PERFORCE change 149717 for review

[Hans Petter Selasky]

http://perforce.freebsd.org/chv.cgi?CH=149717

Change 149717 by hselasky at hselasky_laptop001 on 2008/09/13 17:16:08

	
	Integrate some files because the problems I've tried to fix
	have been fixed. And the fixes are not inter compatible.
	That means you will get a panic with the P4 USB kernel
	unless you have this change included, after my last IFC.

Affected files ...

.. //depot/projects/usb/src/sys/kern/kern_condvar.c#9 integrate
.. //depot/projects/usb/src/sys/kern/kern_synch.c#12 integrate
.. //depot/projects/usb/src/sys/kern/subr_bus.c#12 integrate
.. //depot/projects/usb/src/sys/sys/mutex.h#9 integrate

Differences ...

==== //depot/projects/usb/src/sys/kern/kern_condvar.c#9 (text+ko) ====

@@ -124,7 +124,7 @@
 	sleepq_lock(cvp);
 
 	cvp->cv_waiters++;
-	DROP_GIANT(lock);
+	DROP_GIANT();
 
 	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
 	if (lock != &Giant.lock_object) {
@@ -183,7 +183,7 @@
 	sleepq_lock(cvp);
 
 	cvp->cv_waiters++;
-	DROP_GIANT(lock);
+	DROP_GIANT();
 
 	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
 	if (class->lc_flags & LC_SLEEPABLE)
@@ -241,7 +241,7 @@
 	sleepq_lock(cvp);
 
 	cvp->cv_waiters++;
-	DROP_GIANT(lock);
+	DROP_GIANT();
 
 	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
 	    SLEEPQ_INTERRUPTIBLE, 0);
@@ -306,7 +306,7 @@
 	sleepq_lock(cvp);
 
 	cvp->cv_waiters++;
-	DROP_GIANT(lock);
+	DROP_GIANT();
 
 	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
 	sleepq_set_timeout(cvp, timo);
@@ -374,7 +374,7 @@
 	sleepq_lock(cvp);
 
 	cvp->cv_waiters++;
-	DROP_GIANT(lock);
+	DROP_GIANT();
 
 	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
 	    SLEEPQ_INTERRUPTIBLE, 0);

==== //depot/projects/usb/src/sys/kern/kern_synch.c#12 (text+ko) ====

@@ -181,7 +181,7 @@
 	CTR5(KTR_PROC, "sleep: thread %ld (pid %ld, %s) on %s (%p)",
 	    td->td_tid, p->p_pid, td->td_name, wmesg, ident);
 
-	DROP_GIANT(lock);
+	DROP_GIANT();
 	if (lock != NULL && lock != &Giant.lock_object &&
 	    !(class->lc_flags & LC_SLEEPABLE)) {
 		WITNESS_SAVE(lock, lock_witness);

==== //depot/projects/usb/src/sys/kern/subr_bus.c#12 (text+ko) ====


==== //depot/projects/usb/src/sys/sys/mutex.h#9 (text+ko) ====

@@ -366,44 +366,17 @@
  *
  * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() 
  * The #ifndef is to allow lint-like tools to redefine DROP_GIANT.
- *
- * Note that by default DROP_GIANT takes no argument. Optionally you
- * can specify an argument which explicitly has the name "lock" and
- * type "struct lock_object *". If this "lock" pointer is equal to
- * "&Giant", the DROP_GIANT macro will not do the final drop on the
- * Giant mutex, but expects the calling code to do so. This feature is
- * used by condition variables to allow sleeping on Giant. The
- * condition variable code will then do the final drop!
  */
 #ifndef DROP_GIANT
-#define	DROP_GIANT(arg) DROP_GIANT_SUB_##arg(arg)
-#define	DROP_GIANT_SUB_lock(arg) DROP_GIANT_SUB(arg) /* "lock" argument */
-#define	DROP_GIANT_SUB_(arg) DROP_GIANT_SUB(NULL) /* no argument */
-#define	DROP_GIANT_SUB(lock)						\
+#define DROP_GIANT()							\
 do {									\
-	unsigned int _giantcnt;						\
+	int _giantcnt = 0;						\
 	WITNESS_SAVE_DECL(Giant);					\
 									\
 	if (mtx_owned(&Giant)) {					\
-		unsigned int _giantn;					\
-		if (((void *)(lock)) == ((void *)&Giant)) {		\
-			/* special case */				\
-			_giantn = Giant.mtx_recurse;			\
-		} else {						\
-			/* default case */				\
-			_giantn = Giant.mtx_recurse + 1;		\
-		}							\
-		if (_giantn != 0) {					\
-			WITNESS_SAVE(&Giant.lock_object, Giant);	\
-			_giantcnt = _giantn;				\
-			do {						\
-				mtx_unlock(&Giant);			\
-			} while (--_giantn);				\
-		} else {						\
-			_giantcnt = 0;					\
-		}							\
-	} else {							\
-		_giantcnt = 0;						\
+		WITNESS_SAVE(&Giant.lock_object, Giant);		\
+		for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++)	\
+			mtx_unlock(&Giant);				\
 	}
 
 #define PICKUP_GIANT()							\