md: Factor out RAID6 algorithms into lib/

We'll want to use these in btrfs too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile
new file mode 100644
index 0000000..b2fe4ba
--- /dev/null
+++ b/lib/raid6/Makefile
@@ -0,0 +1,78 @@
+obj-$(CONFIG_RAID6_PQ)	+= raid6_pq.o
+
+raid6_pq-y	+= raid6algos.o raid6recov.o raid6tables.o \
+		   raid6int1.o raid6int2.o raid6int4.o \
+		   raid6int8.o raid6int16.o raid6int32.o \
+		   raid6altivec1.o raid6altivec2.o raid6altivec4.o \
+		   raid6altivec8.o \
+		   raid6mmx.o raid6sse1.o raid6sse2.o
+hostprogs-y	+= mktables
+
+quiet_cmd_unroll = UNROLL  $@
+      cmd_unroll = $(PERL) $(srctree)/$(src)/unroll.pl $(UNROLL) \
+                   < $< > $@ || ( rm -f $@ && exit 1 )
+
+ifeq ($(CONFIG_ALTIVEC),y)
+altivec_flags := -maltivec -mabi=altivec
+endif
+
+targets += raid6int1.c
+$(obj)/raid6int1.c:   UNROLL := 1
+$(obj)/raid6int1.c:   $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int2.c
+$(obj)/raid6int2.c:   UNROLL := 2
+$(obj)/raid6int2.c:   $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int4.c
+$(obj)/raid6int4.c:   UNROLL := 4
+$(obj)/raid6int4.c:   $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int8.c
+$(obj)/raid6int8.c:   UNROLL := 8
+$(obj)/raid6int8.c:   $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int16.c
+$(obj)/raid6int16.c:  UNROLL := 16
+$(obj)/raid6int16.c:  $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int32.c
+$(obj)/raid6int32.c:  UNROLL := 32
+$(obj)/raid6int32.c:  $(src)/raid6int.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec1.o += $(altivec_flags)
+targets += raid6altivec1.c
+$(obj)/raid6altivec1.c:   UNROLL := 1
+$(obj)/raid6altivec1.c:   $(src)/raid6altivec.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec2.o += $(altivec_flags)
+targets += raid6altivec2.c
+$(obj)/raid6altivec2.c:   UNROLL := 2
+$(obj)/raid6altivec2.c:   $(src)/raid6altivec.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec4.o += $(altivec_flags)
+targets += raid6altivec4.c
+$(obj)/raid6altivec4.c:   UNROLL := 4
+$(obj)/raid6altivec4.c:   $(src)/raid6altivec.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec8.o += $(altivec_flags)
+targets += raid6altivec8.c
+$(obj)/raid6altivec8.c:   UNROLL := 8
+$(obj)/raid6altivec8.c:   $(src)/raid6altivec.uc $(src)/unroll.pl FORCE
+	$(call if_changed,unroll)
+
+quiet_cmd_mktable = TABLE   $@
+      cmd_mktable = $(obj)/mktables > $@ || ( rm -f $@ && exit 1 )
+
+targets += raid6tables.c
+$(obj)/raid6tables.c: $(obj)/mktables FORCE
+	$(call if_changed,mktable)