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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 5BB32C433E1 for ; Fri, 21 Aug 2020 08:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 381B5214F1 for ; Fri, 21 Aug 2020 08:59:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20150623.gappssmtp.com header.i=@bgdev-pl.20150623.gappssmtp.com header.b="b0Bt5iII" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728179AbgHUI7e (ORCPT ); Fri, 21 Aug 2020 04:59:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726805AbgHUI7c (ORCPT ); Fri, 21 Aug 2020 04:59:32 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64F4CC061386 for ; Fri, 21 Aug 2020 01:59:31 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id g14so1040530iom.0 for ; Fri, 21 Aug 2020 01:59:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/0dxk+YAxU8AGUSVq8I4mdsBmmP3C22pS73+np6hl8U=; b=b0Bt5iIIABnBan/+FeypOshmjGN854M+FsnCjPSB93/mARJJbae1tfhKhTDKAlf2BR Y7V/EMRRZM3S46/1jcqWMfs0rPEgDZtGqEh73v8jpk7FtOQPS1dFWBmqVSOX80ViseRC SiCFTiG51XfWRxXOtBQJsbYTiFR+9F1f9Jqtvplv70dGOLyeV8/dhXJzKE+NGg1HLIeA LTT3UyGc7NsCj4q9UJZQ06pEqgUB/U7MFLwRem15MZWKMDsD9fEoWQ/tLJ5oOMug6h9a 5lWN55kd3V3bhFSEpm1JtDWp06QM+D4jagJI4NesOy8gYfIBy+LZkJ1oWuKJ1TAF6DLF k7QA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/0dxk+YAxU8AGUSVq8I4mdsBmmP3C22pS73+np6hl8U=; b=JhYoXPoTNmoix57c97LAiDcbVF5K6o0Stua8mEiz8R9kfmOEmNwjmy3gTiC7u7ch2G kXJUlt/aEbOKUtcv7vuh90Ky4g9zjNPHwSPMdVPmZ09roc6zgv4UL1/UxVtpotim+N8J ToR4rZgLcmo+rmh2nF6DkN1+ZzN/4l7lIPrNftFkbI6jJPtl4RUWuhl6OCb5ezJKiq9d o01DjId0mgKOejQAMB+pqpAUHuEH+t39hUQUXsC3b3P/gZQHD5jxXy+NDx8gXcfSYNz9 40cuWYWixByP6T0TgfzbxM6V7Z4Jv2BZ+yH5ehb7QJdxcLe5yCeR7PY7814YTniVqMYp Favg== X-Gm-Message-State: AOAM533xqLlcfsLGYmGT09MwUd+NnDMuyF8LuPlMCc74Xu5mA/1hXBnl s/St94hZozN5KyaegWw45Qh2G9Nv+UjaZxXpT8FtBQ== X-Google-Smtp-Source: ABdhPJxZMDfLVTuLtK0UKeNOHbpwzyh/MLQSbRYHKv4AYJ0os+C4fhkoB2hzOWyUFbN60IpBxRqSGZ3GGupzW5LQIWA= X-Received: by 2002:a5e:8f06:: with SMTP id c6mr1548343iok.119.1598000370739; Fri, 21 Aug 2020 01:59:30 -0700 (PDT) MIME-Version: 1.0 References: <20200820185110.17828-1-brgl@bgdev.pl> <20200820185110.17828-2-brgl@bgdev.pl> <20200821081555.GG1891694@smile.fi.intel.com> In-Reply-To: <20200821081555.GG1891694@smile.fi.intel.com> From: Bartosz Golaszewski Date: Fri, 21 Aug 2020 10:59:19 +0200 Message-ID: Subject: Re: [PATCH v8 1/3] devres: provide devm_krealloc() To: Andy Shevchenko Cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Michal Simek , Greg Kroah-Hartman , Guenter Roeck , linux-iio , Linux ARM , Linux Kernel Mailing List , Bartosz Golaszewski Content-Type: text/plain; charset="UTF-8" Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Fri, Aug 21, 2020 at 10:35 AM Andy Shevchenko wrote: > > On Thu, Aug 20, 2020 at 08:51:08PM +0200, Bartosz Golaszewski wrote: > > From: Bartosz Golaszewski > > > > Implement the managed variant of krealloc(). This function works with > > all memory allocated by devm_kmalloc() (or devres functions using it > > implicitly like devm_kmemdup(), devm_kstrdup() etc.). > > > > Managed realloc'ed chunks can be manually released with devm_kfree(). > > > > Signed-off-by: Bartosz Golaszewski > > Reviewed-by: Andy Shevchenko > > ... > > > +static struct devres *to_devres(void *data) > > +{ > > + return data - ALIGN(sizeof(struct devres), ARCH_KMALLOC_MINALIGN); > > +} > > + > > +static size_t devres_data_size(size_t total_size) > > +{ > > + return total_size - ALIGN(sizeof(struct devres), ARCH_KMALLOC_MINALIGN); > > +} > > I'm fine with above, but here is a side note, perhaps > > offsetof(struct devres, data) > > will be more practical (no duplication of alignment and hence slightly better > maintenance)? (Note, I didn't check if it provides the correct result) > Hi Andy, The data pointer in struct devres is defined as: u8 __aligned(ARCH_KMALLOC_MINALIGN) data[]; And this value (assigned the value of ARCH_DMA_MINALIGN) varies from one arch to another. I wasn't really sure if offsetof() would work for every case so I went with something very explicit. > Another side note: do we have existing users of these helpers? > Which ones? Because I assume you're not referring to the ones I'm adding in this patch. :) Bart