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dosbox-staging/src/cpu/paging.cpp

321 lines
8.3 KiB
C++

/*
* Copyright (C) 2002-2003 The DOSBox Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 Library General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include "dosbox.h"
#include "mem.h"
#include "paging.h"
#include "regs.h"
#include "lazyflags.h"
#include "cpu.h"
#include "debug.h"
#define LINK_TOTAL (64*1024)
PagingBlock paging;
static Bit32u mapfirstmb[LINK_START];
Bitu PageHandler::readb(PhysPt addr) {
E_Exit("No byte handler for read from %d",addr);
return 0;
}
Bitu PageHandler::readw(PhysPt addr) {
return
(readb(addr+0) << 0) |
(readb(addr+1) << 8);
}
Bitu PageHandler::readd(PhysPt addr) {
return
(readb(addr+0) << 0) |
(readb(addr+1) << 8) |
(readb(addr+2) << 16) |
(readb(addr+3) << 24);
}
void PageHandler::writeb(PhysPt addr,Bitu val) {
E_Exit("No byte handler for write to %d",addr);
};
void PageHandler::writew(PhysPt addr,Bitu val) {
writeb(addr+0,(Bit8u) (val >> 0));
writeb(addr+1,(Bit8u) (val >> 8));
}
void PageHandler::writed(PhysPt addr,Bitu val) {
writeb(addr+0,(Bit8u) (val >> 0));
writeb(addr+1,(Bit8u) (val >> 8));
writeb(addr+2,(Bit8u) (val >> 16));
writeb(addr+3,(Bit8u) (val >> 24));
};
HostPt PageHandler::GetHostPt(Bitu phys_page) {
return 0;
}
Bits Full_DeCode(void);
struct PF_Entry {
Bitu cs;
Bitu eip;
Bitu page_addr;
};
#define PF_QUEUESIZE 16
struct {
Bitu used;
PF_Entry entries[PF_QUEUESIZE];
} pf_queue;
static Bits PageFaultCore(void) {
CPU_CycleLeft+=CPU_Cycles;
CPU_Cycles=1;
Bitu ret=Full_DeCode();
CPU_CycleLeft+=CPU_Cycles;
if (ret<0) E_Exit("Got a dosbox close machine in pagefault core?");
if (ret)
return ret;
if (!pf_queue.used) E_Exit("PF Core without PF");
PF_Entry * entry=&pf_queue.entries[pf_queue.used-1];
X86PageEntry pentry;
pentry.load=MEM_PhysReadD(entry->page_addr);
if (pentry.block.p && entry->cs == SegValue(cs) && entry->eip==reg_eip)
return -1;
return 0;
}
#if C_DEBUG
Bitu DEBUG_EnableDebugger(void);
#endif
void PAGING_PageFault(PhysPt lin_addr,Bitu page_addr,Bitu type) {
/* Save the state of the cpu cores */
LazyFlags old_lflags;
memcpy(&old_lflags,&lflags,sizeof(LazyFlags));
CPU_Decoder * old_cpudecoder;
old_cpudecoder=cpudecoder;
cpudecoder=&PageFaultCore;
paging.cr2=lin_addr;
PF_Entry * entry=&pf_queue.entries[pf_queue.used++];
LOG(LOG_PAGING,LOG_NORMAL)("PageFault at %X type %d queue %d",lin_addr,type,pf_queue.used);
entry->cs=SegValue(cs);
entry->eip=reg_eip;
entry->page_addr=page_addr;
//Caused by a write by default?
CPU_Exception(14,0x2 );
#if C_DEBUG
// DEBUG_EnableDebugger();
#endif
DOSBOX_RunMachine();
pf_queue.used--;
LOG(LOG_PAGING,LOG_NORMAL)("Left PageFault for %x queue %d",lin_addr,pf_queue.used);
memcpy(&lflags,&old_lflags,sizeof(LazyFlags));
cpudecoder=old_cpudecoder;
}
void MEM_PhysWriteD(Bitu addr,Bit32u val);
class InitPageHandler : public PageHandler {
public:
InitPageHandler() {flags=PFLAG_INIT|PFLAG_NOCODE;}
Bitu readb(PhysPt addr) {
InitPage(addr);
return mem_readb(addr);
}
Bitu readw(PhysPt addr) {
InitPage(addr);
return mem_readw(addr);
}
Bitu readd(PhysPt addr) {
InitPage(addr);
return mem_readd(addr);
}
void writeb(PhysPt addr,Bitu val) {
InitPage(addr);
mem_writeb(addr,val);
}
void writew(PhysPt addr,Bitu val) {
InitPage(addr);
mem_writew(addr,val);
}
void writed(PhysPt addr,Bitu val) {
InitPage(addr);
mem_writed(addr,val);
}
void InitPage(Bitu lin_addr) {
Bitu lin_page=lin_addr >> 12;
Bitu phys_page;
if (paging.enabled) {
Bitu d_index=lin_page >> 10;
Bitu t_index=lin_page & 0x3ff;
Bitu table_addr=(paging.base.page<<12)+d_index*4;
X86PageEntry table;
table.load=MEM_PhysReadD(table_addr);
if (!table.block.p) {
LOG(LOG_PAGING,LOG_ERROR)("NP Table");
PAGING_PageFault(lin_addr,table_addr,0);
