arm: DT autogeneration - Device Tree generation methods

This patch adds an extra layer to the pyfdt library such that usage
gets easier and device tree nodes can be specified in less code,
without limiting original usage. Note to not import both the pyfdt
and fdthelper in the same namespace (but generally fdthelper is all
you need, because it supplies the same classes even when they are not
extended in any way)

Also, this patch lays out the primary functionality for generating a
device tree, where every SimObject gets an empty generateDeviceTree
method and ArmSystems loop over their children in an effort to merge
all the nodes. Devices are implemented in other patches.

Change-Id: I4d0a0666827287fe42e18447f19acab4dc80cc49
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5962
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

2 files changed, 271 insertions, 0 deletions

diff --git a/src/python/m5/SimObject.py b/src/python/m5/SimObject.py
index cff818c66..919c0e852 100644
--- a/src/python/m5/SimObject.py
+++ b/src/python/m5/SimObject.py
@@ -51,6 +51,9 @@ import inspect
 import m5
 from m5.util import *
 from m5.util.pybind import *
+# Use the pyfdt and not the helper class, because the fdthelper
+# relies on the SimObject definition
+from m5.ext.pyfdt import pyfdt
 
 # Have to import params up top since Param is referenced on initial
 # load (when SimObject class references Param to create a class
@@ -1495,6 +1498,19 @@ class SimObject(object):
         for (attr, portRef) in sorted(self._port_refs.iteritems()):
             portRef.ccConnect()
 
