1 files changed, 22 insertions, 0 deletions

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 29e54807c5bc..b0b5f4694070 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -114,3 +114,25 @@ full_search:
         }
 }
 
+
+/*
+ * You really shouldn't be using read() or write() on /dev/mem.  This
+ * might go away in the future.
+ */
+int valid_phys_addr_range(unsigned long addr, size_t size)
+{
+        if (addr + size > __pa(high_memory))
+                return 0;
+
+        return 1;
+}
+
+/*
+ * We don't use supersection mappings for mmap() on /dev/mem, which
+ * means that we can't map the memory area above the 4G barrier into
+ * userspace.
+ */
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
+{
+        return !(pfn + (size >> PAGE_SHIFT) > 0x00100000);
+}