utility.cc revision 11324 
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 "fputils/fp80.h"
48#include "sim/system.hh"
49
50namespace X86ISA {
51
52uint64_t
53getArgument(ThreadContext *tc, int &number, uint16_t size, bool fp)
54{
55    if (fp) {
56        panic("getArgument(): Floating point arguments not implemented\n");
57    } else if (size != 8) {
58        panic("getArgument(): Can only handle 64-bit arguments.\n");
59    }
60
61    // The first 6 integer arguments are passed in registers, the rest
62    // are passed on the stack.
63    const int int_reg_map[] = {
64        INTREG_RDI, INTREG_RSI, INTREG_RDX,
65        INTREG_RCX, INTREG_R8, INTREG_R9
66    };
67    if (number < sizeof(int_reg_map) / sizeof(*int_reg_map)) {
68        return tc->readIntReg(int_reg_map[number]);
69    } else {
70        panic("getArgument(): Don't know how to handle stack arguments.\n");
71    }
72}
73
74void initCPU(ThreadContext *tc, int cpuId)
75{
76    // This function is essentially performing a reset. The actual INIT
77    // interrupt does a subset of this, so we'll piggyback on some of its
78    // functionality.
79    InitInterrupt init(0);
80    init.invoke(tc);
81
82    PCState pc = tc->pcState();
83    pc.upc(0);
84    pc.nupc(1);
85    tc->pcState(pc);
86
87    // These next two loops zero internal microcode and implicit registers.
88    // They aren't specified by the ISA but are used internally by M5's
89    // implementation.
90    for (int index = 0; index < NumMicroIntRegs; index++) {
91        tc->setIntReg(INTREG_MICRO(index), 0);
92    }
93
94    for (int index = 0; index < NumImplicitIntRegs; index++) {
95        tc->setIntReg(INTREG_IMPLICIT(index), 0);
96    }
97
98    // Set integer register EAX to 0 to indicate that the optional BIST
99    // passed. No BIST actually runs, but software may still check this
100    // register for errors.
101    tc->setIntReg(INTREG_RAX, 0);
102
103    tc->setMiscReg(MISCREG_CR0, 0x0000000060000010ULL);
104    tc->setMiscReg(MISCREG_CR8, 0);
105
106    // TODO initialize x87, 64 bit, and 128 bit media state
107
108    tc->setMiscReg(MISCREG_MTRRCAP, 0x0508);
109    for (int i = 0; i < 8; i++) {
110        tc->setMiscReg(MISCREG_MTRR_PHYS_BASE(i), 0);
111        tc->setMiscReg(MISCREG_MTRR_PHYS_MASK(i), 0);
112    }
113    tc->setMiscReg(MISCREG_MTRR_FIX_64K_00000, 0);
114    tc->setMiscReg(MISCREG_MTRR_FIX_16K_80000, 0);
115    tc->setMiscReg(MISCREG_MTRR_FIX_16K_A0000, 0);
116    tc->setMiscReg(MISCREG_MTRR_FIX_4K_C0000, 0);
117    tc->setMiscReg(MISCREG_MTRR_FIX_4K_C8000, 0);
118    tc->setMiscReg(MISCREG_MTRR_FIX_4K_D0000, 0);
119    tc->setMiscReg(MISCREG_MTRR_FIX_4K_D8000, 0);
120    tc->setMiscReg(MISCREG_MTRR_FIX_4K_E0000, 0);
121    tc->setMiscReg(MISCREG_MTRR_FIX_4K_E8000, 0);
122    tc->setMiscReg(MISCREG_MTRR_FIX_4K_F0000, 0);
123    tc->setMiscReg(MISCREG_MTRR_FIX_4K_F8000, 0);
124
125    tc->setMiscReg(MISCREG_DEF_TYPE, 0);
126
127    tc->setMiscReg(MISCREG_MCG_CAP, 0x104);
128    tc->setMiscReg(MISCREG_MCG_STATUS, 0);
129    tc->setMiscReg(MISCREG_MCG_CTL, 0);
130
131    for (int i = 0; i < 5; i++) {
132        tc->setMiscReg(MISCREG_MC_CTL(i), 0);
