kbuild test robot report below error for randconfig: arch/x86/kernel/ksysfs.c: In function 'get_setup_data_paddr': >> arch/x86/kernel/ksysfs.c:81:3: error: implicit declaration of function 'ioremap_cache' [-Werror=implicit-function-declaration] data = ioremap_cache(pa_data, sizeof(*data)); ^ >> arch/x86/kernel/ksysfs.c:86:3: error: implicit declaration of function 'iounmap' [-Werror=implicit-function-declaration] iounmap(data); ^ Fix it by including <asm/io.h> in ksysfs.c Signed-off-by: Dave Young <dyoung at redhat.com> --- arch/x86/kernel/ksysfs.c | 1 + 1 file changed, 1 insertion(+) Index: linux/arch/x86/kernel/ksysfs.c =================================================================== --- linux.orig/arch/x86/kernel/ksysfs.c +++ linux/arch/x86/kernel/ksysfs.c @@ -16,6 +16,7 @@ #include <linux/stat.h> #include <linux/slab.h> #include <linux/mm.h> +#include <asm/io.h> #include <asm/setup.h>