From nobody Wed Sep 3 05:52:24 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4316AC38A2D for ; Mon, 24 Oct 2022 12:27:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233652AbiJXM1K (ORCPT ); Mon, 24 Oct 2022 08:27:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230439AbiJXM0o (ORCPT ); Mon, 24 Oct 2022 08:26:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E9D158EB5; Mon, 24 Oct 2022 05:00:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA22361291; Mon, 24 Oct 2022 11:58:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06E55C433D6; Mon, 24 Oct 2022 11:58:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666612690; bh=aOvtxZzoxLZvYMnqDsCHT9AR35HDLsRHaZZOOkdNEaQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wwkxBBdVYz6Gen91Jqhbiu0pv7glKyU0m+xuZEUjvhCKq6EYK2+sjt4eb6UsDqsMH DB4wxsteOIXrM1LlsPWL4dhwsUZpXqHAnk8t6ZHvBm5Ym6p7bNE0KY+cULLMkJuG22 KXXCLyd/AGKx/Tu5R71CceEBpS09IiPJPEW4VGGg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej W. Rozycki" , Bjorn Helgaas Subject: [PATCH 4.19 053/229] PCI: Sanitise firmware BAR assignments behind a PCI-PCI bridge Date: Mon, 24 Oct 2022 13:29:32 +0200 Message-Id: <20221024113000.792508891@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Maciej W. Rozycki commit 0e32818397426a688f598f35d3bc762eca6d7592 upstream. When pci_assign_resource() is unable to assign resources to a BAR, it uses pci_revert_fw_address() to fall back to a firmware assignment (if any). Previously pci_revert_fw_address() assumed all addresses could reach the device, but this is not true if the device is below a bridge that only forwards addresses within its windows. This problem was observed on a Tyan Tomcat IV S1564D system where the BIOS did not assign valid addresses to several bridges and USB devices: pci 0000:00:11.0: PCI-to-PCIe bridge to [bus 01-ff] pci 0000:00:11.0: bridge window [io 0xe000-0xefff] pci 0000:01:00.0: PCIe Upstream Port to [bus 02-ff] pci 0000:01:00.0: bridge window [io 0x0000-0x0fff] # unreachable pci 0000:02:02.0: PCIe Downstream Port to [bus 05-ff] pci 0000:02:02.0: bridge window [io 0x0000-0x0fff] # unreachable pci 0000:05:00.0: PCIe-to-PCI bridge to [bus 06-ff] pci 0000:05:00.0: bridge window [io 0x0000-0x0fff] # unreachable pci 0000:06:08.0: USB UHCI 1.1 pci 0000:06:08.0: BAR 4: [io 0xfce0-0xfcff] # unreachable pci 0000:06:08.1: USB UHCI 1.1 pci 0000:06:08.1: BAR 4: [io 0xfce0-0xfcff] # unreachable pci 0000:06:08.0: can't claim BAR 4 [io 0xfce0-0xfcff]: no compatible br= idge window pci 0000:06:08.1: can't claim BAR 4 [io 0xfce0-0xfcff]: no compatible br= idge window During the first pass of assigning unassigned resources, there was not enough I/O space available, so we couldn't assign the 06:08.0 BAR and reverted to the firmware assignment (still unreachable). Reverting the 06:08.1 assignment failed because it conflicted with 06:08.0: pci 0000:00:11.0: bridge window [io 0xe000-0xefff] pci 0000:01:00.0: no space for bridge window [io size 0x2000] pci 0000:02:02.0: no space for bridge window [io size 0x1000] pci 0000:05:00.0: no space for bridge window [io size 0x1000] pci 0000:06:08.0: BAR 4: no space for [io size 0x0020] pci 0000:06:08.0: BAR 4: trying firmware assignment [io 0xfce0-0xfcff] pci 0000:06:08.1: BAR 4: no space for [io size 0x0020] pci 0000:06:08.1: BAR 4: trying firmware assignment [io 0xfce0-0xfcff] pci 0000:06:08.1: BAR 4: [io 0xfce0-0xfcff] conflicts with 0000:06:08.0 = [io 0xfce0-0xfcff] A subsequent pass assigned valid bridge windows and a valid 06:08.1 BAR, but left the 06:08.0 BAR alone, so the UHCI device was still unusable: pci 0000:00:11.0: bridge window [io 0xe000-0xefff] released pci 0000:00:11.0: bridge window [io 0x1000-0x2fff] # reassigned pci 0000:01:00.0: bridge window [io 0x1000-0x2fff] # reassigned pci 0000:02:02.0: bridge window [io 0x2000-0x2fff] # reassigned pci 0000:05:00.0: bridge window [io 0x2000-0x2fff] # reassigned pci 0000:06:08.0: BAR 4: assigned [io 0xfce0-0xfcff] # left alone pci 0000:06:08.1: BAR 4: assigned [io 0x2000-0x201f] ... uhci_hcd 0000:06:08.0: host system error, PCI problems? uhci_hcd 0000:06:08.0: host controller process error, something bad happe= ned! uhci_hcd 0000:06:08.0: host controller halted, very bad! uhci_hcd 0000:06:08.0: HCRESET not completed yet! uhci_hcd 0000:06:08.0: HC died; cleaning up If the address assigned by firmware is not reachable because it's not within upstream bridge windows, fail instead of assigning the unusable address from firmware. [bhelgaas: commit log, use pci_upstream_bridge()] Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D16263 Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203012338460.46819@angie.o= rcam.me.uk Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209211921250.29493@angie.o= rcam.me.uk Fixes: 58c84eda0756 ("PCI: fall back to original BIOS BAR addresses") Signed-off-by: Maciej W. Rozycki Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v2.6.35+ Signed-off-by: Greg Kroah-Hartman --- drivers/pci/setup-res.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -209,6 +209,17 @@ static int pci_revert_fw_address(struct =20 root =3D pci_find_parent_resource(dev, res); if (!root) { + /* + * If dev is behind a bridge, accesses will only reach it + * if res is inside the relevant bridge window. + */ + if (pci_upstream_bridge(dev)) + return -ENXIO; + + /* + * On the root bus, assume the host bridge will forward + * everything. + */ if (res->flags & IORESOURCE_IO) root =3D &ioport_resource; else