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/*
* Copyright (c) 1999-2012 Mark D. Hill and David A. Wood
* Copyright (c) 2013 Advanced Micro Devices, Inc.
* 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 "mem/ruby/structures/CacheMemory.hh"
#include "base/intmath.hh"
#include "debug/RubyCache.hh"
#include "debug/RubyCacheTrace.hh"
#include "debug/RubyResourceStalls.hh"
#include "debug/RubyStats.hh"
#include "mem/protocol/AccessPermission.hh"
#include "mem/ruby/system/RubySystem.hh"
#include "mem/ruby/system/WeightedLRUPolicy.hh"
using namespace std;
ostream&
operator<<(ostream& out, const CacheMemory& obj)
{
obj.print(out);
out << flush;
return out;
}
CacheMemory *
RubyCacheParams::create()
{
return new CacheMemory(this);
}
CacheMemory::CacheMemory(const Params *p)
: SimObject(p),
dataArray(p->dataArrayBanks, p->dataAccessLatency,
p->start_index_bit, p->ruby_system),
tagArray(p->tagArrayBanks, p->tagAccessLatency,
p->start_index_bit, p->ruby_system)
{
m_cache_size = p->size;
m_cache_assoc = p->assoc;
m_replacementPolicy_ptr = p->replacement_policy;
m_replacementPolicy_ptr->setCache(this);
m_start_index_bit = p->start_index_bit;
m_is_instruction_only_cache = p->is_icache;
m_resource_stalls = p->resourceStalls;
m_block_size = p->block_size; // may be 0 at this point. Updated in init()
}
void
CacheMemory::init()
{
if (m_block_size == 0) {
m_block_size = RubySystem::getBlockSizeBytes();
}
m_cache_num_sets = (m_cache_size / m_cache_assoc) / m_block_size;
assert(m_cache_num_sets > 1);
m_cache_num_set_bits = floorLog2(m_cache_num_sets);
assert(m_cache_num_set_bits > 0);
m_cache.resize(m_cache_num_sets,
std::vector<AbstractCacheEntry*>(m_cache_assoc, nullptr));
}
CacheMemory::~CacheMemory()
{
if (m_replacementPolicy_ptr)
delete m_replacementPolicy_ptr;
for (int i = 0; i < m_cache_num_sets; i++) {
for (int j = 0; j < m_cache_assoc; j++) {
delete m_cache[i][j];
}
}
}
// convert a Address to its location in the cache
int64_t
CacheMemory::addressToCacheSet(Addr address) const
{
assert(address == makeLineAddress(address));
return bitSelect(address, m_start_index_bit,
m_start_index_bit + m_cache_num_set_bits - 1);
}
// Given a cache index: returns the index of the tag in a set.
// returns -1 if the tag is not found.
int
CacheMemory::findTagInSet(int64_t cacheSet, Addr tag) const
{
assert(tag == makeLineAddress(tag));
// search the set for the tags
auto it = m_tag_index.find(tag);
if (it != m_tag_index.end())
if (m_cache[cacheSet][it->second]->m_Permission !=
AccessPermission_NotPresent)
return it->second;
return -1; // Not found
}
// Given a cache index: returns the index of the tag in a set.
// returns -1 if the tag is not found.
int
CacheMemory::findTagInSetIgnorePermissions(int64_t cacheSet,
Addr tag) const
{
assert(tag == makeLineAddress(tag));
// search the set for the tags
auto it = m_tag_index.find(tag);
if (it != m_tag_index.end())
return it->second;
return -1; // Not found
}
// Given an unique cache block identifier (idx): return the valid address
// stored by the cache block. If the block is invalid/notpresent, the
// function returns the 0 address
Addr
CacheMemory::getAddressAtIdx(int idx) const
{
Addr tmp(0);
int set = idx / m_cache_assoc;
assert(set < m_cache_num_sets);
int way = idx - set * m_cache_assoc;
assert (way < m_cache_assoc);
AbstractCacheEntry* entry = m_cache[set][way];
if (entry == NULL ||
entry->m_Permission == AccessPermission_Invalid ||
entry->m_Permission == AccessPermission_NotPresent) {
return tmp;
}
return entry->m_Address;
}
bool
CacheMemory::tryCacheAccess(Addr address, RubyRequestType type,
DataBlock*& data_ptr)
{
assert(address == makeLineAddress(address));
DPRINTF(RubyCache, "address: %#x\n", address);
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc != -1) {
// Do we even have a tag match?
