1 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index d4b6e6a29ae3..d03c461e045e 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -83,6 +83,25 @@ int page_is_ram(unsigned long pagenr)
         return 0;
 }
 
+int pagerange_is_ram(unsigned long start, unsigned long end)
+{
+        int ram_page = 0, not_rampage = 0;
+        unsigned long page_nr;
+
+        for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+             ++page_nr) {
+                if (page_is_ram(page_nr))
+                        ram_page = 1;
+                else
+                        not_rampage = 1;
+
+                if (ram_page == not_rampage)
+                        return -1;
+        }
+
+        return ram_page;
+}
+
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.