3 files changed, 14 insertions, 5 deletions

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 912088773a6..c2cf2eda062 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -327,7 +327,7 @@ static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size)
 #define ioremap_wc ioremap_nocache
 #endif
 
-static inline void iounmap(void *addr)
+static inline void iounmap(void __iomem *addr)
 {
 }
 #endif /* CONFIG_MMU */
diff --git a/include/asm-generic/page.h b/include/asm-generic/page.h
index 351889d1de1..37d1fe28960 100644
--- a/include/asm-generic/page.h
+++ b/include/asm-generic/page.h
@@ -71,10 +71,14 @@ extern unsigned long memory_end;
 #define PAGE_OFFSET             (0)
 #endif
 
+#ifndef ARCH_PFN_OFFSET
+#define ARCH_PFN_OFFSET         (PAGE_OFFSET >> PAGE_SHIFT)
+#endif
+
 #ifndef __ASSEMBLY__
 
-#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
-#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
+#define __va(x) ((void *)((unsigned long) (x)))
+#define __pa(x) ((unsigned long) (x))
 
 #define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
 #define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
@@ -86,7 +90,7 @@ extern unsigned long memory_end;
 #define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
 #endif
 
-#define pfn_valid(pfn)          ((pfn) < max_mapnr)
+#define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
 
 #define virt_addr_valid(kaddr)  (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
                                 ((void *)(kaddr) < (void *)memory_end))
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index ac68c999b6c..9788568f797 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -289,9 +289,14 @@ strncpy_from_user(char *dst, const char __user *src, long count)
  * Return 0 on exception, a value greater than N if too long
  */
 #ifndef __strnlen_user
-#define __strnlen_user strnlen
+#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
 #endif
 
+/*
+ * Unlike strnlen, strnlen_user includes the nul terminator in
+ * its returned count. Callers should check for a returned value
+ * greater than N as an indication the string is too long.
+ */
 static inline long strnlen_user(const char __user *src, long n)
 {
         if (!access_ok(VERIFY_READ, src, 1))