Through a labyrinthian sequence of includes, usage of virt_to_phys() is dependent on the include of asm/io.h in asm/realmode.h via asm/acpi.h. Explicitly include asm/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> --- arch/x86/events/intel/ds.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index ce83950036c5..4b94ae4ae369 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -7,6 +7,7 @@ #include <asm/perf_event.h> #include <asm/tlbflush.h> #include <asm/insn.h> +#include <asm/io.h> #include "../perf_event.h" -- 2.24.0