x86/fpu: Move fpu_copy() to fpu/core.c

Move fpu_copy() where its only user is.

Beyond readability this also speeds up compilation, as fpu-internal.h
is included in over a dozen .c files.
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/fpu-internal.h

@@ -565,20 +565,6 @@ extern int fpstate_alloc(struct fpu *fpu);
 extern void fpstate_free(struct fpu *fpu);
 extern int fpu__copy(struct task_struct *dst, struct task_struct *src);
 
-static inline void fpu_copy(struct task_struct *dst, struct task_struct *src)
-{
-	if (use_eager_fpu()) {
-		memset(&dst->thread.fpu.state->xsave, 0, xstate_size);
-		__save_fpu(dst);
-	} else {
-		struct fpu *dfpu = &dst->thread.fpu;
-		struct fpu *sfpu = &src->thread.fpu;
-
-		fpu__save(src);
-		memcpy(dfpu->state, sfpu->state, xstate_size);
-	}
-}
-
 static inline unsigned long
 alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long *buf_fx,
 		unsigned long *size)

arch/x86/kernel/fpu/core.c

@@ -203,6 +203,20 @@ void fpstate_free(struct fpu *fpu)
 }
 EXPORT_SYMBOL_GPL(fpstate_free);
 
+static void fpu_copy(struct task_struct *dst, struct task_struct *src)
+{
+	if (use_eager_fpu()) {
+		memset(&dst->thread.fpu.state->xsave, 0, xstate_size);
+		__save_fpu(dst);
+	} else {
+		struct fpu *dfpu = &dst->thread.fpu;
+		struct fpu *sfpu = &src->thread.fpu;
+
+		fpu__save(src);
+		memcpy(dfpu->state, sfpu->state, xstate_size);
+	}
+}
+
 int fpu__copy(struct task_struct *dst, struct task_struct *src)
 {
 	dst->thread.fpu.counter = 0;