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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75AFFC2D0A3 for ; Thu, 29 Oct 2020 19:14:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C4F62076D for ; Thu, 29 Oct 2020 19:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603998862; bh=AaxLCAvlykJcwyfRw1uBvXkJwNts8lBDG48WJp9AERM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=v1+xNoqIw5eF8k6Uc04HCHTEhu4JEQorzHmF3ZMd5XhuW6DDNF97CPSjXoU82XhQj pzjNeUi5l3Y0PR3jDr2r1siuR47Z1bCAJwcgAf9CI6jZFlbjiF/H6NPhrEdJ+X9hrB R3OnaTFTjQLhb81PvlCqIov86ZCrCHmdd26cW8uA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726112AbgJ2TOV (ORCPT ); Thu, 29 Oct 2020 15:14:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:45282 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726090AbgJ2TOR (ORCPT ); Thu, 29 Oct 2020 15:14:17 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4ABDD2075E; Thu, 29 Oct 2020 19:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603998856; bh=AaxLCAvlykJcwyfRw1uBvXkJwNts8lBDG48WJp9AERM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dAkc6u0GzjbuRskqcMqQi9k+sao6L/pecZUM3il8YPTGFix8ZGBwknOs00Y9dPDpx lBpd8bMOkcObLKPBwsrpaPUYPs/PhjeXJPUYJOdzx7J8KFuy0dKmRgYn1yCMA/hadU dyxakB4JZVAj0m2ksY9w5gYEBJpWD2lMiMleZog8= Date: Thu, 29 Oct 2020 20:15:05 +0100 From: Greg Kroah-Hartman To: Daniel Gutson Cc: Derek Kiernan , Tudor Ambarus , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Mika Westerberg , Arnd Bergmann , Mauro Carvalho Chehab , linux-kernel , Richard Hughes , Alex Bazhaniuk , linux-mtd Subject: Re: [PATCH] mtd: spi-nor: intel-spi: Split intel-spi reading from writing Message-ID: <20201029191505.GC986195@kroah.com> References: <20201028214359.384918-1-daniel.gutson@eclypsium.com> <20201029054110.GA3039992@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2020 at 12:39:08PM -0300, Daniel Gutson wrote: > On Thu, Oct 29, 2020 at 2:40 AM Greg Kroah-Hartman > wrote: > > > > On Wed, Oct 28, 2020 at 06:43:59PM -0300, Daniel Gutson wrote: > > > This patch separates the writing part of the intel-spi drivers > > > so the 'dangerous' part can be set/unset independently. > > > This way, the kernel can be configured to include the reading > > > parts of the driver which can be used without > > > the dangerous write operations that can turn the system > > > unbootable. > > > > > > Signed-off-by: Daniel Gutson > > > --- > > > drivers/mtd/spi-nor/controllers/Kconfig | 39 ++++++++++++--------- > > > drivers/mtd/spi-nor/controllers/intel-spi.c | 12 +++++-- > > > 2 files changed, 33 insertions(+), 18 deletions(-) > > > > > > diff --git a/drivers/mtd/spi-nor/controllers/Kconfig b/drivers/mtd/spi-nor/controllers/Kconfig > > > index 5c0e0ec2e6d1..491c755fea49 100644 > > > --- a/drivers/mtd/spi-nor/controllers/Kconfig > > > +++ b/drivers/mtd/spi-nor/controllers/Kconfig > > > @@ -31,34 +31,41 @@ config SPI_INTEL_SPI > > > tristate > > > > > > config SPI_INTEL_SPI_PCI > > > - tristate "Intel PCH/PCU SPI flash PCI driver (DANGEROUS)" > > > + tristate "Intel PCH/PCU SPI flash PCI driver" > > > depends on X86 && PCI > > > select SPI_INTEL_SPI > > > help > > > - This enables PCI support for the Intel PCH/PCU SPI controller in > > > - master mode. This controller is present in modern Intel hardware > > > - and is used to hold BIOS and other persistent settings. Using > > > - this driver it is possible to upgrade BIOS directly from Linux. > > > - > > > - Say N here unless you know what you are doing. Overwriting the > > > - SPI flash may render the system unbootable. > > > + This enables read only PCI support for the Intel PCH/PCU SPI > > > + controller in master mode. This controller is present in modern > > > + Intel hardware and is used to hold BIOS and other persistent settings. > > > + Using this driver it is possible to read the SPI chip directly > > > + from Linux. > > > > > > To compile this driver as a module, choose M here: the module > > > will be called intel-spi-pci. > > > > > > config SPI_INTEL_SPI_PLATFORM > > > - tristate "Intel PCH/PCU SPI flash platform driver (DANGEROUS)" > > > + tristate "Intel PCH/PCU SPI flash platform driver" > > > depends on X86 > > > select SPI_INTEL_SPI > > > help > > > - This enables platform support for the Intel PCH/PCU SPI > > > + This enables read only platform support for the Intel PCH/PCU SPI > > > controller in master mode. This controller is present in modern > > > - Intel hardware and is used to hold BIOS and other persistent > > > - settings. Using this driver it is possible to upgrade BIOS > > > - directly from Linux. > > > + Intel hardware and is used to hold BIOS and other persistent settings. > > > + Using this driver it is possible to read the SPI chip directly > > > + from Linux. > > > + > > > + To compile this driver as a module, choose M here: the module > > > + will be called intel-spi-pci. > > > + > > > +config SPI_INTEL_SPI_WRITE > > > + bool "Intel PCH/PCU SPI flash drivers write operations (DANGEROUS)" > > > + depends on SPI_INTEL_SPI_PCI || SPI_INTEL_SPI_PLATFORM > > > + help > > > + This enables full read/write support for the Intel PCH/PCU SPI > > > + controller. > > > + Using this option it may be possible to upgrade BIOS directly > > > + from Linux. > > > > > > Say N here unless you know what you are doing. Overwriting the > > > SPI flash may render the system unbootable. > > > - > > > - To compile this driver as a module, choose M here: the module > > > - will be called intel-spi-platform. > > > diff --git a/drivers/mtd/spi-nor/controllers/intel-spi.c b/drivers/mtd/spi-nor/controllers/intel-spi.c > > > index b54a56a68100..8d8053395c3d 100644 > > > --- a/drivers/mtd/spi-nor/controllers/intel-spi.c > > > +++ b/drivers/mtd/spi-nor/controllers/intel-spi.c > > > @@ -266,6 +266,7 @@ static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size) > > > return 0; > > > } > > > > > > +#ifdef CONFIG_SPI_INTEL_SPI_WRITE > > > > > > > > Please do not add #ifdef to .c files, that's not the proper kernel > > coding style at all, and just makes maintaining this file much much > > harder over time. > > > > Split things out into two different files if you really need to do this. > > What about the static functions that I'll need to turn non-static and > in a header file? > I mean, the functions that the functions in the new file will have to call. > Should I do that, turn static functions into non-static and declared > in a header file? No idea, but again, no #ifdefs in .c files like this, that is not the proper kernel coding style as it is not maintainable for the lifespan that we have to maintain code. thanks, greg k-h