3 files changed, 72 insertions, 1 deletions

diff --git a/Source/Parallelization/GuardCellManager.H b/Source/Parallelization/GuardCellManager.H
index 84aa45d38..1583c0bd6 100644
--- a/Source/Parallelization/GuardCellManager.H
+++ b/Source/Parallelization/GuardCellManager.H
@@ -61,6 +61,8 @@ public:
     amrex::IntVect ng_alloc_Rho = amrex::IntVect::TheZeroVector();
     // Guard cells allocated for MultiFab F
     amrex::IntVect ng_alloc_F = amrex::IntVect::TheZeroVector();
+    // Guard cells allocated for MultiFab G
+    amrex::IntVect ng_alloc_G = amrex::IntVect::TheZeroVector();
 
     // Guard cells exchanged for specific parts of the PIC loop
 
@@ -68,6 +70,8 @@ public:
     amrex::IntVect ng_FieldSolver = amrex::IntVect::TheZeroVector();
     // Number of guard cells of F that must exchanged before Field Solver
     amrex::IntVect ng_FieldSolverF = amrex::IntVect::TheZeroVector();
+    // Number of guard cells of G that must be exchanged before Field Solver
+    amrex::IntVect ng_FieldSolverG = amrex::IntVect::TheZeroVector();
     // Number of guard cells of E and B that must exchanged before Field Gather
     amrex::IntVect ng_FieldGather = amrex::IntVect::TheZeroVector();
     // Number of guard cells of E and B that must exchanged before updating the Aux grid
diff --git a/Source/Parallelization/GuardCellManager.cpp b/Source/Parallelization/GuardCellManager.cpp
index b40c4433b..b569c43e7 100644
--- a/Source/Parallelization/GuardCellManager.cpp
+++ b/Source/Parallelization/GuardCellManager.cpp
@@ -122,6 +122,11 @@ guardCellManager::Init (
     if (maxwell_solver_id == MaxwellSolverAlgo::CKC) ng_alloc_F_int = std::max( ng_alloc_F_int, 1 );
     ng_alloc_F = IntVect(AMREX_D_DECL(ng_alloc_F_int, ng_alloc_F_int, ng_alloc_F_int));
 
+    // Used if warpx.do_divb_cleaning = 1
+    int ng_alloc_G_int = (do_moving_window) ? 2 : 1;
+    // TODO Does the CKC solver require one additional guard cell (as for F)?
+    ng_alloc_G = IntVect(AMREX_D_DECL(ng_alloc_G_int, ng_alloc_G_int, ng_alloc_G_int));
+
     if (maxwell_solver_id == MaxwellSolverAlgo::PSATD)
     {
         // The number of guard cells should be enough to contain the stencil of the FFT solver.
@@ -178,9 +183,11 @@ guardCellManager::Init (
     if (maxwell_solver_id == MaxwellSolverAlgo::PSATD) {
         ng_FieldSolver = ng_alloc_EB;
         ng_FieldSolverF = ng_alloc_EB;
+        ng_FieldSolverG = ng_alloc_EB;
     } else {
         ng_FieldSolver = IntVect(AMREX_D_DECL(1, 1, 1));
         ng_FieldSolverF = IntVect(AMREX_D_DECL(1, 1, 1));
+        ng_FieldSolverG = IntVect(AMREX_D_DECL(1, 1, 1));
     }
 
     if (safe_guard_cells){
@@ -188,6 +195,7 @@ guardCellManager::Init (
         // call of FillBoundary
         ng_FieldSolver = ng_alloc_EB;
         ng_FieldSolverF = ng_alloc_F;
+        ng_FieldSolverG = ng_alloc_G;
         ng_FieldGather = ng_alloc_EB;
         ng_UpdateAux = ng_alloc_EB;
         if (do_moving_window){
@@ -217,6 +225,7 @@ guardCellManager::Init (
         ng_FieldGather = ng_FieldGather.min(ng_alloc_EB);
         ng_UpdateAux = ng_UpdateAux.min(ng_alloc_EB);
         ng_FieldSolverF = ng_FieldSolverF.min(ng_alloc_F);
+        ng_FieldSolverG = ng_FieldSolverG.min(ng_alloc_G);
         // Only FillBoundary(ng_FieldGather) is called between consecutive
         // field solves. So ng_FieldGather must have enough cells
         // for the field solve too.
diff --git a/Source/Parallelization/WarpXComm.cpp b/Source/Parallelization/WarpXComm.cpp
index d92cffb11..3badbdf2d 100644
--- a/Source/Parallelization/WarpXComm.cpp
+++ b/Source/Parallelization/WarpXComm.cpp
@@ -457,6 +457,15 @@ WarpX::FillBoundaryF (IntVect ng)
 }
 
 void
+WarpX::FillBoundaryG (IntVect ng)
+{
+    for (int lev = 0; lev <= finest_level; ++lev)
+    {
+        FillBoundaryG(lev, ng);
+    }
+}
+
+void
 WarpX::FillBoundaryB_avg (IntVect ng)
 {
     for (int lev = 0; lev <= finest_level; ++lev)
@@ -702,7 +711,6 @@ WarpX::FillBoundaryB_avg (int lev, PatchType patch_type, IntVect ng)
     }
 }
 
-
 void
 WarpX::FillBoundaryF (int lev, IntVect ng)
 {
@@ -753,6 +761,56 @@ WarpX::FillBoundaryF (int lev, PatchType patch_type, IntVect ng)
     }
 }
 
+void WarpX::FillBoundaryG (int lev, IntVect ng)
+{
+    FillBoundaryG(lev, PatchType::fine, ng);
+
+    if (lev > 0)
+    {
+        FillBoundaryG(lev, PatchType::coarse, ng);
+    }
+}
+
+void WarpX::FillBoundaryG (int lev, PatchType patch_type, IntVect ng)
+{
+    if (patch_type == PatchType::fine && G_fp[lev])
+    {
+        // TODO Exchange in PML cells will go here
+
+        const auto& period = Geom(lev).periodicity();
+
+        if (safe_guard_cells)
+        {
+            G_fp[lev]->FillBoundary(period);
+        }
+        else
+        {
+            AMREX_ALWAYS_ASSERT_WITH_MESSAGE(ng <= G_fp[lev]->nGrowVect(),
+                "Error: in FillBoundaryG, requested more guard cells than allocated");
+
+            G_fp[lev]->FillBoundary(ng, period);
+        }
+    }
+    else if (patch_type == PatchType::coarse && G_cp[lev])
+    {
+        // TODO Exchange in PML cells will go here
+
+        const auto& cperiod = Geom(lev-1).periodicity();
+
+        if (safe_guard_cells)
+        {
+            G_cp[lev]->FillBoundary(cperiod);
+        }
+        else
+        {
+            AMREX_ALWAYS_ASSERT_WITH_MESSAGE(ng <= G_cp[lev]->nGrowVect(),
+                "Error: in FillBoundaryG, requested more guard cells than allocated");
+
+            G_cp[lev]->FillBoundary(ng, cperiod);
+        }
+    }
+}
+
 void
 WarpX::FillBoundaryAux (IntVect ng)
 {