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gem5/arch/alpha/alpha_memory.cc
Steve Reinhardt d53c6c168a Get software prefetching to work in full-system mode. 
Mostly a matter of keeping prefetches to invalid addrs
from messing up VM IPRs.  Also discovered that wh64s were
not being treated as prefetches, when they really should be
(for the most part, anyway).

arch/alpha/alpha_memory.cc:
arch/alpha/alpha_memory.hh:
    - Get rid of intrlock flag for locking VM fault regs (a la EV5);
    instead, just don't update regs on VPTE loads (a la EV6).
    - Add NO_FAULT MemReq flag to indicate references that should not
    cause page faults (i.e., prefetches).
arch/alpha/ev5.cc:
    - Get rid of intrlock flag for locking VM fault regs (a la EV5);
    instead, just don't update regs on VPTE loads (a la EV6).
    - Add Fault trace flag.
arch/alpha/isa_desc:
    - Add NO_FAULT MemReq flag to indicate references that should not
    cause page faults (i.e., prefetches).
    - Mark wh64 as a "data prefetch" instruction so it gets controlled
    properly by the FullCPU data prefetch control switch.
    - Align wh64 EA in decoder so issue stage doesn't need to worry about it.
arch/alpha/isa_traits.hh:
    - Get rid of intrlock flag for locking VM fault regs (a la EV5);
    instead, just don't update regs on VPTE loads (a la EV6).
base/traceflags.py:
    - Add Fault trace flag.
cpu/simple_cpu/simple_cpu.hh:
    - Pass MemReq flags to writeHint() operation.
cpu/static_inst.hh:
    Update comment re: prefetches.

--HG--
extra : convert_revision : 62e466b0f4c0ff9961796270fa2e371ec24bcbb6
2004-06-15 10:48:08 -07:00

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/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sstream>
#include <string>
#include <vector>
#include "base/inifile.hh"
#include "base/str.hh"
#include "base/trace.hh"
#include "cpu/exec_context.hh"
#include "sim/builder.hh"
#include "targetarch/alpha_memory.hh"
#include "targetarch/ev5.hh"
using namespace std;
///////////////////////////////////////////////////////////////////////
//
// Alpha TLB
//
AlphaTLB::AlphaTLB(const string &name, int s)
: SimObject(name), size(s), nlu(0)
{
table = new AlphaISA::PTE[size];
memset(table, 0, sizeof(AlphaISA::PTE[size]));
}
AlphaTLB::~AlphaTLB()
{
if (table)
delete [] table;
}
// look up an entry in the TLB
AlphaISA::PTE *
AlphaTLB::lookup(Addr vpn, uint8_t asn) const
{
DPRINTF(TLB, "lookup %#x\n", vpn);
PageTable::const_iterator i = lookupTable.find(vpn);
if (i == lookupTable.end())
return NULL;
while (i->first == vpn) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
if (vpn == pte->tag && (pte->asma || pte->asn == asn))
return pte;
++i;
}
// not found...
