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mem: More descriptive enum names for address mapping

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This patch changes the slightly ambigious names used for the address
mapping scheme to be more descriptive, and actually spell out what
they do. With this patch we also open up for adding more flavours of
open- and close-type mappings, i.e. interleaving across channels with
the open map.
This commit is contained in:
Andreas Hansson 2013-04-22 13:20:33 -04:00
parent 99b3a12a75
commit e61799aa7c
2 changed files with 17 additions and 15 deletions
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10
src/mem/SimpleDRAM.py
View file

@ -43,10 +43,12 @@ from AbstractMemory import *
# First-Served and a First-Row Hit then First-Come First-Served
class MemSched(Enum): vals = ['fcfs', 'frfcfs']
# Enum for the address mapping, currently corresponding to either
# Enum for the address mapping. With Ra, Co, Ba and Ch denoting rank,
# column, bank and channel, respectively, and going from MSB to LSB,
# the two schemes available are RaBaChCo and CoRaBaCh, either
# optimising for sequential accesses hitting in the open row, or
# striping across banks.
class AddrMap(Enum): vals = ['openmap', 'closemap']
# maximising parallelism.
class AddrMap(Enum): vals = ['RaBaChCo', 'CoRaBaCh']
# Enum for the page policy, either open or close.
class PageManage(Enum): vals = ['open', 'close']
@ -105,7 +107,7 @@ class SimpleDRAM(AbstractMemory):
# scheduler, address map and page policy
mem_sched_policy = Param.MemSched('frfcfs', "Memory scheduling policy")
addr_mapping = Param.AddrMap('openmap', "Address mapping policy")
addr_mapping = Param.AddrMap('RaBaChCo', "Address mapping policy")
page_policy = Param.PageManage('open', "Page closure management policy")
# the physical organisation of the DRAM

22
src/mem/simple_dram.cc
View file

@ -112,15 +112,15 @@ SimpleDRAM::init()
panic("%s has %d interleaved address stripes but %d channel(s)\n",
name(), range.stripes(), channels);
if (addrMapping == Enums::openmap) {
if (addrMapping == Enums::RaBaChCo) {
if (bytesPerCacheLine * linesPerRowBuffer !=
range.granularity()) {
panic("Interleaving of %s doesn't match open address map\n",
panic("Interleaving of %s doesn't match RaBaChCo address map\n",
name());
}
} else if (addrMapping == Enums::closemap) {
} else if (addrMapping == Enums::CoRaBaCh) {
if (bytesPerCacheLine != range.granularity())
panic("Interleaving of %s doesn't match closed address map\n",
panic("Interleaving of %s doesn't match CoRaBaCh address map\n",
name());
}
}
@ -175,9 +175,9 @@ SimpleDRAM::decodeAddr(PacketPtr pkt)
{
// decode the address based on the address mapping scheme
//
// with R, C, B and K denoting rank, column, bank and rank,
// with Ra, Co, Ba and Ch denoting rank, column, bank and channel,
// respectively, and going from MSB to LSB, the two schemes are
// RKBC (openmap) and RCKB (closedmap)
// RaBaChCo and CoRaBaCh
uint8_t rank;
uint16_t bank;
uint16_t row;
@ -191,7 +191,7 @@ SimpleDRAM::decodeAddr(PacketPtr pkt)
// position within the cache line, proceed and select the
// appropriate bits for bank, rank and row (no column address is
// needed)
if (addrMapping == Enums::openmap) {
if (addrMapping == Enums::RaBaChCo) {
// the lowest order bits denote the column to ensure that
// sequential cache lines occupy the same row
addr = addr / linesPerRowBuffer;
@ -201,7 +201,7 @@ SimpleDRAM::decodeAddr(PacketPtr pkt)
// controllers in the address mapping
addr = addr / channels;
// after the column bits, we get the bank bits to interleave
// after the channel bits, we get the bank bits to interleave
// over the banks
bank = addr % banksPerRank;
addr = addr / banksPerRank;
@ -214,7 +214,7 @@ SimpleDRAM::decodeAddr(PacketPtr pkt)
// lastly, get the row bits
row = addr % rowsPerBank;
addr = addr / rowsPerBank;
} else if (addrMapping == Enums::closemap) {
} else if (addrMapping == Enums::CoRaBaCh) {
// optimise for closed page mode and utilise maximum
// parallelism of the DRAM (at the cost of power)
@ -473,8 +473,8 @@ SimpleDRAM::printParams() const
linesPerRowBuffer * rowsPerBank * banksPerRank * ranksPerChannel);
string scheduler = memSchedPolicy == Enums::fcfs ? "FCFS" : "FR-FCFS";
string address_mapping = addrMapping == Enums::openmap ? "OPENMAP" :
"CLOSEMAP";
string address_mapping = addrMapping == Enums::RaBaChCo ? "RaBaChCo" :
"CoRaBaCh";
string page_policy = pageMgmt == Enums::open ? "OPEN" : "CLOSE";
DPRINTF(DRAM,