utility.cc revision 9880 
1/*
2 * Copyright (c) 2007 The Hewlett-Packard Development Company
3 * Copyright (c) 2011 Advanced Micro Devices, Inc.
4 * All rights reserved.
5 *
6 * The license below extends only to copyright in the software and shall
7 * not be construed as granting a license to any other intellectual
8 * property including but not limited to intellectual property relating
9 * to a hardware implementation of the functionality of the software
10 * licensed hereunder.  You may use the software subject to the license
11 * terms below provided that you ensure that this notice is replicated
12 * unmodified and in its entirety in all distributions of the software,
13 * modified or unmodified, in source code or in binary form.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions are
17 * met: redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer;
19 * redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution;
22 * neither the name of the copyright holders nor the names of its
23 * contributors may be used to endorse or promote products derived from
24 * this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
29 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
30 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
31 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
32 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
36 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * Authors: Gabe Black
39 */
40
41#include "arch/x86/interrupts.hh"
42#include "arch/x86/registers.hh"
43#include "arch/x86/tlb.hh"
44#include "arch/x86/utility.hh"
45#include "arch/x86/x86_traits.hh"
46#include "cpu/base.hh"
47#include "sim/system.hh"
48
49namespace X86ISA {
50
51uint64_t
52getArgument(ThreadContext *tc, int &number, uint16_t size, bool fp)
53{
54    panic("getArgument() not implemented for x86!\n");
55    M5_DUMMY_RETURN
56}
57
58void initCPU(ThreadContext *tc, int cpuId)
59{
60    // This function is essentially performing a reset. The actual INIT
61    // interrupt does a subset of this, so we'll piggyback on some of its
62    // functionality.
63    InitInterrupt init(0);
64    init.invoke(tc);
65
66    PCState pc = tc->pcState();
67    pc.upc(0);
68    pc.nupc(1);
69    tc->pcState(pc);
70
71    // These next two loops zero internal microcode and implicit registers.
72    // They aren't specified by the ISA but are used internally by M5's
73    // implementation.
74    for (int index = 0; index < NumMicroIntRegs; index++) {
75        tc->setIntReg(INTREG_MICRO(index), 0);
76    }
77
78    for (int index = 0; index < NumImplicitIntRegs; index++) {
79        tc->setIntReg(INTREG_IMPLICIT(index), 0);
80    }
81
82    // Set integer register EAX to 0 to indicate that the optional BIST
83    // passed. No BIST actually runs, but software may still check this
84    // register for errors.
85    tc->setIntReg(INTREG_RAX, 0);
86
87    tc->setMiscReg(MISCREG_CR0, 0x0000000060000010ULL);
88    tc->setMiscReg(MISCREG_CR8, 0);
89
90    // TODO initialize x87, 64 bit, and 128 bit media state
91
92    tc->setMiscReg(MISCREG_MTRRCAP, 0x0508);
93    for (int i = 0; i < 8; i++) {
94        tc->setMiscReg(MISCREG_MTRR_PHYS_BASE(i), 0);
95        tc->setMiscReg(MISCREG_MTRR_PHYS_MASK(i), 0);
96    }
97    tc->setMiscReg(MISCREG_MTRR_FIX_64K_00000, 0);
98    tc->setMiscReg(MISCREG_MTRR_FIX_16K_80000, 0);
99    tc->setMiscReg(MISCREG_MTRR_FIX_16K_A0000, 0);
100    tc->setMiscReg(MISCREG_MTRR_FIX_4K_C0000, 0);
101    tc->setMiscReg(MISCREG_MTRR_FIX_4K_C8000, 0);
102    tc->setMiscReg(MISCREG_MTRR_FIX_4K_D0000, 0);
103    tc->setMiscReg(MISCREG_MTRR_FIX_4K_D8000, 0);
104    tc->setMiscReg(MISCREG_MTRR_FIX_4K_E0000, 0);
105    tc->setMiscReg(MISCREG_MTRR_FIX_4K_E8000, 0);