AbstractCacheEntry* entry = m_cache[cacheSet][loc];
m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
data_ptr = &(entry->getDataBlk());
if (entry->m_Permission == AccessPermission_Read_Write) {
return true;
}
if ((entry->m_Permission == AccessPermission_Read_Only) &&
(type == RubyRequestType_LD || type == RubyRequestType_IFETCH)) {
return true;
}
// The line must not be accessible
}
data_ptr = NULL;
return false;
}
bool
CacheMemory::testCacheAccess(Addr address, RubyRequestType type,
DataBlock*& data_ptr)
{
assert(address == makeLineAddress(address));
DPRINTF(RubyCache, "address: %#x\n", address);
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc != -1) {
// Do we even have a tag match?
AbstractCacheEntry* entry = m_cache[cacheSet][loc];
m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
data_ptr = &(entry->getDataBlk());
return m_cache[cacheSet][loc]->m_Permission !=
AccessPermission_NotPresent;
}
data_ptr = NULL;
return false;
}
// tests to see if an address is present in the cache
bool
CacheMemory::isTagPresent(Addr address) const
{
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc == -1) {
// We didn't find the tag
DPRINTF(RubyCache, "No tag match for address: %#x\n", address);
return false;
}
DPRINTF(RubyCache, "address: %#x found\n", address);
return true;
}
// Returns true if there is:
// a) a tag match on this address or there is
// b) an unused line in the same cache "way"
bool
CacheMemory::cacheAvail(Addr address) const
{
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
for (int i = 0; i < m_cache_assoc; i++) {
AbstractCacheEntry* entry = m_cache[cacheSet][i];
if (entry != NULL) {
if (entry->m_Address == address ||
entry->m_Permission == AccessPermission_NotPresent) {
// Already in the cache or we found an empty entry
return true;
}
} else {
return true;
}
}
return false;
}
AbstractCacheEntry*
CacheMemory::allocate(Addr address, AbstractCacheEntry *entry, bool touch)
{
assert(address == makeLineAddress(address));
assert(!isTagPresent(address));
assert(cacheAvail(address));
DPRINTF(RubyCache, "address: %#x\n", address);
// Find the first open slot
int64_t cacheSet = addressToCacheSet(address);
std::vector<AbstractCacheEntry*> &set = m_cache[cacheSet];
for (int i = 0; i < m_cache_assoc; i++) {
if (!set[i] || set[i]->m_Permission == AccessPermission_NotPresent) {
if (set[i] && (set[i] != entry)) {
warn_once("This protocol contains a cache entry handling bug: "
"Entries in the cache should never be NotPresent! If\n"
"this entry (%#x) is not tracked elsewhere, it will memory "
"leak here. Fix your protocol to eliminate these!",
address);
}
set[i] = entry; // Init entry
set[i]->m_Address = address;
set[i]->m_Permission = AccessPermission_Invalid;
DPRINTF(RubyCache, "Allocate clearing lock for addr: %x\n",
address);
set[i]->m_locked = -1;
m_tag_index[address] = i;
entry->setSetIndex(cacheSet);
entry->setWayIndex(i);
if (touch) {
m_replacementPolicy_ptr->touch(cacheSet, i, curTick());
}
return entry;
}
}
panic("Allocate didn't find an available entry");
}
void
CacheMemory::deallocate(Addr address)
{
assert(address == makeLineAddress(address));
assert(isTagPresent(address));
DPRINTF(RubyCache, "address: %#x\n", address);
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc != -1) {
delete m_cache[cacheSet][loc];
m_cache[cacheSet][loc] = NULL;
m_tag_index.erase(address);
}
}
// Returns with the physical address of the conflicting cache line
Addr
CacheMemory::cacheProbe(Addr address) const
{
assert(address == makeLineAddress(address));
assert(!cacheAvail(address));
int64_t cacheSet = addressToCacheSet(address);
return m_cache[cacheSet][m_replacementPolicy_ptr->getVictim(cacheSet)]->
m_Address;
}
