lammps/src/USER-CUDA/pair_buck_coul_long_cuda.cpp

/* ----------------------------------------------------------------------
   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. 

   Contributing author: Paul Crozier (SNL)
   ----------------------------------------------------------------------- 

   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 <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "pair_buck_coul_long_cuda.h"
#include "pair_buck_coul_long_cuda_cu.h"
#include "cuda_data.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "kspace.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "cuda_neigh_list.h"
#include "update.h"
#include "integrate.h"
#include "respa.h"
#include "memory.h"
#include "error.h"
#include "cuda.h"

using namespace LAMMPS_NS;

#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) > (b) ? (a) : (b))

#define EWALD_F   1.12837917
#define EWALD_P   0.3275911
#define A1        0.254829592
#define A2       -0.284496736
#define A3        1.421413741
#define A4       -1.453152027
#define A5        1.061405429
/* ---------------------------------------------------------------------- */

PairBuckCoulLongCuda::PairBuckCoulLongCuda(LAMMPS *lmp) : PairBuckCoulLong(lmp)
{
  cuda = lmp->cuda;
   if(cuda == NULL)
        error->all("You cannot use a /cuda class, without activating 'cuda' acceleration. Use no '-a' command line argument, or '-a cuda'.");

	allocated2 = false;
	cuda->shared_data.pair.cudable_force = 1;
	cuda->shared_data.pair.use_block_per_atom = 0;
	cuda->setSystemParams();
}

/* ----------------------------------------------------------------------
   remember pointer to arrays in cuda shared data
------------------------------------------------------------------------- */

void PairBuckCoulLongCuda::allocate()
{
	if(! allocated) PairBuckCoulLong::allocate();
	if(! allocated2)
	{
		allocated2 = true;
		cuda->shared_data.pair.cut     = cut_lj;
		cuda->shared_data.pair.coeff1  = rhoinv;
		cuda->shared_data.pair.coeff2  = buck1;
		cuda->shared_data.pair.coeff3  = buck2;
		cuda->shared_data.pair.coeff4  = a;
		cuda->shared_data.pair.coeff5  = c;
		cuda->shared_data.pair.offset  = offset;
		cuda->shared_data.pair.special_lj  = force->special_lj;
		cuda->shared_data.pair.special_coul  = force->special_coul;
	}
}

/* ---------------------------------------------------------------------- */

void PairBuckCoulLongCuda::compute(int eflag, int vflag)
{
	MYDBG( printf("PairBuckCoulLongCuda compute start\n"); fflush(stdout);)
	if (eflag || vflag) ev_setup(eflag,vflag);
	if(eflag) cuda->cu_eng_vdwl->upload();
	if(eflag) cuda->cu_eng_coul->upload();
	if(vflag) cuda->cu_virial->upload();

	Cuda_PairBuckCoulLongCuda(& cuda->shared_data, & cuda_neigh_list->sneighlist, eflag, vflag, eflag_atom, vflag_atom);

    if(not cuda->shared_data.pair.collect_forces_later)
    {
	  if(eflag) cuda->cu_eng_vdwl->download();
	  if(eflag) cuda->cu_eng_coul->download();
	  if(vflag) cuda->cu_virial->download();
    }
	MYDBG( printf("PairBuckCoulLongCuda compute end\n"); fflush(stdout);)
}

/* ---------------------------------------------------------------------- */

void PairBuckCoulLongCuda::settings(int narg, char **arg)
{
	PairBuckCoulLong::settings(narg, arg);
	cuda->shared_data.pair.cut_global = (F_FLOAT) cut_lj_global;
}

/* ---------------------------------------------------------------------- */

void PairBuckCoulLongCuda::coeff(int narg, char **arg)
{
	PairBuckCoulLong::coeff(narg, arg);
	allocate();
}

void PairBuckCoulLongCuda::init_style()
{
  if (!atom->q_flag)
    error->all("Pair style buck/coul/long requires atom attribute q");
  // request regular or rRESPA neighbor lists

  int irequest;
 
  if (strcmp(update->integrate_style,"respa") == 0) error->all("Integrate Style Respa is not supported by pair style buck/coul/long/cuda");
  	
  	irequest = neighbor->request(this);
    neighbor->requests[irequest]->full = 1;
    neighbor->requests[irequest]->half = 0;
    neighbor->requests[irequest]->cudable = 1;
 

  cut_coulsq = cut_coul * cut_coul;
  cuda->shared_data.pair.cut_coulsq_global=cut_coulsq;

  if (force->kspace == NULL)
    error->all("Pair style is incompatible with KSpace style");
  g_ewald = force->kspace->g_ewald;
  cuda->shared_data.pair.g_ewald=g_ewald;
  cuda->shared_data.pppm.qqrd2e=force->qqrd2e;
  

  if(ncoultablebits) error->warning("# CUDA: You asked for the useage of Coulomb Tables. This is not supported in CUDA Pair forces. Setting is ignored.\n");
}

void PairBuckCoulLongCuda::init_list(int id, NeighList *ptr)
{
	MYDBG(printf("# CUDA PairBuckCoulLongCuda::init_list\n");)
	PairBuckCoulLong::init_list(id, ptr);
	#ifndef CUDA_USE_BINNING
	// right now we can only handle verlet (id 0), not respa
	if(id == 0) cuda_neigh_list = cuda->registerNeighborList(ptr);
	// see Neighbor::init() for details on lammps lists' logic
	#endif
	MYDBG(printf("# CUDA PairBuckCoulLongCuda::init_list end\n");)
}

void PairBuckCoulLongCuda::ev_setup(int eflag, int vflag)
{
	int maxeatomold=maxeatom;
	PairBuckCoulLong::ev_setup(eflag,vflag);

  if (eflag_atom && atom->nmax > maxeatomold) 
	{delete cuda->cu_eatom; cuda->cu_eatom = new cCudaData<double, ENERGY_FLOAT, x > ((double*)eatom, & cuda->shared_data.atom.eatom , atom->nmax  );}

  if (eflag_atom && atom->nmax > maxeatomold) 
	{delete cuda->cu_vatom; cuda->cu_vatom = new cCudaData<double, ENERGY_FLOAT, yx > ((double*)vatom, & cuda->shared_data.atom.eatom , atom->nmax, 6  );}
	
}