xref: /llvm-project/libc/src/__support/OSUtil/linux/arm/syscall.h (revision 5ff3ff33ff930e4ec49da7910612d8a41eb068cb)
1 //===--------- inline implementation of arm syscalls --------------* C++ *-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_SYSCALL_H
10 #define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_SYSCALL_H
11 
12 #include "src/__support/common.h"
13 #include "src/__support/macros/config.h"
14 
15 #ifdef __thumb__
16 #define R7 long r7 = number
17 #define SYSCALL_INSTR(input_constraint)                                        \
18   int temp;                                                                    \
19   LIBC_INLINE_ASM(R"(
20     mov %[temp], r7
21     mov r7, %2
22     svc #0
23     mov r7, %[temp]
24   )"                                                          \
25                   : "=r"(r0), [temp] "=&r"(temp)                               \
26                   : input_constraint                                           \
27                   : "memory", "cc")
28 #else
29 #define R7 register long r7 asm("r7") = number
30 #define SYSCALL_INSTR(input_constraint)                                        \
31   LIBC_INLINE_ASM("svc 0" : "=r"(r0) : input_constraint : "memory", "cc")
32 #endif
33 
34 #define REGISTER_DECL_0                                                        \
35   R7;                                                                          \
36   register long r0 __asm__("r0");
37 #define REGISTER_DECL_1                                                        \
38   R7;                                                                          \
39   register long r0 __asm__("r0") = arg1;
40 #define REGISTER_DECL_2                                                        \
41   REGISTER_DECL_1                                                              \
42   register long r1 __asm__("r1") = arg2;
43 #define REGISTER_DECL_3                                                        \
44   REGISTER_DECL_2                                                              \
45   register long r2 __asm__("r2") = arg3;
46 #define REGISTER_DECL_4                                                        \
47   REGISTER_DECL_3                                                              \
48   register long r3 __asm__("r3") = arg4;
49 #define REGISTER_DECL_5                                                        \
50   REGISTER_DECL_4                                                              \
51   register long r4 __asm__("r4") = arg5;
52 #define REGISTER_DECL_6                                                        \
53   REGISTER_DECL_5                                                              \
54   register long r5 __asm__("r5") = arg6;
55 
56 #define REGISTER_CONSTRAINT_0 "r"(r7)
57 #define REGISTER_CONSTRAINT_1 REGISTER_CONSTRAINT_0, "r"(r0)
58 #define REGISTER_CONSTRAINT_2 REGISTER_CONSTRAINT_1, "r"(r1)
59 #define REGISTER_CONSTRAINT_3 REGISTER_CONSTRAINT_2, "r"(r2)
60 #define REGISTER_CONSTRAINT_4 REGISTER_CONSTRAINT_3, "r"(r3)
61 #define REGISTER_CONSTRAINT_5 REGISTER_CONSTRAINT_4, "r"(r4)
62 #define REGISTER_CONSTRAINT_6 REGISTER_CONSTRAINT_5, "r"(r5)
63 
64 namespace LIBC_NAMESPACE_DECL {
65 
66 LIBC_INLINE long syscall_impl(long number) {
67   REGISTER_DECL_0;
68   SYSCALL_INSTR(REGISTER_CONSTRAINT_0);
69   return r0;
70 }
71 
72 LIBC_INLINE long syscall_impl(long number, long arg1) {
73   REGISTER_DECL_1;
74   SYSCALL_INSTR(REGISTER_CONSTRAINT_1);
75   return r0;
76 }
77 
78 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2) {
79   REGISTER_DECL_2;
80   SYSCALL_INSTR(REGISTER_CONSTRAINT_2);
81   return r0;
82 }
83 
84 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3) {
85   REGISTER_DECL_3;
86   SYSCALL_INSTR(REGISTER_CONSTRAINT_3);
87   return r0;
88 }
89 
90 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
91                               long arg4) {
92   REGISTER_DECL_4;
93   SYSCALL_INSTR(REGISTER_CONSTRAINT_4);
94   return r0;
95 }
96 
97 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
98                               long arg4, long arg5) {
99   REGISTER_DECL_5;
100   SYSCALL_INSTR(REGISTER_CONSTRAINT_5);
101   return r0;
102 }
103 
104 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
105                               long arg4, long arg5, long arg6) {
106   REGISTER_DECL_6;
107   SYSCALL_INSTR(REGISTER_CONSTRAINT_6);
108   return r0;
109 }
110 
111 } // namespace LIBC_NAMESPACE_DECL
112 
113 #undef REGISTER_DECL_0
114 #undef REGISTER_DECL_1
115 #undef REGISTER_DECL_2
116 #undef REGISTER_DECL_3
117 #undef REGISTER_DECL_4
118 #undef REGISTER_DECL_5
119 #undef REGISTER_DECL_6
120 
121 #undef REGISTER_CONSTRAINT_0
122 #undef REGISTER_CONSTRAINT_1
123 #undef REGISTER_CONSTRAINT_2
124 #undef REGISTER_CONSTRAINT_3
125 #undef REGISTER_CONSTRAINT_4
126 #undef REGISTER_CONSTRAINT_5
127 #undef REGISTER_CONSTRAINT_6
128 
129 #endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_SYSCALL_H
130