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Address translation: Make the page table more flexible.

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The page table now stores actual page table entries. It is still a templated
class here, but this will be corrected in the near future.

--HG--
extra : convert_revision : 804dcc6320414c2b3ab76a74a15295bd24e1d13d
This commit is contained in:
Gabe Black
2007-08-26 20:33:57 -07:00
parent 80d51650c8
commit 9b49a78cfd
22 changed files with 298 additions and 310 deletions
Download Patch File Download Diff File Expand all files Collapse all files

81
src/mem/page_table.cc
View File

@@ -63,32 +63,6 @@ PageTable::~PageTable()
{
}
Fault
PageTable::page_check(Addr addr, int64_t size) const
{
if (size < sizeof(uint64_t)) {
if (!isPowerOf2(size)) {
panic("Invalid request size!\n");
return genMachineCheckFault();
}
if ((size - 1) & addr)
return genAlignmentFault();
}
else {
if ((addr & (VMPageSize - 1)) + size > VMPageSize) {
panic("Invalid request size!\n");
return genMachineCheckFault();
}
if ((sizeof(uint64_t) - 1) & addr)
return genAlignmentFault();
}
return NoFault;
}
void
PageTable::allocate(Addr vaddr, int64_t size)
{
@@ -98,62 +72,73 @@ PageTable::allocate(Addr vaddr, int64_t size)
DPRINTF(MMU, "Allocating Page: %#x-%#x\n", vaddr, vaddr+ size);
for (; size > 0; size -= pageSize, vaddr += pageSize) {
m5::hash_map<Addr,Addr>::iterator iter = pTable.find(vaddr);
PTableItr iter = pTable.find(vaddr);
if (iter != pTable.end()) {
// already mapped
fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
fatal("PageTable::allocate: address 0x%x already mapped",
vaddr);
}
pTable[vaddr] = system->new_page();
pTable[vaddr] = TheISA::TlbEntry(system->new_page());
updateCache(vaddr, pTable[vaddr]);
}
}
bool
PageTable::translate(Addr vaddr, Addr &paddr)
PageTable::lookup(Addr vaddr, TheISA::TlbEntry &entry)
{
Addr page_addr = pageAlign(vaddr);
paddr = 0;
if (pTableCache[0].vaddr == page_addr) {
paddr = pTableCache[0].paddr + pageOffset(vaddr);
entry = pTableCache[0].entry;
return true;
}
if (pTableCache[1].vaddr == page_addr) {
paddr = pTableCache[1].paddr + pageOffset(vaddr);
entry = pTableCache[1].entry;
return true;
}
if (pTableCache[2].vaddr == page_addr) {
paddr = pTableCache[2].paddr + pageOffset(vaddr);
entry = pTableCache[2].entry;
return true;
}
m5::hash_map<Addr,Addr>::iterator iter = pTable.find(page_addr);
PTableItr iter = pTable.find(page_addr);
if (iter == pTable.end()) {
return false;
}
updateCache(page_addr, iter->second);
paddr = iter->second + pageOffset(vaddr);
entry = iter->second;
return true;
}
bool
PageTable::translate(Addr vaddr, Addr &paddr)
{
TheISA::TlbEntry entry;
if (!lookup(vaddr, entry))
return false;
paddr = pageOffset(vaddr) + entry.pageStart;
return true;
}
Fault
PageTable::translate(RequestPtr &req)
PageTable::translate(RequestPtr req)
{
Addr paddr;
assert(pageAlign(req->getVaddr() + req->getSize() - 1)
== pageAlign(req->getVaddr()));
if (!translate(req->getVaddr(), paddr)) {
return Fault(new PageTableFault(req->getVaddr()));
return Fault(new GenericPageTableFault(req->getVaddr()));
}
req->setPaddr(paddr);
return page_check(req->getPaddr(), req->getSize());
if ((paddr & (pageSize - 1)) + req->getSize() > pageSize) {
panic("Request spans page boundaries!\n");
return NoFault;
}
return NoFault;
}
void
@@ -163,11 +148,11 @@ PageTable::serialize(std::ostream &os)
int count = 0;
m5::hash_map<Addr,Addr>::iterator iter = pTable.begin();
m5::hash_map<Addr,Addr>::iterator end = pTable.end();
PTableItr iter = pTable.begin();
PTableItr end = pTable.end();
while (iter != end) {
paramOut(os, csprintf("ptable.entry%dvaddr", count), iter->first);
paramOut(os, csprintf("ptable.entry%dpaddr", count), iter->second);
iter->second.serialize(os);
++iter;
++count;
@@ -180,16 +165,16 @@ PageTable::unserialize(Checkpoint *cp, const std::string &section)
{
int i = 0, count;
paramIn(cp, section, "ptable.size", count);
Addr vaddr, paddr;
Addr vaddr;
TheISA::TlbEntry entry;
pTable.clear();
while(i < count) {
paramIn(cp, section, csprintf("ptable.entry%dvaddr", i), vaddr);
paramIn(cp, section, csprintf("ptable.entry%dpaddr", i), paddr);
pTable[vaddr] = paddr;
entry.unserialize(cp, section);
pTable[vaddr] = entry;
++i;
}
}

