Merge branch 'master' into csb1725

[mv-sheeva.git] / arch / arm / mm / mmap.c

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 4f5b39687df541a417d4c3a9ac888fc53a31b999..b0a98305055c53e54cc9be3edda6c82afb6275b8 100644 (file)
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -144,3 +144,25 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
 {
        return !(pfn + (size >> PAGE_SHIFT) > 0x00100000);
 }
+
+#ifdef CONFIG_STRICT_DEVMEM
+
+#include <linux/ioport.h>
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain
+ * address is valid. The argument is a physical page number.
+ * We mimic x86 here by disallowing access to system RAM as well as
+ * device-exclusive MMIO regions. This effectively disable read()/write()
+ * on /dev/mem.
+ */
+int devmem_is_allowed(unsigned long pfn)
+{
+       if (iomem_is_exclusive(pfn << PAGE_SHIFT))
+               return 0;
+       if (!page_is_ram(pfn))
+               return 1;
+       return 0;
+}
+
+#endif