gem5/src/arch/arm/table_walker.cc
2011-04-15 10:44:06 -07:00

734 lines
23 KiB
C++

/*
* Copyright (c) 2010 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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.
*
* Authors: Ali Saidi
*/
#include "arch/arm/faults.hh"
#include "arch/arm/table_walker.hh"
#include "arch/arm/tlb.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "dev/io_device.hh"
#include "sim/system.hh"
using namespace ArmISA;
TableWalker::TableWalker(const Params *p)
: MemObject(p), port(NULL), tlb(NULL), currState(NULL), pending(false),
doL1DescEvent(this), doL2DescEvent(this), doProcessEvent(this)
{
sctlr = 0;
}
TableWalker::~TableWalker()
{
;
}
unsigned int
TableWalker::drain(Event *de)
{
if (stateQueueL1.size() || stateQueueL2.size() || pendingQueue.size())
{
changeState(Draining);
DPRINTF(Checkpoint, "TableWalker busy, wait to drain\n");
return 1;
}
else
{
changeState(Drained);
DPRINTF(Checkpoint, "TableWalker free, no need to drain\n");
return 0;
}
}
void
TableWalker::resume()
{
MemObject::resume();
if ((params()->sys->getMemoryMode() == Enums::timing) && currState) {
delete currState;
currState = NULL;
}
}
Port*
TableWalker::getPort(const std::string &if_name, int idx)
{
if (if_name == "port") {
if (port != NULL)
return port;
System *sys = params()->sys;
Tick minb = params()->min_backoff;
Tick maxb = params()->max_backoff;
port = new DmaPort(this, sys, minb, maxb);
return port;
}
return NULL;
}
Fault
TableWalker::walk(RequestPtr _req, ThreadContext *_tc, uint8_t _cid, TLB::Mode _mode,
TLB::Translation *_trans, bool _timing)
{
if (!currState) {
// For atomic mode, a new WalkerState instance should be only created
// once per TLB. For timing mode, a new instance is generated for every
// TLB miss.
DPRINTF(TLBVerbose, "creating new instance of WalkerState\n");
currState = new WalkerState();
currState->tableWalker = this;
} else if (_timing) {
// This is a translation that was completed and then faulted again
// because some underlying parameters that affect the translation
// changed out from under us (e.g. asid). It will either be a
// misprediction, in which case nothing will happen or we'll use
// this fault to re-execute the faulting instruction which should clean
// up everything.
if (currState->vaddr == _req->getVaddr()) {
return new ReExec;
}
panic("currState should always be empty in timing mode!\n");
}
currState->tc = _tc;
currState->transState = _trans;
currState->req = _req;
currState->fault = NoFault;
currState->contextId = _cid;
currState->timing = _timing;
currState->mode = _mode;
/** @todo These should be cached or grabbed from cached copies in
the TLB, all these miscreg reads are expensive */
currState->vaddr = currState->req->getVaddr();
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR);
sctlr = currState->sctlr;
currState->N = currState->tc->readMiscReg(MISCREG_TTBCR);
currState->isFetch = (currState->mode == TLB::Execute);
currState->isWrite = (currState->mode == TLB::Write);
if (!currState->timing)
return processWalk();
if (pending || pendingQueue.size()) {
pendingQueue.push_back(currState);
currState = NULL;
} else {
pending = true;
return processWalk();
}
return NoFault;
}
