src/gromacs/mdlib/update_constrain_cuda_impl.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2019, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
  12  * of the License, or (at your option) any later version.
  13  *
  14  * GROMACS is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with GROMACS; if not, see
  21  * http://www.gnu.org/licenses, or write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  23  *
  24  * If you want to redistribute modifications to GROMACS, please
  25  * consider that scientific software is very special. Version
  26  * control is crucial - bugs must be traceable. We will be happy to
  27  * consider code for inclusion in the official distribution, but
  28  * derived work must not be called official GROMACS. Details are found
  29  * in the README & COPYING files - if they are missing, get the
  30  * official version at http://www.gromacs.org.
  31  *
  32  * To help us fund GROMACS development, we humbly ask that you cite
  33  * the research papers on the package. Check out http://www.gromacs.org.
  34  */
  35 /*! \internal \file
  36  *
  37  * \brief Declares CUDA implementation class for update and constraints.
  38  *
  39  * This header file is needed to include from both the device-side
  40  * kernels file, and the host-side management code.
  41  *
  42  * \author Artem Zhmurov <zhmurov@gmail.com>
  43  *
  44  * \ingroup module_mdlib
  45  */
  46 #ifndef GMX_MDLIB_UPDATE_CONSTRAIN_CUDA_IMPL_H
  47 #define GMX_MDLIB_UPDATE_CONSTRAIN_CUDA_IMPL_H
  48
  49 #include "gromacs/mdlib/lincs_cuda.cuh"
  50 #include "gromacs/mdlib/update_constrain_cuda.h"
  51 #include "gromacs/mdtypes/inputrec.h"
  52 #include "gromacs/pbcutil/pbc.h"
  53 #include "gromacs/pbcutil/pbc_aiuc_cuda.cuh"
  54 #include "gromacs/topology/idef.h"
  55
  56 #include "leapfrog_cuda_impl.h"
  57 #include "settle_cuda_impl.h"
  58
  59 namespace gmx
  60 {
  61
  62 /*! \internal \brief Class with interfaces and data for CUDA version of Update-Constraint. */
  63 class UpdateConstrainCuda::Impl
  64 {
  65
  66     public:
  67         /*! \brief Create Update-Constrain object
  68          *
  69          * \param[in] numAtoms  Number of atoms.
  70          * \param[in] ir        Input record data: LINCS takes number of iterations and order of
  71          *                      projection from it.
  72          * \param[in] mtop      Topology of the system: SETTLE gets the masses for O and H atoms
  73          *                      and target O-H and H-H distances from this object.
  74          */
  75         Impl(int                   numAtoms,
  76              const t_inputrec     &ir,
  77              const gmx_mtop_t     &mtop);
  78
  79         ~Impl();
  80
  81         /*! \brief Integrate
  82          *
  83          * Integrates the equation of motion using Leap-Frog algorithm and applies
  84          * LINCS and SETTLE constraints.
  85          * Updates d_xp_ and d_v_ fields of this object.
  86          *
  87          * \param[in] dt                Timestep
  88          * \param[in] updateVelocities  If the velocities should be constrained.
  89          * \param[in] computeVirial     If virial should be updated.
  90          * \param[out] virial           Place to save virial tensor.
  91          */
  92         void integrate(const real  dt,
  93                        const bool  updateVelocities,
  94                        const bool  computeVirial,
  95                        tensor      virial);
  96
  97         /*! \brief
  98          * Update data-structures (e.g. after NB search step).
  99          *
 100          * \param[in] idef    System topology
 101          * \param[in] md      Atoms data. Can be used to update masses if needed (not used now).
 102          */
 103         void set(const t_idef     &idef,
 104                  const t_mdatoms  &md);
 105
 106         /*! \brief
 107          * Update PBC data.
 108          *
 109          * Converts PBC data from t_pbc into the PbcAiuc format and stores the latter.
 110          *
 111          * \param[in] pbc The PBC data in t_pbc format.
