From nobody Fri Nov 7 14:21:43 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1548183369858272.68578652143765; Tue, 22 Jan 2019 10:56:09 -0800 (PST) Received: from localhost ([127.0.0.1]:47308 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gm1DQ-000396-QD for importer@patchew.org; Tue, 22 Jan 2019 13:56:04 -0500 Received: from eggs.gnu.org ([209.51.188.92]:49070) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gm16r-0006Ew-Eu for qemu-devel@nongnu.org; Tue, 22 Jan 2019 13:49:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gm16n-0006ov-Ql for qemu-devel@nongnu.org; Tue, 22 Jan 2019 13:49:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44804) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gm16n-0006aw-EZ; Tue, 22 Jan 2019 13:49:13 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F2D3F811DE; Tue, 22 Jan 2019 12:51:41 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-215.ams2.redhat.com [10.36.117.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4131062524; Tue, 22 Jan 2019 12:51:40 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Tue, 22 Jan 2019 13:51:32 +0100 Message-Id: <20190122125133.1191-2-david@redhat.com> In-Reply-To: <20190122125133.1191-1-david@redhat.com> References: <20190122125133.1191-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 22 Jan 2019 12:51:42 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v1 1/2] s390x/pci: Fix primary bus number for PCI bridges X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , David Hildenbrand , Cornelia Huck , Collin Walling , Christian Borntraeger , qemu-s390x@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The primary bus number corresponds always to the bus number of the bus the bridge is attached to. Right now, if we have two bridges attached to the same bus (e.g. root bus) this is however not the case. Fix assignment. While at it - Add a comment why we have to reassign durign every reset (which I found to be supprising) - Drop setting the PCI_SUBORDINATE_BUS temporarily to 0xff. As we are setting it via a DFS and not via a BFS (as discussed e.g. in [1]), this is not necessary. The last number when we return is the highest number. Please note that hotplugging of bridges is in general still broken, will be fixed next. [1] http://www.science.unitn.it/~fiorella/guidelinux/tlk/node76.html Signed-off-by: David Hildenbrand Reviewed-by: Thomas Huth --- hw/s390x/s390-pci-bus.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index f017c1ded0..b7c4613fde 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -862,7 +862,8 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_d= ev, DeviceState *dev, qbus_set_hotplug_handler(bus, DEVICE(s), errp); =20 if (dev->hotplugged) { - pci_default_write_config(pdev, PCI_PRIMARY_BUS, s->bus_no, 1); + pci_default_write_config(pdev, PCI_PRIMARY_BUS, + pci_dev_bus_num(pdev), 1); s->bus_no +=3D 1; pci_default_write_config(pdev, PCI_SECONDARY_BUS, s->bus_no, 1= ); do { @@ -1016,8 +1017,6 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, void *opaque) { S390pciState *s =3D opaque; - unsigned int primary =3D s->bus_no; - unsigned int subordinate =3D 0xff; PCIBus *sec_bus =3D NULL; =20 if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) !=3D @@ -1026,7 +1025,7 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, } =20 (s->bus_no)++; - pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1); + pci_default_write_config(pdev, PCI_PRIMARY_BUS, pci_dev_bus_num(pdev),= 1); pci_default_write_config(pdev, PCI_SECONDARY_BUS, s->bus_no, 1); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, s->bus_no, 1); =20 @@ -1035,7 +1034,7 @@ static void s390_pci_enumerate_bridge(PCIBus *bus, PC= IDevice *pdev, return; } =20 - pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate, 1); + /* Assign numbers to all child bridges. The last is the highest number= . */ pci_for_each_device(sec_bus, pci_bus_num(sec_bus), s390_pci_enumerate_bridge, s); pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, s->bus_no, 1); @@ -1046,6 +1045,10 @@ static void s390_pcihost_reset(DeviceState *dev) S390pciState *s =3D S390_PCI_HOST_BRIDGE(dev); PCIBus *bus =3D s->parent_obj.bus; =20 + /* + * When resetting a PCI bridge, the assigned numbers are set to 0. So + * on every system reset, we also have to reassign numbers. + */ s->bus_no =3D 0; pci_for_each_device(bus, pci_bus_num(bus), s390_pci_enumerate_bridge, = s); } --=20 2.17.2