Add architecture-specific GetPteDistance

xtoskrnl/mm/i686/pagemap.cc

@@ -317,6 +317,28 @@ MM::PageMapBasic::GetPageFrameNumber(IN PMMPTE Pte)
     return Pte->Pml2.Hardware.PageFrameNumber;
 }
 
+/**
+ * Calculates the distance between two PTE pointers.
+ *
+ * @param EndPte
+ *        Pointer to the ending Page Table Entry.
+ *
+ * @param StartPte
+ *        Pointer to the starting Page Table Entry.
+ *
+ * @return This routine returns a signed value representing the number of PTEs between EndPte and StartPte.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+LONG
+MM::PageMapBasic::GetPteDistance(PMMPTE EndPte,
+                                 PMMPTE StartPte)
+{
+    /* Return distance between PTE pointers */
+    return ((ULONG_PTR)EndPte - (ULONG_PTR)StartPte) / sizeof(MMPML2_PTE);
+}
+
 /**
  * Gets the size of a PTE for basic paging (PML2).
  *
@@ -568,6 +590,28 @@ MM::PageMapXpa::GetPageFrameNumber(IN PMMPTE Pte)
     return Pte->Pml3.Hardware.PageFrameNumber;
 }
 
+/**
+ * Calculates the distance between two PTE pointers.
+ *
+ * @param EndPte
+ *        Pointer to the ending Page Table Entry.
+ *
+ * @param StartPte
+ *        Pointer to the starting Page Table Entry.
+ *
+ * @return This routine returns a signed value representing the number of PTEs between EndPte and StartPte.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+LONG
+MM::PageMapXpa::GetPteDistance(PMMPTE EndPte,
+                               PMMPTE StartPte)
+{
+    /* Return distance between PTE pointers */
+    return ((ULONG_PTR)EndPte - (ULONG_PTR)StartPte) / sizeof(MMPML3_PTE);
+}
+
 /**
  * Gets the size of a PTE for XPA paging (PML3).
  *