// looks an address up in the cache
AbstractCacheEntry*
CacheMemory::lookup(Addr address)
{
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc == -1) return NULL;
return m_cache[cacheSet][loc];
}
// looks an address up in the cache
const AbstractCacheEntry*
CacheMemory::lookup(Addr address) const
{
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc == -1) return NULL;
return m_cache[cacheSet][loc];
}
// Sets the most recently used bit for a cache block
void
CacheMemory::setMRU(Addr address)
{
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc != -1)
m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
}
void
CacheMemory::setMRU(const AbstractCacheEntry *e)
{
uint32_t cacheSet = e->getSetIndex();
uint32_t loc = e->getWayIndex();
m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
}
void
CacheMemory::setMRU(Addr address, int occupancy)
{
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
if (loc != -1) {
if (m_replacementPolicy_ptr->useOccupancy()) {
(static_cast<WeightedLRUPolicy*>(m_replacementPolicy_ptr))->
touch(cacheSet, loc, curTick(), occupancy);
} else {
m_replacementPolicy_ptr->
touch(cacheSet, loc, curTick());
}
}
}
int
CacheMemory::getReplacementWeight(int64_t set, int64_t loc)
{
assert(set < m_cache_num_sets);
assert(loc < m_cache_assoc);
int ret = 0;
if (m_cache[set][loc] != NULL) {
ret = m_cache[set][loc]->getNumValidBlocks();
assert(ret >= 0);
}
return ret;
}
void
CacheMemory::recordCacheContents(int cntrl, CacheRecorder* tr) const
{
uint64_t warmedUpBlocks = 0;
uint64_t totalBlocks M5_VAR_USED = (uint64_t)m_cache_num_sets *
(uint64_t)m_cache_assoc;
for (int i = 0; i < m_cache_num_sets; i++) {
for (int j = 0; j < m_cache_assoc; j++) {
if (m_cache[i][j] != NULL) {
AccessPermission perm = m_cache[i][j]->m_Permission;
RubyRequestType request_type = RubyRequestType_NULL;
if (perm == AccessPermission_Read_Only) {
if (m_is_instruction_only_cache) {
request_type = RubyRequestType_IFETCH;
} else {
request_type = RubyRequestType_LD;
}
} else if (perm == AccessPermission_Read_Write) {
request_type = RubyRequestType_ST;
}
if (request_type != RubyRequestType_NULL) {
tr->addRecord(cntrl, m_cache[i][j]->m_Address,
0, request_type,
m_replacementPolicy_ptr->getLastAccess(i, j),
m_cache[i][j]->getDataBlk());
warmedUpBlocks++;
}
}
}
}
DPRINTF(RubyCacheTrace, "%s: %lli blocks of %lli total blocks"
"recorded %.2f%% \n", name().c_str(), warmedUpBlocks,
totalBlocks, (float(warmedUpBlocks) / float(totalBlocks)) * 100.0);
}
void
CacheMemory::print(ostream& out) const
{
out << "Cache dump: " << name() << endl;
for (int i = 0; i < m_cache_num_sets; i++) {
for (int j = 0; j < m_cache_assoc; j++) {
if (m_cache[i][j] != NULL) {
out << " Index: " << i
<< " way: " << j
<< " entry: " << *m_cache[i][j] << endl;
} else {
out << " Index: " << i
<< " way: " << j
<< " entry: NULL" << endl;
}
}
}
}
void
CacheMemory::printData(ostream& out) const
{
out << "printData() not supported" << endl;
}
void
CacheMemory::setLocked(Addr address, int context)
{
DPRINTF(RubyCache, "Setting Lock for addr: %#x to %d\n", address, context);
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
assert(loc != -1);
m_cache[cacheSet][loc]->setLocked(context);
}
void
CacheMemory::clearLocked(Addr address)
{
DPRINTF(RubyCache, "Clear Lock for addr: %#x\n", address);
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
assert(loc != -1);
m_cache[cacheSet][loc]->clearLocked();
}
bool
CacheMemory::isLocked(Addr address, int context)
{
assert(address == makeLineAddress(address));
int64_t cacheSet = addressToCacheSet(address);
int loc = findTagInSet(cacheSet, address);
assert(loc != -1);
DPRINTF(RubyCache, "Testing Lock for addr: %#llx cur %d con %d\n",
address, m_cache[cacheSet][loc]->m_locked, context);
