[XEN PATCH v3 3/3] xen/mm: add declaration for first_valid_mfn

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

Such declaration is needed 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.

On the occasion, use drop a use of u8.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
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.

Changes in v3:
- Drop redundant declarations of first_valid_mfn in asm/numa.h for Arm and PPC.
---
 xen/arch/arm/include/asm/numa.h | 8 ++++----
 xen/arch/ppc/include/asm/numa.h | 7 +++----
 xen/include/xen/mm.h            | 2 ++
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/xen/arch/arm/include/asm/numa.h b/xen/arch/arm/include/asm/numa.h
index e2bee2bd8223..44b689f67db8 100644
--- a/xen/arch/arm/include/asm/numa.h
+++ b/xen/arch/arm/include/asm/numa.h
@@ -2,8 +2,9 @@
 #define __ARCH_ARM_NUMA_H
 
 #include <xen/mm.h>
+#include <xen/types.h>
 
-typedef u8 nodeid_t;
+typedef uint8_t nodeid_t;
 
 #ifndef CONFIG_NUMA
 
@@ -12,10 +13,9 @@ typedef u8 nodeid_t;
 #define node_to_cpumask(node)   (cpu_online_map)
 
 /*
- * TODO: make first_valid_mfn static when NUMA is supported on Arm, this
- * is required because the dummy helpers are using it.
+ * TODO: define here first_valid_mfn as static when NUMA is supported on Arm,
+ * this is required because the dummy helpers are using it.
  */
-extern mfn_t first_valid_mfn;
 
 /* XXX: implement NUMA support */
 #define node_spanned_pages(nid) (max_page - mfn_x(first_valid_mfn))
diff --git a/xen/arch/ppc/include/asm/numa.h b/xen/arch/ppc/include/asm/numa.h
index 7fdf66c3da74..152305ebe446 100644
--- a/xen/arch/ppc/include/asm/numa.h
+++ b/xen/arch/ppc/include/asm/numa.h
@@ -1,8 +1,8 @@
 #ifndef __ASM_PPC_NUMA_H__
 #define __ASM_PPC_NUMA_H__
 
-#include <xen/types.h>
 #include <xen/mm.h>
+#include <xen/types.h>
 
 typedef uint8_t nodeid_t;
 
@@ -11,10 +11,9 @@ typedef uint8_t nodeid_t;
 #define node_to_cpumask(node)   (cpu_online_map)
 
 /*
- * TODO: make first_valid_mfn static when NUMA is supported on PPC, this
- * is required because the dummy helpers are using it.
+ * TODO: define here first_valid_mfn as static when NUMA is supported on PPC,
+ * this is required because the dummy helpers are using it.
  */
-extern mfn_t first_valid_mfn;
 
 /* XXX: implement NUMA support */
 #define node_spanned_pages(nid) (max_page - mfn_x(first_valid_mfn))
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