mm/migrate: mark unmap_and_move() "noinline" to avoid ICE in gcc 4.7.3

With gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) :

mm/migrate.c: In function `migrate_pages':
mm/migrate.c:1148:1: internal compiler error: in push_minipool_fix, at config/arm/arm.c:13500
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccPoM1tr.out file, please attach this to your bugreport.
make[1]: *** [mm/migrate.o] Error 1
make: *** [mm/migrate.o] Error 2

Mark unmap_and_move() (which is used in a single place only) "noinline"
to work around this compiler bug.

[[e-mail]: make it conditional on gcc-4.7.3 and arm]
[[e-mail]: fine-tune compiler versions]
[[e-mail]: fix comment]
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reported-by: Kevin Hilman <[e-mail]>
Cc: Marc Zyngier <[e-mail]>
Tested-by: Kevin Hilman <[e-mail]>
Tested-by: Lina Iyer <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/migrate.c

···
 }
 
 /*
+ * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move().  Work
+ * around it.
+ */
+#if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM)
+#define ICE_noinline noinline
+#else
+#define ICE_noinline
+#endif
+
+/*
  * Obtain the lock on page, remove all ptes and migrate the page
  * to the newly allocated page in newpage.
  */
-static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page,
-			unsigned long private, struct page *page, int force,
-			enum migrate_mode mode)
+static ICE_noinline int unmap_and_move(new_page_t get_new_page,
+				   free_page_t put_new_page,
+				   unsigned long private, struct page *page,
+				   int force, enum migrate_mode mode)
 {
 	int rc = 0;
 	int *result = NULL;