2 files changed, 55 insertions, 0 deletions

diff --git a/include/asm-i386/uaccess.h b/include/asm-i386/uaccess.h
index 1ec65523ea..82af28a943 100644
--- a/include/asm-i386/uaccess.h
+++ b/include/asm-i386/uaccess.h
@@ -390,6 +390,8 @@ unsigned long __must_check __copy_to_user_ll(void __user *to,
                                 const void *from, unsigned long n);
 unsigned long __must_check __copy_from_user_ll(void *to,
                                 const void __user *from, unsigned long n);
+unsigned long __must_check __copy_from_user_ll_nocache(void *to,
+                                const void __user *from, unsigned long n);
 
 /*
  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
@@ -478,12 +480,43 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
         return __copy_from_user_ll(to, from, n);
 }
 
+#define ARCH_HAS_NOCACHE_UACCESS
+
+static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to,
+                                const void __user *from, unsigned long n)
+{
+        if (__builtin_constant_p(n)) {
+                unsigned long ret;
+
+                switch (n) {
+                case 1:
+                        __get_user_size(*(u8 *)to, from, 1, ret, 1);
+                        return ret;
+                case 2:
+                        __get_user_size(*(u16 *)to, from, 2, ret, 2);
+                        return ret;
+                case 4:
+                        __get_user_size(*(u32 *)to, from, 4, ret, 4);
+                        return ret;
+                }
+        }
+        return __copy_from_user_ll_nocache(to, from, n);
+}
+
 static __always_inline unsigned long
 __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
        might_sleep();
        return __copy_from_user_inatomic(to, from, n);
 }
+
+static __always_inline unsigned long
+__copy_from_user_nocache(void *to, const void __user *from, unsigned long n)
+{
+       might_sleep();
+       return __copy_from_user_inatomic_nocache(to, from, n);
+}
+
 unsigned long __must_check copy_to_user(void __user *to,
                                 const void *from, unsigned long n);
 unsigned long __must_check copy_from_user(void *to,
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
new file mode 100644
index 0000000000..391e7ed1eb
--- /dev/null
+++ b/include/linux/uaccess.h
@@ -0,0 +1,22 @@
+#ifndef __LINUX_UACCESS_H__
+#define __LINUX_UACCESS_H__
+
+#include <asm/uaccess.h>
+
+#ifndef ARCH_HAS_NOCACHE_UACCESS
+
+static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
+                                const void __user *from, unsigned long n)
+{
+        return __copy_from_user_inatomic(to, from, n);
+}
+
+static inline unsigned long __copy_from_user_nocache(void *to,
+                                const void __user *from, unsigned long n)
+{
+        return __copy_from_user(to, from, n);
+}
+
+#endif          /* ARCH_HAS_NOCACHE_UACCESS */
+
+#endif          /* __LINUX_UACCESS_H__ */