Merge all MD sf_buf allocators into one MI, residing in kern/subr_sfbuf.c

The MD allocators were very common, however there were some minor
differencies. These differencies were all consolidated in the MI allocator,
under ifdefs. The defines from machine/vmparam.h turn on features required
for a particular machine. For details look in the comment in sys/sf_buf.h.

As result no MD code left in sys/*/*/vm_machdep.c. Some arches still have
machine/sf_buf.h, which is usually quite small.

Tested by:	glebius (i386), tuexen (arm32), kevlo (arm32)
Reviewed by:	kib
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/mips/include/vmparam.h b/sys/mips/include/vmparam.h
index 8922924faa76..d3b833ebd4a8 100644
--- a/sys/mips/include/vmparam.h
+++ b/sys/mips/include/vmparam.h
@@ -187,4 +187,8 @@
 
 #define	ZERO_REGION_SIZE	(64 * 1024)	/* 64KB */
 
+#ifndef __mips_n64
+#define	SFBUF
+#endif
+
 #endif /* !_MACHINE_VMPARAM_H_ */