x86: unify current.h

Simply stitch these together. There are just two definitions that are shared
but the file is resonably small and putting these things together shows that
further unifications requires a unification of the per cpu / pda handling
between both arches.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/current.h

@@ -1,5 +1,39 @@
+#ifndef _X86_CURRENT_H
+#define _X86_CURRENT_H
+
 #ifdef CONFIG_X86_32
-# include "current_32.h"
-#else
-# include "current_64.h"
-#endif
+#include <linux/compiler.h>
+#include <asm/percpu.h>
+
+struct task_struct;
+
+DECLARE_PER_CPU(struct task_struct *, current_task);
+static __always_inline struct task_struct *get_current(void)
+{
+	return x86_read_percpu(current_task);
+}
+
+#else /* X86_32 */
+
+#ifndef __ASSEMBLY__
+#include <asm/pda.h>
+
+struct task_struct;
+
+static __always_inline struct task_struct *get_current(void)
+{
+	return read_pda(pcurrent);
+}
+
+#else /* __ASSEMBLY__ */
+
+#include <asm/asm-offsets.h>
+#define GET_CURRENT(reg) movq %gs:(pda_pcurrent),reg
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* X86_32 */
+
+#define current get_current()
+
+#endif /* X86_CURRENT_H */