svn commit: r237693 - head/sys/dev/sio

[Warner Losh]

Author: imp
Date: Thu Jun 28 07:28:39 2012
New Revision: 237693
URL: http://svn.freebsd.org/changeset/base/237693

Log:
  Document some MP assumptions for sio.
  
  Submitted by:	bde (years ago)

Modified:
  head/sys/dev/sio/sio.c

Modified: head/sys/dev/sio/sio.c
==============================================================================
--- head/sys/dev/sio/sio.c	Thu Jun 28 07:26:44 2012	(r237692)
+++ head/sys/dev/sio/sio.c	Thu Jun 28 07:28:39 2012	(r237693)
@@ -278,6 +278,11 @@ static int	sio_inited;
 
 /* table and macro for fast conversion from a unit number to its com struct */
 devclass_t	sio_devclass;
+/*
+ * XXX Assmues that devclass_get_device, devclass_get_softc and
+ * device_get_softc are fast interrupt safe.  The current implementation
+ * of these functions are.
+ */
 #define	com_addr(unit)	((struct com_s *) \
 			 devclass_get_softc(sio_devclass, unit)) /* XXX */