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authorNilay Vaish <nilay@cs.wisc.edu>2014-10-11 15:02:23 -0500
committerNilay Vaish <nilay@cs.wisc.edu>2014-10-11 15:02:23 -0500
commitb80e574d01a0453acfe33084f288ac6fb3cd9cbb (patch)
tree55b8b9b1ac9caa49f5394e5de9b33a6aa708910a
parente7f918d8cd7ecc1c122dfae1204b44bf26a1dafc (diff)
downloadgem5-b80e574d01a0453acfe33084f288ac6fb3cd9cbb.tar.xz
config: separate function for instantiating a memory controller
This patch moves code for instantiating a single memory controller from the function config_mem() to a separate function. This is being done so that memory controllers can be instantiated without assuming that they will be attached to the system in a particular fashion.
-rw-r--r--configs/common/MemConfig.py83
1 files changed, 48 insertions, 35 deletions
diff --git a/configs/common/MemConfig.py b/configs/common/MemConfig.py
index e954407bc..d203118aa 100644
--- a/configs/common/MemConfig.py
+++ b/configs/common/MemConfig.py
@@ -126,6 +126,50 @@ for alias, target in _mem_aliases_all:
# Normal alias
_mem_aliases[alias] = target
+def create_mem_ctrl(cls, r, i, nbr_mem_ctrls, intlv_bits, cache_line_size):
+ """
+ Helper function for creating a single memoy controller from the given
+ options. This function is invoked multiple times in config_mem function
+ to create an array of controllers.
+ """
+
+ import math
+ # The default behaviour is to interleave on cache line granularity
+ cache_line_bit = int(math.log(cache_line_size, 2)) - 1
+ intlv_low_bit = cache_line_bit
+
+ # Create an instance so we can figure out the address
+ # mapping and row-buffer size
+ ctrl = cls()
+
+ # Only do this for DRAMs
+ if issubclass(cls, m5.objects.DRAMCtrl):
+ # Inform each controller how many channels to account
+ # for
+ ctrl.channels = nbr_mem_ctrls
+
+ # If the channel bits are appearing after the column
+ # bits, we need to add the appropriate number of bits
+ # for the row buffer size
+ if ctrl.addr_mapping.value == 'RoRaBaChCo':
+ # This computation only really needs to happen
+ # once, but as we rely on having an instance we
+ # end up having to repeat it for each and every
+ # one
+ rowbuffer_size = ctrl.device_rowbuffer_size.value * \
+ ctrl.devices_per_rank.value
+
+ intlv_low_bit = int(math.log(rowbuffer_size, 2)) - 1
+
+ # We got all we need to configure the appropriate address
+ # range
+ ctrl.range = m5.objects.AddrRange(r.start, size = r.size(),
+ intlvHighBit = \
+ intlv_low_bit + intlv_bits,
+ intlvBits = intlv_bits,
+ intlvMatch = i)
+ return ctrl
+
def config_mem(options, system):
"""
Create the memory controllers based on the options and attach them.
@@ -143,49 +187,18 @@ def config_mem(options, system):
intlv_bits = int(math.log(nbr_mem_ctrls, 2))
if 2 ** intlv_bits != nbr_mem_ctrls:
fatal("Number of memory channels must be a power of 2")
+
cls = get(options.mem_type)
mem_ctrls = []
- # The default behaviour is to interleave on cache line granularity
- cache_line_bit = int(math.log(system.cache_line_size.value, 2)) - 1
- intlv_low_bit = cache_line_bit
-
# For every range (most systems will only have one), create an
# array of controllers and set their parameters to match their
# address mapping in the case of a DRAM
for r in system.mem_ranges:
for i in xrange(nbr_mem_ctrls):
- # Create an instance so we can figure out the address
- # mapping and row-buffer size
- ctrl = cls()
-
- # Only do this for DRAMs
- if issubclass(cls, m5.objects.DRAMCtrl):
- # Inform each controller how many channels to account
- # for
- ctrl.channels = nbr_mem_ctrls
-
- # If the channel bits are appearing after the column
- # bits, we need to add the appropriate number of bits
- # for the row buffer size
- if ctrl.addr_mapping.value == 'RoRaBaChCo':
- # This computation only really needs to happen
- # once, but as we rely on having an instance we
- # end up having to repeat it for each and every
- # one
- rowbuffer_size = ctrl.device_rowbuffer_size.value * \
- ctrl.devices_per_rank.value
-
- intlv_low_bit = int(math.log(rowbuffer_size, 2)) - 1
-
- # We got all we need to configure the appropriate address
- # range
- ctrl.range = m5.objects.AddrRange(r.start, size = r.size(),
- intlvHighBit = \
- intlv_low_bit + intlv_bits,
- intlvBits = intlv_bits,
- intlvMatch = i)
- mem_ctrls.append(ctrl)
+ mem_ctrls.append(create_mem_ctrl(cls, r, i, nbr_mem_ctrls,
+ intlv_bits,
+ system.cache_line_size.value))
system.mem_ctrls = mem_ctrls