At least on sparc64 these modules require ata_machdep.c.

MFC after:	3 days

sys/modules/ata/atadisk/Makefile

@@ -1,9 +1,13 @@
 # $FreeBSD$
 
-.PATH: ${.CURDIR}/../../../dev/ata
+.PATH: ${.CURDIR}/../../../dev/ata ${.CURDIR}/../../../${MACHINE}/${MACHINE}
 
 KMOD=	atadisk
-SRCS=	ata-disk.c
+SRCS=	ata-disk.c ${ata_machdep}
 SRCS+=  opt_ata.h ata_if.h device_if.h bus_if.h pci_if.h
 
+.if exists(${.CURDIR}/../../../${MACHINE}/${MACHINE}/ata_machdep.c)
+ata_machdep=	ata_machdep.c
+.endif
+
 .include <bsd.kmod.mk>

sys/modules/cam/Makefile

@@ -2,7 +2,7 @@
 
 S=	${.CURDIR}/../..
 
-.PATH: $S/cam $S/cam/scsi $S/cam/ata
+.PATH: $S/cam $S/cam/scsi $S/cam/ata $S/${MACHINE}/${MACHINE}
 
 KMOD=	cam
 
@@ -28,6 +28,9 @@ SRCS+=	scsi_xpt.c
 SRCS+=	ata_all.c
 SRCS+=	ata_xpt.c
 SRCS+=	ata_da.c
+.if exists($S/${MACHINE}/${MACHINE}/ata_machdep.c)
+SRCS+=  ata_machdep.c
+.endif
 SRCS+=	ata_pmp.c
 
 EXPORT_SYMS=	YES	# XXX evaluate