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ARM: Allow multiple outstanding TLB walks to queue.

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This commit is contained in:
Dam Sunwoo 2010-06-02 12:58:18 -05:00
parent 2bad5138e4
commit 4325519fc5
3 changed files with 248 additions and 170 deletions
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306
src/arch/arm/table_walker.cc
View file

@ -43,13 +43,16 @@
#include "dev/io_device.hh"
#include "cpu/thread_context.hh"
#define NUM_WALKERS 2 // 2 should be enough to handle crossing page boundaries
using namespace ArmISA;
TableWalker::TableWalker(const Params *p)
: MemObject(p), port(NULL), tlb(NULL), tc(NULL), req(NULL),
doL1DescEvent(this), doL2DescEvent(this)
{}
: MemObject(p), stateQueue(NUM_WALKERS), port(NULL), tlb(NULL),
currState(NULL), doL1DescEvent(this), doL2DescEvent(this)
{
sctlr = NULL;
}
TableWalker::~TableWalker()
{
@ -83,80 +86,99 @@ Fault
TableWalker::walk(RequestPtr _req, ThreadContext *_tc, uint8_t _cid, TLB::Mode _mode,
TLB::Translation *_trans, bool _timing)
{
// Right now 1 CPU == 1 TLB == 1 TLB walker
// In the future we might want to change this as multiple
// threads/contexts could share a walker and/or a TLB
if (tc || req)
panic("Overlapping TLB walks attempted\n");
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");
tc = _tc;
transState = _trans;
req = _req;
fault = NoFault;
contextId = _cid;
timing = _timing;
mode = _mode;
currState = new WalkerState();
currState->tableWalker = this;
}
else if (_timing) {
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 */
vaddr = req->getVaddr() & ~PcModeMask;
sctlr = tc->readMiscReg(MISCREG_SCTLR);
cpsr = tc->readMiscReg(MISCREG_CPSR);
N = tc->readMiscReg(MISCREG_TTBCR);
currState->vaddr = currState->req->getVaddr() & ~PcModeMask;
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR);
sctlr = currState->sctlr;
currState->cpsr = currState->tc->readMiscReg(MISCREG_CPSR);
currState->N = currState->tc->readMiscReg(MISCREG_TTBCR);
currState->isFetch = (currState->mode == TLB::Execute);
currState->isWrite = (currState->mode == TLB::Write);
currState->isPriv = (currState->cpsr.mode != MODE_USER);
Addr ttbr = 0;
isFetch = (mode == TLB::Execute);
isWrite = (mode == TLB::Write);
isPriv = (cpsr.mode != MODE_USER);
// If translation isn't enabled, we shouldn't be here
assert(sctlr.m);
assert(currState->sctlr.m);
DPRINTF(TLB, "Begining table walk for address %#x, TTBCR: %#x, bits:%#x\n",
vaddr, N, mbits(vaddr, 31, 32-N));
currState->vaddr, currState->N, mbits(currState->vaddr, 31,
32-currState->N));
if (N == 0 || !mbits(vaddr, 31, 32-N)) {
if (currState->N == 0 || !mbits(currState->vaddr, 31, 32-currState->N)) {
DPRINTF(TLB, " - Selecting TTBR0\n");
ttbr = tc->readMiscReg(MISCREG_TTBR0);
ttbr = currState->tc->readMiscReg(MISCREG_TTBR0);
} else {
DPRINTF(TLB, " - Selecting TTBR1\n");
ttbr = tc->readMiscReg(MISCREG_TTBR1);
N = 0;
ttbr = currState->tc->readMiscReg(MISCREG_TTBR1);
currState->N = 0;
}
Addr l1desc_addr = mbits(ttbr, 31, 14-N) | (bits(vaddr,31-N,20) << 2);
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 = tlb->walkTrickBoxCheck(l1desc_addr, vaddr, sizeof(uint32_t),
isFetch, isWrite, 0, true);
if (fault) {
tc = NULL;
req = NULL;
return fault;
Fault f;
f = tlb->walkTrickBoxCheck(l1desc_addr, currState->vaddr, sizeof(uint32_t),
currState->isFetch, currState->isWrite, 0, true);
if (f) {
currState->tc = NULL;
currState->req = NULL;
return f;
}
if (timing) {
if (currState->timing) {
port->dmaAction(MemCmd::ReadReq, l1desc_addr, sizeof(uint32_t),
&doL1DescEvent, (uint8_t*)&l1Desc.data, (Tick)0);
&doL1DescEvent, (uint8_t*)&currState->l1Desc.data, (Tick)0);
DPRINTF(TLBVerbose, "Adding to walker fifo: %d free before adding\n",
stateQueue.free_slots());
stateQueue.add(*currState);
currState = NULL;
} else {
