-#define inb(port) ({ unsigned char val; asm volatile("inb %%dx, %0" : "=a" ((unsigned char)(val)) : "d" ((unsigned short)(port))); val; })
-#define inw(port) ({ unsigned short val; asm volatile("inw %%dx, %0" : "=a" ((unsigned short)(val)) : "d" ((unsigned short)(port))); val; })
-#define inl(port) ({ unsigned long val; asm volatile("inl %%dx, %0" : "=a" ((unsigned long)(val)) : "d" ((unsigned short)(port))); val; })
-#define outb(port, val) ({ asm volatile("outb %0, %%dx" : : "a" ((unsigned char)(val)) , "d" ((unsigned short)(port))); })
-#define outw(port, val) ({ asm volatile("outw %0, %%dx" : : "a" ((unsigned short)(val)) , "d" ((unsigned short)(port))); })
-#define outl(port, val) ({ asm volatile("outl %0, %%dx" : : "a" ((unsigned long)(val)) , "d" ((unsigned short)(port))); })
+#define inb(port) __extension__ ({ unsigned char val; asm volatile("inb %%dx, %0" : "=a" ((unsigned char)(val)) : "d" ((unsigned short)(port))); val; })
+#define inw(port) __extension__ ({ unsigned short val; asm volatile("inw %%dx, %0" : "=a" ((unsigned short)(val)) : "d" ((unsigned short)(port))); val; })
+#define inl(port) __extension__ ({ unsigned long val; asm volatile("inl %%dx, %0" : "=a" ((unsigned long)(val)) : "d" ((unsigned short)(port))); val; })
+#define outb(port, val) __extension__ ({ asm volatile("outb %0, %%dx" : : "a" ((unsigned char)(val)) , "d" ((unsigned short)(port))); })
+#define outw(port, val) __extension__ ({ asm volatile("outw %0, %%dx" : : "a" ((unsigned short)(val)) , "d" ((unsigned short)(port))); })
+#define outl(port, val) __extension__ ({ asm volatile("outl %0, %%dx" : : "a" ((unsigned long)(val)) , "d" ((unsigned short)(port))); })