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authorOmar Naji <Omar.Naji@arm.com>2014-10-20 18:03:52 -0400
committerOmar Naji <Omar.Naji@arm.com>2014-10-20 18:03:52 -0400
commit29dd2887f4e1c2ee7689f912c705552afaac4d03 (patch)
treef54c1d931e92ac574a7ca76c0a774cea5a6482f0 /src/mem
parentd2a0f60b69313ad869f81fb006c8e998e40cb3c1 (diff)
downloadgem5-29dd2887f4e1c2ee7689f912c705552afaac4d03.tar.xz
mem: Add DRAM device size and check against config
This patch adds the size of the DRAM device to the DRAM config. It also compares the actual DRAM size (calculated using information from the config) to the size defined in the system. If these two values do not match gem5 will print a warning. In order to do correct DRAM research the size of the memory defined in the system should match the size of the DRAM in the config. The timing and current parameters found in the DRAM configs are defined for a DRAM device with a specific size and would differ for another device with a different size.
Diffstat (limited to 'src/mem')
-rw-r--r--src/mem/DRAMCtrl.py18
-rw-r--r--src/mem/dram_ctrl.cc11
-rw-r--r--src/mem/dram_ctrl.hh1
3 files changed, 30 insertions, 0 deletions
diff --git a/src/mem/DRAMCtrl.py b/src/mem/DRAMCtrl.py
index f5b405d09..642e9d525 100644
--- a/src/mem/DRAMCtrl.py
+++ b/src/mem/DRAMCtrl.py
@@ -96,6 +96,9 @@ class DRAMCtrl(AbstractMemory):
max_accesses_per_row = Param.Unsigned(16, "Max accesses per row before "
"closing");
+ # size of DRAM Chip in Bytes
+ device_size = Param.MemorySize("Size of DRAM chip")
+
# pipeline latency of the controller and PHY, split into a
# frontend part and a backend part, with reads and writes serviced
# by the queues only seeing the frontend contribution, and reads
@@ -305,6 +308,9 @@ class DRAMCtrl(AbstractMemory):
# timings based on a DDR3-1600 4 Gbit datasheet (Micron MT41J512M8) in
# an 8x8 configuration.
class DDR3_1600_x64(DRAMCtrl):
+ # size of device in bytes
+ device_size = '512MB'
+
# 8x8 configuration, 8 devices each with an 8-bit interface
device_bus_width = 8
@@ -397,6 +403,9 @@ class DDR3_2133_x64(DDR3_1600_x64):
# timings based on a DDR4-2400 4 Gbit datasheet (Micron MT40A512M8)
# in an 8x8 configuration.
class DDR4_2400_x64(DRAMCtrl):
+ # size of device
+ device_size = '512MB'
+
# 8x8 configuration, 8 devices each with an 8-bit interface
device_bus_width = 8
@@ -488,6 +497,9 @@ class LPDDR2_S4_1066_x32(DRAMCtrl):
# No DLL in LPDDR2
dll = False
+ # size of device
+ device_size = '512MB'
+
# 1x32 configuration, 1 device with a 32-bit interface
device_bus_width = 32
@@ -572,6 +584,9 @@ class WideIO_200_x128(DRAMCtrl):
# No DLL for WideIO
dll = False
+ # size of device
+ device_size = '1024MB'
+
# 1x128 configuration, 1 device with a 128-bit interface
device_bus_width = 128
@@ -638,6 +653,9 @@ class LPDDR3_1600_x32(DRAMCtrl):
# No DLL for LPDDR3
dll = False
+ # size of device
+ device_size = '512MB'
+
# 1x32 configuration, 1 device with a 32-bit interface
device_bus_width = 32
diff --git a/src/mem/dram_ctrl.cc b/src/mem/dram_ctrl.cc
index ac78a3d1e..c9d944faa 100644
--- a/src/mem/dram_ctrl.cc
+++ b/src/mem/dram_ctrl.cc
@@ -62,6 +62,7 @@ DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) :
nextReqEvent(this), respondEvent(this), activateEvent(this),
prechargeEvent(this), refreshEvent(this), powerEvent(this),
drainManager(NULL),
+ deviceSize(p->device_size),
deviceBusWidth(p->device_bus_width), burstLength(p->burst_length),
deviceRowBufferSize(p->device_rowbuffer_size),
devicesPerRank(p->devices_per_rank),
@@ -139,6 +140,16 @@ DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) :
// determine the rows per bank by looking at the total capacity
uint64_t capacity = ULL(1) << ceilLog2(AbstractMemory::size());
+ // determine the dram actual capacity from the DRAM config in Mbytes
+ uint64_t deviceCapacity = deviceSize / (1024 * 1024) * devicesPerRank *
+ ranksPerChannel;
+
+ // if actual DRAM size does not match memory capacity in system warn!
+ if (deviceCapacity != capacity / (1024 * 1024))
+ warn("DRAM device capacity (%d Mbytes) does not match the "
+ "address range assigned (%d Mbytes)\n", deviceCapacity,
+ capacity / (1024 * 1024));
+
DPRINTF(DRAM, "Memory capacity %lld (%lld) bytes\n", capacity,
AbstractMemory::size());
diff --git a/src/mem/dram_ctrl.hh b/src/mem/dram_ctrl.hh
index cb2197841..0c4e53ca1 100644
--- a/src/mem/dram_ctrl.hh
+++ b/src/mem/dram_ctrl.hh
@@ -463,6 +463,7 @@ class DRAMCtrl : public AbstractMemory
* The rowsPerBank is determined based on the capacity, number of
* ranks and banks, the burst size, and the row buffer size.
*/
+ const uint32_t deviceSize;
const uint32_t deviceBusWidth;
const uint32_t burstLength;
const uint32_t deviceRowBufferSize;