 112          */
 113         void setPbc(const t_pbc *pbc);
 114
 115         /*! \brief
 116          * Copy coordinates from CPU to GPU.
 117          *
 118          * The data are assumed to be in float3/fvec format (single precision).
 119          *
 120          * \param[in] h_x  CPU pointer where coordinates should be copied from.
 121          */
 122         void copyCoordinatesToGpu(const rvec *h_x);
 123
 124         /*! \brief
 125          * Copy velocities from CPU to GPU.
 126          *
 127          * The data are assumed to be in float3/fvec format (single precision).
 128          *
 129          * \param[in] h_v  CPU pointer where velocities should be copied from.
 130          */
 131         void copyVelocitiesToGpu(const rvec *h_v);
 132
 133         /*! \brief
 134          * Copy forces from CPU to GPU.
 135          *
 136          * The data are assumed to be in float3/fvec format (single precision).
 137          *
 138          * \param[in] h_f  CPU pointer where forces should be copied from.
 139          */
 140         void copyForcesToGpu(const rvec *h_f);
 141
 142         /*! \brief
 143          * Copy coordinates from GPU to CPU.
 144          *
 145          * The data are assumed to be in float3/fvec format (single precision).
 146          *
 147          * \param[out] h_xp CPU pointer where coordinates should be copied to.
 148          */
 149         void copyCoordinatesFromGpu(rvec *h_xp);
 150
 151         /*! \brief
 152          * Copy velocities from GPU to CPU.
 153          *
 154          * The velocities are assumed to be in float3/fvec format (single precision).
 155          *
 156          * \param[in] h_v  Pointer to velocities data.
 157          */
 158         void copyVelocitiesFromGpu(rvec *h_v);
 159
 160         /*! \brief
 161          * Copy forces from GPU to CPU.
 162          *
 163          * The forces are assumed to be in float3/fvec format (single precision).
 164          *
 165          * \param[in] h_f  Pointer to forces data.
 166          */
 167         void copyForcesFromGpu(rvec *h_f);
 168
 169         /*! \brief
 170          * Set the internal GPU-memory x, xprime and v pointers.
 171          *
 172          * Data is not copied. The data are assumed to be in float3/fvec format
 173          * (float3 is used internally, but the data layout should be identical).
 174          *
 175          * \param[in] d_x   Pointer to the coordinates for the input (on GPU)
 176          * \param[in] d_xp  Pointer to the coordinates for the output (on GPU)
 177          * \param[in] d_v   Pointer to the velocities (on GPU)
 178          * \param[in] d_f   Pointer to the forces (on GPU)
 179          */
 180         void setXVFPointers(rvec *d_x, rvec *d_xp, rvec *d_v, rvec *d_f);
 181
 182     private:
 183
 184         //! CUDA stream
 185         cudaStream_t        stream_;
 186
 187         //! Periodic boundary data
 188         PbcAiuc             pbcAiuc_;
 189
 190         //! Number of atoms
 191         int                 numAtoms_;
 192
 193         //! Coordinates before the timestep (on GPU)
 194         float3             *d_x_;
 195         //! Coordinates after the timestep (on GPU).
 196         float3             *d_xp_;
 197         //! Velocities of atoms (on GPU)
 198         float3             *d_v_;
 199         //! Forces, exerted by atoms (on GPU)
 200         float3             *d_f_;
 201
 202         //! 1/mass for all atoms (GPU)
 203         real               *d_inverseMasses_;
 204
 205         //! Leap-Frog integrator
 206         std::unique_ptr<LeapFrogCuda::Impl>  integrator_;
 207         //! LINCS CUDA object to use for non-water constraints
 208         std::unique_ptr<LincsCuda>           lincsCuda_;
 209         //! SETTLE CUDA object for water constrains
 210         std::unique_ptr<SettleCuda::Impl>    settleCuda_;
 211
 212 };
 213
 214 } // namespace gmx
 215
 216 #endif