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Check out http://www.gromacs.org. 34 */ 35 /*! \libinternal \file 36 * 37 * \brief Declarations for GPU implementation of Leap-Frog. 38 * 39 * \author Artem Zhmurov <zhmurov@gmail.com> 40 * 41 * \ingroup module_mdlib 42 * \inlibraryapi 43 */ 44 #ifndef GMX_MDLIB_LEAPFROG_GPU_H 45 #define GMX_MDLIB_LEAPFROG_GPU_H 46 47 #include "config.h" 48 49 #if GMX_GPU_CUDA 50 # include "gromacs/gpu_utils/devicebuffer.cuh" 51 # include "gromacs/gpu_utils/gputraits.cuh" 52 #endif 53 #if GMX_GPU_SYCL 54 # include "gromacs/gpu_utils/devicebuffer_sycl.h" 55 # include "gromacs/gpu_utils/gputraits_sycl.h" 56 #endif 57 58 #include "gromacs/gpu_utils/hostallocator.h" 59 #include "gromacs/pbcutil/pbc.h" 60 #include "gromacs/pbcutil/pbc_aiuc.h" 61 #include "gromacs/utility/arrayref.h" 62 #include "gromacs/utility/classhelpers.h" 63 64 class DeviceContext; 65 class DeviceStream; 66 struct t_grp_tcstat; 67 68 namespace gmx 69 { 70 71 72 /*! \brief Sets the number of different temperature coupling values 73 * 74 * This is needed to template the kernel 75 * \todo Unify with similar enum in CPU update module 76 */ 77 enum class NumTempScaleValues 78 { 79 None = 0, //!< No temperature coupling 80 Single = 1, //!< Single T-scaling value (one group) 81 Multiple = 2, //!< Multiple T-scaling values, need to use T-group indices 82 Count = 3 //!< Number of valid values 83 }; 84 85 /*! \brief Different variants of the Parrinello-Rahman velocity scaling 86 * 87 * This is needed to template the kernel 88 * \todo Unify with similar enum in CPU update module 89 */ 90 enum class VelocityScalingType 91 { 92 None = 0, //!< Do not apply velocity scaling (not a PR-coupling run or step) 93 Diagonal = 1, //!< Apply velocity scaling using a diagonal matrix 94 Count = 2 //!< Number of valid values 95 }; 96 97 class LeapFrogGpu 98 { 99 100 public: 101 /*! \brief Constructor. 102 * 103 * \param[in] deviceContext Device context (dummy in CUDA). 104 * \param[in] deviceStream Device stream to use. 105 */ 106 LeapFrogGpu(const DeviceContext& deviceContext, const DeviceStream& deviceStream); 107 ~LeapFrogGpu(); 108 109 /*! \brief Integrate 110 * 111 * Integrates the equation of motion using Leap-Frog algorithm. 112 * Updates coordinates and velocities on the GPU. The current coordinates are saved for constraints. 113 * 114 * \param[in,out] d_x Coordinates to update 115 * \param[out] d_xp Place to save the values of initial coordinates coordinates to. 116 * \param[in,out] d_v Velocities (will be updated). 117 * \param[in] d_f Forces. 118 * \param[in] dt Timestep. 119 * \param[in] doTemperatureScaling If velocities should be scaled for temperature coupling. 120 * \param[in] tcstat Temperature coupling data. 121 * \param[in] doParrinelloRahman If current step is a Parrinello-Rahman pressure coupling step. 122 * \param[in] dtPressureCouple Period between pressure coupling steps 123 * \param[in] prVelocityScalingMatrix Parrinello-Rahman velocity scaling matrix 124 */ 125 void integrate(const DeviceBuffer<float3> d_x, 126 DeviceBuffer<float3> d_xp, 127 DeviceBuffer<float3> d_v, 128 const DeviceBuffer<float3> d_f, 129 const real dt, 130 const bool doTemperatureScaling, 131 gmx::ArrayRef<const t_grp_tcstat> tcstat, 132 const bool doParrinelloRahman, 133 const float dtPressureCouple, 134 const matrix prVelocityScalingMatrix); 135 136 /*! \brief Set the integrator 137 * 138 * Allocates memory for inverse masses, and, if needed for temperature scaling factor(s) 139 * and temperature coupling groups. Copies inverse masses and temperature coupling groups 140 * to the GPU. 141 * 142 * \param[in] numAtoms Number of atoms in the system. 143 * \param[in] inverseMasses Inverse masses of atoms. 144 * \param[in] numTempScaleValues Number of temperature scale groups. 145 * \param[in] tempScaleGroups Maps the atom index to temperature scale value. 146 */ 147 void set(const int numAtoms, 148 const real* inverseMasses, 149 int numTempScaleValues, 150 const unsigned short* tempScaleGroups); 151 152 /*! \brief Class with hardware-specific interfaces and implementations.*/ 153 class Impl; 154 155 private: 156 //! GPU context object 157 const DeviceContext& deviceContext_; 158 //! GPU stream 159 const DeviceStream& deviceStream_; 160 //! GPU kernel launch config 161 KernelLaunchConfig kernelLaunchConfig_; 162 //! Number of atoms 163 int numAtoms_; 164 165 //! 1/mass for all atoms (GPU) 166 DeviceBuffer<float> d_inverseMasses_; 167 //! Current size of the reciprocal masses array 168 int numInverseMasses_ = -1; 169 //! Maximum size of the reciprocal masses array 170 int numInverseMassesAlloc_ = -1; 171 172 //! Number of temperature coupling groups (zero = no coupling) 173 int numTempScaleValues_ = 0; 174 /*! \brief Array with temperature scaling factors. 175 * This is temporary solution to remap data from t_grp_tcstat into plain array. 176 * Not used in SYCL. 177 * \todo Replace with better solution. 178 */ 179 gmx::HostVector<float> h_lambdas_; 180 //! Device-side temperature scaling factors 181 DeviceBuffer<float> d_lambdas_; 182 //! Current size of the array with temperature scaling factors (lambdas) 183 int numLambdas_ = -1; 184 //! Maximum size of the array with temperature scaling factors (lambdas) 185 int numLambdasAlloc_ = -1; 186 187 188 //! Array that maps atom index onto the temperature scaling group to get scaling parameter 189 DeviceBuffer<unsigned short> d_tempScaleGroups_; 190 //! Current size of the temperature coupling groups array 191 int numTempScaleGroups_ = -1; 192 //! Maximum size of the temperature coupling groups array 193 int numTempScaleGroupsAlloc_ = -1; 194 195 //! Vector with diagonal elements of the Parrinello-Rahman pressure coupling velocity rescale factors 196 float3 prVelocityScalingMatrixDiagonal_; 197 }; 198 199 } // namespace gmx 200 201 #endif 202