38
src/mem/page_table.hh
View File

@@ -40,11 +40,11 @@
#include "sim/faults.hh"
#include "arch/isa_traits.hh"
#include "arch/tlb.hh"
#include "base/hashmap.hh"
#include "base/trace.hh"
#include "mem/request.hh"
#include "mem/packet.hh"
#include "sim/sim_object.hh"
#include "sim/host.hh"
#include "sim/serialize.hh"
class System;
@@ -54,12 +54,14 @@ class System;
class PageTable
{
protected:
m5::hash_map<Addr,Addr> pTable;
typedef m5::hash_map<Addr, TheISA::TlbEntry> PTable;
typedef PTable::iterator PTableItr;
PTable pTable;
struct cacheElement {
Addr paddr;
Addr vaddr;
} ;
TheISA::TlbEntry entry;
};
struct cacheElement pTableCache[3];
@@ -77,10 +79,15 @@ class PageTable
Addr pageAlign(Addr a) { return (a & ~offsetMask); }
Addr pageOffset(Addr a) { return (a & offsetMask); }
Fault page_check(Addr addr, int64_t size) const;
void allocate(Addr vaddr, int64_t size);
/**
* Lookup function
* @param vaddr The virtual address.
* @return entry The page table entry corresponding to vaddr.
*/
bool lookup(Addr vaddr, TheISA::TlbEntry &entry);
/**
* Translate function
* @param vaddr The virtual address.
@@ -90,28 +97,29 @@ class PageTable
/**
* Perform a translation on the memory request, fills in paddr
* field of mem_req.
* field of req.
* @param req The memory request.
*/
Fault translate(RequestPtr &req);
Fault translate(RequestPtr req);
/**
* Update the page table cache.
* @param vaddr virtual address (page aligned) to check
* @param paddr physical address (page aligned) to return
* @param pte page table entry to return
*/
inline void updateCache(Addr vaddr, Addr paddr)
inline void updateCache(Addr vaddr, TheISA::TlbEntry entry)
{
pTableCache[2].paddr = pTableCache[1].paddr;
pTableCache[2].entry = pTableCache[1].entry;
pTableCache[2].vaddr = pTableCache[1].vaddr;
pTableCache[1].paddr = pTableCache[0].paddr;
pTableCache[1].entry = pTableCache[0].entry;
pTableCache[1].vaddr = pTableCache[0].vaddr;
pTableCache[0].paddr = paddr;
pTableCache[0].entry = entry;
pTableCache[0].vaddr = vaddr;
}
void serialize(std::ostream &os);
void unserialize(Checkpoint *cp, const std::string &section);
};