x86: inline I/O port functions

arch/x86/include/arch/port.h

@@ -21,13 +21,29 @@
 
 #ifndef _ASM_SOURCE
 
+#include <gay/cdefs.h>
+
+/** @brief Induce a brief CPU delay by writing zero to I/O port 0x80. */
+extern void x86_io_wait(void);
+
 /**
  * @brief Read a byte from the I/O bus.
  *
  * @param port Port number
  * @return The byte that was read
  */
-extern u8 x86_inb(u16 port);
+inline u8 x86_inb(u16 port)
+{
+	u8 data;
+
+	__asm__ volatile(
+"	inb	%1,	%0	\n"
+	: "=a"(data)
+	: "Nd"(port)
+	);
+
+	return data;
+}
 
 /**
  * @brief Read a word from the I/O bus.
@@ -35,7 +51,18 @@ extern u8 x86_inb(u16 port);
  * @param port Port number
  * @return The word that was read
  */
-extern u16 x86_inw(u16 port);
+inline u16 x86_inw(u16 port)
+{
+	u16 data;
+
+	__asm__ volatile(
+"	inw	%1,	%0	\n"
+	: "=a"(data)
+	: "Nd"(port)
+	);
+
+	return data;
+}
 
 /**
  * @brief Read a longword from the I/O bus.
@@ -43,7 +70,18 @@ extern u16 x86_inw(u16 port);
  * @param port Port number
  * @return The longword that was read
  */
-extern u32 x86_inl(u16 port);
+inline u32 x86_inl(u16 port)
+{
+	u32 data;
+
+	__asm__ volatile(
+"	inl	%1,	%0	\n"
+	: "=a"(data)
+	: "Nd"(port)
+	);
+
+	return data;
+}
 
 /**
  * @brief Write a byte to the I/O bus.
@@ -51,7 +89,14 @@ extern u32 x86_inl(u16 port);
  * @param port Port number
  * @param data Byte to send through the port
  */
-extern void x86_outb(u16 port, u8 data);
+inline void x86_outb(u16 port, u8 data)
+{
+	__asm__ volatile(
+"	outb	%0,	%1	\n"
+	:
+	: "a"(data), "Nd"(port)
+	);
+}
 
 /**
  * @brief Write a word to the I/O bus.
@@ -59,7 +104,14 @@ extern void x86_outb(u16 port, u8 data);
  * @param port Port number
  * @param data Word to send through the port
  */
-extern void x86_outw(u16 port, u16 data);
+inline void x86_outw(u16 port, u16 data)
+{
+	__asm__ volatile(
+"	outw	%0,	%1	\n"
+	:
+	: "a"(data), "Nd"(port)
+	);
+}
 
 /**
  * @brief Write a longword to the I/O bus.
@@ -67,7 +119,14 @@ extern void x86_outw(u16 port, u16 data);
  * @param port Port number
  * @param data Longword to send through the port
  */
-extern void x86_outl(u16 port, u32 data);
+inline void x86_outl(u16 port, u32 data)
+{
+	__asm__ volatile(
+"	outl	%0,	%1	\n"
+	:
+	: "a"(data), "Nd"(port)
+	);
+}
 
 #endif /* not _ASM_SOURCE */
 

arch/x86/sys/port.S

@@ -4,6 +4,13 @@
 
 	.text
 
+/* void x86_io_wait(void); */
+ASM_ENTRY(x86_io_wait)
+	xor	%al, %al
+	outb	%al, $0x80
+	ret
+ASM_END(x86_io_wait)
+
 /* u8 x86_inb(u16 port); */
 ASM_ENTRY(x86_inb)
 	mov	4(%esp), %edx