[PATCH 4.9 081/108] mn10300: fix build error of missing fpu_save()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>


[ Upstream commit 3705ccfdd1e8b539225ce20e3925a945cc788d67 ]

When CONFIG_FPU is not enabled on arch/mn10300, <asm/switch_to.h> causes
a build error with a call to fpu_save():

  kernel/built-in.o: In function `.L410':
  core.c:(.sched.text+0x28a): undefined reference to `fpu_save'

Fix this by including <asm/fpu.h> in <asm/switch_to.h> so that an empty
static inline fpu_save() is defined.

Link: http://lkml.kernel.org/r/dc421c4f-4842-4429-1b99-92865c2f24b6@xxxxxxxxxxxxx
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/mn10300/include/asm/switch_to.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mn10300/include/asm/switch_to.h
+++ b/arch/mn10300/include/asm/switch_to.h
@@ -16,7 +16,7 @@
 struct task_struct;
 struct thread_struct;
 
-#if !defined(CONFIG_LAZY_SAVE_FPU)
+#if defined(CONFIG_FPU) && !defined(CONFIG_LAZY_SAVE_FPU)
 struct fpu_state_struct;
 extern asmlinkage void fpu_save(struct fpu_state_struct *);
 #define switch_fpu(prev, next)						\