1 files changed, 73 insertions, 0 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
new file mode 100644
index 0000000000..27ea642527
--- /dev/null
+++ b/arch/x86/include/asm/io.h
@@ -0,0 +1,73 @@
+/*
+ * Mostly stolen from the linux kernel
+ */
+
+/**
+ * @file
+ * @brief x86 IO access functions
+ */
+
+#ifndef __ASM_X86_IO_H
+#define __ASM_X86_IO_H
+
+static inline void outb(unsigned char value, int port)
+{
+	asm volatile("outb %b0, %w1" : : "a"(value), "Nd"(port));
+}
+
+static inline void outw(unsigned short value, int port)
+{
+	asm volatile("outw %w0, %w1" : : "a"(value), "Nd"(port));
+}
+
+static inline void outl(unsigned long value, int port)
+{
+	asm volatile("outl %0, %w1" : : "a"(value), "Nd"(port));
+}
+
+static inline unsigned char inb(int port)
+{
+	unsigned char value;
+	asm volatile("inb %w1, %b0" : "=a"(value) : "Nd"(port));
+	return value;
+}
+
+static inline unsigned short inw(int port)
+{
+	unsigned short value;
+	asm volatile("inw %w1, %w0" : "=a"(value) : "Nd"(port));
+	return value;
+}
+
+static inline unsigned long inl(int port)
+{
+	unsigned long value;
+	asm volatile("inl %w1, %0" : "=a"(value) : "Nd"(port));
+	return value;
+}
+
+#define build_mmio_read(name, size, type, reg, barrier) \
+ static inline type name(const volatile void *addr) \
+ { type ret; asm volatile("mov" size " %1,%0":reg (ret) \
+ :"m" (*(volatile type*)addr) barrier); return ret; }
+
+build_mmio_read(readb, "b", unsigned char, "=q", :"memory")
+build_mmio_read(readw, "w", unsigned short, "=r", :"memory")
+build_mmio_read(readl, "l", unsigned int, "=r", :"memory")
+
+#define build_mmio_write(name, size, type, reg, barrier) \
+ static inline void name(type val, volatile void *addr) \
+ { asm volatile("mov" size " %0,%1": :reg (val), \
+ "m" (*(volatile type*)addr) barrier); }
+
+build_mmio_write(writeb, "b", unsigned char, "q", :"memory")
+build_mmio_write(writew, "w", unsigned short, "r", :"memory")
+build_mmio_write(writel, "l", unsigned int, "r", :"memory")
+
+/* do a tiny io delay */
+static inline void io_delay(void)
+{
+	inb(0x80);
+}
+
+#endif	/* __ASM_X86_IO_H */