fbdev: detect primary display device

Add function helper, fb_is_primary_device().  Given struct fb_info, it will
return a nonzero value if the device is the primary display.

Currently, only the i386 is supported where the function checks for the
IORESOURCE_ROM_SHADOW flag.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/asm-s390/fb.h b/include/asm-s390/fb.h
index 9f8c88d05df4..c7df38030992 100644
--- a/include/asm-s390/fb.h
+++ b/include/asm-s390/fb.h
@@ -1,6 +1,12 @@
 #ifndef _ASM_FB_H_
 #define _ASM_FB_H_
+#include <linux/fb.h>
 
 #define fb_pgprotect(...) do {} while (0)
 
+static inline int fb_is_primary_device(struct fb_info *info)
+{
+        return 0;
+}
+
 #endif /* _ASM_FB_H_ */