x86/fpu: Move fpu_alloc() out of line

This is not a small function, and it's used in several places,
one of them a popular module (KVM).

Move the function out of line. This saves a bit of text,
even with the symbol export overhead:

   text    data     bss     dec     hex filename
   12566052        1619504 1089536 15275092         e91454 vmlinux.before
   12566046        1619504 1089536 15275086         e9144e vmlinux.after

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

@@ -569,16 +569,7 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
 	}
 }
 
-static inline int fpu_alloc(struct fpu *fpu)
-{
-	if (fpu->state)
-		return 0;
-	fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL);
-	if (!fpu->state)
-		return -ENOMEM;
-	WARN_ON((unsigned long)fpu->state & 15);
-	return 0;
-}
+extern int fpu_alloc(struct fpu *fpu);
 
 static inline void fpu_free(struct fpu *fpu)
 {

arch/x86/kernel/i387.c

@@ -246,6 +246,18 @@ void fpu_finit(struct fpu *fpu)
 }
 EXPORT_SYMBOL_GPL(fpu_finit);
 
+int fpu_alloc(struct fpu *fpu)
+{
+	if (fpu->state)
+		return 0;
+	fpu->state = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL);
+	if (!fpu->state)
+		return -ENOMEM;
+	WARN_ON((unsigned long)fpu->state & 15);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fpu_alloc);
+
 /*
  * Allocate the backing store for the current task's FPU registers
  * and initialize the registers themselves as well.