106    tc->setMiscReg(MISCREG_MTRR_FIX_4K_F0000, 0);
107    tc->setMiscReg(MISCREG_MTRR_FIX_4K_F8000, 0);
108
109    tc->setMiscReg(MISCREG_DEF_TYPE, 0);
110
111    tc->setMiscReg(MISCREG_MCG_CAP, 0x104);
112    tc->setMiscReg(MISCREG_MCG_STATUS, 0);
113    tc->setMiscReg(MISCREG_MCG_CTL, 0);
114
115    for (int i = 0; i < 5; i++) {
116        tc->setMiscReg(MISCREG_MC_CTL(i), 0);
117        tc->setMiscReg(MISCREG_MC_STATUS(i), 0);
118        tc->setMiscReg(MISCREG_MC_ADDR(i), 0);
119        tc->setMiscReg(MISCREG_MC_MISC(i), 0);
120    }
121
122    tc->setMiscReg(MISCREG_TSC, 0);
123    tc->setMiscReg(MISCREG_TSC_AUX, 0);
124
125    for (int i = 0; i < 4; i++) {
126        tc->setMiscReg(MISCREG_PERF_EVT_SEL(i), 0);
127        tc->setMiscReg(MISCREG_PERF_EVT_CTR(i), 0);
128    }
129
130    tc->setMiscReg(MISCREG_STAR, 0);
131    tc->setMiscReg(MISCREG_LSTAR, 0);
132    tc->setMiscReg(MISCREG_CSTAR, 0);
133
134    tc->setMiscReg(MISCREG_SF_MASK, 0);
135
136    tc->setMiscReg(MISCREG_KERNEL_GS_BASE, 0);
137
138    tc->setMiscReg(MISCREG_SYSENTER_CS, 0);
139    tc->setMiscReg(MISCREG_SYSENTER_ESP, 0);
140    tc->setMiscReg(MISCREG_SYSENTER_EIP, 0);
141
142    tc->setMiscReg(MISCREG_PAT, 0x0007040600070406ULL);
143
144    tc->setMiscReg(MISCREG_SYSCFG, 0x20601);
145
146    tc->setMiscReg(MISCREG_IORR_BASE0, 0);
147    tc->setMiscReg(MISCREG_IORR_BASE1, 0);
148
149    tc->setMiscReg(MISCREG_IORR_MASK0, 0);
150    tc->setMiscReg(MISCREG_IORR_MASK1, 0);
151
152    tc->setMiscReg(MISCREG_TOP_MEM, 0x4000000);
153    tc->setMiscReg(MISCREG_TOP_MEM2, 0x0);
154
155    tc->setMiscReg(MISCREG_DEBUG_CTL_MSR, 0);
156    tc->setMiscReg(MISCREG_LAST_BRANCH_FROM_IP, 0);
157    tc->setMiscReg(MISCREG_LAST_BRANCH_TO_IP, 0);
158    tc->setMiscReg(MISCREG_LAST_EXCEPTION_FROM_IP, 0);
159    tc->setMiscReg(MISCREG_LAST_EXCEPTION_TO_IP, 0);
160
161    // Invalidate the caches (this should already be done for us)
162
163    LocalApicBase lApicBase = 0;
164    lApicBase.base = 0xFEE00000 >> 12;
165    lApicBase.enable = 1;
166    lApicBase.bsp = (cpuId == 0);
167    tc->setMiscReg(MISCREG_APIC_BASE, lApicBase);
168
169    Interrupts * interrupts = dynamic_cast<Interrupts *>(
170            tc->getCpuPtr()->getInterruptController());
171    assert(interrupts);
172
173    interrupts->setRegNoEffect(APIC_ID, cpuId << 24);
174
175    interrupts->setRegNoEffect(APIC_VERSION, (5 << 16) | 0x14);
176
177    // TODO Set the SMRAM base address (SMBASE) to 0x00030000
178
179    tc->setMiscReg(MISCREG_VM_CR, 0);
180    tc->setMiscReg(MISCREG_IGNNE, 0);
181    tc->setMiscReg(MISCREG_SMM_CTL, 0);
182    tc->setMiscReg(MISCREG_VM_HSAVE_PA, 0);
183}
184
185void startupCPU(ThreadContext *tc, int cpuId)
186{
187    if (cpuId == 0 || !FullSystem) {
188        tc->activate(Cycles(0));
189    } else {
190        // This is an application processor (AP). It should be initialized to
191        // look like only the BIOS POST has run on it and put then put it into
192        // a halted state.
193        tc->suspend(Cycles(0));
194    }
195}
196
197void
198copyMiscRegs(ThreadContext *src, ThreadContext *dest)
199{
200    // This function assumes no side effects other than TLB invalidation
201    // need to be considered while copying state. That will likely not be
202    // true in the future.
203    for (int i = 0; i < NUM_MISCREGS; ++i) {
204        if ( ( i != MISCREG_CR1 &&
205             !(i > MISCREG_CR4 && i < MISCREG_CR8) &&
206             !(i > MISCREG_CR8 && i <= MISCREG_CR15) ) == false) {
207             continue;
208        }
209        dest->setMiscRegNoEffect(i, src->readMiscRegNoEffect(i));
210    }
211
212    // The TSC has to be updated with side-effects if the CPUs in a
213    // CPU switch have different frequencies.
