xref: /linux/arch/arm64/include/asm/hyp_image.h (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2020 Google LLC.
4  * Written by David Brazdil <dbrazdil@google.com>
5  */
6 
7 #ifndef __ARM64_HYP_IMAGE_H__
8 #define __ARM64_HYP_IMAGE_H__
9 
10 #define __HYP_CONCAT(a, b)	a ## b
11 #define HYP_CONCAT(a, b)	__HYP_CONCAT(a, b)
12 
13 #ifndef __KVM_NVHE_HYPERVISOR__
14 /*
15  * KVM nVHE code has its own symbol namespace prefixed with __kvm_nvhe_,
16  * to separate it from the kernel proper.
17  */
18 #define kvm_nvhe_sym(sym)	__kvm_nvhe_##sym
19 #else
20 #define kvm_nvhe_sym(sym)	sym
21 #endif
22 
23 #ifdef LINKER_SCRIPT
24 
25 /*
26  * KVM nVHE ELF section names are prefixed with .hyp, to separate them
27  * from the kernel proper.
28  */
29 #define HYP_SECTION_NAME(NAME)	.hyp##NAME
30 
31 /* Symbol defined at the beginning of each hyp section. */
32 #define HYP_SECTION_SYMBOL_NAME(NAME) \
33 	HYP_CONCAT(__hyp_section_, HYP_SECTION_NAME(NAME))
34 
35 /*
36  * Helper to generate linker script statements starting a hyp section.
37  *
38  * A symbol with a well-known name is defined at the first byte. This
39  * is used as a base for hyp relocations (see gen-hyprel.c). It must
40  * be defined inside the section so the linker of `vmlinux` cannot
41  * separate it from the section data.
42  */
43 #define BEGIN_HYP_SECTION(NAME)				\
44 	HYP_SECTION_NAME(NAME) : {			\
45 		HYP_SECTION_SYMBOL_NAME(NAME) = .;
46 
47 /* Helper to generate linker script statements ending a hyp section. */
48 #define END_HYP_SECTION					\
49 	}
50 
51 /* Defines an ELF hyp section from input section @NAME and its subsections. */
52 #define HYP_SECTION(NAME)			\
53 	BEGIN_HYP_SECTION(NAME)			\
54 		*(NAME NAME##.*)		\
55 	END_HYP_SECTION
56 
57 /*
58  * Defines a linker script alias of a kernel-proper symbol referenced by
59  * KVM nVHE hyp code.
60  */
61 #define KVM_NVHE_ALIAS(sym)	kvm_nvhe_sym(sym) = sym;
62 
63 /* Defines a linker script alias for KVM nVHE hyp symbols */
64 #define KVM_NVHE_ALIAS_HYP(first, sec)	kvm_nvhe_sym(first) = kvm_nvhe_sym(sec);
65 
66 #endif /* LINKER_SCRIPT */
67 
68 #endif /* __ARM64_HYP_IMAGE_H__ */
69