From owner-svn-src-all@freebsd.org Mon Aug 22 14:51:08 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6A5A8BC2758; Mon, 22 Aug 2016 14:51:08 +0000 (UTC) (envelope-from cem@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 mx1.freebsd.org (Postfix) with ESMTPS id 23730174E; Mon, 22 Aug 2016 14:51:08 +0000 (UTC) (envelope-from cem@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u7MEp7Dm072576; Mon, 22 Aug 2016 14:51:07 GMT (envelope-from cem@FreeBSD.org) Received: (from cem@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u7MEp7li072575; Mon, 22 Aug 2016 14:51:07 GMT (envelope-from cem@FreeBSD.org) Message-Id: <201608221451.u7MEp7li072575@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cem set sender to cem@FreeBSD.org using -f From: "Conrad E. Meyer" Date: Mon, 22 Aug 2016 14:51:07 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304602 - head/sys/dev/ioat X-SVN-Group: head 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: 2.1.22 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: Mon, 22 Aug 2016 14:51:08 -0000 Author: cem Date: Mon Aug 22 14:51:07 2016 New Revision: 304602 URL: https://svnweb.freebsd.org/changeset/base/304602 Log: ioat(4): Don't process events past queue head Fix a race where the completion routine could overrun the active ring area in some situations. Modified: head/sys/dev/ioat/ioat.c Modified: head/sys/dev/ioat/ioat.c ============================================================================== --- head/sys/dev/ioat/ioat.c Mon Aug 22 13:43:25 2016 (r304601) +++ head/sys/dev/ioat/ioat.c Mon Aug 22 14:51:07 2016 (r304602) @@ -678,19 +678,12 @@ ioat_process_events(struct ioat_softc *i } completed = 0; - comp_update = *ioat->comp_update; + comp_update = ioat_get_chansts(ioat); + CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx", + __func__, ioat->chan_idx, comp_update, ioat->last_seen); status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK; - if (status == ioat->last_seen) { - /* - * If we landed in process_events and nothing has been - * completed, check for a timeout due to channel halt. - */ - comp_update = ioat_get_chansts(ioat); - goto out; - } - - while (1) { + while (ioat_get_active(ioat) > 0) { desc = ioat_get_ring_entry(ioat, ioat->tail); dmadesc = &desc->bus_dmadesc; CTR4(KTR_IOAT, "channel=%u completing desc %u ok cb %p(%p)", @@ -704,17 +697,13 @@ ioat_process_events(struct ioat_softc *i ioat->tail++; if (desc->hw_desc_bus_addr == status) break; - - KASSERT(ioat_get_active(ioat) > 0, ("overrunning ring t:%u " - "h:%u st:0x%016lx last_seen:%016lx completed:%u\n", - ioat->tail, ioat->head, comp_update, ioat->last_seen, - completed)); } - ioat->last_seen = desc->hw_desc_bus_addr; - ioat->stats.descriptors_processed += completed; + if (completed != 0) { + ioat->last_seen = desc->hw_desc_bus_addr; + ioat->stats.descriptors_processed += completed; + } -out: ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN); /* Perform a racy check first; only take the locks if it passes. */