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1 /*
2  * Macros for asm code.
3  *
4  * Copyright (c) 2019-2020, Arm Limited.
5  * SPDX-License-Identifier: MIT
6  */
7 
8 #ifndef _ASMDEFS_H
9 #define _ASMDEFS_H
10 
11 #if defined(__aarch64__)
12 
13 /* Branch Target Identitication support.  */
14 #define BTI_C		hint	34
15 #define BTI_J		hint	36
16 /* Return address signing support (pac-ret).  */
17 #define PACIASP		hint	25; .cfi_window_save
18 #define AUTIASP		hint	29; .cfi_window_save
19 
20 /* GNU_PROPERTY_AARCH64_* macros from elf.h.  */
21 #define FEATURE_1_AND 0xc0000000
22 #define FEATURE_1_BTI 1
23 #define FEATURE_1_PAC 2
24 
25 /* Add a NT_GNU_PROPERTY_TYPE_0 note.  */
26 #define GNU_PROPERTY(type, value)	\
27   .section .note.gnu.property, "a";	\
28   .p2align 3;				\
29   .word 4;				\
30   .word 16;				\
31   .word 5;				\
32   .asciz "GNU";				\
33   .word type;				\
34   .word 4;				\
35   .word value;				\
36   .word 0;				\
37   .text
38 
39 /* If set then the GNU Property Note section will be added to
40    mark objects to support BTI and PAC-RET.  */
41 #ifndef WANT_GNU_PROPERTY
42 #define WANT_GNU_PROPERTY 1
43 #endif
44 
45 #if WANT_GNU_PROPERTY
46 /* Add property note with supported features to all asm files.  */
47 GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC)
48 #endif
49 
50 #define ENTRY_ALIGN(name, alignment)	\
51   .global name;		\
52   .type name,%function;	\
53   .align alignment;		\
54   name:			\
55   .cfi_startproc;	\
56   BTI_C;
57 
58 #else
59 
60 #define END_FILE
61 
62 #define ENTRY_ALIGN(name, alignment)	\
63   .global name;		\
64   .type name,%function;	\
65   .align alignment;		\
66   name:			\
67   .cfi_startproc;
68 
69 #endif
70 
71 #define ENTRY(name)	ENTRY_ALIGN(name, 6)
72 
73 #define ENTRY_ALIAS(name)	\
74   .global name;		\
75   .type name,%function;	\
76   name:
77 
78 #define END(name)	\
79   .cfi_endproc;		\
80   .size name, .-name;
81 
82 #define L(l) .L ## l
83 
84 #ifdef __ILP32__
85   /* Sanitize padding bits of pointer arguments as per aapcs64 */
86 #define PTR_ARG(n)  mov w##n, w##n
87 #else
88 #define PTR_ARG(n)
89 #endif
90 
91 #ifdef __ILP32__
92   /* Sanitize padding bits of size arguments as per aapcs64 */
93 #define SIZE_ARG(n)  mov w##n, w##n
94 #else
95 #define SIZE_ARG(n)
96 #endif
97 
98 #endif
99