port->dmaAction(MemCmd::ReadReq, l1desc_addr, sizeof(uint32_t),
NULL, (uint8_t*)&l1Desc.data, (Tick)0);
NULL, (uint8_t*)&currState->l1Desc.data, (Tick)0);
doL1Descriptor();
f = currState->fault;
}
return fault;
return f;
}
void
TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, SCTLR sctlr,
uint8_t texcb, bool s)
{
// Note: tc local variable is hiding tc class variable
// 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
bool outer_shareable = false;
if (sctlr.tre == 0) {
if (sctlr.tre == 0 || ((sctlr.tre == 1) && (sctlr.m == 0))) {
switch(texcb) {
case 0: // Stongly-ordered
te.nonCacheable = true;
@ -192,8 +214,10 @@ TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
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;
@ -209,6 +233,7 @@ TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
te.outerAttrs = 0;
break;
case 9 ... 15: // Reserved
panic("Reserved texcb value!\n");
break;
case 16 ... 31: // Cacheable Memory
te.mtype = TlbEntry::Normal;
@ -303,7 +328,6 @@ TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
te.shareable = true;
if (prrr.ns0 && !s)
te.shareable = true;
//te.shareable = outer_shareable;
break;
case 3:
panic("Reserved type");
@ -343,6 +367,9 @@ TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
}
}
}
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)
@ -375,49 +402,54 @@ TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s)
void
TableWalker::doL1Descriptor()
{
DPRINTF(TLB, "L1 descriptor for %#x is %#x\n", vaddr, l1Desc.data);
DPRINTF(TLB, "L1 descriptor for %#x is %#x\n",
currState->vaddr, currState->l1Desc.data);
TlbEntry te;
switch (l1Desc.type()) {
switch (currState->l1Desc.type()) {
case L1Descriptor::Ignore:
case L1Descriptor::Reserved:
if (!delayed) {
tc = NULL;
req = NULL;
if (!currState->delayed) {
currState->tc = NULL;
currState->req = NULL;
}
DPRINTF(TLB, "L1 Descriptor Reserved/Ignore, causing fault\n");
if (isFetch)
fault = new PrefetchAbort(vaddr, ArmFault::Translation0);
if (currState->isFetch)
currState->fault =
new PrefetchAbort(currState->vaddr, ArmFault::Translation0);
else
fault = new DataAbort(vaddr, NULL, isWrite,
currState->fault =
new DataAbort(currState->vaddr, NULL, currState->isWrite,
ArmFault::Translation0);
return;
case L1Descriptor::Section:
if (sctlr.afe && bits(l1Desc.ap(), 0) == 0) {
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
*/
fault = new DataAbort(vaddr, NULL, isWrite,
currState->fault =
new DataAbort(currState->vaddr, NULL, currState->isWrite,
ArmFault::AccessFlag0);
}
if (l1Desc.supersection()) {
if (currState->l1Desc.supersection()) {
panic("Haven't implemented supersections\n");
}
te.N = 20;
te.pfn = l1Desc.pfn();
te.pfn = currState->l1Desc.pfn();
te.size = (1<<te.N) - 1;
te.global = !l1Desc.global();
te.global = !currState->l1Desc.global();
te.valid = true;
te.vpn = vaddr >> te.N;
te.vpn = currState->vaddr >> te.N;
te.sNp = true;
te.xn = l1Desc.xn();
te.ap = l1Desc.ap();
te.domain = l1Desc.domain();
te.asid = contextId;
memAttrs(tc, te, l1Desc.texcb(), l1Desc.shareable());
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",
@ -425,40 +457,44 @@ TableWalker::doL1Descriptor()
DPRINTF(TLB, " - vpn:%#x sNp: %d xn:%d ap:%d domain: %d asid:%d\n",
te.vpn, te.sNp, te.xn, te.ap, te.domain, te.asid);
DPRINTF(TLB, " - domain from l1 desc: %d data: %#x bits:%d\n",
l1Desc.domain(), l1Desc.data, (l1Desc.data >> 5) & 0xF );
currState->l1Desc.domain(), currState->l1Desc.data,
(currState->l1Desc.data >> 5) & 0xF );
if (!timing) {
tc = NULL;
req = NULL;
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
tlb->insert(vaddr, te);
tlb->insert(currState->vaddr, te);
return;
case L1Descriptor::PageTable:
Addr l2desc_addr;
l2desc_addr = l1Desc.l2Addr() | (bits(vaddr, 19,12) << 2);
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
fault = tlb->walkTrickBoxCheck(l2desc_addr, vaddr, sizeof(uint32_t),
