this is a backport of commit 7aa54be297655 ("locking/qspinlock, x86: Provide liveness guarantee") for the v4.19 stable tree.
Initially I assumed that this was merged late in v4.19-rc but actually it is just part v4.20-rc1.
For v4.19, most things are already in the tree. The GEN_BINARY_RMWcc macro is still "old" and I skipped the documentation update.
Sebastian