1// SPDX-License-Identifier: GPL-2.0+ 2(* 3 * Copyright (C) 2015 Jade Alglave <j.alglave@ucl.ac.uk>, 4 * Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria 5 * Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>, 6 * Andrea Parri <parri.andrea@gmail.com> 7 * 8 * An earlier version of this file appears in the companion webpage for 9 * "Frightening small children and disconcerting grown-ups: Concurrency 10 * in the Linux kernel" by Alglave, Maranget, McKenney, Parri, and Stern, 11 * which is to appear in ASPLOS 2018. 12 *) 13 14"Linux-kernel memory consistency model" 15 16enum Accesses = 'once (*READ_ONCE,WRITE_ONCE,ACCESS_ONCE*) || 17 'release (*smp_store_release*) || 18 'acquire (*smp_load_acquire*) || 19 'noreturn (* R of non-return RMW *) 20instructions R[{'once,'acquire,'noreturn}] 21instructions W[{'once,'release}] 22instructions RMW[{'once,'acquire,'release}] 23 24enum Barriers = 'wmb (*smp_wmb*) || 25 'rmb (*smp_rmb*) || 26 'mb (*smp_mb*) || 27 'rcu-lock (*rcu_read_lock*) || 28 'rcu-unlock (*rcu_read_unlock*) || 29 'sync-rcu (*synchronize_rcu*) || 30 'before-atomic (*smp_mb__before_atomic*) || 31 'after-atomic (*smp_mb__after_atomic*) || 32 'after-spinlock (*smp_mb__after_spinlock*) 33instructions F[Barriers] 34 35(* Compute matching pairs of nested Rcu-lock and Rcu-unlock *) 36let matched = let rec 37 unmatched-locks = Rcu-lock \ domain(matched) 38 and unmatched-unlocks = Rcu-unlock \ range(matched) 39 and unmatched = unmatched-locks | unmatched-unlocks 40 and unmatched-po = [unmatched] ; po ; [unmatched] 41 and unmatched-locks-to-unlocks = 42 [unmatched-locks] ; po ; [unmatched-unlocks] 43 and matched = matched | (unmatched-locks-to-unlocks \ 44 (unmatched-po ; unmatched-po)) 45 in matched 46 47(* Validate nesting *) 48flag ~empty Rcu-lock \ domain(matched) as unbalanced-rcu-locking 49flag ~empty Rcu-unlock \ range(matched) as unbalanced-rcu-locking 50 51(* Outermost level of nesting only *) 52let crit = matched \ (po^-1 ; matched ; po^-1) 53