1 /* 2 * Copyright (c) 2021 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29 #ifndef _MACHINE_STATIC_IF_H 30 #error "do not include this file directly, use <machine/static_if.h>" 31 #else 32 33 #define STATIC_IF_RELATIVE 0 34 #define STATIC_IF_INSN_SIZE 5 35 36 typedef long static_if_offset_t; 37 38 struct static_if_entry { 39 static_if_offset_t sie_base; 40 static_if_offset_t sie_target; 41 unsigned long sie_link; 42 }; 43 44 /* generates a struct static_if_entry */ 45 #define STATIC_IF_ENTRY(n) \ 46 ".pushsection " STATIC_IF_SEGSECT ",regular,live_support" "\n\t" \ 47 ".align 3" "\n\t" \ 48 ".quad 1b" "\n\t" \ 49 ".quad %l1" "\n\t" \ 50 ".quad _" #n "_jump_key + %c0" "\n\t" \ 51 ".popsection" 52 53 /* From "Recommended Multi-Byte Sequence of NOP Instruction" */ 54 #define STATIC_IF_NOP(n, label) \ 55 asm goto("1: .byte 0x0F,0x1F,0x44,0x00,0x00" "\n\t" \ 56 STATIC_IF_ENTRY(n) : : "i"(0) : : label) 57 58 /* 32-bit jump */ 59 #define STATIC_IF_BRANCH(n, label) \ 60 asm goto("1: .byte 0xE9; .long %l1 - 2f; 2:" "\n\t" \ 61 STATIC_IF_ENTRY(n) : : "i"(1) : : label) 62 63 #endif /* _MACHINE_STATIC_IF_H */ 64