void
TableWalker::processWalkWrapper()
{
assert(!currState);
assert(pendingQueue.size());
currState = pendingQueue.front();
pendingQueue.pop_front();
pending = true;
processWalk();
}
Fault
TableWalker::processWalk()
{
Addr ttbr = 0;
// If translation isn't enabled, we shouldn't be here
assert(currState->sctlr.m);
DPRINTF(TLB, "Begining table walk for address %#x, TTBCR: %#x, bits:%#x\n",
currState->vaddr, currState->N, mbits(currState->vaddr, 31,
32-currState->N));
if (currState->N == 0 || !mbits(currState->vaddr, 31, 32-currState->N)) {
DPRINTF(TLB, " - Selecting TTBR0\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR0);
} else {
DPRINTF(TLB, " - Selecting TTBR1\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR1);
currState->N = 0;
}
Addr l1desc_addr = mbits(ttbr, 31, 14-currState->N) |
(bits(currState->vaddr,31-currState->N,20) << 2);
DPRINTF(TLB, " - Descriptor at address %#x\n", l1desc_addr);
// Trickbox address check
Fault f;
f = tlb->walkTrickBoxCheck(l1desc_addr, currState->vaddr, sizeof(uint32_t),
currState->isFetch, currState->isWrite, 0, true);
if (f) {
DPRINTF(TLB, "Trickbox check caused fault on %#x\n", currState->vaddr);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
Request::Flags flag = 0;
if (currState->sctlr.c == 0) {
flag = Request::UNCACHEABLE;
}
if (currState->timing) {
port->dmaAction(MemCmd::ReadReq, l1desc_addr, sizeof(uint32_t),
&doL1DescEvent, (uint8_t*)&currState->l1Desc.data,
currState->tc->getCpuPtr()->ticks(1), flag);
DPRINTF(TLBVerbose, "Adding to walker fifo: queue size before adding: %d\n",
stateQueueL1.size());
stateQueueL1.push_back(currState);
currState = NULL;
} else {
port->dmaAction(MemCmd::ReadReq, l1desc_addr, sizeof(uint32_t),
NULL, (uint8_t*)&currState->l1Desc.data,
currState->tc->getCpuPtr()->ticks(1), flag);
doL1Descriptor();
f = currState->fault;
}
return f;
}
void
TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, SCTLR sctlr,
uint8_t texcb, bool s)
{
// Note: tc and sctlr local variables are hiding tc and sctrl class
// variables
DPRINTF(TLBVerbose, "memAttrs texcb:%d s:%d\n", texcb, s);
te.shareable = false; // default value
te.nonCacheable = false;
bool outer_shareable = false;
if (sctlr.tre == 0 || ((sctlr.tre == 1) && (sctlr.m == 0))) {
switch(texcb) {
case 0: // Stongly-ordered
te.nonCacheable = true;
te.mtype = TlbEntry::StronglyOrdered;
te.shareable = true;
te.innerAttrs = 1;
te.outerAttrs = 0;
break;
case 1: // Shareable Device
te.nonCacheable = true;
te.mtype = TlbEntry::Device;
te.shareable = true;
te.innerAttrs = 3;
te.outerAttrs = 0;
break;
case 2: // Outer and Inner Write-Through, no Write-Allocate
te.mtype = TlbEntry::Normal;
te.shareable = s;
te.innerAttrs = 6;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 3: // Outer and Inner Write-Back, no Write-Allocate
te.mtype = TlbEntry::Normal;
te.shareable = s;
te.innerAttrs = 7;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 4: // Outer and Inner Non-cacheable
te.nonCacheable = true;
te.mtype = TlbEntry::Normal;
te.shareable = s;
te.innerAttrs = 0;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 5: // Reserved
panic("Reserved texcb value!\n");
break;
case 6: // Implementation Defined
