GpuJac.hpp

/*
  Copyright 2022-2023 SINTEF AS

  This file is part of the Open Porous Media project (OPM).

  OPM is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_GPUJAC_HPP
#define OPM_GPUJAC_HPP

#include <dune/istl/preconditioner.hh>
#include <opm/simulators/linalg/PreconditionerWithUpdate.hpp>
#include <opm/simulators/linalg/gpuistl/GpuSparseMatrixWrapper.hpp>
#include <opm/simulators/linalg/gpuistl/detail/CuMatrixDescription.hpp>
#include <opm/simulators/linalg/gpuistl/detail/CuSparseHandle.hpp>
#include <opm/simulators/linalg/gpuistl/detail/CuSparseResource.hpp>



namespace Opm::gpuistl
{
template <class M, class X, class Y, int l = 1>
class GpuJac : public Dune::PreconditionerWithUpdate<X, Y>
{
public:
    using matrix_type = typename std::remove_const<M>::type;
    using domain_type = X;
    using range_type = Y;
    using field_type = typename X::field_type;

    GpuJac(const M& A, field_type w);

    virtual void pre(X& x, Y& b) override;

    virtual void apply(X& v, const Y& d) override;

    virtual void post(X& x) override;

    virtual Dune::SolverCategory::Category category() const override;

    virtual void update() override;


    static constexpr bool shouldCallPre()
    {
        return false;
    }

    static constexpr bool shouldCallPost()
    {
        return false;
    }

    virtual bool hasPerfectUpdate() const override {
        return true;
    }


private:
    const M& m_matrix;
    const field_type m_relaxationFactor;
    GpuVector<field_type> m_diagInvFlattened;

    void invertDiagonalAndFlatten();

    template<int blocksize>
    void dispatchInvertDiagonalAndFlatten();
};
} // end namespace Opm::gpuistl

#endif