1 files changed, 19 insertions, 7 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 597ac155c91c..bc7527e109c8 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -50,6 +50,21 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size,
         return err;
 }
 
+static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
+                               void *arg)
+{
+        unsigned long i;
+
+        for (i = 0; i < nr_pages; ++i)
+                if (pfn_valid(start_pfn + i) &&
+                    !PageReserved(pfn_to_page(start_pfn + i)))
+                        return 1;
+
+        WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn);
+
+        return 0;
+}
+
 /*
  * Remap an arbitrary physical address space into the kernel virtual
  * address space. Needed when the kernel wants to access high addresses
@@ -93,14 +108,11 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
         /*
          * Don't allow anybody to remap normal RAM that we're using..
          */
+        pfn      = phys_addr >> PAGE_SHIFT;
         last_pfn = last_addr >> PAGE_SHIFT;
-        for (pfn = phys_addr >> PAGE_SHIFT; pfn <= last_pfn; pfn++) {
-                int is_ram = page_is_ram(pfn);
-
-                if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
-                        return NULL;
-                WARN_ON_ONCE(is_ram);
-        }
+        if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
+                                  __ioremap_check_ram) == 1)
+                return NULL;
 
         /*
          * Mappings have to be page-aligned