - 1;
180        break;
181      case MISCREG_FISEG:
182      case MISCREG_FOSEG:
183        if (m5Reg.submode != SixtyFourBitMode)
184            val &= (1ULL << 16) - 1;
185        break;
186      case MISCREG_FIOFF:
187      case MISCREG_FOOFF:
188        if (m5Reg.submode != SixtyFourBitMode)
189            val &= (1ULL << 32) - 1;
190        break;
191      default:
192        break;
193    }
194
195    regVal[miscReg] = val;
196}
197
198void
199ISA::setMiscReg(int miscReg, MiscReg val, ThreadContext * tc)
200{
201    MiscReg newVal = val;
202    switch(miscReg)
203    {
204      case MISCREG_CR0:
205        {
206            CR0 toggled = regVal[miscReg] ^ val;
207            CR0 newCR0 = val;
208            Efer efer = regVal[MISCREG_EFER];
209            if (toggled.pg && efer.lme) {
210                if (newCR0.pg) {
211                    //Turning on long mode
212                    efer.lma = 1;
213                    regVal[MISCREG_EFER] = efer;
214                } else {
215                    //Turning off long mode
216                    efer.lma = 0;
217                    regVal[MISCREG_EFER] = efer;
218                }
219            }
220            if (toggled.pg) {
221                tc->getITBPtr()->flushAll();
222                tc->getDTBPtr()->flushAll();
223            }
224            //This must always be 1.
225            newCR0.et = 1;
226            newVal = newCR0;
227            updateHandyM5Reg(regVal[MISCREG_EFER],
228                             newCR0,
229                             regVal[MISCREG_CS_ATTR],
230                             regVal[MISCREG_SS_ATTR],
231                             regVal[MISCREG_RFLAGS],
232                             tc);
233        }
234        break;
235      case MISCREG_CR2:
236        break;
237      case MISCREG_CR3:
238        tc->getITBPtr()->flushNonGlobal();
239        tc->getDTBPtr()->flushNonGlobal();
240        break;
241      case MISCREG_CR4:
242        {
243            CR4 toggled = regVal[miscReg] ^ val;
244            if (toggled.pae || toggled.pse || toggled.pge) {
245                tc->getITBPtr()->flushAll();
246                tc->getDTBPtr()->flushAll();
247            }
248        }
249        break;
250      case MISCREG_CR8:
251        break;
252      case MISCREG_CS_ATTR:
253        {
254            SegAttr toggled = regVal[miscReg] ^ val;
255            SegAttr newCSAttr = val;
256            if (toggled.longMode) {
257                if (newCSAttr.longMode) {
258                    regVal[MISCREG_ES_EFF_BASE] = 0;
259                    regVal[MISCREG_CS_EFF_BASE] = 0;
260                    regVal[MISCREG_SS_EFF_BASE] = 0;
261                    regVal[MISCREG_DS_EFF_BASE] = 0;
262                } else {
263                    regVal[MISCREG_ES_EFF_BASE] = regVal[MISCREG_ES_BASE];
264                    regVal[MISCREG_CS_EFF_BASE] = regVal[MISCREG_CS_BASE];
265                    regVal[MISCREG_SS_EFF_BASE] = regVal[MISCREG_SS_BASE];
266                    regVal[MISCREG_DS_EFF_BASE] = regVal[MISCREG_DS_BASE];
267                }
268            }
269            updateHandyM5Reg(regVal[MISCREG_EFER],
270                             regVal[MISCREG_CR0],
271                             newCSAttr,
272                             regVal[MISCREG_SS_ATTR],
273                             regVal[MISCREG_RFLAGS],
274                             tc);
275        }
276        break;
277      case MISCREG_SS_ATTR:
278        updateHandyM5Reg(regVal[MISCREG_EFER],
279                         regVal[MISCREG_CR0],
280                         regVal[MISCREG_CS_ATTR],
281                         val,
282                         regVal[MISCREG_RFLAGS],
283                         tc);
284        break;
285      // These segments always actually use their bases, or in other words
286      // their effective bases must stay equal to their actual bases.
287      case MISCREG_FS_BASE:
288      case MISCREG_GS_BASE:
289      case MISCREG_HS_BASE:
290      case MISCREG_TSL_BASE:
291      case MISCREG_TSG_BASE:
292      case MISCREG_TR_BASE:
293      case MISCREG_IDTR_BASE:
294        regVal[MISCREG_SEG_EFF_BASE(miscReg - MISCREG_SEG_BASE_BASE)] = val;
295        break;
296      // These segments ignore their bases in 64 bit mode.
297      // their effective bases must stay equal to their actual bases.
