mirror of https://gitee.com/openkylin/linux.git
144 lines
4.5 KiB
Plaintext
144 lines
4.5 KiB
Plaintext
// 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"
|
|
|
|
(*
|
|
* The lock-related events generated by herd7 are as follows:
|
|
*
|
|
* LKR Lock-Read: the read part of a spin_lock() or successful
|
|
* spin_trylock() read-modify-write event pair
|
|
* LKW Lock-Write: the write part of a spin_lock() or successful
|
|
* spin_trylock() RMW event pair
|
|
* UL Unlock: a spin_unlock() event
|
|
* LF Lock-Fail: a failed spin_trylock() event
|
|
* RL Read-Locked: a spin_is_locked() event which returns True
|
|
* RU Read-Unlocked: a spin_is_locked() event which returns False
|
|
*
|
|
* LKR and LKW events always come paired, like all RMW event sequences.
|
|
*
|
|
* LKR, LF, RL, and RU are read events; LKR has Acquire ordering.
|
|
* LKW and UL are write events; UL has Release ordering.
|
|
* LKW, LF, RL, and RU have no ordering properties.
|
|
*)
|
|
|
|
(* Backward compatibility *)
|
|
let RL = try RL with emptyset
|
|
let RU = try RU with emptyset
|
|
|
|
(* Treat RL as a kind of LF: a read with no ordering properties *)
|
|
let LF = LF | RL
|
|
|
|
(* There should be no ordinary R or W accesses to spinlocks *)
|
|
let ALL-LOCKS = LKR | LKW | UL | LF | RU
|
|
flag ~empty [M \ IW] ; loc ; [ALL-LOCKS] as mixed-lock-accesses
|
|
|
|
(* Link Lock-Reads to their RMW-partner Lock-Writes *)
|
|
let lk-rmw = ([LKR] ; po-loc ; [LKW]) \ (po ; po)
|
|
let rmw = rmw | lk-rmw
|
|
|
|
(* The litmus test is invalid if an LKR/LKW event is not part of an RMW pair *)
|
|
flag ~empty LKW \ range(lk-rmw) as unpaired-LKW
|
|
flag ~empty LKR \ domain(lk-rmw) as unpaired-LKR
|
|
|
|
(*
|
|
* An 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 ; [LKR]) \ (po-loc ; [UL] ; po-loc) as lock-nest
|
|
|
|
(* 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 | RU
|
|
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-lf = rfe-lf | rfi-lf
|
|
|
|
(*
|
|
* RU, i.e., spin_is_locked() returning False, is slightly different.
|
|
* We rely on the memory model to rule out cases where spin_is_locked()
|
|
* within one of the lock's critical sections returns False.
|
|
*)
|
|
|
|
(* rfi for RU events: an RU may read from the last po-previous UL *)
|
|
let rfi-ru = ([UL] ; po-loc ; [RU]) \ ([UL] ; po-loc ; [LKW] ; po-loc)
|
|
|
|
(* rfe for RU events: an RU may read from an external UL or the initial write *)
|
|
let all-possible-rfe-ru =
|
|
let possible-rfe-ru r =
|
|
let pair-to-relation p = p ++ 0
|
|
in map pair-to-relation (((UL | IW) * {r}) & loc & ext)
|
|
in map possible-rfe-ru RU
|
|
|
|
(* Generate all rf relations for RU events *)
|
|
with rfe-ru from cross(all-possible-rfe-ru)
|
|
let rf-ru = rfe-ru | rfi-ru
|
|
|
|
(* Final rf relation *)
|
|
let rf = rf | rf-lf | rf-ru
|
|
|
|
(* 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
|