text: /*
   ***********************************************************************************************************************
   *
   *  Copyright (c) 2016-2021 Advanced Micro Devices, Inc. All Rights Reserved.
   *
   *  Permission is hereby granted, free of charge, to any person obtaining a copy
   *  of this software and associated documentation files (the "Software"), to deal
   *  in the Software without restriction, including without limitation the rights
   *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   *  copies of the Software, and to permit persons to whom the Software is
   *  furnished to do so, subject to the following conditions:
   *
   *  The above copyright notice and this permission notice shall be included in all
   *  copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   *  SOFTWARE.
   *
   **********************************************************************************************************************/
  
  #pragma once
  
  #include "palMutex.h"
  #include "palBestFitAllocator.h"
  #include "core/platform.h"
  
  namespace Pal
  {
  class Platform;
  
  // =====================================================================================================================
  // SvmMgr provides a clean interface between PAL and the BestFitAllocator, which is used to allocate and free GPU
  // virtual address space for SVM allocations on Windows and Linux platforms.
  // This GPU virtual address is shared with CPU.
  //
  // Some commonly used abbreviations throughout the implementation of this class:
  //     - VA:  Virtual address
  //     - SVM: Shared Virtual Memory
  class SvmMgr
  {
  public:
      explicit SvmMgr(Device* pDevice);
      virtual ~SvmMgr();
  
      Result Init(VaRangeInfo* pSvmVaInfo);
      Result Cleanup();
  
      Result AllocVa(gpusize size, uint32 align, gpusize* pVirtualAddress);
      void   FreeVa(gpusize virtualAddress);
  
      gpusize GetStartAddr() const { return m_vaStart; }
  
  private:
      Device*const m_pDevice;
      gpusize      m_vaStart;
      gpusize      m_vaSize;
  
      Util::BestFitAllocator<Pal::Platform>* m_pSubAllocator;  // Suballocator used for the suballocation
  
      Util::Mutex  m_allocFreeVaLock;                          // Mutex protecting allocation and free of SVM va
  
      PAL_DISALLOW_DEFAULT_CTOR(SvmMgr);
      PAL_DISALLOW_COPY_AND_ASSIGN(SvmMgr);
  };
  
  } // Pal
  