return NULL;
}
void
AlphaTLB::checkCacheability(MemReqPtr &req)
{
// in Alpha, cacheability is controlled by upper-level bits of the
// physical address
if (req->paddr & PA_UNCACHED_BIT) {
if (PA_IPR_SPACE(req->paddr)) {
// IPR memory space not implemented
if (!req->xc->misspeculating()) {
switch (req->paddr) {
case ULL(0xFFFFF00188):
req->data = 0;
break;
default:
panic("IPR memory space not implemented! PA=%x\n",
req->paddr);
}
}
} else {
// mark request as uncacheable
req->flags |= UNCACHEABLE;
}
}
}
// insert a new TLB entry
void
AlphaTLB::insert(Addr vaddr, AlphaISA::PTE &pte)
{
if (table[nlu].valid) {
Addr oldvpn = table[nlu].tag;
PageTable::iterator i = lookupTable.find(oldvpn);
if (i == lookupTable.end())
panic("TLB entry not found in lookupTable");
int index;
while ((index = i->second) != nlu) {
if (table[index].tag != oldvpn)
panic("TLB entry not found in lookupTable");
++i;
}
DPRINTF(TLB, "remove @%d: %#x -> %#x\n", nlu, oldvpn, table[nlu].ppn);
lookupTable.erase(i);
}
Addr vpn = VA_VPN(vaddr);
DPRINTF(TLB, "insert @%d: %#x -> %#x\n", nlu, vpn, pte.ppn);
table[nlu] = pte;
table[nlu].tag = vpn;
table[nlu].valid = true;
lookupTable.insert(make_pair(vpn, nlu));
nextnlu();
}
void
AlphaTLB::flushAll()
{
memset(table, 0, sizeof(AlphaISA::PTE[size]));
lookupTable.clear();
nlu = 0;
}
void
AlphaTLB::flushProcesses()
{
PageTable::iterator i = lookupTable.begin();
PageTable::iterator end = lookupTable.end();
while (i != end) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
if (!pte->asma) {
DPRINTF(TLB, "flush @%d: %#x -> %#x\n", index, pte->tag, pte->ppn);
pte->valid = false;
lookupTable.erase(i);
}
++i;
}
}
void
AlphaTLB::flushAddr(Addr vaddr, uint8_t asn)
{
Addr vpn = VA_VPN(vaddr);
PageTable::iterator i = lookupTable.find(vpn);
if (i == lookupTable.end())
return;
while (i->first == vpn) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
if (vpn == pte->tag && (pte->asma || pte->asn == asn)) {
DPRINTF(TLB, "flushaddr @%d: %#x -> %#x\n", index, vpn, pte->ppn);
// invalidate this entry
pte->valid = false;
lookupTable.erase(i);
}
++i;
}
}
void
AlphaTLB::serialize(ostream &os)
{
SERIALIZE_SCALAR(size);
SERIALIZE_SCALAR(nlu);
for (int i = 0; i < size; i++) {
nameOut(os, csprintf("%s.PTE%d", name(), i));
table[i].serialize(os);
}
}
void
AlphaTLB::unserialize(Checkpoint *cp, const string &section)
{
UNSERIALIZE_SCALAR(size);
UNSERIALIZE_SCALAR(nlu);
for (int i = 0; i < size; i++) {
table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
if (table[i].valid) {
lookupTable.insert(make_pair(table[i].tag, i));
}
}
}
///////////////////////////////////////////////////////////////////////
//
// Alpha ITB
//
AlphaITB::AlphaITB(const std::string &name, int size)
: AlphaTLB(name, size)
{}
void
AlphaITB::regStats()
{
hits
.name(name() + ".hits")
.desc("ITB hits");
misses
.name(name() + ".misses")
.desc("ITB misses");
acv
.name(name() + ".acv")
.desc("ITB acv");
accesses
.name(name() + ".accesses")
.desc("ITB accesses");
accesses = hits + misses;
}
void
AlphaITB::fault(Addr pc, ExecContext *xc) const
{
uint64_t *ipr = xc->regs.ipr;
if (!xc->misspeculating()) {
ipr[AlphaISA::IPR_ITB_TAG] = pc;
ipr[AlphaISA::IPR_IFAULT_VA_FORM] =
ipr[AlphaISA::IPR_IVPTBR] | (VA_VPN(pc) << 3);
}
}
Fault
AlphaITB::translate(MemReqPtr &req) const
{
InternalProcReg *ipr = req->xc->regs.ipr;
if (PC_PAL(req->vaddr)) {
// strip off PAL PC marker (lsb is 1)
req->paddr = (req->vaddr & ~3) & PA_IMPL_MASK;
hits++;
return No_Fault;
}
if (req->flags & PHYSICAL) {
req->paddr = req->vaddr;
} else {
// verify that this is a good virtual address
if (!validVirtualAddress(req->vaddr)) {
fault(req->vaddr, req->xc);
acv++;
return ITB_Acv_Fault;
}
// Check for "superpage" mapping: when SP<1> is set, and
// VA<42:41> == 2, VA<39:13> maps directly to PA<39:13>.
