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 # SPDX-License-Identifier: BSD-2-Clause-Patent
   9 #
  10 #------------------------------------------------------------------------------
  11
  12 .text
  13 .p2align 2
  14 GCC_ASM_EXPORT(GetInterruptState)
  15
  16 .set DAIF_RD_IRQ_BIT,   (1 << 7)
  17
  18 #/**
  19 #  Retrieves the current CPU interrupt state.
  20 #
  21 #  Returns TRUE is interrupts are currently enabled. Otherwise
  22 #  returns FALSE.
  23 #
  24 #  @retval TRUE  CPU interrupts are enabled.
  25 #  @retval FALSE CPU interrupts are disabled.
  26 #
  27 #**/
  28 #
  29 #BOOLEAN
  30 #EFIAPI
  31 #GetInterruptState (
  32 #  VOID
  33 # );
  34 #
  35 ASM_PFX(GetInterruptState):
  36     mrs    x0, daif
  37     tst    x0, #DAIF_RD_IRQ_BIT   // Check IRQ mask; set Z=1 if clear/unmasked
  38     cset   w0, eq                 // if Z=1 (eq) return 1, else 0
  39     ret