1: #include <petscsys.h>
  2: #include <petscdevice_cuda.h>

  4: static PetscErrorCode PetscCUDAHostMalloc(size_t a, PetscBool, int, const char[], const char[], void **result)
  5: {
  6:   PetscCallCUDA(cudaMallocHost(result, a));
  7:   return PETSC_SUCCESS;
  8: }

 10: static PetscErrorCode PetscCUDAHostFree(void *aa, int, const char[], const char[])
 11: {
 12:   PetscCallCUDA(cudaFreeHost(aa));
 13:   return PETSC_SUCCESS;
 14: }

 16: static PetscErrorCode PetscCUDAHostRealloc(size_t, int, const char[], const char[], void **)
 17: {
 18:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_MEM, "CUDA has no Realloc()");
 19: }

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

 25: /*@
 26:   PetscMallocSetCUDAHost - Set `PetscMalloc()` to use `CUDAHostMalloc()`
 27:   Switch the current malloc and free routines to the CUDA malloc and free routines

 29:   Not Collective

 31:   Level: developer

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

 37: .seealso: `PetscCUDAHostMalloc()`, `PetscMallocResetCUDAHost()`, `PetscMallocSetHIPHost()`
 38: @*/
 39: PetscErrorCode PetscMallocSetCUDAHost(void)
 40: {
 41:   PetscFunctionBegin;
 42:   /* Save the previous choice */
 43:   PetscMallocOld  = PetscTrMalloc;
 44:   PetscReallocOld = PetscTrRealloc;
 45:   PetscFreeOld    = PetscTrFree;
 46:   PetscTrMalloc   = PetscCUDAHostMalloc;
 47:   PetscTrRealloc  = PetscCUDAHostRealloc;
 48:   PetscTrFree     = PetscCUDAHostFree;
 49:   PetscFunctionReturn(PETSC_SUCCESS);
 50: }

 52: /*@
 53:   PetscMallocResetCUDAHost - Reset the changes made by `PetscMallocSetCUDAHost()`

 55:   Not Collective

 57:   Level: developer

 59: .seealso: `PetscCUDAHostMalloc()`, `PetscMallocSetCUDAHost()`
 60: @*/
 61: PetscErrorCode PetscMallocResetCUDAHost(void)
 62: {
 63:   PetscFunctionBegin;
 64:   PetscTrMalloc  = PetscMallocOld;
 65:   PetscTrRealloc = PetscReallocOld;
 66:   PetscTrFree    = PetscFreeOld;
 67:   PetscFunctionReturn(PETSC_SUCCESS);
 68: }