DRM: Fix build error in include/drm/ttm/ttm_memory.h

include/drm/ttm/ttm_memory.h uses struct page * without having included the required headers or a forward declaration resulting in the following build error for mtx1_defconfig on Linus' master branch, possibly others:

CC [M] drivers/gpu/drm/ttm/ttm_memory.o
In file included from /home/ralf/src/linux/linux-mips/drivers/gpu/drm/ttm/ttm_memory.c:28:
/home/ralf/src/linux/linux-mips/include/drm/ttm/ttm_memory.h:154: warning: ‘struct page’ declared inside parameter list /home/ralf/src/linux/linux-mips/include/drm/ttm/ttm_memory.h:154: warning: its scope is only this definition or declaration, which is probably not what you want /home/ralf/src/linux/linux-mips/include/drm/ttm/ttm_memory.h:156: warning: ‘struct page’ declared inside parameter list /home/ralf/src/linux/linux-mips/drivers/gpu/drm/ttm/ttm_memory.c:537: error: conflicting types for ‘ttm_mem_global_alloc_page’ /home/ralf/src/linux/linux-mips/include/drm/ttm/ttm_memory.h:152: note: previous declaration of ‘ttm_mem_global_alloc_page’ was here /home/ralf/src/linux/linux-mips/drivers/gpu/drm/ttm/ttm_memory.c:560: error: conflicting types for ‘ttm_mem_global_free_page’ /home/ralf/src/linux/linux-mips/include/drm/ttm/ttm_memory.h:155: note: previous declaration of ‘ttm_mem_global_free_page’ was here make[6]: *** [drivers/gpu/drm/ttm/ttm_memory.o] Error 1
make[5]: *** [drivers/gpu/drm/ttm] Error 2
make[4]: *** [drivers/gpu/drm] Error 2
make[3]: *** [drivers/gpu] Error 2
make[2]: *** [drivers] Error 2
make[1]: *** [sub-make] Error 2
make: *** [all] Error 2

Fixed by adding a forward declaration.

 include/drm/ttm/ttm_memory.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

index 6983a7c..95355ee 100644
@@ -143,6 +143,8 @@ static inline void ttm_mem_unregister_shrink(struct ttm_mem_global *glob,
 	spin_unlock(&glob->lock);
 }
 
+struct page;
+
 extern int ttm_mem_global_init(struct ttm_mem_global *glob);
 extern void ttm_mem_global_release(struct ttm_mem_global *glob);
 extern int ttm_mem_global_alloc(struct ttm_mem_global *glob, uint64_t memory,

I sent such a patch several weeks ago but unfortunately it hasn't been applied yet:
http://www.mail-archive.com/[email protected]/msg44711.html

Martin Michlmayr
http://www.cyrius.com/