Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

5 files changed, 40 insertions, 55 deletions

diff --git a/sys/powerpc/aim/vm_machdep.c b/sys/powerpc/aim/vm_machdep.c
index 6d96337..851b1878 100644
--- a/sys/powerpc/aim/vm_machdep.c
+++ b/sys/powerpc/aim/vm_machdep.c
@@ -253,8 +253,8 @@ cpu_exit(p)
 {
 	alpha_fpstate_drop(p);
 
-	mtx_enter(&sched_lock, MTX_SPIN);
-	mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
+	mtx_lock_spin(&sched_lock);
+	mtx_unlock_flags(&Giant, MTX_NOSWITCH);
 	mtx_assert(&Giant, MA_NOTOWNED);
 
 	/*
@@ -437,7 +437,7 @@ vm_page_zero_idle()
 	if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count))
 		return(0);
 
-	if (mtx_try_enter(&Giant, MTX_DEF)) {
+	if (mtx_trylock(&Giant)) {
 		s = splvm();
 		m = vm_page_list_find(PQ_FREE, free_rover, FALSE);
 		zero_state = 0;
@@ -466,7 +466,7 @@ vm_page_zero_idle()
 		}
 		free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK;
 		splx(s);
-		mtx_exit(&Giant, MTX_DEF);
+		mtx_unlock(&Giant);
 		return (1);
 	}
 	return (0);
diff --git a/sys/powerpc/include/mutex.h b/sys/powerpc/include/mutex.h
index 40717b0..564ad19 100644
--- a/sys/powerpc/include/mutex.h
+++ b/sys/powerpc/include/mutex.h
@@ -39,26 +39,12 @@
 /*
  * Debugging
  */
-#ifdef MUTEX_DEBUG
-
-#ifdef _KERN_MUTEX_C_
-char STR_IEN[] = "ps & IPL == IPL_0";
-char STR_IDIS[] = "ps & IPL == IPL_HIGH";
-char STR_SIEN[] = "mpp->mtx_saveintr == IPL_0";
-#else	/* _KERN_MUTEX_C_ */
-extern char STR_IEN[];
-extern char STR_IDIS[];
-extern char STR_SIEN[];
-#endif	/* _KERN_MUTEX_C_ */
-
-#endif	/* MUTEX_DEBUG */
-
 #define	ASS_IEN		MPASS2((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK)	\
-			       == ALPHA_PSL_IPL_0, STR_IEN)
+			       == ALPHA_PSL_IPL_0, "ps & IPL == IPL_0")
 #define	ASS_IDIS	MPASS2((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK)	\
-			       == ALPHA_PSL_IPL_HIGH, STR_IDIS)
+			       == ALPHA_PSL_IPL_HIGH, "ps & IPL == IPL_HIGH")
 #define ASS_SIEN(mpp)	MPASS2((mpp)->mtx_saveintr \
-			       == ALPHA_PSL_IPL_0, STR_SIEN)
+			       == ALPHA_PSL_IPL_0, "mpp->mtx_saveintr == IPL_0")
 
 #define	mtx_legal2block()						\
 	((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK) == ALPHA_PSL_IPL_0)
@@ -68,34 +54,33 @@ extern char STR_SIEN[];
  *--------------------------------------------------------------------------
  */
 
-#ifdef _KERN_MUTEX_C_
-
-#define	_V(x)	__STRING(x)
-
 /*
- * Get a spin lock, handle recusion inline (as the less common case)
+ * Get a spin lock, handle recusion inline.
  */
-
-#define	_getlock_spin_block(mp, tid, type) do {				\
+#define _get_spin_lock(mp, tid, opts) do {				\
 	u_int _ipl = alpha_pal_swpipl(ALPHA_PSL_IPL_HIGH);		\
-	if (!_obtain_lock(mp, tid))					\
-		mtx_enter_hard(mp, (type) & MTX_HARDOPTS, _ipl);	\
-	else {								\
+	if (!_obtain_lock((mp), (tid))) {				\
+		if ((mp)->mtx_lock == (uintptr_t)(tid))			\
+			(mp)->mtx_recurse++;				\
+		else							\
+			_mtx_lock_spin((mp), (opts), _ipl, __FILE__,	\
+			    __LINE__);					\
+	} else {							\
 		alpha_mb();						\
 		(mp)->mtx_saveintr = _ipl;				\
 	}								\
 } while (0)
 
