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# SPDX-License-Identifier: GPL-2.0
#
# Radix Tree Parser
#
# Copyright (c) 2016 Linaro Ltd
# Copyright (c) 2023 Broadcom
#
# Authors:
# Kieran Bingham <[email protected]>
# Florian Fainelli <[email protected]>
import gdb
from linux import utils
from linux import constants
radix_tree_root_type = utils.CachedType("struct xarray")
radix_tree_node_type = utils.CachedType("struct xa_node")
def is_internal_node(node):
long_type = utils.get_long_type()
return ((node.cast(long_type) & constants.LX_RADIX_TREE_ENTRY_MASK) == constants.LX_RADIX_TREE_INTERNAL_NODE)
def entry_to_node(node):
long_type = utils.get_long_type()
node_type = node.type
indirect_ptr = node.cast(long_type) & ~constants.LX_RADIX_TREE_INTERNAL_NODE
return indirect_ptr.cast(radix_tree_node_type.get_type().pointer())
def node_maxindex(node):
return (constants.LX_RADIX_TREE_MAP_SIZE << node['shift']) - 1
def lookup(root, index):
if root.type == radix_tree_root_type.get_type().pointer():
node = root.dereference()
elif root.type != radix_tree_root_type.get_type():
raise gdb.GdbError("must be {} not {}"
.format(radix_tree_root_type.get_type(), root.type))
node = root['xa_head']
if node == 0:
return None
if not (is_internal_node(node)):
if (index > 0):
return None
return node
node = entry_to_node(node)
maxindex = node_maxindex(node)
if (index > maxindex):
return None
shift = node['shift'] + constants.LX_RADIX_TREE_MAP_SHIFT
while True:
offset = (index >> node['shift']) & constants.LX_RADIX_TREE_MAP_MASK
slot = node['slots'][offset]
if slot == 0:
return None
node = slot.cast(node.type.pointer()).dereference()
if node == 0:
return None
shift -= constants.LX_RADIX_TREE_MAP_SHIFT
if (shift <= 0):
break
return node
class LxRadixTree(gdb.Function):
""" Lookup and return a node from a RadixTree.
$lx_radix_tree_lookup(root_node [, index]): Return the node at the given index.
If index is omitted, the root node is dereference and returned."""
def __init__(self):
super(LxRadixTree, self).__init__("lx_radix_tree_lookup")
def invoke(self, root, index=0):
result = lookup(root, index)
if result is None:
raise gdb.GdbError("No entry in tree at index {}".format(index))
return result
LxRadixTree()
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