/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> */ #ifndef _ORC_LOOKUP_H #define _ORC_LOOKUP_H /* * This is a lookup table for speeding up access to the .orc_unwind table. * Given an input address offset, the corresponding lookup table entry * specifies a subset of the .orc_unwind table to search. * * Each block represents the end of the previous range and the start of the * next range. An extra block is added to give the last range an end. * * The block size should be a power of 2 to avoid a costly 'div' instruction. * * A block size of 256 was chosen because it roughly doubles unwinder * performance while only adding ~5% to the ORC data footprint. */ #define LOOKUP_BLOCK_ORDER 8 #define LOOKUP_BLOCK_SIZE (1 << LOOKUP_BLOCK_ORDER) #ifndef LINKER_SCRIPT extern unsigned int orc_lookup[]; extern unsigned int orc_lookup_end[]; #define LOOKUP_START_IP (unsigned long)_stext #define LOOKUP_STOP_IP (unsigned long)_etext #endif /* LINKER_SCRIPT */ #endif /* _ORC_LOOKUP_H */