xen: Introduce xen_pfn_t for pfn and mfn types

All the original Xen headers have xen_pfn_t as mfn and pfn type, however
when they have been imported in Linux, xen_pfn_t has been replaced with
unsigned long. That might work for x86 and ia64 but it does not for arm.
Bring back xen_pfn_t and let each architecture define xen_pfn_t as they
see fit.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index 8d4efc1..d8e33a9 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -31,7 +31,7 @@
      *   OUT: GMFN bases of extents that were allocated
      *   (NB. This command also updates the mach_to_phys translation table)
      */
-    GUEST_HANDLE(ulong) extent_start;
+    GUEST_HANDLE(xen_pfn_t) extent_start;
 
     /* Number of extents, and size/alignment of each (2^extent_order pages). */
     unsigned long  nr_extents;
@@ -130,7 +130,7 @@
      * any large discontiguities in the machine address space, 2MB gaps in
      * the machphys table will be represented by an MFN base of zero.
      */
-    GUEST_HANDLE(ulong) extent_start;
+    GUEST_HANDLE(xen_pfn_t) extent_start;
 
     /*
      * Number of extents written to the above array. This will be smaller
@@ -175,7 +175,7 @@
     unsigned long idx;
 
     /* GPFN where the source mapping page should appear. */
-    unsigned long gpfn;
+    xen_pfn_t gpfn;
 };
 DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap);