audk/ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressLibCTA15-A7/CTA15-A7Helper.S

//
//  Copyright (c) 2012-2013, ARM Limited. All rights reserved.
//
//  This program and the accompanying materials
//  are licensed and made available under the terms and conditions of the BSD License
//  which accompanies this distribution.  The full text of the license may be found at
//  http://opensource.org/licenses/bsd-license.php
//
//  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
//  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
//
//

#include <AsmMacroIoLib.h>
#include <Library/ArmLib.h>

#include <ArmPlatform.h>

.text 
.align 3

GCC_ASM_EXPORT(ArmPlatformGetCorePosition)
GCC_ASM_EXPORT(ArmPlatformIsPrimaryCore)

//UINTN
//ArmPlatformGetCorePosition (
//  IN UINTN MpId
//  );
ASM_PFX(ArmPlatformGetCorePosition):
  and	r1, r0, #ARM_CORE_MASK
  and	r0, r0, #ARM_CLUSTER_MASK
  add	r0, r1, r0, LSR #7
  bx 	lr

//UINTN
//ArmPlatformIsPrimaryCore (
//  IN UINTN MpId
//  );
ASM_PFX(ArmPlatformIsPrimaryCore):
  // Extract cpu_id and cluster_id from ARM_SCC_CFGREG48
  // with cpu_id[0:3] and cluster_id[4:7]
  LoadConstantToReg (ARM_CTA15A7_SCC_CFGREG48, r1)
  ldr   r1, [r1]
  lsr   r1, #24

  // Shift the SCC value to get the cluster ID at the offset #8
  lsl   r2, r1, #4
  and   r2, r2, #0xF00

  // Keep only the cpu ID from the original SCC
  and   r1, r1, #0x0F
  // Add the Cluster ID to the Cpu ID
  orr   r1, r1, r2

  // Keep the Cluster ID and Core ID from the MPID
  LoadConstantToReg (ARM_CLUSTER_MASK | ARM_CORE_MASK, r2)
  and   r0, r0, r2

  // Compare mpid and boot cpu from ARM_SCC_CFGREG48
  cmp   r0, r1
  moveq r0, #1
  movne r0, #0
  bx    lr