159 lines
5.0 KiB
C++
Executable File
159 lines
5.0 KiB
C++
Executable File
/////////////////////////////////////////////////////////////////////////
|
|
// $Id: icache.h,v 1.6 2005-04-10 19:42:47 sshwarts Exp $
|
|
/////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (C) 2001 MandrakeSoft S.A.
|
|
//
|
|
// MandrakeSoft S.A.
|
|
// 43, rue d'Aboukir
|
|
// 75002 Paris - France
|
|
// http://www.linux-mandrake.com/
|
|
// http://www.mandrakesoft.com/
|
|
//
|
|
// This library is free software; you can redistribute it and/or
|
|
// modify it under the terms of the GNU Lesser General Public
|
|
// License as published by the Free Software Foundation; either
|
|
// version 2 of the License, or (at your option) any later version.
|
|
//
|
|
// This library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
// Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public
|
|
// License along with this library; if not, write to the Free Software
|
|
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
|
|
#ifndef BX_ICACHE_H
|
|
#define BX_ICACHE_H
|
|
|
|
#define BxICacheEntries (32 * 1024) // Must be a power of 2.
|
|
|
|
// bit31: 1=CS is 32/64-bit, 0=CS is 16-bit.
|
|
// bit30: 1=Long Mode, 0=not Long Mode.
|
|
// bit29: 1=iCache page, 0=Data.
|
|
#define ICacheWriteStampInvalid 0x1fffffff
|
|
#define ICacheWriteStampMax 0x1fffffff // Decrements from here.
|
|
#define ICacheWriteStampMask 0x1fffffff
|
|
#define ICacheFetchModeMask (~ICacheWriteStampMask)
|
|
#define iCachePageDataMask 0x20000000
|
|
|
|
class bxICacheEntry_c {
|
|
public:
|
|
|
|
Bit32u pAddr; // Physical address of the instruction.
|
|
Bit32u writeStamp; // Generation ID. Each write to a physical page
|
|
// decrements this value.
|
|
bxInstruction_c i; // The instruction decode information.
|
|
};
|
|
|
|
class BOCHSAPI bxICache_c {
|
|
public:
|
|
bxICacheEntry_c entry[BxICacheEntries];
|
|
Bit32u fetchModeMask;
|
|
|
|
public:
|
|
bxICache_c()
|
|
{
|
|
// Initially clear the iCache;
|
|
for (unsigned i=0; i<BxICacheEntries; i++) {
|
|
entry[i].writeStamp = ICacheWriteStampInvalid;
|
|
}
|
|
fetchModeMask = 0; // CS is 16-bit, Long Mode disabled, Data page
|
|
}
|
|
|
|
BX_CPP_INLINE unsigned hash(Bit32u pAddr) const
|
|
{
|
|
// A pretty dumb hash function for now.
|
|
return pAddr & (BxICacheEntries-1);
|
|
}
|
|
|
|
BX_CPP_INLINE void invalidatePage(Bit32u a20Addr);
|
|
};
|
|
|
|
BX_CPP_INLINE void bxICache_c::invalidatePage(Bit32u a20Addr)
|
|
{
|
|
// Take the hash of the 0th page offset.
|
|
unsigned iCacheHash = hash(a20Addr & 0xfffff000);
|
|
for (unsigned o=0; o<4096; o++) {
|
|
entry[iCacheHash].writeStamp = ICacheWriteStampInvalid;
|
|
iCacheHash = (iCacheHash + 1) % BxICacheEntries;
|
|
}
|
|
}
|
|
|
|
extern void invalidateIcacheEntries(Bit32u a20AddrPage);
|
|
|
|
class bxPageWriteStampTable {
|
|
|
|
// A table (dynamically allocated) to store write-stamp generation IDs.
|
|
// Each time a write occurs to a physical page, a generation ID is
|
|
// decremented. Only iCache entries which have write stamps matching
|
|
// the physical page write stamp are valid.
|
|
|
|
Bit32u *pageWriteStampTable;
|
|
Bit32u memSizeInBytes;
|
|
|
|
public:
|
|
bxPageWriteStampTable(): pageWriteStampTable(NULL), memSizeInBytes(0) {}
|
|
bxPageWriteStampTable(Bit32u memSize) { alloc(memSize); }
|
|
~bxPageWriteStampTable() { delete [] pageWriteStampTable; }
|
|
|
|
BX_CPP_INLINE void alloc(Bit32u memSize)
|
|
{
|
|
memSizeInBytes = memSize;
|
|
pageWriteStampTable = new Bit32u [memSizeInBytes>>12];
|
|
|
|
for (Bit32u i=0; i<(memSizeInBytes>>12); i++) {
|
|
pageWriteStampTable[i] = ICacheWriteStampInvalid;
|
|
}
|
|
}
|
|
|
|
BX_CPP_INLINE Bit32u getPageWriteStamp(Bit32u pAddr) const
|
|
{
|
|
if (pAddr < memSizeInBytes)
|
|
return pageWriteStampTable[pAddr>>12];
|
|
else
|
|
return ICacheWriteStampInvalid;
|
|
}
|
|
|
|
BX_CPP_INLINE void setPageWriteStamp(Bit32u pAddr, Bit32u pageWriteStamp)
|
|
{
|
|
if (pAddr < memSizeInBytes)
|
|
pageWriteStampTable[pAddr>>12] = pageWriteStamp;
|
|
}
|
|
|
|
BX_CPP_INLINE void decWriteStamp(Bit32u a20Addr);
|
|
};
|
|
|
|
BX_CPP_INLINE void bxPageWriteStampTable::decWriteStamp(Bit32u a20Addr)
|
|
{
|
|
// Increment page write stamp, so iCache entries with older stamps
|
|
// are effectively invalidated.
|
|
Bit32u pageIndex = a20Addr >> 12;
|
|
Bit32u writeStamp = pageWriteStampTable[pageIndex];
|
|
|
|
if (writeStamp & iCachePageDataMask)
|
|
{
|
|
// Page possibly contains iCache code.
|
|
if (writeStamp & ICacheWriteStampMask) {
|
|
// Short case: there is room to decrement the generation counter.
|
|
pageWriteStampTable[pageIndex]--;
|
|
}
|
|
else {
|
|
// Long case: there is no more room to decrement. We have to dump
|
|
// all iCache entries which can possibly hash to this page since
|
|
// we don't keep track of individual entries.
|
|
invalidateIcacheEntries(a20Addr);
|
|
|
|
// Reset write stamp to highest value to begin the decrementing
|
|
// process again.
|
|
pageWriteStampTable[pageIndex] = ICacheWriteStampInvalid;
|
|
}
|
|
}
|
|
}
|
|
|
|
extern bxPageWriteStampTable pageWriteStampTable;
|
|
|
|
#endif
|