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/*! \libinternal \file
 *  \brief Declare interface for GPU data transfer for NBNXN module
 *
 *  \author Szilard Pall <pall.szilard@gmail.com>
 *  \author Mark Abraham <mark.j.abraham@gmail.com>
 *  \ingroup module_nbnxm
 *  \inlibraryapi
 */

#ifndef GMX_NBNXN_GPU_DATA_MGMT_H
#define GMX_NBNXN_GPU_DATA_MGMT_H

#include <memory>

#include "gromacs/gpu_utils/devicebuffer_datatype.h"
#include "gromacs/gpu_utils/gpu_macros.h"
#include "gromacs/mdtypes/locality.h"

struct NbnxmGpu;
struct DeviceInformation;
struct gmx_wallclock_gpu_nbnxn_t;
struct nbnxn_atomdata_t;
struct NbnxnPairlistGpu;
struct PairlistParams;
struct interaction_const_t;

class DeviceStream;

namespace gmx
{
class DeviceStreamManager;
}

namespace Nbnxm
{

/** Initializes the data structures related to GPU nonbonded calculations. */
GPU_FUNC_QUALIFIER
NbnxmGpu* gpu_init(const gmx::DeviceStreamManager gmx_unused& deviceStreamManager,
                   const interaction_const_t gmx_unused* ic,
                   const PairlistParams gmx_unused& listParams,
                   const nbnxn_atomdata_t gmx_unused* nbat,
                   /* true if both local and non-local are done on GPU */
                   bool gmx_unused bLocalAndNonlocal) GPU_FUNC_TERM_WITH_RETURN(nullptr);

/** Initializes pair-list data for GPU, called at every pair search step. */
GPU_FUNC_QUALIFIER
void gpu_init_pairlist(NbnxmGpu gmx_unused*          nb,
                       const struct NbnxnPairlistGpu gmx_unused* h_nblist,
                       gmx::InteractionLocality gmx_unused iloc) GPU_FUNC_TERM;

/** Initializes atom-data on the GPU, called at every pair search step. */
GPU_FUNC_QUALIFIER
void gpu_init_atomdata(NbnxmGpu gmx_unused* nb, const nbnxn_atomdata_t gmx_unused* nbat) GPU_FUNC_TERM;

/*! \brief Re-generate the GPU Ewald force table, resets rlist, and update the
 *  electrostatic type switching to twin cut-off (or back) if needed.
 */
GPU_FUNC_QUALIFIER
void gpu_pme_loadbal_update_param(const struct nonbonded_verlet_t gmx_unused* nbv,
                                  const interaction_const_t gmx_unused* ic) GPU_FUNC_TERM;

/** Uploads shift vector to the GPU if the box is dynamic (otherwise just returns). */
GPU_FUNC_QUALIFIER
void gpu_upload_shiftvec(NbnxmGpu gmx_unused* nb, const nbnxn_atomdata_t gmx_unused* nbatom) GPU_FUNC_TERM;

/** Clears GPU outputs: nonbonded force, shift force and energy. */
GPU_FUNC_QUALIFIER
void gpu_clear_outputs(NbnxmGpu gmx_unused* nb, bool gmx_unused computeVirial) GPU_FUNC_TERM;

/** Frees all GPU resources used for the nonbonded calculations. */
GPU_FUNC_QUALIFIER
void gpu_free(NbnxmGpu gmx_unused* nb) GPU_FUNC_TERM;

/** Returns the GPU timings structure or NULL if GPU is not used or timing is off. */
GPU_FUNC_QUALIFIER
struct gmx_wallclock_gpu_nbnxn_t* gpu_get_timings(NbnxmGpu gmx_unused* nb)
        GPU_FUNC_TERM_WITH_RETURN(nullptr);

/** Resets nonbonded GPU timings. */
GPU_FUNC_QUALIFIER
void gpu_reset_timings(struct nonbonded_verlet_t gmx_unused* nbv) GPU_FUNC_TERM;

/** Calculates the minimum size of proximity lists to improve SM load balance
 *  with GPU non-bonded kernels. */
GPU_FUNC_QUALIFIER
int gpu_min_ci_balanced(NbnxmGpu gmx_unused* nb) GPU_FUNC_TERM_WITH_RETURN(-1);

/** Returns if analytical Ewald GPU kernels are used. */
GPU_FUNC_QUALIFIER
bool gpu_is_kernel_ewald_analytical(const NbnxmGpu gmx_unused* nb) GPU_FUNC_TERM_WITH_RETURN(FALSE);

/** Returns an opaque pointer to the GPU command stream
 *  Note: CUDA only.
 */
CUDA_FUNC_QUALIFIER
const DeviceStream* gpu_get_command_stream(NbnxmGpu gmx_unused* nb, gmx::InteractionLocality gmx_unused iloc)
        CUDA_FUNC_TERM_WITH_RETURN(nullptr);

/** Returns an opaque pointer to the GPU coordinate+charge array
 *  Note: CUDA only.
 */
CUDA_FUNC_QUALIFIER
void* gpu_get_xq(NbnxmGpu gmx_unused* nb) CUDA_FUNC_TERM_WITH_RETURN(nullptr);

/** Returns an opaque pointer to the GPU force array
 *  Note: CUDA only.
 */
CUDA_FUNC_QUALIFIER
DeviceBuffer<gmx::RVec> gpu_get_f(NbnxmGpu gmx_unused* nb)
        CUDA_FUNC_TERM_WITH_RETURN(DeviceBuffer<gmx::RVec>{});

/** Returns an opaque pointer to the GPU shift force array
 *  Note: CUDA only.
 */
CUDA_FUNC_QUALIFIER
DeviceBuffer<gmx::RVec> gpu_get_fshift(NbnxmGpu gmx_unused* nb)
        CUDA_FUNC_TERM_WITH_RETURN(DeviceBuffer<gmx::RVec>{});

} // namespace Nbnxm

#endif
