xen: allow compilation with non-flat memory

There's no real reason we can't support sparsemem/discontigmem, so do so.
This is mostly useful to support hotplug memory.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bc129146f99f..c8a56e457d61 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -669,7 +669,9 @@ static void xen_write_cr3(unsigned long cr3)
    everything is pinned. */
 static __init void xen_alloc_pte_init(struct mm_struct *mm, u32 pfn)
 {
+#ifdef CONFIG_FLATMEM
         BUG_ON(mem_map);        /* should only be used early */
+#endif
         make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
 }