Index: head/sys/modules/crypto/Makefile
===================================================================
--- head/sys/modules/crypto/Makefile	(revision 366595)
+++ head/sys/modules/crypto/Makefile	(revision 366596)
@@ -1,73 +1,77 @@
 # $FreeBSD$
 
 LIBSODIUM=${SRCTOP}/sys/contrib/libsodium/src/libsodium
 
 .PATH:	${SRCTOP}/sys/opencrypto
 .PATH:	${SRCTOP}/sys/crypto
 .PATH:	${SRCTOP}/sys/crypto/camellia
 .PATH:	${SRCTOP}/sys/crypto/des
 .PATH:	${SRCTOP}/sys/crypto/rijndael
 .PATH:	${SRCTOP}/sys/crypto/sha2
 .PATH:	${SRCTOP}/sys/crypto/siphash
 .PATH:	${SRCTOP}/sys/crypto/skein
 .PATH:	${SRCTOP}/sys/crypto/blake2
 .PATH:	${SRCTOP}/sys/crypto/chacha20
 .PATH:	${SRCTOP}/sys/contrib/libb2
 .PATH:	${LIBSODIUM}/crypto_onetimeauth/poly1305
 .PATH:	${LIBSODIUM}/crypto_onetimeauth/poly1305/donna
 .PATH:	${LIBSODIUM}/crypto_verify/sodium
 .PATH:	${SRCTOP}/sys/crypto/libsodium
 
 KMOD	= crypto
 SRCS	= crypto.c cryptodev_if.c
 SRCS	+= criov.c cryptosoft.c xform.c
 SRCS	+= cryptodeflate.c rmd160.c rijndael-alg-fst.c rijndael-api.c rijndael-api-fst.c
 SRCS	+= camellia.c camellia-api.c
 SRCS	+= des_ecb.c des_enc.c des_setkey.c
 SRCS	+= sha1.c sha256c.c sha512c.c
 SRCS	+= skein.c skein_block.c
 # unroll the 256 and 512 loops, half unroll the 1024
 CFLAGS.skein_block.c	+= -DSKEIN_LOOP=995
-#.if exists(${MACHINE_ARCH}/skein_block_asm.S)
-#.PATH:	${SRCTOP}/sys/crypto/skein/${MACHINE_ARCH}
-#SRCS	+= skein_block_asm.S
-#CFLAGS	+= -DSKEIN_ASM -DSKEIN_USE_ASM=1792 # list of block functions to replace with assembly: 256+512+1024 = 1792
-#ACFLAGS	+= -DELF -Wa,--noexecstack
-## Fully unroll all loops in the assembly optimized version
-#ACFLAGS	+= -DSKEIN_LOOP=0
-#.endif
+.if exists(${MACHINE_ARCH}/skein_block_asm.S)
+.PATH:	${SRCTOP}/sys/crypto/skein/${MACHINE_ARCH}
+SRCS	+= skein_block_asm.S
+CFLAGS	+= -DSKEIN_ASM -DSKEIN_USE_ASM=1792 # list of block functions to replace with assembly: 256+512+1024 = 1792
+ACFLAGS	+= -DELF -Wa,--noexecstack
+# Fully unroll all loops in the assembly optimized version
+ACFLAGS	+= -DSKEIN_LOOP=0
+# 20201002 Add explict Makefile dependency for reenabled assembly optimized
+# version. SKEIN_USE_ASM determines which routines should come from the assembly
+# vs C versions, and skein_block needs to be rebuilt if it changes.
+skein_block.o: Makefile
+.endif
 SRCS	+= siphash.c
 SRCS	+= gmac.c gfmult.c
 SRCS	+= blake2b-ref.c
 SRCS	+= blake2s-ref.c
 SRCS	+= blake2-sw.c
 CFLAGS.blake2b-ref.c	+= -I${SRCTOP}/sys/crypto/blake2 -DSUFFIX=_ref
 CFLAGS.blake2s-ref.c	+= -I${SRCTOP}/sys/crypto/blake2 -DSUFFIX=_ref
 CFLAGS.blake2-sw.c	+= -I${SRCTOP}/sys/crypto/blake2
 CWARNFLAGS.blake2b-ref.c	+= -Wno-cast-qual -Wno-unused-function
 CWARNFLAGS.blake2s-ref.c	+= -Wno-cast-qual -Wno-unused-function
 SRCS	+= chacha.c
 SRCS	+= chacha-sw.c
 
 LIBSODIUM_INC=${LIBSODIUM}/include
 LIBSODIUM_COMPAT=${SRCTOP}/sys/crypto/libsodium
 SRCS	+= xform_poly1305.c
 CFLAGS.xform_poly1305.c		+= -I${LIBSODIUM_INC} -I${LIBSODIUM_COMPAT}
 SRCS	+= onetimeauth_poly1305.c
 CFLAGS.onetimeauth_poly1305.c	+= -I${LIBSODIUM_INC}/sodium -I${LIBSODIUM_COMPAT}
 SRCS	+= poly1305_donna.c
 CFLAGS.poly1305_donna.c		+= -I${LIBSODIUM_INC}/sodium -I${LIBSODIUM_COMPAT}
 SRCS	+= verify.c
 CFLAGS.verify.c			+= -I${LIBSODIUM_INC}/sodium -I${LIBSODIUM_COMPAT}
 SRCS	+= randombytes.c
 CFLAGS.randombytes.c		+= -I${LIBSODIUM_INC} -I${LIBSODIUM_COMPAT}
 SRCS	+= utils.c
 CFLAGS.utils.c			+= -I${LIBSODIUM_INC} -I${LIBSODIUM_COMPAT}
 
 SRCS	+= opt_param.h cryptodev_if.h bus_if.h device_if.h
 SRCS	+= opt_compat.h
 SRCS	+= opt_ddb.h
 SRCS	+= cbc_mac.c
 SRCS	+= xform_cbc_mac.c
 
 .include <bsd.kmod.mk>