table.load=MEM_PhysReadD(table_addr);
if (!table.block.p)
E_Exit("Pagefault didn't correct table");
}
table.block.a=table.block.d=1; //Set access/Dirty
MEM_PhysWriteD(table_addr,table.load);
X86PageEntry entry;
Bitu entry_addr=(table.block.base<<12)+t_index*4;
entry.load=MEM_PhysReadD(entry_addr);
if (!entry.block.p) {
LOG(LOG_PAGING,LOG_ERROR)("NP Page");
PAGING_PageFault(lin_addr,entry_addr,0);
entry.load=MEM_PhysReadD(entry_addr);
if (!entry.block.p)
E_Exit("Pagefault didn't correct page");
}
entry.block.a=entry.block.d=1; //Set access/Dirty
MEM_PhysWriteD(entry_addr,entry.load);
phys_page=entry.block.base;
} else {
if (lin_page<LINK_START) phys_page=mapfirstmb[lin_page];
else phys_page=lin_page;
}
PAGING_LinkPage(lin_page,phys_page);
}
};
bool PAGING_MakePhysPage(Bitu & page) {
if (paging.enabled) {
Bitu d_index=page >> 10;
Bitu t_index=page & 0x3ff;
X86PageEntry table;
table.load=MEM_PhysReadD((paging.base.page<<12)+d_index*4);
if (!table.block.p) return false;
X86PageEntry entry;
entry.load=MEM_PhysReadD((table.block.base<<12)+t_index*4);
if (!entry.block.p) return false;
page=entry.block.base;
} else {
if (page<LINK_START) page=mapfirstmb[page];
//Else keep it the same
}
return true;
}
static InitPageHandler init_page_handler;
Bitu PAGING_GetDirBase(void) {
return paging.cr3;
}
void PAGING_InitTLB(void) {
for (Bitu i=0;i<TLB_SIZE;i++) {
paging.tlb.read[i]=0;
paging.tlb.write[i]=0;
paging.tlb.handler[i]=&init_page_handler;
}
paging.links.used=0;
}
void PAGING_ClearTLB(void) {
Bit32u * entries=&paging.links.entries[0];
for (;paging.links.used>0;paging.links.used--) {
Bitu page=*entries++;
paging.tlb.read[page]=0;
paging.tlb.write[page]=0;
paging.tlb.handler[page]=&init_page_handler;
}
paging.links.used=0;
}
void PAGING_UnlinkPages(Bitu lin_page,Bitu pages) {
for (;pages>0;pages--) {
paging.tlb.read[lin_page]=0;
paging.tlb.write[lin_page]=0;
paging.tlb.handler[lin_page]=&init_page_handler;
}
}
void PAGING_LinkPage(Bitu lin_page,Bitu phys_page) {
PageHandler * handler=MEM_GetPageHandler(phys_page);
Bitu lin_base=lin_page << 12;
if (lin_page>=TLB_SIZE || phys_page>=TLB_SIZE)
E_Exit("Illegal page");
HostPt host_mem=handler->GetHostPt(phys_page);
paging.tlb.phys_page[lin_page]=phys_page;
if (handler->flags & PFLAG_READABLE) paging.tlb.read[lin_page]=host_mem-lin_base;
else paging.tlb.read[lin_page]=0;
if (handler->flags & PFLAG_WRITEABLE) paging.tlb.write[lin_page]=host_mem-lin_base;
else paging.tlb.write[lin_page]=0;
if (paging.links.used>=PAGING_LINKS) E_Exit("Not enough paging links");
paging.links.entries[paging.links.used++]=lin_page;
paging.tlb.handler[lin_page]=handler;
}
void PAGING_MapPage(Bitu lin_page,Bitu phys_page) {
if (lin_page<LINK_START) {
mapfirstmb[lin_page]=phys_page;
paging.tlb.read[lin_page]=0;
paging.tlb.write[lin_page]=0;
paging.tlb.handler[lin_page]=&init_page_handler;
} else {
PAGING_LinkPage(lin_page,phys_page);
}
}
void PAGING_SetDirBase(Bitu cr3) {
paging.cr3=cr3;
paging.base.page=cr3 >> 12;
paging.base.addr=cr3 & ~4095;
LOG(LOG_PAGING,LOG_NORMAL)("CR3:%X Base %X",cr3,paging.base.page);
if (paging.enabled) {
PAGING_ClearTLB();
}
}
void PAGING_Enable(bool enabled) {
/* If paging is disable we work from a default paging table */
if (paging.enabled==enabled) return;
paging.enabled=enabled;
if (!enabled) {
LOG(LOG_PAGING,LOG_NORMAL)("Disabled");
} else {
LOG(LOG_PAGING,LOG_NORMAL)("Enabled");
#if !(C_DEBUG)
E_Exit("CPU Paging features aren't supported");
#endif
PAGING_SetDirBase(paging.cr3);
}
PAGING_ClearTLB();
}
bool PAGING_Enabled(void) {
return paging.enabled;
}
void PAGING_Init(Section * sec) {
/* Setup default Page Directory, force it to update */
paging.enabled=false;
PAGING_InitTLB();
Bitu i;
for (i=0;i<LINK_START;i++) {
mapfirstmb[i]=i;
}
pf_queue.used=0;
}