tools/memory-model/linux-kernel.bell

1 // SPDX-License-Identifier: GPL-2.0+
9  * "Frightening small children and disconcerting grown-ups: Concurrency
14 "Linux-kernel memory consistency model"
19 		'noreturn (* R of non-return RMW *)
28 		'rcu-lock (*rcu_read_lock*)  ||
29 		'rcu-unlock (*rcu_read_unlock*) ||
30 		'sync-rcu (*synchronize_rcu*) ||
31 		'before-atomic (*smp_mb__before_atomic*) ||
32 		'after-atomic (*smp_mb__after_atomic*) ||
33 		'after-spinlock (*smp_mb__after_spinlock*) ||
34 		'after-unlock-lock (*smp_mb__after_unlock_lock*) ||
35 		'after-srcu-read-unlock (*smp_mb__after_srcu_read_unlock*)
39 enum SRCU = 'srcu-lock || 'srcu-unlock || 'sync-srcu
42 let Srcu = Srcu-lock | Srcu-unlock | Sync-srcu
44 (* Compute matching pairs of nested Rcu-lock and Rcu-unlock *)
45 let rcu-rscs = let rec
46 	    unmatched-locks = Rcu-lock \ domain(matched)
47 	and unmatched-unlocks = Rcu-unlock \ range(matched)
48 	and unmatched = unmatched-locks | unmatched-unlocks
49 	and unmatched-po = [unmatched] ; po ; [unmatched]
50 	and unmatched-locks-to-unlocks =
51 		[unmatched-locks] ; po ; [unmatched-unlocks]
52 	and matched = matched | (unmatched-locks-to-unlocks \
53 		(unmatched-po ; unmatched-po))
57 flag ~empty Rcu-lock \ domain(rcu-rscs) as unmatched-rcu-lock
58 flag ~empty Rcu-unlock \ range(rcu-rscs) as unmatched-rcu-unlock
60 (* Compute matching pairs of nested Srcu-lock and Srcu-unlock *)
61 let carry-srcu-data = (data ; [~ Srcu-unlock] ; rf)*
62 let srcu-rscs = ([Srcu-lock] ; carry-srcu-data ; data ; [Srcu-unlock]) & loc
65 flag ~empty Srcu-lock \ domain(srcu-rscs) as unmatched-srcu-lock
66 flag ~empty Srcu-unlock \ range(srcu-rscs) as unmatched-srcu-unlock
67 flag ~empty (srcu-rscs^-1 ; srcu-rscs) \ id as multiple-srcu-matches
70 flag ~empty rcu-rscs & (po ; [Sync-srcu] ; po) as invalid-sleep
73 flag ~empty different-values(srcu-rscs) as srcu-bad-value-match
77 		LKR | LKW | UL | LF | RL | RU | Srcu-lock | Srcu-unlock
81 let carry-dep = (data ; [~ Srcu-unlock] ; rfi)*
82 let addr = carry-dep ; addr
83 let ctrl = carry-dep ; ctrl
84 let data = carry-dep ; data