Merge tag 'lkmm.2023.02.15a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull LKMM (Linux Kernel Memory Model) updates from Paul McKenney:
 "Documentation updates.

  Add read-modify-write sequences, which means that stronger primitives
  more consistently result in stronger ordering, while still remaining
  in the envelope of the hardware that supports Linux.

  Address, data, and control dependencies used to ignore data that was
  stored in temporaries. This update extends these dependency chains to
  include unmarked intra-thread stores and loads. Note that these
  unmarked stores and loads should not be concurrently accessed from
  multiple threads, and doing so will cause LKMM to flag such accesses
  as data races"

* tag 'lkmm.2023.02.15a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  tools: memory-model: Make plain accesses carry dependencies
  Documentation: Fixed a typo in atomic_t.txt
  tools: memory-model: Add rmw-sequences to the LKMM
  locking/memory-barriers.txt: Improve documentation for writel() example

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/memory-model/linux-kernel.bell b/tools/memory-model/linux-kernel.bell
index 5be86b1025e8..70a9073dec3e 100644
--- a/tools/memory-model/linux-kernel.bell
+++ b/tools/memory-model/linux-kernel.bell
@@ -82,3 +82,9 @@ flag ~empty different-values(srcu-rscs) as srcu-bad-nesting
 let Marked = (~M) | IW | Once | Release | Acquire | domain(rmw) | range(rmw) |
 		LKR | LKW | UL | LF | RL | RU
 let Plain = M \ Marked
+
+(* Redefine dependencies to include those carried through plain accesses *)
+let carry-dep = (data ; rfi)*
+let addr = carry-dep ; addr
+let ctrl = carry-dep ; ctrl
+let data = carry-dep ; data