xref: /linux/arch/arm64/include/asm/hyp_image.h (revision 7b4a7b5e6fefd15f708f959dd43e188444e252ec)
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 /*
14  * KVM nVHE code has its own symbol namespace prefixed with __kvm_nvhe_,
15  * to separate it from the kernel proper.
16  */
17 #define kvm_nvhe_sym(sym)	__kvm_nvhe_##sym
18 
19 #ifdef LINKER_SCRIPT
20 
21 /*
22  * KVM nVHE ELF section names are prefixed with .hyp, to separate them
23  * from the kernel proper.
24  */
25 #define HYP_SECTION_NAME(NAME)	.hyp##NAME
26 
27 /* Symbol defined at the beginning of each hyp section. */
28 #define HYP_SECTION_SYMBOL_NAME(NAME) \
29 	HYP_CONCAT(__hyp_section_, HYP_SECTION_NAME(NAME))
30 
31 /*
32  * Helper to generate linker script statements starting a hyp section.
33  *
34  * A symbol with a well-known name is defined at the first byte. This
35  * is used as a base for hyp relocations (see gen-hyprel.c). It must
36  * be defined inside the section so the linker of `vmlinux` cannot
37  * separate it from the section data.
38  */
39 #define BEGIN_HYP_SECTION(NAME)				\
40 	HYP_SECTION_NAME(NAME) : {			\
41 		HYP_SECTION_SYMBOL_NAME(NAME) = .;
42 
43 /* Helper to generate linker script statements ending a hyp section. */
44 #define END_HYP_SECTION					\
45 	}
46 
47 /* Defines an ELF hyp section from input section @NAME and its subsections. */
48 #define HYP_SECTION(NAME)			\
49 	BEGIN_HYP_SECTION(NAME)			\
50 		*(NAME NAME##.*)		\
51 	END_HYP_SECTION
52 
53 /*
54  * Defines a linker script alias of a kernel-proper symbol referenced by
55  * KVM nVHE hyp code.
56  */
57 #define KVM_NVHE_ALIAS(sym)	kvm_nvhe_sym(sym) = sym;
58 
59 /* Defines a linker script alias for KVM nVHE hyp symbols */
60 #define KVM_NVHE_ALIAS_HYP(first, sec)	kvm_nvhe_sym(first) = kvm_nvhe_sym(sec);
61 
62 #endif /* LINKER_SCRIPT */
63 
64 #endif /* __ARM64_HYP_IMAGE_H__ */
65