panic("Implementation-defined texcb value!\n");
break;
case 7: // Outer and Inner Write-Back, Write-Allocate
te.mtype = TlbEntry::Normal;
te.shareable = s;
te.innerAttrs = 5;
te.outerAttrs = 1;
break;
case 8: // Non-shareable Device
te.nonCacheable = true;
te.mtype = TlbEntry::Device;
te.shareable = false;
te.innerAttrs = 3;
te.outerAttrs = 0;
break;
case 9 ... 15: // Reserved
panic("Reserved texcb value!\n");
break;
case 16 ... 31: // Cacheable Memory
te.mtype = TlbEntry::Normal;
te.shareable = s;
if (bits(texcb, 1,0) == 0 || bits(texcb, 3,2) == 0)
te.nonCacheable = true;
te.innerAttrs = bits(texcb, 1, 0);
te.outerAttrs = bits(texcb, 3, 2);
break;
default:
panic("More than 32 states for 5 bits?\n");
}
} else {
assert(tc);
PRRR prrr = tc->readMiscReg(MISCREG_PRRR);
NMRR nmrr = tc->readMiscReg(MISCREG_NMRR);
DPRINTF(TLBVerbose, "memAttrs PRRR:%08x NMRR:%08x\n", prrr, nmrr);
uint8_t curr_tr = 0, curr_ir = 0, curr_or = 0;
switch(bits(texcb, 2,0)) {
case 0:
curr_tr = prrr.tr0;
curr_ir = nmrr.ir0;
curr_or = nmrr.or0;
outer_shareable = (prrr.nos0 == 0);
break;
case 1:
curr_tr = prrr.tr1;
curr_ir = nmrr.ir1;
curr_or = nmrr.or1;
outer_shareable = (prrr.nos1 == 0);
break;
case 2:
curr_tr = prrr.tr2;
curr_ir = nmrr.ir2;
curr_or = nmrr.or2;
outer_shareable = (prrr.nos2 == 0);
break;
case 3:
curr_tr = prrr.tr3;
curr_ir = nmrr.ir3;
curr_or = nmrr.or3;
outer_shareable = (prrr.nos3 == 0);
break;
case 4:
curr_tr = prrr.tr4;
curr_ir = nmrr.ir4;
curr_or = nmrr.or4;
outer_shareable = (prrr.nos4 == 0);
break;
case 5:
curr_tr = prrr.tr5;
curr_ir = nmrr.ir5;
curr_or = nmrr.or5;
outer_shareable = (prrr.nos5 == 0);
break;
case 6:
panic("Imp defined type\n");
case 7:
curr_tr = prrr.tr7;
curr_ir = nmrr.ir7;
curr_or = nmrr.or7;
outer_shareable = (prrr.nos7 == 0);
break;
}
switch(curr_tr) {
case 0:
DPRINTF(TLBVerbose, "StronglyOrdered\n");
te.mtype = TlbEntry::StronglyOrdered;
te.nonCacheable = true;
te.innerAttrs = 1;
te.outerAttrs = 0;
te.shareable = true;
break;
case 1:
DPRINTF(TLBVerbose, "Device ds1:%d ds0:%d s:%d\n",
prrr.ds1, prrr.ds0, s);
te.mtype = TlbEntry::Device;
te.nonCacheable = true;
te.innerAttrs = 3;
te.outerAttrs = 0;
if (prrr.ds1 && s)
te.shareable = true;
if (prrr.ds0 && !s)
te.shareable = true;
break;
case 2:
DPRINTF(TLBVerbose, "Normal ns1:%d ns0:%d s:%d\n",
prrr.ns1, prrr.ns0, s);
te.mtype = TlbEntry::Normal;
if (prrr.ns1 && s)
te.shareable = true;
if (prrr.ns0 && !s)
te.shareable = true;
break;
case 3:
panic("Reserved type");
}
if (te.mtype == TlbEntry::Normal){
switch(curr_ir) {
case 0:
te.nonCacheable = true;
te.innerAttrs = 0;
break;
case 1:
te.innerAttrs = 5;
break;
case 2:
te.innerAttrs = 6;
break;
case 3:
te.innerAttrs = 7;
break;
}
switch(curr_or) {
case 0:
te.nonCacheable = true;
te.outerAttrs = 0;
break;
case 1:
te.outerAttrs = 1;
break;
case 2:
te.outerAttrs = 2;
break;
case 3:
te.outerAttrs = 3;
break;
}
}
}
DPRINTF(TLBVerbose, "memAttrs: shareable: %d, innerAttrs: %d, \
outerAttrs: %d\n",
te.shareable, te.innerAttrs, te.outerAttrs);
/** Formatting for Physical Address Register (PAR)
* Only including lower bits (TLB info here)
* PAR:
* PA [31:12]
* Reserved [11]
* TLB info [10:1]
* NOS [10] (Not Outer Sharable)
* NS [9] (Non-Secure)
