Update io.h

adding the missing io

kernel/io.h

@@ -13,4 +13,24 @@ static inline uint8_t inb(uint16_t port) {
     return ret;
 }
 
+static inline void outw(uint16_t port, uint16_t val) {
+    __asm__("outw %0, %1" : : "a"(val), "Nd"(port));
+}
+
+static inline uint16_t inw(uint16_t port) {
+    uint16_t ret;
+    __asm__("inw %1, %0" : "=a"(ret) : "Nd"(port));
+    return ret;
+}
+
+static inline void outl(uint16_t port, uint32_t val) {
+    __asm__("outl %0, %1" : : "a"(val), "Nd"(port));
+}
+
+static inline uint32_t inl(uint16_t port) {
+    uint32_t ret;
+    __asm__("inl %1, %0" : "=a"(ret) : "Nd"(port));
+    return ret;
+}
+
 #endif