From mboxrd@z Thu Jan 1 00:00:00 1970 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 9BA02C43334 for ; Fri, 17 Jun 2022 07:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbiFQHqk (ORCPT ); Fri, 17 Jun 2022 03:46:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229981AbiFQHqk (ORCPT ); Fri, 17 Jun 2022 03:46:40 -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 46B3D674F7 for ; Fri, 17 Jun 2022 00:46:39 -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 D741E61F68 for ; Fri, 17 Jun 2022 07:46:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E92F7C3411C; Fri, 17 Jun 2022 07:46:35 +0000 (UTC) From: Huacai Chen To: Bjorn Helgaas , Lorenzo Pieralisi , Rob Herring , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= Cc: linux-pci@vger.kernel.org, Jianmin Lv , Xuefeng Li , Huacai Chen , Jiaxun Yang , Huacai Chen Subject: [PATCH V14 4/7] PCI: loongson: Don't access non-existant devices Date: Fri, 17 Jun 2022 15:43:27 +0800 Message-Id: <20220617074330.12605-5-chenhuacai@loongson.cn> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220617074330.12605-1-chenhuacai@loongson.cn> References: <20220617074330.12605-1-chenhuacai@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On LS2K/LS7A, some non-existant devices don't return 0xffffffff when scanning. This is a hardware flaw but we can only avoid it by software now. Signed-off-by: Huacai Chen --- drivers/pci/controller/pci-loongson.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pci-loongson.c b/drivers/pci/controller/pci-loongson.c index a1222fc15454..e22142f75d97 100644 --- a/drivers/pci/controller/pci-loongson.c +++ b/drivers/pci/controller/pci-loongson.c @@ -134,10 +134,20 @@ static void __iomem *cfg0_map(struct loongson_pci *priv, int bus, return priv->cfg0_base + addroff; } +static bool pdev_is_existant(unsigned char bus, unsigned int device, unsigned int function) +{ + if ((bus == 0) && (device >= 9 && device <= 20) && (function > 0)) + return false; + + return true; +} + static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devfn, int where) { unsigned char busnum = bus->number; + unsigned int device = PCI_SLOT(devfn); + unsigned int function = PCI_FUNC(devfn); struct loongson_pci *priv = pci_bus_to_loongson_pci(bus); if (pci_is_root_bus(bus)) @@ -147,8 +157,13 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devf * Do not read more than one device on the bus other than * the host bus. */ - if (priv->data->flags & FLAG_DEV_FIX && - !pci_is_root_bus(bus) && PCI_SLOT(devfn) > 0) + if ((priv->data->flags & FLAG_DEV_FIX) && bus->self) { + if (!pci_is_root_bus(bus) && (device > 0)) + return NULL; + } + + /* Don't access non-existant devices */ + if (!pdev_is_existant(busnum, device, function)) return NULL; /* CFG0 can only access standard space */ -- 2.27.0