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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-30 05:29:23 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-30 05:29:23 +0400
commit88502b9c0a5dcc884c0dbfb6ddf964ff5da5d8d3 (patch)
treef79f728c308100bc3e57d0d2f5d1e00d90406a0d /lib
parente18945b159a1cdbc031f1d3b0b7e515a33bdcbf7 (diff)
parent15c03dd4859ab16f9212238f29dd315654aa94f6 (diff)
downloadlinux-88502b9c0a5dcc884c0dbfb6ddf964ff5da5d8d3.tar.xz
Merge 3.12-rc3 into driver-core-next
We want the driver core and sysfs fixes in here to make merges and development easier. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/kobject.c5
-rw-r--r--lib/lockref.c23
2 files changed, 21 insertions, 7 deletions
diff --git a/lib/kobject.c b/lib/kobject.c
index a5a9b13b0648..151089788c21 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -1006,10 +1006,7 @@ const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
bool kobj_ns_current_may_mount(enum kobj_ns_type type)
{
- bool may_mount = false;
-
- if (type == KOBJ_NS_TYPE_NONE)
- return true;
+ bool may_mount = true;
spin_lock(&kobj_ns_type_lock);
if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
diff --git a/lib/lockref.c b/lib/lockref.c
index 677d036cf3c7..6f9d434c1521 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -4,6 +4,22 @@
#ifdef CONFIG_CMPXCHG_LOCKREF
/*
+ * Allow weakly-ordered memory architectures to provide barrier-less
+ * cmpxchg semantics for lockref updates.
+ */
+#ifndef cmpxchg64_relaxed
+# define cmpxchg64_relaxed cmpxchg64
+#endif
+
+/*
+ * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP.
+ * This is useful for architectures with an expensive cpu_relax().
+ */
+#ifndef arch_mutex_cpu_relax
+# define arch_mutex_cpu_relax() cpu_relax()
+#endif
+
+/*
* Note that the "cmpxchg()" reloads the "old" value for the
* failure case.
*/
@@ -14,12 +30,13 @@
while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) { \
struct lockref new = old, prev = old; \
CODE \
- old.lock_count = cmpxchg64(&lockref->lock_count, \
- old.lock_count, new.lock_count); \
+ old.lock_count = cmpxchg64_relaxed(&lockref->lock_count, \
+ old.lock_count, \
+ new.lock_count); \
if (likely(old.lock_count == prev.lock_count)) { \
SUCCESS; \
} \
- cpu_relax(); \
+ arch_mutex_cpu_relax(); \
} \
} while (0)