clang/lib/Headers/arm_cmse.h

   1 //===---- arm_cmse.h - Arm CMSE support -----------------------------------===//
   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 __ARM_CMSE_H
  10 #define __ARM_CMSE_H
  11
  12 #if (__ARM_FEATURE_CMSE & 0x1)
  13 #include <stddef.h>
  14 #include <stdint.h>
  15
  16 #define __ARM_CMSE_SECURE_MODE (__ARM_FEATURE_CMSE & 0x2)
  17 #define CMSE_MPU_READWRITE 1 /* checks if readwrite_ok field is set */
  18 #define CMSE_AU_NONSECURE  2 /* checks if permissions have secure field unset */
  19 #define CMSE_MPU_UNPRIV    4 /* sets T flag on TT insrtuction */
  20 #define CMSE_MPU_READ      8 /* checks if read_ok field is set */
  21 #define CMSE_MPU_NONSECURE 16 /* sets A flag, checks if secure field unset */
  22 #define CMSE_NONSECURE (CMSE_AU_NONSECURE | CMSE_MPU_NONSECURE)
  23
  24 #define cmse_check_pointed_object(p, f) \
  25   cmse_check_address_range((p), sizeof(*(p)), (f))
  26
  27 #if defined(__cplusplus)
  28 extern "C" {
  29 #endif
  30
  31 typedef union {
  32   struct cmse_address_info {
  33 #ifdef __ARM_BIG_ENDIAN
  34     /* __ARM_BIG_ENDIAN */
  35 #if (__ARM_CMSE_SECURE_MODE)
  36     unsigned idau_region : 8;
  37     unsigned idau_region_valid : 1;
  38     unsigned secure : 1;
  39     unsigned nonsecure_readwrite_ok : 1;
  40     unsigned nonsecure_read_ok : 1;
  41 #else
  42     unsigned : 12;
  43 #endif
  44     unsigned readwrite_ok : 1;
  45     unsigned read_ok : 1;
  46 #if (__ARM_CMSE_SECURE_MODE)
  47     unsigned sau_region_valid : 1;
  48 #else
  49     unsigned : 1;
  50 #endif
  51     unsigned mpu_region_valid : 1;
  52 #if (__ARM_CMSE_SECURE_MODE)
  53     unsigned sau_region : 8;
  54 #else
  55     unsigned : 8;
  56 #endif
  57     unsigned mpu_region : 8;
  58
  59 #else /* __ARM_LITTLE_ENDIAN */
  60     unsigned mpu_region : 8;
  61 #if (__ARM_CMSE_SECURE_MODE)
  62     unsigned sau_region : 8;
  63 #else
  64     unsigned : 8;
  65 #endif
  66     unsigned mpu_region_valid : 1;
  67 #if (__ARM_CMSE_SECURE_MODE)
  68     unsigned sau_region_valid : 1;
  69 #else
  70     unsigned : 1;
  71 #endif
  72     unsigned read_ok : 1;
  73     unsigned readwrite_ok : 1;
  74 #if (__ARM_CMSE_SECURE_MODE)
  75     unsigned nonsecure_read_ok : 1;
  76     unsigned nonsecure_readwrite_ok : 1;
  77     unsigned secure : 1;
  78     unsigned idau_region_valid : 1;
  79     unsigned idau_region : 8;
  80 #else
  81     unsigned : 12;
  82 #endif
  83 #endif /*__ARM_LITTLE_ENDIAN */
  84   } flags;
  85   unsigned value;
  86 } cmse_address_info_t;
  87
  88 static cmse_address_info_t __attribute__((__always_inline__, __nodebug__))
  89 cmse_TT(void *__p) {
  90   cmse_address_info_t __u;
  91   __u.value = __builtin_arm_cmse_TT(__p);
  92   return __u;
  93 }
  94 static cmse_address_info_t __attribute__((__always_inline__, __nodebug__))
  95 cmse_TTT(void *__p) {
  96   cmse_address_info_t __u;
  97   __u.value = __builtin_arm_cmse_TTT(__p);
  98   return __u;
  99 }
 100
 101 #if __ARM_CMSE_SECURE_MODE
 102 static cmse_address_info_t __attribute__((__always_inline__, __nodebug__))
 103 cmse_TTA(void *__p) {
 104   cmse_address_info_t __u;
 105   __u.value = __builtin_arm_cmse_TTA(__p);
 106   return __u;
 107 }
 108 static cmse_address_info_t __attribute__((__always_inline__, __nodebug__))
 109 cmse_TTAT(void *__p) {
 110   cmse_address_info_t __u;
 111   __u.value = __builtin_arm_cmse_TTAT(__p);
 112   return __u;
 113 }
 114 #endif
 115
 116 #define cmse_TT_fptr(p) cmse_TT(__builtin_bit_cast(void *, (p)))
 117 #define cmse_TTT_fptr(p) cmse_TTT(__builtin_bit_cast(void *, (p)))
