Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking changes from Ingo Molnar:
 "The biggest changes:

   - add lockdep support for seqcount/seqlocks structures, this
     unearthed both bugs and required extra annotation.

   - move the various kernel locking primitives to the new
     kernel/locking/ directory"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  block: Use u64_stats_init() to initialize seqcounts
  locking/lockdep: Mark __lockdep_count_forward_deps() as static
  lockdep/proc: Fix lock-time avg computation
  locking/doc: Update references to kernel/mutex.c
  ipv6: Fix possible ipv6 seqlock deadlock
  cpuset: Fix potential deadlock w/ set_mems_allowed
  seqcount: Add lockdep functionality to seqcount/seqlock structures
  net: Explicitly initialize u64_stats_sync structures for lockdep
  locking: Move the percpu-rwsem code to kernel/locking/
  locking: Move the lglocks code to kernel/locking/
  locking: Move the rwsem code to kernel/locking/
  locking: Move the rtmutex code to kernel/locking/
  locking: Move the semaphore core to kernel/locking/
  locking: Move the spinlock code to kernel/locking/
  locking: Move the lockdep code to kernel/locking/
  locking: Move the mutex code to kernel/locking/
  hung_task debugging: Add tracepoint to report the hang
  x86/locking/kconfig: Update paravirt spinlock Kconfig description
  lockstat: Report avg wait and hold times
  lockdep, x86/alternatives: Drop ancient lockdep fixup message
  ...

1 files changed, 89 insertions, 0 deletions

diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
new file mode 100644
index 0000000..86ae2ae
--- /dev/null
+++ b/kernel/locking/lglock.c
@@ -0,0 +1,89 @@
+/* See include/linux/lglock.h for description */
+#include <linux/module.h>
+#include <linux/lglock.h>
+#include <linux/cpu.h>
+#include <linux/string.h>
+
+/*
+ * Note there is no uninit, so lglocks cannot be defined in
+ * modules (but it's fine to use them from there)
+ * Could be added though, just undo lg_lock_init
+ */
+
+void lg_lock_init(struct lglock *lg, char *name)
+{
+	LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
+}
+EXPORT_SYMBOL(lg_lock_init);
+
+void lg_local_lock(struct lglock *lg)
+{
+	arch_spinlock_t *lock;
+
+	preempt_disable();
+	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+	lock = this_cpu_ptr(lg->lock);
+	arch_spin_lock(lock);
+}
+EXPORT_SYMBOL(lg_local_lock);
+
+void lg_local_unlock(struct lglock *lg)
+{
+	arch_spinlock_t *lock;
+
+	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
+	lock = this_cpu_ptr(lg->lock);
+	arch_spin_unlock(lock);
+	preempt_enable();
+}
+EXPORT_SYMBOL(lg_local_unlock);
+
+void lg_local_lock_cpu(struct lglock *lg, int cpu)
+{
+	arch_spinlock_t *lock;
+
+	preempt_disable();
+	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+	lock = per_cpu_ptr(lg->lock, cpu);
+	arch_spin_lock(lock);
+}
+EXPORT_SYMBOL(lg_local_lock_cpu);
+
+void lg_local_unlock_cpu(struct lglock *lg, int cpu)
+{
+	arch_spinlock_t *lock;
+
+	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
+	lock = per_cpu_ptr(lg->lock, cpu);
+	arch_spin_unlock(lock);
+	preempt_enable();
+}
+EXPORT_SYMBOL(lg_local_unlock_cpu);
+
+void lg_global_lock(struct lglock *lg)
+{
+	int i;
+
+	preempt_disable();
+	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+	for_each_possible_cpu(i) {
+		arch_spinlock_t *lock;
+		lock = per_cpu_ptr(lg->lock, i);
+		arch_spin_lock(lock);
+	}
+}
+EXPORT_SYMBOL(lg_global_lock);
+
+void lg_global_unlock(struct lglock *lg)
+{
+	int i;
+
+	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
+	for_each_possible_cpu(i) {
+		arch_spinlock_t *lock;
+		lock = per_cpu_ptr(lg->lock, i);
+		arch_spin_unlock(lock);
+	}
+	preempt_enable();
+}
+EXPORT_SYMBOL(lg_global_unlock);