diff --git a/include/asm-mips/ioctl.h b/include/asm-mips/ioctl.h
index cba641a..2036fcb 100644
--- a/include/asm-mips/ioctl.h
+++ b/include/asm-mips/ioctl.h
@@ -38,11 +38,6 @@
 #define _IOC_DIRSHIFT	(_IOC_SIZESHIFT+_IOC_SIZEBITS)
 
 /*
- * We to additionally limit parameters to a maximum 255 bytes.
- */
-#define _IOC_SLMASK	0xff
-
-/*
  * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit.
  * And this turns out useful to catch old ioctl numbers in header
  * files for us.