--- a/usr/src/uts/common/io/mac/mac.c	Fri Aug 07 15:12:49 2009 -0700
+++ b/usr/src/uts/common/io/mac/mac.c	Sat Aug 08 19:40:49 2009 -0700
@@ -417,11 +417,11 @@
 
 	/*
 	 * Allocate an id space to manage minor numbers. The range of the
-	 * space will be from MAC_MAX_MINOR+1 to MAXMIN32 (maximum legal
-	 * minor number is MAXMIN, but id_t is type of integer and does not
-	 * allow MAXMIN).
+	 * space will be from MAC_MAX_MINOR+1 to MAC_PRIVATE_MINOR-1.  This
+	 * leaves half of the 32-bit minors available for driver private use.
 	 */
-	minor_ids = id_space_create("mac_minor_ids", MAC_MAX_MINOR+1, MAXMIN32);
+	minor_ids = id_space_create("mac_minor_ids", MAC_MAX_MINOR+1,
+	    MAC_PRIVATE_MINOR-1);
 	ASSERT(minor_ids != NULL);
 	minor_count = 0;
 

--- a/usr/src/uts/common/sys/mac_provider.h	Fri Aug 07 15:12:49 2009 -0700
+++ b/usr/src/uts/common/sys/mac_provider.h	Sat Aug 08 19:40:49 2009 -0700
@@ -31,6 +31,7 @@
 #include <sys/ddi.h>
 #include <sys/sunddi.h>
 #include <sys/stream.h>
+#include <sys/mkdev.h>
 #include <sys/mac_flow.h>
 #include <sys/mac.h>
 
@@ -49,6 +50,19 @@
 #define	MAC_VERSION	0x2
 
 /*
+ * This is the first minor number available for MAC provider private
+ * use.  This makes it possible to deliver a driver that is both a MAC
+ * provider and a regular character/block device.  See PSARC 2009/380
+ * for more detail about the construction of such devices.  The value
+ * chosen leaves half of the 32-bit minor numbers (which are really
+ * only 18 bits wide) available for driver private use.  Drivers can
+ * easily identify their private number by the presence of this value
+ * in the bits that make up the minor number, since its just the
+ * highest bit available for such minor numbers.
+ */
+#define	MAC_PRIVATE_MINOR	((MAXMIN32 + 1) / 2)
+
+/*
  * Opaque handle types
  */
 typedef struct __mac_rule_handle	*mac_rule_handle_t;