libc/src/__support/OSUtil/linux/arm/syscall.h

   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
  14 #ifdef __thumb__
  15 #error "The arm syscall implementation does not yet support thumb flavor."
  16 #endif // __thumb__
  17
  18 #define REGISTER_DECL_0                                                        \
  19   register long r7 __asm__("r7") = number;                                     \
  20   register long r0 __asm__("r0");
  21 #define REGISTER_DECL_1                                                        \
  22   register long r7 __asm__("r7") = number;                                     \
  23   register long r0 __asm__("r0") = arg1;
  24 #define REGISTER_DECL_2                                                        \
  25   REGISTER_DECL_1                                                              \
  26   register long r1 __asm__("r1") = arg2;
  27 #define REGISTER_DECL_3                                                        \
  28   REGISTER_DECL_2                                                              \
  29   register long r2 __asm__("r2") = arg3;
  30 #define REGISTER_DECL_4                                                        \
  31   REGISTER_DECL_3                                                              \
  32   register long r3 __asm__("r3") = arg4;
  33 #define REGISTER_DECL_5                                                        \
  34   REGISTER_DECL_4                                                              \
  35   register long r4 __asm__("r4") = arg5;
  36 #define REGISTER_DECL_6                                                        \
  37   REGISTER_DECL_5                                                              \
  38   register long r5 __asm__("r5") = arg6;
  39
  40 #define REGISTER_CONSTRAINT_0 "r"(r7)
  41 #define REGISTER_CONSTRAINT_1 REGISTER_CONSTRAINT_0, "r"(r0)
  42 #define REGISTER_CONSTRAINT_2 REGISTER_CONSTRAINT_1, "r"(r1)
  43 #define REGISTER_CONSTRAINT_3 REGISTER_CONSTRAINT_2, "r"(r2)
  44 #define REGISTER_CONSTRAINT_4 REGISTER_CONSTRAINT_3, "r"(r3)
  45 #define REGISTER_CONSTRAINT_5 REGISTER_CONSTRAINT_4, "r"(r4)
  46 #define REGISTER_CONSTRAINT_6 REGISTER_CONSTRAINT_5, "r"(r5)
  47
  48 #define SYSCALL_INSTR(input_constraint)                                        \
  49   LIBC_INLINE_ASM("svc 0" : "=r"(r0) : input_constraint : "memory", "cc")
  50
  51 namespace LIBC_NAMESPACE {
  52
  53 LIBC_INLINE long syscall_impl(long number) {
  54   REGISTER_DECL_0;
  55   SYSCALL_INSTR(REGISTER_CONSTRAINT_0);
  56   return r0;
  57 }
  58
  59 LIBC_INLINE long syscall_impl(long number, long arg1) {
  60   REGISTER_DECL_1;
  61   SYSCALL_INSTR(REGISTER_CONSTRAINT_1);
  62   return r0;
  63 }
  64
  65 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2) {
  66   REGISTER_DECL_2;
  67   SYSCALL_INSTR(REGISTER_CONSTRAINT_2);
  68   return r0;
  69 }
  70
  71 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3) {
  72   REGISTER_DECL_3;
  73   SYSCALL_INSTR(REGISTER_CONSTRAINT_3);
  74   return r0;
  75 }
  76
  77 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
  78                               long arg4) {
  79   REGISTER_DECL_4;
  80   SYSCALL_INSTR(REGISTER_CONSTRAINT_4);
  81   return r0;
  82 }
  83
  84 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
  85                               long arg4, long arg5) {
  86   REGISTER_DECL_5;
  87   SYSCALL_INSTR(REGISTER_CONSTRAINT_5);
  88   return r0;
  89 }
  90
  91 LIBC_INLINE long syscall_impl(long number, long arg1, long arg2, long arg3,
  92                               long arg4, long arg5, long arg6) {
  93   REGISTER_DECL_6;
  94   SYSCALL_INSTR(REGISTER_CONSTRAINT_6);
  95   return r0;
  96 }
  97
  98 } // namespace LIBC_NAMESPACE
  99
 100 #undef REGISTER_DECL_0
 101 #undef REGISTER_DECL_1
 102 #undef REGISTER_DECL_2
 103 #undef REGISTER_DECL_3
 104 #undef REGISTER_DECL_4
 105 #undef REGISTER_DECL_5
 106 #undef REGISTER_DECL_6
 107
 108 #undef REGISTER_CONSTRAINT_0
 109 #undef REGISTER_CONSTRAINT_1
 110 #undef REGISTER_CONSTRAINT_2
 111 #undef REGISTER_CONSTRAINT_3
 112 #undef REGISTER_CONSTRAINT_4
 113 #undef REGISTER_CONSTRAINT_5
 114 #undef REGISTER_CONSTRAINT_6
 115
 116 #endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_SYSCALL_H