MdePkg/Library/BaseLib/AArch64/GetInterruptsState.asm

   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   EXPORT GetInterruptState
  13   AREA BaseLib_LowLevel, CODE, READONLY
  14
  15 DAIF_RD_IRQ_BIT     EQU     (1 << 7)
  16
  17 ;/**
  18 ;  Retrieves the current CPU interrupt state.
  19 ;
  20 ;  Returns TRUE is interrupts are currently enabled. Otherwise
  21 ;  returns FALSE.
  22 ;
  23 ;  @retval TRUE  CPU interrupts are enabled.
  24 ;  @retval FALSE CPU interrupts are disabled.
  25 ;
  26 ;**/
  27 ;
  28 ;BOOLEAN
  29 ;EFIAPI
  30 ;GetInterruptState (
  31 ;  VOID
  32 ; );
  33 ;
  34 GetInterruptState
  35     mrs    x0, daif
  36     mov    w0, wzr
  37     tst    x0, #DAIF_RD_IRQ_BIT   // Check IRQ mask; set Z=1 if clear/unmasked
  38     bne    exit                   // if Z=1 (eq) return 1, else 0
  39     mov    w0, #1
  40 exit
  41     ret
  42
  43   END