/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator 

   Original Version:
   http://lammps.sandia.gov, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov 

   See the README file in the top-level LAMMPS directory. 

   ----------------------------------------------------------------------- 

   USER-CUDA Package and associated modifications:
   https://sourceforge.net/projects/lammpscuda/ 

   Christian Trott, christian.trott@tu-ilmenau.de
   Lars Winterfeld, lars.winterfeld@tu-ilmenau.de
   Theoretical Physics II, University of Technology Ilmenau, Germany 

   See the README file in the USER-CUDA directory. 

   This software is distributed under the GNU General Public License.
------------------------------------------------------------------------- */

#include <stdio.h>
#define MY_PREFIX fix_gravity_cuda
#include "cuda_shared.h"
#include "cuda_common.h"
#include "crm_cuda_utils.cu"

#include "fix_gravity_cuda_cu.h"
#include "fix_gravity_cuda_kernel.cu"

void Cuda_FixGravityCuda_UpdateBuffer(cuda_shared_data* sdata)
{
        int3 layout=getgrid(sdata->atom.nlocal,3*sizeof(F_FLOAT));
	    dim3 threads(layout.z, 1, 1);
	    dim3 grid(layout.x, layout.y, 1);		
	    int size=(unsigned)(layout.z*layout.y*layout.x)*3*sizeof(F_FLOAT);
		if(sdata->buffersize<size)
		{
			MYDBG(printf("Cuda_FixGravityCuda Resizing Buffer at %p with %i kB to\n",sdata->buffer,sdata->buffersize);)
			CudaWrapper_FreeCudaData(sdata->buffer,sdata->buffersize);
			sdata->buffer = CudaWrapper_AllocCudaData(size);
			sdata->buffersize=size;
			sdata->buffer_new++;
			MYDBG(printf("New buffer at %p with %i kB\n",sdata->buffer,sdata->buffersize);)
			
		}
		cudaMemcpyToSymbol(MY_CONST(buffer) , & sdata->buffer, sizeof(int*)     );
}

void Cuda_FixGravityCuda_UpdateNmax(cuda_shared_data* sdata)
{
		cudaMemcpyToSymbol(MY_CONST(mask)    , & sdata->atom.mask .dev_data, sizeof(int*)     );
		cudaMemcpyToSymbol(MY_CONST(nlocal)  , & sdata->atom.nlocal        , sizeof(int)      );
		cudaMemcpyToSymbol(MY_CONST(nmax)    , & sdata->atom.nmax          , sizeof(int)      );
		cudaMemcpyToSymbol(MY_CONST(x)       , & sdata->atom.x    .dev_data, sizeof(X_FLOAT*) );
		cudaMemcpyToSymbol(MY_CONST(f)       , & sdata->atom.f    .dev_data, sizeof(F_FLOAT*) );
		cudaMemcpyToSymbol(MY_CONST(type)       , & sdata->atom.type    .dev_data, sizeof(int*) );
		cudaMemcpyToSymbol(MY_CONST(rmass_flag)       , & sdata->atom.rmass_flag, sizeof(int) );
		cudaMemcpyToSymbol(MY_CONST(rmass)       , & sdata->atom.rmass    .dev_data, sizeof(V_FLOAT*) );
		cudaMemcpyToSymbol(MY_CONST(mass)       , & sdata->atom.mass    .dev_data, sizeof(V_FLOAT*) );
}

void Cuda_FixGravityCuda_Init(cuda_shared_data* sdata)
{
	Cuda_FixGravityCuda_UpdateNmax(sdata);
		
}


void Cuda_FixGravityCuda_PostForce(cuda_shared_data* sdata, int groupbit,F_FLOAT xacc,F_FLOAT yacc,F_FLOAT zacc)
{
	if(sdata->atom.update_nmax) 
		Cuda_FixGravityCuda_UpdateNmax(sdata);
	if(sdata->atom.update_nlocal) 		
		cudaMemcpyToSymbol(MY_CONST(nlocal)  , & sdata->atom.nlocal        , sizeof(int)      );
	if(sdata->buffer_new)
		Cuda_FixGravityCuda_UpdateBuffer(sdata);
	
	
	int3 layout=getgrid(sdata->atom.nlocal);
	dim3 threads(layout.z, 1, 1);
	dim3 grid(layout.x, layout.y, 1);
	
	Cuda_FixGravityCuda_PostForce_Kernel<<<grid, threads>>> (groupbit,xacc,yacc,zacc);
	cudaThreadSynchronize();
	CUT_CHECK_ERROR("Cuda_Cuda_FixGravityCuda_PostForce: fix add_force post_force compute Kernel execution failed");
}