133        tc->setMiscReg(MISCREG_MC_STATUS(i), 0);
134        tc->setMiscReg(MISCREG_MC_ADDR(i), 0);
135        tc->setMiscReg(MISCREG_MC_MISC(i), 0);
136    }
137
138    tc->setMiscReg(MISCREG_TSC, 0);
139    tc->setMiscReg(MISCREG_TSC_AUX, 0);
140
141    for (int i = 0; i < 4; i++) {
142        tc->setMiscReg(MISCREG_PERF_EVT_SEL(i), 0);
143        tc->setMiscReg(MISCREG_PERF_EVT_CTR(i), 0);
144    }
145
146    tc->setMiscReg(MISCREG_STAR, 0);
147    tc->setMiscReg(MISCREG_LSTAR, 0);
148    tc->setMiscReg(MISCREG_CSTAR, 0);
149
150    tc->setMiscReg(MISCREG_SF_MASK, 0);
151
152    tc->setMiscReg(MISCREG_KERNEL_GS_BASE, 0);
153
154    tc->setMiscReg(MISCREG_SYSENTER_CS, 0);
155    tc->setMiscReg(MISCREG_SYSENTER_ESP, 0);
156    tc->setMiscReg(MISCREG_SYSENTER_EIP, 0);
157
158    tc->setMiscReg(MISCREG_PAT, 0x0007040600070406ULL);
159
160    tc->setMiscReg(MISCREG_SYSCFG, 0x20601);
161
162    tc->setMiscReg(MISCREG_IORR_BASE0, 0);
163    tc->setMiscReg(MISCREG_IORR_BASE1, 0);
164
165    tc->setMiscReg(MISCREG_IORR_MASK0, 0);
166    tc->setMiscReg(MISCREG_IORR_MASK1, 0);
167
168    tc->setMiscReg(MISCREG_TOP_MEM, 0x4000000);
169    tc->setMiscReg(MISCREG_TOP_MEM2, 0x0);
170
171    tc->setMiscReg(MISCREG_DEBUG_CTL_MSR, 0);
172    tc->setMiscReg(MISCREG_LAST_BRANCH_FROM_IP, 0);
173    tc->setMiscReg(MISCREG_LAST_BRANCH_TO_IP, 0);
174    tc->setMiscReg(MISCREG_LAST_EXCEPTION_FROM_IP, 0);
175    tc->setMiscReg(MISCREG_LAST_EXCEPTION_TO_IP, 0);
176
177    // Invalidate the caches (this should already be done for us)
178
179    LocalApicBase lApicBase = 0;
180    lApicBase.base = 0xFEE00000 >> 12;
181    lApicBase.enable = 1;
182    lApicBase.bsp = (cpuId == 0);
183    tc->setMiscReg(MISCREG_APIC_BASE, lApicBase);
184
185    Interrupts * interrupts = dynamic_cast<Interrupts *>(
186            tc->getCpuPtr()->getInterruptController(0));
187    assert(interrupts);
188
189    interrupts->setRegNoEffect(APIC_ID, cpuId << 24);
190
191    interrupts->setRegNoEffect(APIC_VERSION, (5 << 16) | 0x14);
192
193    // TODO Set the SMRAM base address (SMBASE) to 0x00030000
194
195    tc->setMiscReg(MISCREG_VM_CR, 0);
196    tc->setMiscReg(MISCREG_IGNNE, 0);
197    tc->setMiscReg(MISCREG_SMM_CTL, 0);
198    tc->setMiscReg(MISCREG_VM_HSAVE_PA, 0);
199}
200
201void startupCPU(ThreadContext *tc, int cpuId)
202{
203    if (cpuId == 0 || !FullSystem) {
204        tc->activate();
205    } else {
206        // This is an application processor (AP). It should be initialized to
207        // look like only the BIOS POST has run on it and put then put it into
208        // a halted state.
209        tc->suspend();
210    }
211}
212
213void
214copyMiscRegs(ThreadContext *src, ThreadContext *dest)
215{
216    // This function assumes no side effects other than TLB invalidation
217    // need to be considered while copying state. That will likely not be
218    // true in the future.
219    for (int i = 0; i < NUM_MISCREGS; ++i) {
220        if (!isValidMiscReg(i))
221             continue;
222
223        dest->setMiscRegNoEffect(i, src->readMiscRegNoEffect(i));
224    }
225
226    // The TSC has to be updated with side-effects if the CPUs in a
227    // CPU switch have different frequencies.
