Bochs/bochs/cpu/icache.h
Stanislav Shwartsman 8db1de7124 - Fixed several issues, each cause to NullTimer function never be called, the method is required for icache correct functionalit
- Speed-up icache by correct purging of Icache entries
- Several new assertions for timers, to prevent bugs in future
2006-05-16 20:55:55 +00:00

181 lines
5.4 KiB
C++
Executable File

/////////////////////////////////////////////////////////////////////////
// $Id: icache.h,v 1.15 2006-05-16 20:55:55 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
#include <assert.h>
// 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.
const Bit32u ICacheWriteStampInvalid = 0x1fffffff;
const Bit32u ICacheWriteStampStart = 0x1fffffff;
const Bit32u ICacheWriteStampMask = 0x1fffffff;
const Bit32u ICacheFetchModeMask = ~ICacheWriteStampMask;
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];
resetWriteStamps();
}
BX_CPP_INLINE Bit32u getPageWriteStamp(bx_phy_address pAddr) const
{
if (pAddr < memSizeInBytes)
return pageWriteStampTable[pAddr>>12];
else
return ICacheWriteStampInvalid;
}
BX_CPP_INLINE const Bit32u *getPageWriteStampPtr(bx_phy_address pAddr) const
{
if (pAddr < memSizeInBytes)
return &pageWriteStampTable[pAddr>>12];
else
return &ICacheWriteStampInvalid;
}
BX_CPP_INLINE void setPageWriteStamp(bx_phy_address pAddr, Bit32u pageWriteStamp)
{
if (pAddr < memSizeInBytes)
pageWriteStampTable[pAddr>>12] = pageWriteStamp;
}
BX_CPP_INLINE void decWriteStamp(bx_phy_address pAddr)
{
assert(pAddr < memSizeInBytes);
// Decrement page write stamp, so iCache entries with older stamps
// are effectively invalidated.
pageWriteStampTable[pAddr >> 12]--;
}
BX_CPP_INLINE void resetWriteStamps(void);
BX_CPP_INLINE void purgeWriteStamps(void);
};
BX_CPP_INLINE void bxPageWriteStampTable::resetWriteStamps(void)
{
for (Bit32u i=0; i<(memSizeInBytes>>12); i++) {
pageWriteStampTable[i] = ICacheWriteStampInvalid;
}
}
BX_CPP_INLINE void bxPageWriteStampTable::purgeWriteStamps(void)
{
for (Bit32u i=0; i<(memSizeInBytes>>12); i++) {
pageWriteStampTable[i] |= ICacheWriteStampMask;
}
}
extern bxPageWriteStampTable pageWriteStampTable;
#define BxICacheEntries (32 * 1024) // Must be a power of 2.
struct bxICacheEntry_c
{
bx_phy_address 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];
public:
bxICache_c() { flushICacheEntries(); }
BX_CPP_INLINE unsigned hash(bx_phy_address pAddr) const
{
// A pretty dumb hash function for now.
return pAddr & (BxICacheEntries-1);
}
BX_CPP_INLINE void invalidatePage(bx_phy_address pAddr);
BX_CPP_INLINE void purgeICacheEntries(void);
BX_CPP_INLINE void flushICacheEntries(void);
};
BX_CPP_INLINE void bxICache_c::flushICacheEntries(void)
{
bxICacheEntry_c* e = entry;
for (unsigned i=0; i<BxICacheEntries; i++, e++) {
e->writeStamp = ICacheWriteStampInvalid;
}
}
BX_CPP_INLINE void bxICache_c::purgeICacheEntries(void)
{
bxICacheEntry_c* e = entry;
// Since the write stamps may overflow if we always simply decrese them,
// this function has to be called often enough that we can reset them
// (without invalidating the cache).
for (unsigned i=0;i<BxICacheEntries;i++,e++)
{
Bit32u pageWriteStamp = pageWriteStampTable.getPageWriteStamp(e->pAddr);
if (e->writeStamp != pageWriteStamp)
e->writeStamp = ICacheWriteStampInvalid; // invalidate entry
else
e->writeStamp |= ICacheWriteStampMask;
}
}
BX_CPP_INLINE void bxICache_c::invalidatePage(bx_phy_address pAddr)
{
// Take the hash of the 0th page offset.
unsigned iCacheHash = hash(pAddr & 0xfffff000);
for (unsigned o=0; o<4096; o++) {
entry[iCacheHash].writeStamp = ICacheWriteStampInvalid;
iCacheHash = (iCacheHash + 1) % BxICacheEntries;
}
}
extern void purgeICaches(void);
extern void flushICaches(void);
#endif