xen/e820: if there is no dom0_mem=, don't tweak extra_pages.

[pandora-kernel.git] / arch / x86 / xen / setup.c

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index ff3dfa1..09688eb 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -305,10 +305,12 @@ char * __init xen_memory_setup(void)
        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
        extra_limit = xen_get_max_pages();
-       if (extra_limit >= max_pfn)
-               extra_pages = extra_limit - max_pfn;
-       else
-               extra_pages = 0;
+       if (max_pfn + extra_pages > extra_limit) {
+               if (extra_limit > max_pfn)
+                       extra_pages = extra_limit - max_pfn;
+               else
+                       extra_pages = 0;
+       }
 
        extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);