228    dest->setMiscReg(MISCREG_TSC, src->readMiscReg(MISCREG_TSC));
229
230    dest->getITBPtr()->flushAll();
231    dest->getDTBPtr()->flushAll();
232}
233
234void
235copyRegs(ThreadContext *src, ThreadContext *dest)
236{
237    //copy int regs
238    for (int i = 0; i < NumIntRegs; ++i)
239         dest->setIntRegFlat(i, src->readIntRegFlat(i));
240    //copy float regs
241    for (int i = 0; i < NumFloatRegs; ++i)
242         dest->setFloatRegBitsFlat(i, src->readFloatRegBitsFlat(i));
243    //copy condition-code regs
244    for (int i = 0; i < NumCCRegs; ++i)
245         dest->setCCRegFlat(i, src->readCCRegFlat(i));
246    copyMiscRegs(src, dest);
247    dest->pcState(src->pcState());
248}
249
250void
251skipFunction(ThreadContext *tc)
252{
253    panic("Not implemented for x86\n");
254}
255
256uint64_t
257getRFlags(ThreadContext *tc)
258{
259    const uint64_t ncc_flags(tc->readMiscRegNoEffect(MISCREG_RFLAGS));
260    const uint64_t cc_flags(tc->readCCReg(X86ISA::CCREG_ZAPS));
261    const uint64_t cfof_bits(tc->readCCReg(X86ISA::CCREG_CFOF));
262    const uint64_t df_bit(tc->readCCReg(X86ISA::CCREG_DF));
263    // ecf (PSEUDO(3)) & ezf (PSEUDO(4)) are only visible to
264    // microcode, so we can safely ignore them.
265
266    // Reconstruct the real rflags state, mask out internal flags, and
267    // make sure reserved bits have the expected values.
268    return ((ncc_flags | cc_flags | cfof_bits | df_bit) & 0x3F7FD5)
269        | 0x2;
270}
271
272void
273setRFlags(ThreadContext *tc, uint64_t val)
274{
275    tc->setCCReg(X86ISA::CCREG_ZAPS, val & ccFlagMask);
276    tc->setCCReg(X86ISA::CCREG_CFOF, val & cfofMask);
277    tc->setCCReg(X86ISA::CCREG_DF, val & DFBit);
278
279    // Internal microcode registers (ECF & EZF)
280    tc->setCCReg(X86ISA::CCREG_ECF, 0);
281    tc->setCCReg(X86ISA::CCREG_EZF, 0);
282
283    // Update the RFLAGS misc reg with whatever didn't go into the
284    // magic registers.
285    tc->setMiscReg(MISCREG_RFLAGS, val & ~(ccFlagMask | cfofMask | DFBit));
286}
287
288uint8_t
289convX87TagsToXTags(uint16_t ftw)
290{
291    uint8_t ftwx(0);
292    for (int i = 0; i < 8; ++i) {
293        // Extract the tag for the current element on the FP stack
294        const unsigned tag((ftw >> (2 * i)) & 0x3);
295
296        /*
297         * Check the type of the current FP element. Valid values are:
298         * 0 == Valid
299         * 1 == Zero
300         * 2 == Special (Nan, unsupported, infinity, denormal)
301         * 3 == Empty
302         */
303        // The xsave version of the tag word only keeps track of
304        // whether the element is empty or not. Set the corresponding
305        // bit in the ftwx if it's not empty,
306        if (tag != 0x3)
307            ftwx |= 1 << i;
308    }
309
310    return ftwx;
311}
312
313uint16_t
314convX87XTagsToTags(uint8_t ftwx)
315{
316    uint16_t ftw(0);
317    for (int i = 0; i < 8; ++i) {
318        const unsigned xtag(((ftwx >> i) & 0x1));
319
320        // The xtag for an x87 stack position is 0 for empty stack positions.
321        if (!xtag) {
322            // Set the tag word to 3 (empty) for the current element.
323            ftw |= 0x3 << (2 * i);
324        } else {
325            // TODO: We currently assume that non-empty elements are
326            // valid (0x0), but we should ideally reconstruct the full
327            // state (valid/zero/special).
328        }
329    }
330
331    return ftw;
332}
333
334uint16_t
335genX87Tags(uint16_t ftw, uint8_t top, int8_t spm)
336{
337    const uint8_t new_top((top + spm + 8) % 8);
338
339    if (spm > 0) {
340        // Removing elements from the stack. Flag the elements as empty.
341        for (int i = top; i != new_top; i = (i + 1 + 8) % 8)
342            ftw |= 0x3 << (2 * i);
343    } else if (spm < 0) {
344        // Adding elements to the stack. Flag the new elements as
345        // valid. We should ideally decode them and "do the right
346        // thing".
347        for (int i = new_top; i != top; i = (i + 1 + 8) % 8)
348            ftw &= ~(0x3 << (2 * i));
349    }
350
351    return ftw;
352}
353
354double
355loadFloat80(const void *_mem)
356{
357    const fp80_t *fp80((const fp80_t *)_mem);
358
359    return fp80_cvtd(*fp80);
360}
361
362void
363storeFloat80(void *_mem, double value)
364{
365    fp80_t *fp80((fp80_t *)_mem);
366
367    *fp80 = fp80_cvfd(value);
368}
369
370} // namespace X86_ISA
371