* -- [8] (Implementation Defined)
* SH [7] (Sharable)
* Inner[6:4](Inner memory attributes)
* Outer[3:2](Outer memory attributes)
* SS [1] (SuperSection)
* F [0] (Fault, Fault Status in [6:1] if faulted)
*/
te.attributes = (
((outer_shareable ? 0:1) << 10) |
// TODO: NS Bit
((te.shareable ? 1:0) << 7) |
(te.innerAttrs << 4) |
(te.outerAttrs << 2)
// TODO: Supersection bit
// TODO: Fault bit
);
}
void
TableWalker::doL1Descriptor()
{
DPRINTF(TLB, "L1 descriptor for %#x is %#x\n",
currState->vaddr, currState->l1Desc.data);
TlbEntry te;
switch (currState->l1Desc.type()) {
case L1Descriptor::Ignore:
case L1Descriptor::Reserved:
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
DPRINTF(TLB, "L1 Descriptor Reserved/Ignore, causing fault\n");
if (currState->isFetch)
currState->fault =
new PrefetchAbort(currState->vaddr, ArmFault::Translation0);
else
currState->fault =
new DataAbort(currState->vaddr, 0, currState->isWrite,
ArmFault::Translation0);
return;
case L1Descriptor::Section:
if (currState->sctlr.afe && bits(currState->l1Desc.ap(), 0) == 0) {
/** @todo: check sctlr.ha (bit[17]) if Hardware Access Flag is
* enabled if set, do l1.Desc.setAp0() instead of generating
* AccessFlag0
*/
currState->fault = new DataAbort(currState->vaddr,
currState->l1Desc.domain(), currState->isWrite,
ArmFault::AccessFlag0);
}
if (currState->l1Desc.supersection()) {
panic("Haven't implemented supersections\n");
}
te.N = 20;
te.pfn = currState->l1Desc.pfn();
te.size = (1<<te.N) - 1;
te.global = !currState->l1Desc.global();
te.valid = true;
te.vpn = currState->vaddr >> te.N;
te.sNp = true;
te.xn = currState->l1Desc.xn();
te.ap = currState->l1Desc.ap();
te.domain = currState->l1Desc.domain();
te.asid = currState->contextId;
memAttrs(currState->tc, te, currState->sctlr,
currState->l1Desc.texcb(), currState->l1Desc.shareable());
DPRINTF(TLB, "Inserting Section Descriptor into TLB\n");
DPRINTF(TLB, " - N:%d pfn:%#x size: %#x global:%d valid: %d\n",
te.N, te.pfn, te.size, te.global, te.valid);
DPRINTF(TLB, " - vpn:%#x sNp: %d xn:%d ap:%d domain: %d asid:%d nc:%d\n",
te.vpn, te.sNp, te.xn, te.ap, te.domain, te.asid,
te.nonCacheable);
DPRINTF(TLB, " - domain from l1 desc: %d data: %#x bits:%d\n",
currState->l1Desc.domain(), currState->l1Desc.data,
(currState->l1Desc.data >> 5) & 0xF );
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
tlb->insert(currState->vaddr, te);
return;
case L1Descriptor::PageTable:
Addr l2desc_addr;
l2desc_addr = currState->l1Desc.l2Addr() |
(bits(currState->vaddr, 19,12) << 2);
DPRINTF(TLB, "L1 descriptor points to page table at: %#x\n",
l2desc_addr);
// Trickbox address check
currState->fault = tlb->walkTrickBoxCheck(l2desc_addr, currState->vaddr,
sizeof(uint32_t), currState->isFetch, currState->isWrite,
currState->l1Desc.domain(), false);
if (currState->fault) {
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
return;
}
if (currState->timing) {
currState->delayed = true;
port->dmaAction(MemCmd::ReadReq, l2desc_addr, sizeof(uint32_t),
&doL2DescEvent, (uint8_t*)&currState->l2Desc.data,
currState->tc->getCpuPtr()->ticks(1));
} else {
port->dmaAction(MemCmd::ReadReq, l2desc_addr, sizeof(uint32_t),
NULL, (uint8_t*)&currState->l2Desc.data,
