arm, dev: Add a NAND flash timing model

This adds a NAND flash timing model. This model takes the number of
planes into account and is ultimately intended to be used as a
high-level performance model for any device using flash. To access the
memory, use either readMemory or writeMemory.

To make use of the model you will need an interface model
such as UFSHostDevice, which is part of a separate patch.

At the moment the flash device is part of the ARM device tree since
the only use if the UFSHostDevice, and that in turn relies on the ARM
GIC.

1 files changed, 74 insertions, 0 deletions

diff --git a/src/dev/arm/FlashDevice.py b/src/dev/arm/FlashDevice.py
new file mode 100644
index 000000000..ed3b9d04d
--- /dev/null
+++ b/src/dev/arm/FlashDevice.py
@@ -0,0 +1,74 @@
+# Copyright (c) 2013-2015 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# 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.
+#
+# Authors: Rene de Jong
+#
+
+from m5.params import *
+from m5.proxy import *
+from AbstractNVM import *
+
+#Distribution of the data.
+#sequential: sequential (address n+1 is likely to be on the same plane as n)
+#Random: @TODO Not yet implemented
+#stripe: striping over all the planes
+class DataDistribution(Enum): vals = ['sequential', 'stripe']
+
+class FlashDevice(AbstractNVM):
+    type = 'FlashDevice'
+    cxx_header = "dev/arm/flash_device.hh"
+    # default blocksize is 128 kB.This seems to be the most common size in
+    # mobile devices (not the image blocksize)
+    blk_size = Param.MemorySize("128kB", "Size of one disk block")
+    # disk page size is 2 kB. This is the most commonly used page size in
+    # flash devices
+    page_size = Param.MemorySize("2kB", "Size of one disk page")
+    # There are many GC flavours. It is impossible to cover them all; this
+    # parameter enables the approximation of different GC algorithms
+    GC_active = Param.Percent(50, "Percentage of the time (in whole numbers) \
+        that the GC is activated if a block is full")
+    # Access latencies. Different devices will have different latencies, but
+    # the latencies will be around the default values.
+    read_lat = Param.Latency("25us", "Read Latency")
+    write_lat = Param.Latency("200us", "Write Latency")
+    erase_lat = Param.Latency("1500us", "Erase Delay")
+    # Number of planes ought to be a power of two according to ONFI standard
+    num_planes = Param.UInt32(1, "Number of planes per die")
+    # Data distribution. Default is none. It is adviced to switch to stripe
+    # when more than one plane is used.
+    data_distribution = Param.DataDistribution('sequential', "Distribution \
+        of the data in the adress table; Stripe needed for multiple\
+        planes; otherwise use: sequential")
+