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 A0A4BC001DE for ; Fri, 21 Jul 2023 17:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230518AbjGURWl (ORCPT ); Fri, 21 Jul 2023 13:22:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229452AbjGURWj (ORCPT ); Fri, 21 Jul 2023 13:22:39 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CF85113; Fri, 21 Jul 2023 10:22:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689960159; x=1721496159; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=us9CRrn80BeO09+83BBkmkXoBKksmGaBRjQFHkDWvhw=; b=QnROFwH2hmPaY6l0lpYWBLBg5PxPqBbfXVK/U8JMQZSOfJC4Q8tGMnOT GCrBtIUniNOnPpKgcl5uLXeoi/t9E1fffjrEToWJKNZRSVkH4BLk6TmS2 468snSWk0tp5lAfO3Hy7QZD+yDRqpCjQpD9NE9t/X5qXCh4gSnzPkISkm +RgBk2f3xIklDDQNIypySj2bgGjjuQNdTTGu2aJPCrnDJma04WQmDaiFx /LB7CGWmVJIaiVbXRX3af/ptfq2I80LibzbN3k8ao6KYzL9IzC3FKd4Ki CHCmo5cnvwaCI9ecSisAmA5ITkWqpZKBYzusNRcOqw6HgdeIJXyMgTM9+ A==; X-IronPort-AV: E=McAfee;i="6600,9927,10778"; a="397968049" X-IronPort-AV: E=Sophos;i="6.01,222,1684825200"; d="scan'208";a="397968049" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jul 2023 10:22:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10778"; a="898774970" X-IronPort-AV: E=Sophos;i="6.01,222,1684825200"; d="scan'208";a="898774970" Received: from smile.fi.intel.com ([10.237.72.54]) by orsmga005.jf.intel.com with ESMTP; 21 Jul 2023 10:22:37 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.96) (envelope-from ) id 1qMtpr-00ELGI-1d; Fri, 21 Jul 2023 20:22:35 +0300 Date: Fri, 21 Jul 2023 20:22:35 +0300 From: Andy Shevchenko To: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jonathan Cameron , Lars-Peter Clausen , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Nuno Sa Subject: Re: [PATCH v2 1/8] iio: core: Add opaque_struct_size() helper and use it Message-ID: References: <20230721170022.3461-1-andriy.shevchenko@linux.intel.com> <20230721170022.3461-2-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230721170022.3461-2-andriy.shevchenko@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 21, 2023 at 08:00:15PM +0300, Andy Shevchenko wrote: > Introduce opaque_struct_size() helper, which may be moved > to overflow.h in the future, and use it in the IIO core. ... > +#define opaque_struct_size(p, a, s) ({ \ > + size_t _psize = sizeof(*(p)); \ > + size_t _asize = ALIGN(_psize, (a)); \ > + size_t _ssize = s; \ > + _ssize ? size_add(_asize, _ssize) : _psize; \ > +}) > + > +#define opaque_struct_data(p, a) \ > + ((void *)(p) + ALIGN(sizeof(*(p)), (a))) Hmm... This can potentially evaluate p twice. Perhaps this variant is better: #define opaque_struct_data(p, a) ALIGN((p) + 1, (a))) Besides, I don't think we should worry about @s evaluation in the main macro which may be simplified to #define opaque_struct_size(p, a, s) \ ((s) ? size_add(ALIGN(sizeof(*(p)), (a)), (s)) : sizeof(*(p))) Thoughts? -- With Best Regards, Andy Shevchenko