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 ; 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   EXPORT GetInterruptState
  19   AREA BaseLib_LowLevel, CODE, READONLY
  20
  21 DAIF_RD_IRQ_BIT     EQU     (1 << 7)
  22
  23 ;/**
  24 ;  Retrieves the current CPU interrupt state.
  25 ;
  26 ;  Returns TRUE is interrupts are currently enabled. Otherwise
  27 ;  returns FALSE.
  28 ;
  29 ;  @retval TRUE  CPU interrupts are enabled.
  30 ;  @retval FALSE CPU interrupts are disabled.
  31 ;
  32 ;**/
  33 ;
  34 ;BOOLEAN
  35 ;EFIAPI
  36 ;GetInterruptState (
  37 ;  VOID
  38 ; );
  39 ;
  40 GetInterruptState
  41     mrs    x0, daif
  42     mov    w0, wzr
  43     tst    x0, #DAIF_RD_IRQ_BIT   // Check IRQ mask; set Z=1 if clear/unmasked
  44     bne    exit                   // if Z=1 (eq) return 1, else 0
  45     mov    w0, #1
  46 exit
  47     ret
  48
  49   END