214    dest->setMiscReg(MISCREG_TSC, src->readMiscReg(MISCREG_TSC));
215
216    dest->getITBPtr()->flushAll();
217    dest->getDTBPtr()->flushAll();
218}
219
220void
221copyRegs(ThreadContext *src, ThreadContext *dest)
222{
223    //copy int regs
224    for (int i = 0; i < NumIntRegs; ++i)
225         dest->setIntReg(i, src->readIntReg(i));
226    //copy float regs
227    for (int i = 0; i < NumFloatRegs; ++i)
228         dest->setFloatRegBits(i, src->readFloatRegBits(i));
229    copyMiscRegs(src, dest);
230    dest->pcState(src->pcState());
231}
232
233void
234skipFunction(ThreadContext *tc)
235{
236    panic("Not implemented for x86\n");
237}
238
239uint64_t
240getRFlags(ThreadContext *tc)
241{
242    const uint64_t ncc_flags(tc->readMiscRegNoEffect(MISCREG_RFLAGS));
243    const uint64_t cc_flags(tc->readIntReg(X86ISA::INTREG_PSEUDO(0)));
244    const uint64_t cfof_bits(tc->readIntReg(X86ISA::INTREG_PSEUDO(1)));
245    const uint64_t df_bit(tc->readIntReg(X86ISA::INTREG_PSEUDO(2)));
246    // ecf (PSEUDO(3)) & ezf (PSEUDO(4)) are only visible to
247    // microcode, so we can safely ignore them.
248
249    // Reconstruct the real rflags state, mask out internal flags, and
250    // make sure reserved bits have the expected values.
251    return ((ncc_flags | cc_flags | cfof_bits | df_bit) & 0x3F7FD5)
252        | 0x2;
253}
254
255void
256setRFlags(ThreadContext *tc, uint64_t val)
257{
258    tc->setIntReg(X86ISA::INTREG_PSEUDO(0), val & ccFlagMask);
259    tc->setIntReg(X86ISA::INTREG_PSEUDO(1), val & cfofMask);
260    tc->setIntReg(X86ISA::INTREG_PSEUDO(2), val & DFBit);
261
262    // Internal microcode registers (ECF & EZF)
263    tc->setIntReg(X86ISA::INTREG_PSEUDO(3), 0);
264    tc->setIntReg(X86ISA::INTREG_PSEUDO(4), 0);
265
266    // Update the RFLAGS misc reg with whatever didn't go into the
267    // magic registers.
268    tc->setMiscReg(MISCREG_RFLAGS, val & ~(ccFlagMask | cfofMask | DFBit));
269}
270
271uint8_t
272convX87TagsToXTags(uint16_t ftw)
273{
274    uint8_t ftwx(0);
275    for (int i = 0; i < 8; ++i) {
276        // Extract the tag for the current element on the FP stack
277        const unsigned tag((ftw >> (2 * i)) & 0x3);
278
279        /*
280         * Check the type of the current FP element. Valid values are:
281         * 0 == Valid
282         * 1 == Zero
283         * 2 == Special (Nan, unsupported, infinity, denormal)
284         * 3 == Empty
285         */
286        // The xsave version of the tag word only keeps track of
287        // whether the element is empty or not. Set the corresponding
288        // bit in the ftwx if it's not empty,
289        if (tag != 0x3)
290            ftwx |= 1 << i;
291    }
292
293    return ftwx;
294}
295
296uint16_t
297convX87XTagsToTags(uint8_t ftwx)
298{
299    uint16_t ftw(0);
300    for (int i = 0; i < 8; ++i) {
301        const unsigned xtag(((ftwx >> i) & 0x1));
302
303        // The xtag for an x87 stack position is 0 for empty stack positions.
304        if (!xtag) {
305            // Set the tag word to 3 (empty) for the current element.
306            ftw |= 0x3 << (2 * i);
307        } else {
308            // TODO: We currently assume that non-empty elements are
309            // valid (0x0), but we should ideally reconstruct the full
310            // state (valid/zero/special).
311        }
312    }
313
314    return ftw;
315}
316
317uint16_t
318genX87Tags(uint16_t ftw, uint8_t top, int8_t spm)
319{
320    const uint8_t new_top((top + spm + 8) % 8);
321
322    if (spm > 0) {
323        // Removing elements from the stack. Flag the elements as empty.
324        for (int i = top; i != new_top; i = (i + 1 + 8) % 8)
325            ftw |= 0x3 << (2 * i);
326    } else if (spm < 0) {
327        // Adding elements to the stack. Flag the new elements as
328        // valid. We should ideally decode them and "do the right
329        // thing".
330        for (int i = new_top; i != top; i = (i + 1 + 8) % 8)
331            ftw &= ~(0x3 << (2 * i));
332    }
333
334    return ftw;
335}
336
337} // namespace X86_ISA
338