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 A59B5C433EF for ; Wed, 9 Feb 2022 06:43:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233909AbiBIGnM (ORCPT ); Wed, 9 Feb 2022 01:43:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232439AbiBIGnK (ORCPT ); Wed, 9 Feb 2022 01:43:10 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12898C043181 for ; Tue, 8 Feb 2022 22:43:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644388994; x=1675924994; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=zlXbUZz2vYoVlpMq7pYN1eHaPofiuIFPWABuJTqRbIw=; b=HIUFe8zzzKbvUGf45gvki5l/bqjNZqukZ43ID2+NL4ITeiOldF8+Ve10 NGHX6uVbppyiBaEtRzLLVGLotlreH63PIj+MuGFhOABehhUZMflRpECOu ssK3G3RKhDU5cZsbHkvuA0eq4OaD8IadKMbUFNUtEeqO9DQqbcePcgIGT Jls3TIM8sYJouga6D9+3d6E0hOYWd01dADr+Y4wKEHCxS1qfjswHmqxk4 fi/beDLIBSbtcWpnZWzq0g2ER1ixkIZm0CUDg1GMoZZgziNgrNgVtF8C5 Of4Xec50gulRKDh/cIuQD/1JO5njY/8mzIqBsgFUFoP4FldWukNsN76d1 A==; X-IronPort-AV: E=McAfee;i="6200,9189,10252"; a="249342332" X-IronPort-AV: E=Sophos;i="5.88,354,1635231600"; d="scan'208";a="249342332" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2022 22:43:13 -0800 X-IronPort-AV: E=Sophos;i="5.88,354,1635231600"; d="scan'208";a="540964099" Received: from ymtarple-mobl1.amr.corp.intel.com (HELO ldmartin-desk2) ([10.212.231.100]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2022 22:43:13 -0800 Date: Tue, 8 Feb 2022 22:43:13 -0800 From: Lucas De Marchi To: Thomas Zimmermann Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Matthew Brost , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , linux-kernel@vger.kernel.org, Daniele Ceraolo Spurio , Mauro Carvalho Chehab , Christian =?utf-8?B?S8O2bmln?= , John Harrison Subject: Re: [PATCH v2 02/18] iosys-map: Add a few more helpers Message-ID: <20220209064313.ithagwtjztcf4jfb@ldmartin-desk2> X-Patchwork-Hint: comment References: <20220208104524.2516209-1-lucas.demarchi@intel.com> <20220208104524.2516209-3-lucas.demarchi@intel.com> <863e61f9-2888-11a2-271b-a443f4681987@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <863e61f9-2888-11a2-271b-a443f4681987@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 09, 2022 at 07:23:04AM +0100, Thomas Zimmermann wrote: >Hi > >Am 08.02.22 um 11:45 schrieb Lucas De Marchi: >>First the simplest ones: >> >> - iosys_map_memset(): when abstracting system and I/O memory, >> just like the memcpy() use case, memset() also has dedicated >> functions to be called for using IO memory. >> - iosys_map_memcpy_from(): we may need to copy data from I/O >> memory, not only to. >> >>In certain situations it's useful to be able to read or write to an >>offset that is calculated by having the memory layout given by a struct >>declaration. Usually we are going to read/write a u8, u16, u32 or u64. >> >>As a pre-requisite for the implementation, add iosys_map_memcpy_from() >>to be the equivalent of iosys_map_memcpy_to(), but in the other >>direction. Then add 2 pairs of macros: >> >> - iosys_map_rd() / iosys_map_wr() >> - iosys_map_rd_field() / iosys_map_wr_field() >> >>The first pair takes the C-type and offset to read/write. The second >>pair uses a struct describing the layout of the mapping in order to >>calculate the offset and size being read/written. >> >>We could use readb, readw, readl, readq and the write* counterparts, >>however due to alignment issues this may not work on all architectures. >>If alignment needs to be checked to call the right function, it's not >>possible to decide at compile-time which function to call: so just leave >>the decision to the memcpy function that will do exactly that. >> >>Finally, in order to use the above macros with a map derived from >>another, add another initializer: IOSYS_MAP_INIT_OFFSET(). >> >>v2: >> - Rework IOSYS_MAP_INIT_OFFSET() so it doesn't rely on aliasing rules >> within the union >> - Add offset to both iosys_map_rd_field() and iosys_map_wr_field() to >> allow the struct itself to be at an offset from the mapping >> - Add documentation to iosys_map_rd_field() with example and expected >> memory layout >> >>Cc: Sumit Semwal >>Cc: Christian König >>Cc: Thomas Zimmermann >>Cc: Mauro Carvalho Chehab >>Cc: dri-devel@lists.freedesktop.org >>Cc: linux-kernel@vger.kernel.org >>Signed-off-by: Lucas De Marchi >>--- >> include/linux/iosys-map.h | 202 ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 202 insertions(+) >> >>diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h >>index edd730b1e899..c6b223534b21 100644 >>--- a/include/linux/iosys-map.h >>+++ b/include/linux/iosys-map.h >>@@ -6,6 +6,7 @@ >> #ifndef __IOSYS_MAP_H__ >> #define __IOSYS_MAP_H__ >>+#include >> #include >> #include > >Alphabetically sorted, please. > >What requires kernel.h? Can this be reduced to another include >statement? Maybe stddef.h for offsetof() ? Humn... I believe it was something in the previous implementation that is not there anymore. Because this builds fine without the include now and I don't think it is something being included by the headers already here. So this additional include can just be removed. Lucas De Marchi