currState->tc->getCpuPtr()->ticks(1));
doL2Descriptor();
}
return;
default:
panic("A new type in a 2 bit field?\n");
}
}
void
TableWalker::doL2Descriptor()
{
DPRINTF(TLB, "L2 descriptor for %#x is %#x\n",
currState->vaddr, currState->l2Desc.data);
TlbEntry te;
if (currState->l2Desc.invalid()) {
DPRINTF(TLB, "L2 descriptor invalid, causing fault\n");
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
if (currState->isFetch)
currState->fault =
new PrefetchAbort(currState->vaddr, ArmFault::Translation1);
else
currState->fault =
new DataAbort(currState->vaddr, currState->l1Desc.domain(),
currState->isWrite, ArmFault::Translation1);
return;
}
if (currState->sctlr.afe && bits(currState->l2Desc.ap(), 0) == 0) {
/** @todo: check sctlr.ha (bit[17]) if Hardware Access Flag is enabled
* if set, do l2.Desc.setAp0() instead of generating AccessFlag0
*/
currState->fault =
new DataAbort(currState->vaddr, 0, currState->isWrite,
ArmFault::AccessFlag1);
}
if (currState->l2Desc.large()) {
te.N = 16;
te.pfn = currState->l2Desc.pfn();
} else {
te.N = 12;
te.pfn = currState->l2Desc.pfn();
}
te.valid = true;
te.size = (1 << te.N) - 1;
te.asid = currState->contextId;
te.sNp = false;
te.vpn = currState->vaddr >> te.N;
te.global = currState->l2Desc.global();
te.xn = currState->l2Desc.xn();
te.ap = currState->l2Desc.ap();
te.domain = currState->l1Desc.domain();
memAttrs(currState->tc, te, currState->sctlr, currState->l2Desc.texcb(),
currState->l2Desc.shareable());
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
tlb->insert(currState->vaddr, te);
}
void
TableWalker::doL1DescriptorWrapper()
{
currState = stateQueueL1.front();
currState->delayed = false;
DPRINTF(TLBVerbose, "L1 Desc object host addr: %p\n",&currState->l1Desc.data);
DPRINTF(TLBVerbose, "L1 Desc object data: %08x\n",currState->l1Desc.data);
DPRINTF(TLBVerbose, "calling doL1Descriptor for vaddr:%#x\n", currState->vaddr);
doL1Descriptor();
stateQueueL1.pop_front();
// Check if fault was generated
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
}
else if (!currState->delayed) {
// delay is not set so there is no L2 to do
DPRINTF(TLBVerbose, "calling translateTiming again\n");
currState->fault = tlb->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode);
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
} else {
// need to do L2 descriptor
stateQueueL2.push_back(currState);
}
currState = NULL;
}
void
TableWalker::doL2DescriptorWrapper()
{
currState = stateQueueL2.front();
assert(currState->delayed);
DPRINTF(TLBVerbose, "calling doL2Descriptor for vaddr:%#x\n",
currState->vaddr);
doL2Descriptor();
// Check if fault was generated
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
}
else {
DPRINTF(TLBVerbose, "calling translateTiming again\n");
currState->fault = tlb->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode);
}
stateQueueL2.pop_front();
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
currState = NULL;
}
void
TableWalker::nextWalk(ThreadContext *tc)
{
if (pendingQueue.size())
schedule(doProcessEvent, tc->getCpuPtr()->nextCycle(curTick()+1));
}
ArmISA::TableWalker *
ArmTableWalkerParams::create()
{
return new ArmISA::TableWalker(this);
}