if ((MCSR_SP(ipr[AlphaISA::IPR_MCSR]) & 2) &&
VA_SPACE(req->vaddr) == 2) {
// only valid in kernel mode
if (ICM_CM(ipr[AlphaISA::IPR_ICM]) != AlphaISA::mode_kernel) {
fault(req->vaddr, req->xc);
acv++;
return ITB_Acv_Fault;
}
req->paddr = req->vaddr & PA_IMPL_MASK;
} else {
// not a physical address: need to look up pte
AlphaISA::PTE *pte = lookup(VA_VPN(req->vaddr),
DTB_ASN_ASN(ipr[AlphaISA::IPR_DTB_ASN]));
if (!pte) {
fault(req->vaddr, req->xc);
misses++;
return ITB_Fault_Fault;
}
req->paddr = PA_PFN2PA(pte->ppn) + VA_POFS(req->vaddr & ~3);
// check permissions for this access
if (!(pte->xre & (1 << ICM_CM(ipr[AlphaISA::IPR_ICM])))) {
// instruction access fault
fault(req->vaddr, req->xc);
acv++;
return ITB_Acv_Fault;
}
hits++;
}
}
// check that the physical address is ok (catch bad physical addresses)
if (req->paddr & ~PA_IMPL_MASK)
return Machine_Check_Fault;
checkCacheability(req);
return No_Fault;
}
///////////////////////////////////////////////////////////////////////
//
// Alpha DTB
//
AlphaDTB::AlphaDTB(const std::string &name, int size)
: AlphaTLB(name, size)
{}
void
AlphaDTB::regStats()
{
read_hits
.name(name() + ".read_hits")
.desc("DTB read hits")
;
read_misses
.name(name() + ".read_misses")
.desc("DTB read misses")
;
read_acv
.name(name() + ".read_acv")
.desc("DTB read access violations")
;
read_accesses
.name(name() + ".read_accesses")
.desc("DTB read accesses")
;
write_hits
.name(name() + ".write_hits")
.desc("DTB write hits")
;
write_misses
.name(name() + ".write_misses")
.desc("DTB write misses")
;
write_acv
.name(name() + ".write_acv")
.desc("DTB write access violations")
;
write_accesses
.name(name() + ".write_accesses")
.desc("DTB write accesses")
;
hits
.name(name() + ".hits")
.desc("DTB hits")
;
misses
.name(name() + ".misses")
.desc("DTB misses")
;
acv
.name(name() + ".acv")
.desc("DTB access violations")
;
accesses
.name(name() + ".accesses")
.desc("DTB accesses")
;
hits = read_hits + write_hits;
misses = read_misses + write_misses;
acv = read_acv + write_acv;
accesses = read_accesses + write_accesses;
}
void
AlphaDTB::fault(MemReqPtr &req, uint64_t flags) const
{
ExecContext *xc = req->xc;
Addr vaddr = req->vaddr;
uint64_t *ipr = xc->regs.ipr;
// Set fault address and flags. Even though we're modeling an
// EV5, we use the EV6 technique of not latching fault registers
// on VPTE loads (instead of locking the registers until IPR_VA is
// read, like the EV5). The EV6 approach is cleaner and seems to
// work with EV5 PAL code, but not the other way around.
if (!xc->misspeculating()
&& !(req->flags & VPTE) && !(req->flags & NO_FAULT)) {
// set VA register with faulting address
ipr[AlphaISA::IPR_VA] = vaddr;
// set MM_STAT register flags
ipr[AlphaISA::IPR_MM_STAT] = (((OPCODE(xc->getInst()) & 0x3f) << 11)
| ((RA(xc->getInst()) & 0x1f) << 6)
| (flags & 0x3f));
// set VA_FORM register with faulting formatted address
ipr[AlphaISA::IPR_VA_FORM] =
ipr[AlphaISA::IPR_MVPTBR] | (VA_VPN(vaddr) << 3);
}
}
Fault
AlphaDTB::translate(MemReqPtr &req, bool write) const
{
RegFile *regs = &req->xc->regs;
Addr pc = regs->pc;
InternalProcReg *ipr = regs->ipr;
AlphaISA::mode_type mode =
(AlphaISA::mode_type)DTB_CM_CM(ipr[AlphaISA::IPR_DTB_CM]);
if (PC_PAL(pc)) {
mode = (req->flags & ALTMODE) ?
