Add x86 port io accessors

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

lib/x86/io.h

+#ifndef IO_H
+#define IO_H
+
+static inline unsigned char inb(unsigned short port)
+{
+    unsigned char value;
+    asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port));
+    return value;
+}
+
+static inline unsigned short inw(unsigned short port)
+{
+    unsigned short value;
+    asm volatile("inw %w1, %0" : "=a" (value) : "Nd" (port));
+    return value;
+}
+
+static inline unsigned int inl(unsigned short port)
+{
+    unsigned int value;
+    asm volatile("inl %w1, %0" : "=a" (value) : "Nd" (port));
+    return value;
+}
+
+static inline void outb(unsigned char value, unsigned short port)
+{
+    asm volatile("outb %b0, %w1" : : "a"(value), "Nd"(port));
+}
+
+static inline void outw(unsigned short value, unsigned short port)
+{
+    asm volatile("outw %w0, %w1" : : "a"(value), "Nd"(port));
+}
+
+static inline void outl(unsigned int value, unsigned short port)
+{
+    asm volatile("outl %0, %w1" : : "a"(value), "Nd"(port));
+}
+
+#endif