-#undef _V
-
-#endif	/* _KERN_MUTEX_C_ */
-
 #endif	/* _KERNEL */
 
 #else	/* !LOCORE */
 
 /*
  * Simple assembly macros to get and release non-recursive spin locks
+ *
+ * XXX: These are presently unused and cannot be used right now. Need to be
+ *	re-written (they are wrong). If you plan to use this and still see
+ *	this message, know not to unless you fix them first! :-)
  */
 #define MTX_ENTER(lck)				\
 	ldiq	a0, ALPHA_PSL_IPL_HIGH;		\
diff --git a/sys/powerpc/powerpc/mp_machdep.c b/sys/powerpc/powerpc/mp_machdep.c
index 20e16b9..6a46c28 100644
--- a/sys/powerpc/powerpc/mp_machdep.c
+++ b/sys/powerpc/powerpc/mp_machdep.c
@@ -150,7 +150,7 @@ void
 smp_init_secondary(void)
 {
 
-	mtx_enter(&Giant, MTX_DEF);
+	mtx_lock(&Giant);
 
 	printf("smp_init_secondary: called\n");
 	CTR0(KTR_SMP, "smp_init_secondary");
@@ -163,7 +163,7 @@ smp_init_secondary(void)
 		mp_ncpus = PCPU_GET(cpuno) + 1;
 	spl0();
 
-	mtx_exit(&Giant, MTX_DEF);
+	mtx_unlock(&Giant);
 }
 
 extern void smp_init_secondary_glue(void);
@@ -379,7 +379,7 @@ smp_rendezvous(void (* setup_func)(void *),
 {
 
 	/* obtain rendezvous lock */
-	mtx_enter(&smp_rv_mtx, MTX_SPIN);
+	mtx_lock_spin(&smp_rv_mtx);
 
 	/* set static function pointers */
 	smp_rv_setup_func = setup_func;
@@ -393,7 +393,7 @@ smp_rendezvous(void (* setup_func)(void *),
 	smp_rendezvous_action();
 
 	/* release lock */
-	mtx_exit(&smp_rv_mtx, MTX_SPIN);
+	mtx_unlock_spin(&smp_rv_mtx);
 }
 
 static u_int64_t
diff --git a/sys/powerpc/powerpc/procfs_machdep.c b/sys/powerpc/powerpc/procfs_machdep.c
index 229d2f9..c0766ca 100644
--- a/sys/powerpc/powerpc/procfs_machdep.c
+++ b/sys/powerpc/powerpc/procfs_machdep.c
@@ -86,12 +86,12 @@ procfs_read_regs(p, regs)
 	struct reg *regs;
 {
 
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if ((p->p_sflag & PS_INMEM) == 0) {
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		return (EIO);
 	}
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 	return (fill_regs(p, regs));
 }
 
@@ -101,12 +101,12 @@ procfs_write_regs(p, regs)
 	struct reg *regs;
 {
 
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if ((p->p_sflag & PS_INMEM) == 0) {
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		return (EIO);
 	}
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 	return (set_regs(p, regs));
 }
 
@@ -121,12 +121,12 @@ procfs_read_fpregs(p, fpregs)
 	struct fpreg *fpregs;
 {
 
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if ((p->p_sflag & PS_INMEM) == 0) {
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		return (EIO);
 	}
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 	return (fill_fpregs(p, fpregs));
 }
 
@@ -136,12 +136,12 @@ procfs_write_fpregs(p, fpregs)
 	struct fpreg *fpregs;
 {
 
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if ((p->p_sflag & PS_INMEM) == 0) {
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		return (EIO);
 	}
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 	return (set_fpregs(p, fpregs));
 }
 
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index 6d96337..851b1878 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -253,8 +253,8 @@ cpu_exit(p)
 {
 	alpha_fpstate_drop(p);
 
-	mtx_enter(&sched_lock, MTX_SPIN);
-	mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
+	mtx_lock_spin(&sched_lock);
+	mtx_unlock_flags(&Giant, MTX_NOSWITCH);
 	mtx_assert(&Giant, MA_NOTOWNED);
 
 	/*
@@ -437,7 +437,7 @@ vm_page_zero_idle()
 	if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count))
 		return(0);
 
-	if (mtx_try_enter(&Giant, MTX_DEF)) {
+	if (mtx_trylock(&Giant)) {
 		s = splvm();
 		m = vm_page_list_find(PQ_FREE, free_rover, FALSE);
 		zero_state = 0;
@@ -466,7 +466,7 @@ vm_page_zero_idle()
 		}
 		free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK;
 		splx(s);
-		mtx_exit(&Giant, MTX_DEF);
+		mtx_unlock(&Giant);
 		return (1);
 	}
 	return (0);