(AlphaISA::mode_type)ALT_MODE_AM(ipr[AlphaISA::IPR_ALT_MODE])
: AlphaISA::mode_kernel;
}
if (req->flags & PHYSICAL) {
req->paddr = req->vaddr;
} else {
// verify that this is a good virtual address
if (!validVirtualAddress(req->vaddr)) {
fault(req, ((write ? MM_STAT_WR_MASK : 0) | MM_STAT_BAD_VA_MASK |
MM_STAT_ACV_MASK));
if (write) { write_acv++; } else { read_acv++; }
return DTB_Fault_Fault;
}
// Check for "superpage" mapping: when SP<1> is set, and
// VA<42:41> == 2, VA<39:13> maps directly to PA<39:13>.
if ((MCSR_SP(ipr[AlphaISA::IPR_MCSR]) & 2) &&
VA_SPACE(req->vaddr) == 2) {
// only valid in kernel mode
if (DTB_CM_CM(ipr[AlphaISA::IPR_DTB_CM]) !=
AlphaISA::mode_kernel) {
fault(req, ((write ? MM_STAT_WR_MASK : 0) | MM_STAT_ACV_MASK));
if (write) { write_acv++; } else { read_acv++; }
return DTB_Acv_Fault;
}
req->paddr = req->vaddr & PA_IMPL_MASK;
} else {
if (write)
write_accesses++;
else
read_accesses++;
// not a physical address: need to look up pte
AlphaISA::PTE *pte = lookup(VA_VPN(req->vaddr),
DTB_ASN_ASN(ipr[AlphaISA::IPR_DTB_ASN]));
if (!pte) {
// page fault
fault(req,
(write ? MM_STAT_WR_MASK : 0) | MM_STAT_DTB_MISS_MASK);
if (write) { write_misses++; } else { read_misses++; }
return (req->flags & VPTE) ? Pdtb_Miss_Fault : Ndtb_Miss_Fault;
}
req->paddr = PA_PFN2PA(pte->ppn) | VA_POFS(req->vaddr);
if (write) {
if (!(pte->xwe & MODE2MASK(mode))) {
// declare the instruction access fault
fault(req, (MM_STAT_WR_MASK | MM_STAT_ACV_MASK |
(pte->fonw ? MM_STAT_FONW_MASK : 0)));
write_acv++;
return DTB_Fault_Fault;
}
if (pte->fonw) {
fault(req, MM_STAT_WR_MASK | MM_STAT_FONW_MASK);
write_acv++;
return DTB_Fault_Fault;
}
} else {
if (!(pte->xre & MODE2MASK(mode))) {
fault(req, (MM_STAT_ACV_MASK |
(pte->fonr ? MM_STAT_FONR_MASK : 0)));
read_acv++;
return DTB_Acv_Fault;
}
if (pte->fonr) {
fault(req, MM_STAT_FONR_MASK);
read_acv++;
return DTB_Fault_Fault;
}
}
}
if (write)
write_hits++;
else
read_hits++;
}
// check that the physical address is ok (catch bad physical addresses)
if (req->paddr & ~PA_IMPL_MASK)
return Machine_Check_Fault;
checkCacheability(req);
return No_Fault;
}
AlphaISA::PTE &
AlphaTLB::index(bool advance)
{
AlphaISA::PTE *pte = &table[nlu];
if (advance)
nextnlu();
return *pte;
}
DEFINE_SIM_OBJECT_CLASS_NAME("AlphaTLB", AlphaTLB)
BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
Param<int> size;
END_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaITB)
INIT_PARAM_DFLT(size, "TLB size", 48)
END_INIT_SIM_OBJECT_PARAMS(AlphaITB)
CREATE_SIM_OBJECT(AlphaITB)
{
return new AlphaITB(getInstanceName(), size);
}
REGISTER_SIM_OBJECT("AlphaITB", AlphaITB)
BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
Param<int> size;
END_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
INIT_PARAM_DFLT(size, "TLB size", 64)
END_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
CREATE_SIM_OBJECT(AlphaDTB)
{
return new AlphaDTB(getInstanceName(), size);
}
REGISTER_SIM_OBJECT("AlphaDTB", AlphaDTB)
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