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 70D9BC433F5 for ; Thu, 16 Dec 2021 00:22:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229917AbhLPAWC (ORCPT ); Wed, 15 Dec 2021 19:22:02 -0500 Received: from mail-wr1-f44.google.com ([209.85.221.44]:46895 "EHLO mail-wr1-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbhLPAWB (ORCPT ); Wed, 15 Dec 2021 19:22:01 -0500 Received: by mail-wr1-f44.google.com with SMTP id i22so11227262wrb.13; Wed, 15 Dec 2021 16:22:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=5WVeXX6wF7Rq2S+DCKKRBlsrDqOKaYzTtLcyOXsKktU=; b=71Fyb9Y2z5XfTVJQkLUZsQI6fw/2m6QPaR9OedB+1Hr3Ab/CKeqRfoPXJLd7r/D1mr ble9h5LzXogAB0LexPnfwPf9BEW+h/jwIj+hDiJrC6eT1gs5JQzV6uRAo3t9YlT7Hl1I KpYbV/gxVMaZWuH31q/8Uk+cEfLyCnjOVEWJ1NS6D9EtOrh6om2YlS9r2vmcZ8p33s5H M04hA7Nv0dDHDmbgWPeG91xxeRiT99iw5IXpuWB1v2zuvmYQxojZyJlkduN/B1+xrjf2 dxH6OfeHUJ/N/wcXUpE4HM2WxFItnlF01wEVgAbOU8DsAFdCNyVkwbrKxO3NqnNoTyey mjqA== X-Gm-Message-State: AOAM532WDvGT0LBymqSmZ6h2EDxjfKKPaiWMlUj8bgBsxHszqrE1qk8k pfXIVuo980YZqDOb2+BzSOQ= X-Google-Smtp-Source: ABdhPJxLZqT3HVtWQiBLR32v2gzej5zHFQfgYEBY+Q1JCFyIlLTVOST7lpHyp2N5Yf05rj757fhaTw== X-Received: by 2002:a5d:59af:: with SMTP id p15mr6457665wrr.561.1639614120352; Wed, 15 Dec 2021 16:22:00 -0800 (PST) Received: from rocinante ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id g13sm3932678wri.102.2021.12.15.16.21.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Dec 2021 16:21:59 -0800 (PST) Date: Thu, 16 Dec 2021 01:21:58 +0100 From: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= To: =?utf-8?Q?Micha=C5=82?= Winiarski Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas , Christian =?utf-8?B?S8O2bmln?= , Ard Biesheuvel , "Michael J . Ruhl" , Rodrigo Vivi Subject: Re: [PATCH 1/2] PCI: Add support for VF Resizable Bar extended cap Message-ID: References: <20211215141626.3090807-1-michal.winiarski@intel.com> <20211215141626.3090807-2-michal.winiarski@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20211215141626.3090807-2-michal.winiarski@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Michał, [...] > +static int pci_memory_decoding(struct pci_dev *dev) > +{ > + u16 cmd; > + > + pci_read_config_word(dev, PCI_COMMAND, &cmd); > + if (cmd & PCI_COMMAND_MEMORY) > + return -EBUSY; > + > + return 0; > +} > + > +#ifdef CONFIG_PCI_IOV > +static int pci_vf_memory_decoding(struct pci_dev *dev) > +{ > + u16 cmd; > + > + pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd); > + if (cmd & PCI_SRIOV_CTRL_MSE) > + return -EBUSY; > + > + return 0; > +} > +#endif > + > int pci_resize_resource(struct pci_dev *dev, int resno, int size) > { > struct resource *res = dev->resource + resno; > struct pci_host_bridge *host; > int old, ret; > u32 sizes; > - u16 cmd; > > /* Check if we must preserve the firmware's resource assignment */ > host = pci_find_host_bridge(dev->bus); > @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size) > if (!(res->flags & IORESOURCE_UNSET)) > return -EBUSY; > > - pci_read_config_word(dev, PCI_COMMAND, &cmd); > - if (cmd & PCI_COMMAND_MEMORY) > - return -EBUSY; > +#ifdef CONFIG_PCI_IOV > + if (resno >= PCI_IOV_RESOURCES) > + ret = pci_vf_memory_decoding(dev); > + else > +#endif > + ret = pci_memory_decoding(dev); > + if (ret) > + return ret; The above else works, however, it does trip our static analysis tools, and lack of the indentation makes it slightly confusing to read, at least at the first glance. Thus, I wonder whether it would be possible to combine the pci_vf_memory_decoding() and pci_memory_decoding() somehow neatly into a private helper that takes a boolean to indicate whether it's a VF or not. Then, we could drop the if-statement, since some of the logic could live within the helper. What do you think? Krzysztof