summaryrefslogtreecommitdiff
path: root/tools/memory-model/lock.cat
diff options
context:
space:
mode:
Diffstat (limited to 'tools/memory-model/lock.cat')
-rw-r--r--tools/memory-model/lock.cat99
1 files changed, 99 insertions, 0 deletions
diff --git a/tools/memory-model/lock.cat b/tools/memory-model/lock.cat
new file mode 100644
index 000000000000..ba4a4ec6d313
--- /dev/null
+++ b/tools/memory-model/lock.cat
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0+
+(*
+ * Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria
+ * Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>
+ *)
+
+(* Generate coherence orders and handle lock operations *)
+
+include "cross.cat"
+
+(* From lock reads to their partner lock writes *)
+let lk-rmw = ([LKR] ; po-loc ; [LKW]) \ (po ; po)
+let rmw = rmw | lk-rmw
+
+(*
+ * A paired LKR must always see an unlocked value; spin_lock() calls nested
+ * inside a critical section (for the same lock) always deadlock.
+ *)
+empty ([LKW] ; po-loc ; [domain(lk-rmw)]) \ (po-loc ; [UL] ; po-loc)
+ as lock-nest
+
+(* The litmus test is invalid if an LKW event is not part of an RMW pair *)
+flag ~empty LKW \ range(lk-rmw) as unpaired-LKW
+
+(* This will be allowed if we implement spin_is_locked() *)
+flag ~empty LKR \ domain(lk-rmw) as unpaired-LKR
+
+(* There should be no R or W accesses to spinlocks *)
+let ALL-LOCKS = LKR | LKW | UL | LF
+flag ~empty [M \ IW] ; loc ; [ALL-LOCKS] as mixed-lock-accesses
+
+(* The final value of a spinlock should not be tested *)
+flag ~empty [FW] ; loc ; [ALL-LOCKS] as lock-final
+
+
+(*
+ * Put lock operations in their appropriate classes, but leave UL out of W
+ * until after the co relation has been generated.
+ *)
+let R = R | LKR | LF
+let W = W | LKW
+
+let Release = Release | UL
+let Acquire = Acquire | LKR
+
+
+(* Match LKW events to their corresponding UL events *)
+let critical = ([LKW] ; po-loc ; [UL]) \ (po-loc ; [LKW | UL] ; po-loc)
+
+flag ~empty UL \ range(critical) as unmatched-unlock
+
+(* Allow up to one unmatched LKW per location; more must deadlock *)
+let UNMATCHED-LKW = LKW \ domain(critical)
+empty ([UNMATCHED-LKW] ; loc ; [UNMATCHED-LKW]) \ id as unmatched-locks
+
+
+(* rfi for LF events: link each LKW to the LF events in its critical section *)
+let rfi-lf = ([LKW] ; po-loc ; [LF]) \ ([LKW] ; po-loc ; [UL] ; po-loc)
+
+(* rfe for LF events *)
+let all-possible-rfe-lf =
+ (*
+ * Given an LF event r, compute the possible rfe edges for that event
+ * (all those starting from LKW events in other threads),
+ * and then convert that relation to a set of single-edge relations.
+ *)
+ let possible-rfe-lf r =
+ let pair-to-relation p = p ++ 0
+ in map pair-to-relation ((LKW * {r}) & loc & ext)
+ (* Do this for each LF event r that isn't in rfi-lf *)
+ in map possible-rfe-lf (LF \ range(rfi-lf))
+
+(* Generate all rf relations for LF events *)
+with rfe-lf from cross(all-possible-rfe-lf)
+let rf = rf | rfi-lf | rfe-lf
+
+
+(* Generate all co relations, including LKW events but not UL *)
+let co0 = co0 | ([IW] ; loc ; [LKW]) |
+ (([LKW] ; loc ; [UNMATCHED-LKW]) \ [UNMATCHED-LKW])
+include "cos-opt.cat"
+let W = W | UL
+let M = R | W
+
+(* Merge UL events into co *)
+let co = (co | critical | (critical^-1 ; co))+
+let coe = co & ext
+let coi = co & int
+
+(* Merge LKR events into rf *)
+let rf = rf | ([IW | UL] ; singlestep(co) ; lk-rmw^-1)
+let rfe = rf & ext
+let rfi = rf & int
+
+let fr = rf^-1 ; co
+let fre = fr & ext
+let fri = fr & int
+
+show co,rf,fr