 118
 119 #if __ARM_CMSE_SECURE_MODE
 120 #define cmse_TTA_fptr(p) cmse_TTA(__builtin_bit_cast(void *, (p)))
 121 #define cmse_TTAT_fptr(p) cmse_TTAT(__builtin_bit_cast(void *, (p)))
 122 #endif
 123
 124 static void *__attribute__((__always_inline__))
 125 cmse_check_address_range(void *__pb, size_t __s, int __flags) {
 126   uintptr_t __begin = (uintptr_t)__pb;
 127   uintptr_t __end = __begin + __s - 1;
 128
 129   if (__end < __begin)
 130     return NULL; /* wrap around check */
 131
 132   /* Check whether the range crosses a 32-bytes aligned address */
 133   const int __single_check = (__begin ^ __end) < 0x20u;
 134
 135   /* execute the right variant of the TT instructions */
 136   void *__pe = (void *)__end;
 137   cmse_address_info_t __permb, __perme;
 138   switch (__flags & (CMSE_MPU_UNPRIV | CMSE_MPU_NONSECURE)) {
 139   case 0:
 140     __permb = cmse_TT(__pb);
 141     __perme = __single_check ? __permb : cmse_TT(__pe);
 142     break;
 143   case CMSE_MPU_UNPRIV:
 144     __permb = cmse_TTT(__pb);
 145     __perme = __single_check ? __permb : cmse_TTT(__pe);
 146     break;
 147 #if __ARM_CMSE_SECURE_MODE
 148   case CMSE_MPU_NONSECURE:
 149     __permb = cmse_TTA(__pb);
 150     __perme = __single_check ? __permb : cmse_TTA(__pe);
 151     break;
 152   case CMSE_MPU_UNPRIV | CMSE_MPU_NONSECURE:
 153     __permb = cmse_TTAT(__pb);
 154     __perme = __single_check ? __permb : cmse_TTAT(__pe);
 155     break;
 156 #endif
 157   /* if CMSE_NONSECURE is specified w/o __ARM_CMSE_SECURE_MODE */
 158   default:
 159     return NULL;
 160   }
 161
 162   /* check that the range does not cross MPU, SAU, or IDAU region boundaries */
 163   if (__permb.value != __perme.value)
 164     return NULL;
 165 #if !(__ARM_CMSE_SECURE_MODE)
 166   /* CMSE_AU_NONSECURE is only supported when __ARM_FEATURE_CMSE & 0x2 */
 167   if (__flags & CMSE_AU_NONSECURE)
 168     return NULL;
 169 #endif
 170
 171   /* check the permission on the range */
 172   switch (__flags & ~(CMSE_MPU_UNPRIV | CMSE_MPU_NONSECURE)) {
 173 #if (__ARM_CMSE_SECURE_MODE)
 174   case CMSE_MPU_READ | CMSE_MPU_READWRITE | CMSE_AU_NONSECURE:
 175   case CMSE_MPU_READWRITE | CMSE_AU_NONSECURE:
 176     return __permb.flags.nonsecure_readwrite_ok ? __pb : NULL;
 177
 178   case CMSE_MPU_READ | CMSE_AU_NONSECURE:
 179     return __permb.flags.nonsecure_read_ok ? __pb : NULL;
 180
 181   case CMSE_AU_NONSECURE:
 182     return __permb.flags.secure ? NULL : __pb;
 183 #endif
 184   case CMSE_MPU_READ | CMSE_MPU_READWRITE:
 185   case CMSE_MPU_READWRITE:
 186     return __permb.flags.readwrite_ok ? __pb : NULL;
 187
 188   case CMSE_MPU_READ:
 189     return __permb.flags.read_ok ? __pb : NULL;
 190
 191   default:
 192     return NULL;
 193   }
 194 }
 195
 196 #if __ARM_CMSE_SECURE_MODE
 197 static int __attribute__((__always_inline__, __nodebug__))
 198 cmse_nonsecure_caller(void) {
 199   return !((uintptr_t)__builtin_return_address(0) & 1);
 200 }
 201
 202 #define cmse_nsfptr_create(p)                                                  \
 203   __builtin_bit_cast(__typeof__(p),                                            \
 204                      (__builtin_bit_cast(uintptr_t, p) & ~(uintptr_t)1))
 205
 206 #define cmse_is_nsfptr(p) ((__builtin_bit_cast(uintptr_t, p) & 1) == 0)
 207
 208 #endif /* __ARM_CMSE_SECURE_MODE */
 209
 210 void __attribute__((__noreturn__)) cmse_abort(void);
 211 #if defined(__cplusplus)
 212 }
 213 #endif
 214
 215 #endif /* (__ARM_FEATURE_CMSE & 0x1) */
 216
 217 #endif /* __ARM_CMSE_H */