isFetch, isWrite, l1Desc.domain(), false);
if (fault) {
if (!timing) {
tc = NULL;
req = NULL;
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 (timing) {
delayed = true;
if (currState->timing) {
currState->delayed = true;
port->dmaAction(MemCmd::ReadReq, l2desc_addr, sizeof(uint32_t),
&doL2DescEvent, (uint8_t*)&l2Desc.data, 0);
&doL2DescEvent, (uint8_t*)&currState->l2Desc.data, 0);
} else {
port->dmaAction(MemCmd::ReadReq, l2desc_addr, sizeof(uint32_t),
NULL, (uint8_t*)&l2Desc.data, 0);
NULL, (uint8_t*)&currState->l2Desc.data, 0);
doL2Descriptor();
}
return;
@ -470,103 +506,125 @@ TableWalker::doL1Descriptor()
void
TableWalker::doL2Descriptor()
{
DPRINTF(TLB, "L2 descriptor for %#x is %#x\n", vaddr, l2Desc.data);
DPRINTF(TLB, "L2 descriptor for %#x is %#x\n",
currState->vaddr, currState->l2Desc.data);
TlbEntry te;
if (l2Desc.invalid()) {
if (currState->l2Desc.invalid()) {
DPRINTF(TLB, "L2 descriptor invalid, causing fault\n");
if (!delayed) {
tc = NULL;
req = NULL;
if (!currState->delayed) {
currState->tc = NULL;
currState->req = NULL;
}
if (isFetch)
fault = new PrefetchAbort(vaddr, ArmFault::Translation1);
if (currState->isFetch)
currState->fault =
new PrefetchAbort(currState->vaddr, ArmFault::Translation1);
else
fault = new DataAbort(vaddr, l1Desc.domain(), isWrite,
ArmFault::Translation1);
currState->fault =
new DataAbort(currState->vaddr, currState->l1Desc.domain(),
currState->isWrite, ArmFault::Translation1);
return;
}
if (sctlr.afe && bits(l2Desc.ap(), 0) == 0) {
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
*/
fault = new DataAbort(vaddr, NULL, isWrite, ArmFault::AccessFlag1);
currState->fault =
new DataAbort(currState->vaddr, NULL, currState->isWrite,
ArmFault::AccessFlag1);
}
if (l2Desc.large()) {
if (currState->l2Desc.large()) {
te.N = 16;
te.pfn = l2Desc.pfn();
te.pfn = currState->l2Desc.pfn();
} else {
te.N = 12;
te.pfn = l2Desc.pfn();
te.pfn = currState->l2Desc.pfn();
}
te.valid = true;
te.size = (1 << te.N) - 1;
te.asid = contextId;
te.asid = currState->contextId;
te.sNp = false;
te.vpn = vaddr >> te.N;
te.global = l2Desc.global();
te.xn = l2Desc.xn();
te.ap = l2Desc.ap();
te.domain = l1Desc.domain();
memAttrs(tc, te, l2Desc.texcb(), l2Desc.shareable());
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 (!delayed) {
tc = NULL;
req = NULL;
if (!currState->delayed) {
currState->tc = NULL;
currState->req = NULL;
}
tlb->insert(vaddr, te);
tlb->insert(currState->vaddr, te);
}
void
TableWalker::doL1DescriptorWrapper()
{
delayed = false;
currState = stateQueue.peek();
currState->delayed = false;
DPRINTF(TLBVerbose, "calling doL1Descriptor\n");
DPRINTF(TLBVerbose, "calling doL1Descriptor for vaddr:%#x\n", currState->vaddr);
doL1Descriptor();
// Check if fault was generated
if (fault != NoFault) {
transState->finish(fault, req, tc, mode);
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
req = NULL;
tc = NULL;
delayed = false;
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
stateQueue.remove();
}
else if (!delayed) {
else if (!currState->delayed) {
DPRINTF(TLBVerbose, "calling translateTiming again\n");
fault = tlb->translateTiming(req, tc, transState, mode);
currState->fault = tlb->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode);
req = NULL;
tc = NULL;
delayed = false;
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
stateQueue.remove();
}
currState = NULL;
}
void
TableWalker::doL2DescriptorWrapper()
{
assert(delayed);
currState = stateQueue.peek();
assert(currState->delayed);
DPRINTF(TLBVerbose, "calling doL2Descriptor\n");
DPRINTF(TLBVerbose, "calling doL2Descriptor for vaddr:%#x\n",
currState->vaddr);
doL2Descriptor();
// Check if fault was generated
if (fault != NoFault) {
transState->finish(fault, req, tc, mode);
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
}
else {
DPRINTF(TLBVerbose, "calling translateTiming again\n");
