mirror of https://github.com/crash-utility/crash
83 lines
1.6 KiB
C
83 lines
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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#ifndef _MAPLE_TREE_H
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#define _MAPLE_TREE_H
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/*
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* Maple Tree - An RCU-safe adaptive tree for storing ranges
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* Copyright (c) 2018-2022 Oracle
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* Authors: Liam R. Howlett <Liam.Howlett@Oracle.com>
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* Matthew Wilcox <willy@infradead.org>
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*
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* eXtensible Arrays
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* Copyright (c) 2017 Microsoft Corporation
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* Author: Matthew Wilcox <willy@infradead.org>
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*
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* See Documentation/core-api/xarray.rst for how to use the XArray.
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*/
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#include <stdbool.h>
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#include <limits.h>
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#include <sys/types.h>
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/*
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* The following are copied and modified from include/linux/maple_tree.h
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*/
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enum maple_type {
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maple_dense,
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maple_leaf_64,
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maple_range_64,
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maple_arange_64,
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};
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#define MAPLE_NODE_MASK 255UL
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#define MT_FLAGS_HEIGHT_OFFSET 0x02
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#define MT_FLAGS_HEIGHT_MASK 0x7C
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#define MAPLE_NODE_TYPE_MASK 0x0F
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#define MAPLE_NODE_TYPE_SHIFT 0x03
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#define MAPLE_RESERVED_RANGE 4096
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/*
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* The following are copied and modified from include/linux/xarray.h
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*/
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#define XA_ZERO_ENTRY xa_mk_internal(257)
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static inline ulong xa_mk_internal(ulong v)
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{
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return (v << 2) | 2;
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}
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static inline bool xa_is_internal(ulong entry)
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{
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return (entry & 3) == 2;
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}
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static inline bool xa_is_node(ulong entry)
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{
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return xa_is_internal(entry) && entry > 4096;
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}
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static inline bool xa_is_value(ulong entry)
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{
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return entry & 1;
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}
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static inline bool xa_is_zero(ulong entry)
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{
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return entry == XA_ZERO_ENTRY;
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}
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static inline unsigned long xa_to_internal(ulong entry)
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{
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return entry >> 2;
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}
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static inline unsigned long xa_to_value(ulong entry)
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{
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return entry >> 1;
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}
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#endif /* _MAPLE_TREE_H */
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