Merge tag 'lkmm.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull memory model documentation updates from Paul McKenney:
 "This series contains documentation and litmus tests for locking,
  courtesy of Boqun Feng"

* tag 'lkmm.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  tools/memory-model: litmus: Add two tests for unlock(A)+lock(B) ordering
  tools/memory-model: doc: Describe the requirement of the litmus-tests directory
  tools/memory-model: Provide extra ordering for unlock+lock pair on the same CPU