fault = tlb->translateTiming(req, tc, transState, mode);
currState->fault = tlb->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode);
}
req = NULL;
tc = NULL;
delayed = false;
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
stateQueue.remove();
currState = NULL;
}
ArmISA::TableWalker *

110
src/arch/arm/table_walker.hh
View file

@ -48,6 +48,7 @@
#include "params/ArmTableWalker.hh"
#include "sim/faults.hh"
#include "sim/eventq.hh"
#include "base/fifo_buffer.hh"
class DmaPort;
class ThreadContext;
@ -241,59 +242,77 @@ class TableWalker : public MemObject
};
struct WalkerState //: public SimObject
{
/** Thread context that we're doing the walk for */
ThreadContext *tc;
/** Request that is currently being serviced */
RequestPtr req;
/** Context ID that we're servicing the request under */
uint8_t contextId;
/** Translation state for delayed requests */
TLB::Translation *transState;
/** The fault that we are going to return */
Fault fault;
/** The virtual address that is being translated */
Addr vaddr;
/** Cached copy of the sctlr as it existed when translation began */
SCTLR sctlr;
/** Cached copy of the cpsr as it existed when the translation began */
CPSR cpsr;
/** Width of the base address held in TTRB0 */
uint32_t N;
/** If the access is a write */
bool isWrite;
/** If the access is not from user mode */
bool isPriv;
/** If the access is a fetch (for execution, and no-exec) must be checked?*/
bool isFetch;
/** If the mode is timing or atomic */
bool timing;
/** Save mode for use in delayed response */
BaseTLB::Mode mode;
L1Descriptor l1Desc;
L2Descriptor l2Desc;
/** Whether L1/L2 descriptor response is delayed in timing mode */
bool delayed;
TableWalker *tableWalker;
void doL1Descriptor();
void doL2Descriptor();
std::string name() const {return tableWalker->name();}
};
FifoBuffer<WalkerState> stateQueue;
/** Port to issue translation requests from */
DmaPort *port;
/** TLB that is initiating these table walks */
TLB *tlb;
/** Thread context that we're doing the walk for */
ThreadContext *tc;
/** Request that is currently being serviced */
RequestPtr req;
/** Context ID that we're servicing the request under */
uint8_t contextId;
/** Translation state for delayed requests */
TLB::Translation *transState;
/** The fault that we are going to return */
Fault fault;
/** The virtual address that is being translated */
Addr vaddr;
/** Cached copy of the sctlr as it existed when translation began */
SCTLR sctlr;
/** Cached copy of the cpsr as it existed when the translation began */
CPSR cpsr;
/** Width of the base address held in TTRB0 */
uint32_t N;
/** If the access is a write */
bool isWrite;
/** If the access is not from user mode */
bool isPriv;
/** If the access is a fetch (for execution, and no-exec) must be checked?*/
bool isFetch;
/** If the mode is timing or atomic */
bool timing;
L1Descriptor l1Desc;
L2Descriptor l2Desc;
/** Save mode for use in delayed response */
BaseTLB::Mode mode;
/** Whether L1/L2 descriptor response is delayed in timing mode */
bool delayed;
WalkerState *currState;
public:
typedef ArmTableWalkerParams Params;
@ -313,7 +332,8 @@ class TableWalker : public MemObject
TLB::Translation *_trans, bool timing);
void setTlb(TLB *_tlb) { tlb = _tlb; }
void memAttrs(ThreadContext *tc, TlbEntry &te, uint8_t texcb, bool s);
void memAttrs(ThreadContext *tc, TlbEntry &te, SCTLR sctlr,
uint8_t texcb, bool s);
private:

2
src/arch/arm/tlb.cc
View file

@ -387,7 +387,7 @@ TLB::translateFs(RequestPtr req, ThreadContext *tc, Mode mode,
// Set memory attributes
TlbEntry temp_te;
tableWalker->memAttrs(tc, temp_te, 0, 1);
tableWalker->memAttrs(tc, temp_te, sctlr, 0, 1);
temp_te.shareable = true;
DPRINTF(TLBVerbose, "(No MMU) setting memory attributes: shareable:\
%d, innerAttrs: %d, outerAttrs: %d\n", temp_te.shareable,