From owner-svn-src-all@freebsd.org Fri Jun 8 18:32:27 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A344DFD05E5; Fri, 8 Jun 2018 18:32:27 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 553596E8F8; Fri, 8 Jun 2018 18:32:27 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 37C1812C8C; Fri, 8 Jun 2018 18:32:27 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w58IWRB9024946; Fri, 8 Jun 2018 18:32:27 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w58IWRth024945; Fri, 8 Jun 2018 18:32:27 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201806081832.w58IWRth024945@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Fri, 8 Jun 2018 18:32:27 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r334851 - head/sys/arm64/arm64 X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/arm64/arm64 X-SVN-Commit-Revision: 334851 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jun 2018 18:32:27 -0000 Author: kib Date: Fri Jun 8 18:32:26 2018 New Revision: 334851 URL: https://svnweb.freebsd.org/changeset/base/334851 Log: Restore release semantic for the old thread unlock on arm64. With the introduction of pmap_switch(), the DSB instruction on the address map switch is not necessary executed, which is fixed by changing the unlock store to release. Also remove comment which documented pre-pmap_switch() code. Reviewed by: andrew Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/arm64/arm64/swtch.S Modified: head/sys/arm64/arm64/swtch.S ============================================================================== --- head/sys/arm64/arm64/swtch.S Fri Jun 8 18:24:46 2018 (r334850) +++ head/sys/arm64/arm64/swtch.S Fri Jun 8 18:32:26 2018 (r334851) @@ -165,10 +165,9 @@ ENTRY(cpu_switch) mov x0, x19 /* - * Release the old thread. This doesn't need to be a store-release - * as the above dsb instruction will provide release semantics. + * Release the old thread. */ - str x2, [x0, #TD_LOCK] + stlr x2, [x0, #TD_LOCK] #if defined(SCHED_ULE) && defined(SMP) /* Spin if TD_LOCK points to a blocked_lock */ ldr x2, =_C_LABEL(blocked_lock)