MFC r268780

Nuke the never-used RF_TIMESHARE feature, reducing the complexity of the
code.  The consensus on arch@ is that this feature might have been useful
in the distant past, but is now just unnecessary bloat.

The int_rman_activate_resource() and int_rman_deactivate_resource()
functions become trivial, so manually inline them.

The special deferred handling of RF_ACTIVE is no longer needed in
reserve_resource_bound(), so eliminate the associated code at the
end of the function.

These changes reduce the object file size by more than 500 bytes on i386.

Update the rman.9 man page to reflect the removal of the RF_TIMESHARE
feature.

1 files changed, 10 insertions, 102 deletions

diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c
index cc41e29..568f566 100644
--- a/sys/kern/subr_rman.c
+++ b/sys/kern/subr_rman.c
@@ -110,9 +110,6 @@ static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
 
 struct rman_head rman_head;
 static struct mtx rman_mtx; /* mutex to protect rman_head */
-static int int_rman_activate_resource(struct rman *rm, struct resource_i *r,
-				       struct resource_i **whohas);
-static int int_rman_deactivate_resource(struct resource_i *r);
 static int int_rman_release_resource(struct rman *rm, struct resource_i *r);
 
 static __inline struct resource_i *
@@ -322,7 +319,7 @@ rman_adjust_resource(struct resource *rr, u_long start, u_long end)
 
 	/* Not supported for shared resources. */
 	r = rr->__r_i;
-	if (r->r_flags & (RF_TIMESHARE | RF_SHAREABLE))
+	if (r->r_flags & RF_SHAREABLE)
 		return (EINVAL);
 
 	/*
@@ -435,7 +432,7 @@ rman_adjust_resource(struct resource *rr, u_long start, u_long end)
 	return (0);
 }
 
-#define	SHARE_TYPE(f)	(f & (RF_SHAREABLE | RF_TIMESHARE | RF_PREFETCHABLE))
+#define	SHARE_TYPE(f)	(f & (RF_SHAREABLE | RF_PREFETCHABLE))
 
 struct resource *
 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
@@ -452,10 +449,9 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
 	       "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end,
 	       count, flags,
 	       dev == NULL ? "<null>" : device_get_nameunit(dev)));
-	KASSERT((flags & (RF_WANTED | RF_FIRSTSHARE)) == 0,
+	KASSERT((flags & RF_FIRSTSHARE) == 0,
 	    ("invalid flags %#x", flags));
-	new_rflags = (flags & ~(RF_ACTIVE | RF_WANTED | RF_FIRSTSHARE)) |
-	    RF_ALLOCATED;
+	new_rflags = (flags & ~RF_FIRSTSHARE) | RF_ALLOCATED;
 
 	mtx_lock(rm->rm_mtx);
 
@@ -601,7 +597,7 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
 	 * additional work, but this does not seem warranted.)
 	 */
 	DPRINTF(("no unshared regions found\n"));
-	if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
+	if ((flags & RF_SHAREABLE) == 0)
 		goto out;
 
 	for (s = r; s && s->r_end <= end; s = TAILQ_NEXT(s, r_link)) {
@@ -636,25 +632,11 @@ rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
 			goto out;
 		}
 	}
-
 	/*
 	 * We couldn't find anything.
 	 */
-out:
-	/*
-	 * If the user specified RF_ACTIVE in flags, we attempt to atomically
-	 * activate the resource.  If this fails, we release the resource
-	 * and indicate overall failure.  (This behavior probably doesn't
-	 * make sense for RF_TIMESHARE-type resources.)
-	 */
-	if (rv && (flags & RF_ACTIVE) != 0) {
-		struct resource_i *whohas;
-		if (int_rman_activate_resource(rm, rv, &whohas)) {
-			int_rman_release_resource(rm, rv);
-			rv = NULL;
-		}
-	}
 
+out:
 	mtx_unlock(rm->rm_mtx);
 	return (rv == NULL ? NULL : &rv->r_r);
 }
@@ -668,91 +650,17 @@ rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
 	    dev));
 }
 
-static int
-int_rman_activate_resource(struct rman *rm, struct resource_i *r,
-			   struct resource_i **whohas)
-{
-	struct resource_i *s;
-	int ok;
-
-	/*
-	 * If we are not timesharing, then there is nothing much to do.
-	 * If we already have the resource, then there is nothing at all to do.
-	 * If we are not on a sharing list with anybody else, then there is
-	 * little to do.
-	 */
-	if ((r->r_flags & RF_TIMESHARE) == 0
-	    || (r->r_flags & RF_ACTIVE) != 0
-	    || r->r_sharehead == NULL) {
-		r->r_flags |= RF_ACTIVE;
-		return 0;
-	}
-
-	ok = 1;
-	for (s = LIST_FIRST(r->r_sharehead); s && ok;
-	     s = LIST_NEXT(s, r_sharelink)) {
-		if ((s->r_flags & RF_ACTIVE) != 0) {
-			ok = 0;
-			*whohas = s;
-		}
-	}
-	if (ok) {
-		r->r_flags |= RF_ACTIVE;
-		return 0;
-	}
-	return EBUSY;
-}
-
 int
 rman_activate_resource(struct resource *re)
 {
-	int rv;
-	struct resource_i *r, *whohas;
+	struct resource_i *r;
 	struct rman *rm;
 
 	r = re->__r_i;
 	rm = r->r_rm;
 	mtx_lock(rm->rm_mtx);
-	rv = int_rman_activate_resource(rm, r, &whohas);
+	r->r_flags |= RF_ACTIVE;
 	mtx_unlock(rm->rm_mtx);
-	return rv;
-}
-
-int
-rman_await_resource(struct resource *re, int pri, int timo)
-{
-	int rv;
-	struct resource_i *r, *whohas;
-	struct rman *rm;
-
-	r = re->__r_i;
-	rm = r->r_rm;
-	mtx_lock(rm->rm_mtx);
-	for (;;) {
-		rv = int_rman_activate_resource(rm, r, &whohas);
-		if (rv != EBUSY)
-			return (rv);	/* returns with mutex held */
-
-		if (r->r_sharehead == NULL)
-			panic("rman_await_resource");
-		whohas->r_flags |= RF_WANTED;
-		rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
-		if (rv) {
-			mtx_unlock(rm->rm_mtx);
-			return (rv);
-		}
-	}
-}
-
-static int
-int_rman_deactivate_resource(struct resource_i *r)
-{
-
-	r->r_flags &= ~RF_ACTIVE;
-	if (r->r_flags & RF_WANTED) {
-		r->r_flags &= ~RF_WANTED;
-		wakeup(r->r_sharehead);
-	}
 	return 0;
 }
 
@@ -763,7 +671,7 @@ rman_deactivate_resource(struct resource *r)
 
 	rm = r->__r_i->r_rm;
 	mtx_lock(rm->rm_mtx);
-	int_rman_deactivate_resource(r->__r_i);
+	r->__r_i->r_flags &= ~RF_ACTIVE;
 	mtx_unlock(rm->rm_mtx);
 	return 0;
 }
@@ -774,7 +682,7 @@ int_rman_release_resource(struct rman *rm, struct resource_i *r)
 	struct resource_i *s, *t;
 
 	if (r->r_flags & RF_ACTIVE)
-		int_rman_deactivate_resource(r);
+		r->r_flags &= ~RF_ACTIVE;
 
 	/*
 	 * Check for a sharing list first.  If there is one, then we don't