#include <petscsys.h>    /*I   "petscsys.h"   I*/
#include <petscdevice.h> /* Needed to provide PetscCallCUDA() */

static PetscErrorCode PetscCUDAHostMalloc(size_t a, PetscBool clear, int lineno, const char function[], const char filename[], void **result) {
  PetscCallCUDA(cudaMallocHost(result, a));
  return 0;
}

static PetscErrorCode PetscCUDAHostFree(void *aa, int lineno, const char function[], const char filename[]) {
  PetscCallCUDA(cudaFreeHost(aa));
  return 0;
}

static PetscErrorCode PetscCUDAHostRealloc(size_t a, int lineno, const char function[], const char filename[], void **result) {
  SETERRQ(PETSC_COMM_SELF, PETSC_ERR_MEM, "CUDA has no Realloc()");
}

static PetscErrorCode (*PetscMallocOld)(size_t, PetscBool, int, const char[], const char[], void **);
static PetscErrorCode (*PetscReallocOld)(size_t, int, const char[], const char[], void **);
static PetscErrorCode (*PetscFreeOld)(void *, int, const char[], const char[]);

/*@C
   PetscMallocSetCUDAHost - Set PetscMalloc to use CUDAHostMalloc
     Switch the current malloc and free routines to the CUDA malloc and free routines

   Not Collective

   Level: developer

   Notes:
     This provides a way to use the CUDA malloc and free routines temporarily. One
     can switch back to the previous choice by calling PetscMallocResetCUDAHost().

.seealso: `PetscMallocResetCUDAHost()`
@*/
PetscErrorCode PetscMallocSetCUDAHost(void) {
  PetscFunctionBegin;
  /* Save the previous choice */
  PetscMallocOld  = PetscTrMalloc;
  PetscReallocOld = PetscTrRealloc;
  PetscFreeOld    = PetscTrFree;
  PetscTrMalloc   = PetscCUDAHostMalloc;
  PetscTrRealloc  = PetscCUDAHostRealloc;
  PetscTrFree     = PetscCUDAHostFree;
  PetscFunctionReturn(0);
}

/*@C
   PetscMallocResetCUDAHost - Reset the changes made by PetscMallocSetCUDAHost

   Not Collective

   Level: developer

.seealso: `PetscMallocSetCUDAHost()`
@*/
PetscErrorCode PetscMallocResetCUDAHost(void) {
  PetscFunctionBegin;
  PetscTrMalloc  = PetscMallocOld;
  PetscTrRealloc = PetscReallocOld;
  PetscTrFree    = PetscFreeOld;
  PetscFunctionReturn(0);
}