Convert pcbinfo and inpcb mutexes to rwlocks, and modify macros to

explicitly select write locking for all use of the inpcb mutex.
Update some pcbinfo lock assertions to assert locked rather than
write-locked, although in practice almost all uses of the pcbinfo
rwlock main exclusive, and all instances of inpcb lock acquisition
are exclusive.

This change should introduce (ideally) little functional change.
However, it lays the groundwork for significantly increased
parallelism in the TCP/IP code.

MFC after:	3 months
Tested by:	kris (superset of committered patch)

1 files changed, 5 insertions, 5 deletions

diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index da114f1..f54e087 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -346,7 +346,7 @@ static struct witness_order_list_entry order_lists[] = {
 	/*
 	 * Multicast - protocol locks before interface locks, after UDP locks.
 	 */
-	{ "udpinp", &lock_class_mtx_sleep },
+	{ "udpinp", &lock_class_rw },
 	{ "in_multi_mtx", &lock_class_mtx_sleep },
 	{ "igmp_mtx", &lock_class_mtx_sleep },
 	{ "if_addr_mtx", &lock_class_mtx_sleep },
@@ -360,15 +360,15 @@ static struct witness_order_list_entry order_lists[] = {
 	/*
 	 * UDP/IP
 	 */
-	{ "udp", &lock_class_mtx_sleep },
-	{ "udpinp", &lock_class_mtx_sleep },
+	{ "udp", &lock_class_rw },
+	{ "udpinp", &lock_class_rw },
 	{ "so_snd", &lock_class_mtx_sleep },
 	{ NULL, NULL },
 	/*
 	 * TCP/IP
 	 */
-	{ "tcp", &lock_class_mtx_sleep },
-	{ "tcpinp", &lock_class_mtx_sleep },
+	{ "tcp", &lock_class_rw },
+	{ "tcpinp", &lock_class_rw },
 	{ "so_snd", &lock_class_mtx_sleep },
 	{ NULL, NULL },
 	/*