[XEN PATCH v2 3/3] xen/mm: add declaration for first_valid_mfn

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

Such declaration is needed to comply with MISRA C Rule 8.4, because a
compatible declaration is not visible in xen/common/page_alloc.c, where the
variable is defined. That variable can't yet be static because of the lack of
support from ARM and PPC for NUMA.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
Having this declaration essentially sidesteps the current impossibility
of having a static variable, as described in the comments in
ARM and PCC's asm/numa.h.
---
 xen/include/xen/mm.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 3d9b2d05a5c8..a13a9a46ced7 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -118,6 +118,8 @@ int destroy_xen_mappings(unsigned long s, unsigned long e);
 /* Retrieve the MFN mapped by VA in Xen virtual address space. */
 mfn_t xen_map_to_mfn(unsigned long va);
 
+extern mfn_t first_valid_mfn;
+
 /*
  * Create only non-leaf page table entries for the
  * page range in Xen virtual address space.
-- 
2.34.1