+    # Default function for generating the device structure.
+    # Can be overloaded by the inheriting class
+    def generateDeviceTree(self, state):
+        return # return without yielding anything
+        yield  # make this function a (null) generator
+
+    def recurseDeviceTree(self, state):
+        for child in [getattr(self, c) for c in self._children]:
+            for item in child: # For looping over SimObjectVectors
+                if isinstance(item, SimObject):
+                    for dt in item.generateDeviceTree(state):
+                        yield dt
+
 # Function to provide to C++ so it can look up instances based on paths
 def resolveSimObject(name):
     obj = instanceDict[name]
diff --git a/src/python/m5/util/fdthelper.py b/src/python/m5/util/fdthelper.py
new file mode 100644
index 000000000..bd04b4154
--- /dev/null
+++ b/src/python/m5/util/fdthelper.py
@@ -0,0 +1,255 @@
+# Copyright (c) 2016 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.
+#
+# Author: Glenn Bergmans
+
+from m5.ext.pyfdt import pyfdt
+import re
+import os
+from m5.SimObject import SimObject
+
+class FdtProperty(pyfdt.FdtProperty):
+    """Create a property without values."""
+    pass
+
+class FdtPropertyWords(pyfdt.FdtPropertyWords):
+    """Create a property with word (32-bit unsigned) values."""
+    def __init__(self, name, words):
+        if type(words) != list:
+            words = [words]
+        # Make sure all values are ints (use automatic base detection if the
+        # type is str)
+        words = [long(w, base=0) if type(w) == str else long(w) for w in words]
+        super(FdtPropertyWords, self).__init__(name, words)
+
+class FdtPropertyStrings(pyfdt.FdtPropertyStrings):
+    """Create a property with string values."""
+
+    def __init__(self, name, strings):
+        if type(strings) == str:
+            strings = [strings]
+        strings = [str(string) for string in strings] # Make all values strings
+        super(FdtPropertyStrings, self).__init__(name, strings)
+
+class FdtPropertyBytes(pyfdt.FdtPropertyBytes):
+    """Create a property with integer (8-bit signed) values."""
+
+    def __init__(self, name, values):
+        if type(values) != list:
+            values = [values]
+        # Make sure all values are ints (use automatic base detection if the
+        # type is str)
+        values = [int(v, base=0)
+                   if isinstance(v, str) else int(v) for v in values]
+        super(FdtPropertyBytes, self).__init__(name, values)
+
+class FdtState(object):
+    """Class for maintaining state while recursively generating a flattened
+    device tree. The state tracks address, size and CPU address cell sizes, and
+    maintains a dictionary of allocated phandles."""
+
+    phandle_counter = 0
+    phandles = dict()
+
+    def __init__(self, addr_cells, size_cells, cpu_cells):
+        """Instantiate values of this state. The state can only be initialized
+        once."""
+
+        self.addr_cells = addr_cells
+        self.size_cells = size_cells
+        self.cpu_cells = cpu_cells
+
+    def phandle(self, obj):
+        """Return a unique phandle number for a key. The key can be a SimObject
+        or any value that is castable to a string. If the phandle doesn't exist
+        a new one is created, otherwise the existing one is returned."""
+
+        if isinstance(obj, SimObject):
+            key = str(id(obj))
+        else:
+            try:
+                key = str(obj)
+            except ValueError:
+                raise ValueError('Phandle keys must be castable to str')
+
+        if not key in FdtState.phandles:
+            FdtState.phandle_counter += 1
+
+        return FdtState.phandles.setdefault(key, FdtState.phandle_counter)
+
+    def resetPhandles(self):
+        FdtState.phandle_counter = 0
+        FdtState.phandles = dict()
+
+    def int_to_cells(self, value, cells):
+        """Helper function for: generates a list of 32 bit cells from an int,
+        used to split up addresses in appropriate 32 bit chunks."""
+        value = long(value)
+
+        if (value >> (32 * cells)) != 0:
+            fatal("Value %d doesn't fit in %d cells" % (value, cells))
+
+        return [(value >> 32*(x-1)) & 0xFFFFFFFF for x in range(cells, 0, -1)]
+
+    def addrCells(self, addr):
+        """Format an integer type according to the address_cells value of this
+        state."""
+        return self.int_to_cells(addr, self.addr_cells)
+
+    def CPUAddrCells(self, addr):
+        """Format an integer type according to the cpu_cells value of this
+        state."""
+        return self.int_to_cells(addr, self.cpu_cells)
+
+    def sizeCells(self, size):
+        """Format an integer type according to the size_cells value of this
+        state."""
+        return self.int_to_cells(size, self.size_cells)
+
+    def addrCellsProperty(self):
+        """Return an #address-cells property with the value of this state."""
+        return FdtPropertyWords("#address-cells", self.addr_cells)
+
+    def sizeCellsProperty(self):
+        """Return an #size-cells property with the value of this state."""
+        return FdtPropertyWords("#size-cells", self.size_cells)
+
+    def CPUCellsProperty(self):
+        """Return an #address-cells property for cpu nodes with the value
+        of this state."""
+        return FdtPropertyWords("#address-cells", self.cpu_cells)
+
+class FdtNop(pyfdt.FdtNop):
+    """Create an empty node."""
+    pass
+
+class FdtNode(pyfdt.FdtNode):
+    def __init__(self, name, obj=None):
+        """Create a new node and immediately set the phandle property, if obj
+        is supplied"""
+        super(FdtNode, self).__init__(name)
+        if obj != None:
+            self.appendPhandle(obj)
+
+    def append(self, subnodes):
+        """Change the behavior of the normal append to override if a node with
+        the same name already exists or merge if the name exists and is a node
+        type. Can also take a list of subnodes, that each get appended."""
+        if not hasattr(subnodes, '__iter__'):
+            subnodes = [subnodes]
+
+        for subnode in subnodes:
+            try:
+                if not issubclass(type(subnode), pyfdt.FdtNop):
+                    index = self.index(subnode.name)
+                    item = self.pop(index)
+                else:
+                    item = None
+            except ValueError:
+                item = None
+
+            if isinstance(item,  pyfdt.FdtNode) and \
+               isinstance(subnode,  pyfdt.FdtNode):
+                item.merge(subnode)
+                subnode = item
+
+            super(FdtNode, self).append(subnode)
+
+    def appendList(self, subnode_list):
+        """Append all properties/nodes in the iterable."""
+        for subnode in subnode_list:
+            self.append(subnode)
+
+    def appendCompatible(self, compatible):
+        """Append a compatible property with the supplied compatibility
+        strings."""
+        if isinstance(compatible, str):
+            compatible = [compatible]
+        self.append(FdtPropertyStrings('compatible', compatible))
+
+    def appendPhandle(self, obj):
+        """Append a phandle property to this node with the phandle of the
+        supplied object."""
+        # Create a bogus state because we only need the Phandle dictionary
+        state = FdtState(addr_cells=1, size_cells=1, cpu_cells=1)
+
+        phandle = state.phandle(obj)
+        self.append(FdtPropertyWords("phandle", [phandle]))
+
+class Fdt(pyfdt.Fdt):
+    def sortNodes(self, node):
+        """Move all properties to the beginning and subnodes to the end
+        while maintaining the order of the subnodes. DTB files require the
+        properties to go before the nodes, but the PyFdt doesn't account for
+        defining nodes and properties in a random order."""
+        properties = FdtNode(node.name)
+        subnodes = FdtNode(node.name)
+
+        while len(node):
+            subnode = node.pop(0)
+            if issubclass(type(subnode), pyfdt.FdtNode):
+                subnode = self.sortNodes(subnode)
+                subnodes.append(subnode)
+            else:
+                properties.append(subnode)
+
+        properties.merge(subnodes)
+
+        return properties
+
+    def add_rootnode(self, rootnode, prenops=None, postnops=None):
+        """First sort the device tree, so that properties are before nodes."""
+        rootnode = self.sortNodes(rootnode)
+        super(Fdt, self).add_rootnode(rootnode, prenops, postnops)
+
+    def writeDtbFile(self, filename):
+        """Convert the device tree to DTB and write to a file."""
+        filename = os.path.realpath(filename)
+        try:
+            with open(filename, 'wb') as f:
+                f.write(self.to_dtb())
+            return filename
+        except IOError:
+            raise RuntimeError("Failed to open DTB output file")
+
+    def writeDtsFile(self, filename):
+        """Convert the device tree to DTS and write to a file."""
+        filename = os.path.realpath(filename)
+        try:
+            with open(filename, 'w') as f:
+                f.write(self.to_dts())
+            return filename
+        except IOError:
+            raise RuntimeError("Failed to open DTS output file")