Through a labyrinthian sequence of includes, usage of page_to_phys() is dependent on the include of asm/io.h in x86's asm/realmode.h, which is included in x86's asm/acpi.h and thus by linux/acpi.h. Explicitly include linux/io.h to break the dependency on realmode.h so that a future patch can remove the realmode.h include from acpi.h without breaking the build. Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- drivers/firmware/efi/capsule-loader.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c index b1395133389e..d3067cbd5114 100644 --- a/drivers/firmware/efi/capsule-loader.c +++ b/drivers/firmware/efi/capsule-loader.c @@ -11,6 +11,7 @@ #include <linux/module.h> #include <linux/miscdevice.h> #include <linux/highmem.h> +#include <linux/io.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/efi.h> -- 2.24.0