return m_cache[cacheSet][loc]->isLocked(context);
}
void
CacheMemory::regStats()
{
SimObject::regStats();
m_demand_hits
.name(name() + ".demand_hits")
.desc("Number of cache demand hits")
;
m_demand_misses
.name(name() + ".demand_misses")
.desc("Number of cache demand misses")
;
m_demand_accesses
.name(name() + ".demand_accesses")
.desc("Number of cache demand accesses")
;
m_demand_accesses = m_demand_hits + m_demand_misses;
m_sw_prefetches
.name(name() + ".total_sw_prefetches")
.desc("Number of software prefetches")
.flags(Stats::nozero)
;
m_hw_prefetches
.name(name() + ".total_hw_prefetches")
.desc("Number of hardware prefetches")
.flags(Stats::nozero)
;
m_prefetches
.name(name() + ".total_prefetches")
.desc("Number of prefetches")
.flags(Stats::nozero)
;
m_prefetches = m_sw_prefetches + m_hw_prefetches;
m_accessModeType
.init(RubyRequestType_NUM)
.name(name() + ".access_mode")
.flags(Stats::pdf | Stats::total)
;
for (int i = 0; i < RubyAccessMode_NUM; i++) {
m_accessModeType
.subname(i, RubyAccessMode_to_string(RubyAccessMode(i)))
.flags(Stats::nozero)
;
}
numDataArrayReads
.name(name() + ".num_data_array_reads")
.desc("number of data array reads")
.flags(Stats::nozero)
;
numDataArrayWrites
.name(name() + ".num_data_array_writes")
.desc("number of data array writes")
.flags(Stats::nozero)
;
numTagArrayReads
.name(name() + ".num_tag_array_reads")
.desc("number of tag array reads")
.flags(Stats::nozero)
;
numTagArrayWrites
.name(name() + ".num_tag_array_writes")
.desc("number of tag array writes")
.flags(Stats::nozero)
;
numTagArrayStalls
.name(name() + ".num_tag_array_stalls")
.desc("number of stalls caused by tag array")
.flags(Stats::nozero)
;
numDataArrayStalls
.name(name() + ".num_data_array_stalls")
.desc("number of stalls caused by data array")
.flags(Stats::nozero)
;
}
// assumption: SLICC generated files will only call this function
// once **all** resources are granted
void
CacheMemory::recordRequestType(CacheRequestType requestType, Addr addr)
{
DPRINTF(RubyStats, "Recorded statistic: %s\n",
CacheRequestType_to_string(requestType));
switch(requestType) {
case CacheRequestType_DataArrayRead:
if (m_resource_stalls)
dataArray.reserve(addressToCacheSet(addr));
numDataArrayReads++;
return;
case CacheRequestType_DataArrayWrite:
if (m_resource_stalls)
dataArray.reserve(addressToCacheSet(addr));
numDataArrayWrites++;
return;
case CacheRequestType_TagArrayRead:
if (m_resource_stalls)
tagArray.reserve(addressToCacheSet(addr));
numTagArrayReads++;
return;
case CacheRequestType_TagArrayWrite:
if (m_resource_stalls)
tagArray.reserve(addressToCacheSet(addr));
numTagArrayWrites++;
return;
default:
warn("CacheMemory access_type not found: %s",
CacheRequestType_to_string(requestType));
}
}
bool
CacheMemory::checkResourceAvailable(CacheResourceType res, Addr addr)
{
if (!m_resource_stalls) {
return true;
}
if (res == CacheResourceType_TagArray) {
if (tagArray.tryAccess(addressToCacheSet(addr))) return true;
else {
DPRINTF(RubyResourceStalls,
"Tag array stall on addr %#x in set %d\n",
addr, addressToCacheSet(addr));
numTagArrayStalls++;
return false;
}
} else if (res == CacheResourceType_DataArray) {
if (dataArray.tryAccess(addressToCacheSet(addr))) return true;
else {
DPRINTF(RubyResourceStalls,
"Data array stall on addr %#x in set %d\n",
addr, addressToCacheSet(addr));
numDataArrayStalls++;
return false;
}
} else {
assert(false);
return true;
}
}
bool
CacheMemory::isBlockInvalid(int64_t cache_set, int64_t loc)
{
return (m_cache[cache_set][loc]->m_Permission == AccessPermission_Invalid);
}
bool
CacheMemory::isBlockNotBusy(int64_t cache_set, int64_t loc)
{
return (m_cache[cache_set][loc]->m_Permission != AccessPermission_Busy);
}