MdePkg/Library/BaseLib/AArch64/GetInterruptsState.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # GetInterruptState() function for AArch64
   4 #
   5 # Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
   6 # Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   7 # Portions copyright (c) 2011 - 2013, ARM Ltd. All rights reserved.<BR>
   8 # This program and the accompanying materials
   9 # are licensed and made available under the terms and conditions of the BSD License
  10 # which accompanies this distribution.  The full text of the license may be found at
  11 # http://opensource.org/licenses/bsd-license.php.
  12 #
  13 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15 #
  16 #------------------------------------------------------------------------------
  17
  18 .text
  19 .p2align 2
  20 GCC_ASM_EXPORT(GetInterruptState)
  21
  22 .set DAIF_RD_IRQ_BIT,   (1 << 7)
  23
  24 #/**
  25 #  Retrieves the current CPU interrupt state.
  26 #
  27 #  Returns TRUE is interrupts are currently enabled. Otherwise
  28 #  returns FALSE.
  29 #
  30 #  @retval TRUE  CPU interrupts are enabled.
  31 #  @retval FALSE CPU interrupts are disabled.
  32 #
  33 #**/
  34 #
  35 #BOOLEAN
  36 #EFIAPI
  37 #GetInterruptState (
  38 #  VOID
  39 # );
  40 #
  41 ASM_PFX(GetInterruptState):
  42     mrs    x0, daif
  43     tst    x0, #DAIF_RD_IRQ_BIT   // Check IRQ mask; set Z=1 if clear/unmasked
  44     cset   w0, eq                 // if Z=1 (eq) return 1, else 0
  45     ret