298      case MISCREG_ES_BASE:
299      case MISCREG_CS_BASE:
300      case MISCREG_SS_BASE:
301      case MISCREG_DS_BASE:
302        {
303            Efer efer = regVal[MISCREG_EFER];
304            SegAttr csAttr = regVal[MISCREG_CS_ATTR];
305            if (!efer.lma || !csAttr.longMode) // Check for non 64 bit mode.
306                regVal[MISCREG_SEG_EFF_BASE(miscReg -
307                        MISCREG_SEG_BASE_BASE)] = val;
308        }
309        break;
310      case MISCREG_TSC:
311        regVal[MISCREG_TSC] = val - tc->getCpuPtr()->curCycle();
312        return;
313      case MISCREG_DR0:
314      case MISCREG_DR1:
315      case MISCREG_DR2:
316      case MISCREG_DR3:
317        /* These should eventually set up breakpoints. */
318        break;
319      case MISCREG_DR4:
320        miscReg = MISCREG_DR6;
321        /* Fall through to have the same effects as DR6. */
322      case MISCREG_DR6:
323        {
324            DR6 dr6 = regVal[MISCREG_DR6];
325            DR6 newDR6 = val;
326            dr6.b0 = newDR6.b0;
327            dr6.b1 = newDR6.b1;
328            dr6.b2 = newDR6.b2;
329            dr6.b3 = newDR6.b3;
330            dr6.bd = newDR6.bd;
331            dr6.bs = newDR6.bs;
332            dr6.bt = newDR6.bt;
333            newVal = dr6;
334        }
335        break;
336      case MISCREG_DR5:
337        miscReg = MISCREG_DR7;
338        /* Fall through to have the same effects as DR7. */
339      case MISCREG_DR7:
340        {
341            DR7 dr7 = regVal[MISCREG_DR7];
342            DR7 newDR7 = val;
343            dr7.l0 = newDR7.l0;
344            dr7.g0 = newDR7.g0;
345            if (dr7.l0 || dr7.g0) {
346                panic("Debug register breakpoints not implemented.\n");
347            } else {
348                /* Disable breakpoint 0. */
349            }
350            dr7.l1 = newDR7.l1;
351            dr7.g1 = newDR7.g1;
352            if (dr7.l1 || dr7.g1) {
353                panic("Debug register breakpoints not implemented.\n");
354            } else {
355                /* Disable breakpoint 1. */
356            }
357            dr7.l2 = newDR7.l2;
358            dr7.g2 = newDR7.g2;
359            if (dr7.l2 || dr7.g2) {
360                panic("Debug register breakpoints not implemented.\n");
361            } else {
362                /* Disable breakpoint 2. */
363            }
364            dr7.l3 = newDR7.l3;
365            dr7.g3 = newDR7.g3;
366            if (dr7.l3 || dr7.g3) {
367                panic("Debug register breakpoints not implemented.\n");
368            } else {
369                /* Disable breakpoint 3. */
370            }
371            dr7.gd = newDR7.gd;
372            dr7.rw0 = newDR7.rw0;
373            dr7.len0 = newDR7.len0;
374            dr7.rw1 = newDR7.rw1;
375            dr7.len1 = newDR7.len1;
376            dr7.rw2 = newDR7.rw2;
377            dr7.len2 = newDR7.len2;
378            dr7.rw3 = newDR7.rw3;
379            dr7.len3 = newDR7.len3;
380        }
381        break;
382      case MISCREG_M5_REG:
383        // Writing anything to the m5reg with side effects makes it update
384        // based on the current values of the relevant registers. The actual
385        // value written is discarded.
386        updateHandyM5Reg(regVal[MISCREG_EFER],
387                         regVal[MISCREG_CR0],
388                         regVal[MISCREG_CS_ATTR],
389                         regVal[MISCREG_SS_ATTR],
390                         regVal[MISCREG_RFLAGS],
391                         tc);
392        return;
393      default:
394        break;
395    }
396    setMiscRegNoEffect(miscReg, newVal);
397}
398
399void
400ISA::serialize(CheckpointOut &cp) const
401{
402    SERIALIZE_ARRAY(regVal, NumMiscRegs);
403}
404
405void
406ISA::unserialize(CheckpointIn &cp)
407{
408    UNSERIALIZE_ARRAY(regVal, NumMiscRegs);
409    updateHandyM5Reg(regVal[MISCREG_EFER],
410                     regVal[MISCREG_CR0],
411                     regVal[MISCREG_CS_ATTR],
412                     regVal[MISCREG_SS_ATTR],
413                     regVal[MISCREG_RFLAGS],
414                     NULL);
415}
416
417void
418ISA::startup(ThreadContext *tc)
419{
420    tc->getDecoderPtr()->setM5Reg(regVal[MISCREG_M5_REG]);
421}
422
423}
424
425X86ISA::ISA *
426X86ISAParams::create()
427{
428    return new X86ISA::ISA(this);
429}
430