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=-13.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS 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 5A476C282C3 for ; Tue, 22 Jan 2019 09:25:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27A0A218D9 for ; Tue, 22 Jan 2019 09:25:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548149104; bh=0eBPhqV+QY8H/+vRW93zrXRI0S+oLIFcI56mTmyrljw=; h=Subject:To:From:Date:List-ID:From; b=G1cXt3gOjs+FkdIwR6X2Djow9wYl2mVwTkdSB0wg6Gv7TI3ZFTSQtFIiHt5Thhtmo /jQdP4xhpKotgGccxJiiWXfxN1XFh3TjVOGu6zZ4XIHjaJw3FY0T5fCY6lVdCBLVad j6A4izoryo4wA2Php+e9noMpuWCYX1PClCAsITSc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727993AbfAVJYw (ORCPT ); Tue, 22 Jan 2019 04:24:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:48548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727509AbfAVJYu (ORCPT ); Tue, 22 Jan 2019 04:24:50 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 79B11218D9; Tue, 22 Jan 2019 09:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548149090; bh=0eBPhqV+QY8H/+vRW93zrXRI0S+oLIFcI56mTmyrljw=; h=Subject:To:From:Date:From; b=W2WR/nR2I4TrLzcSosSbcLZTaKDqJSWPypYS2Oxz8qZDzXeruWr5fY9YJ2liCl3/R z2OPh/z5wpnbp31OYDIXbnbJ6pM0HHu/cxdI8HMlwDbojKynk+EOEdOYwF8gqz6kX7 CTzF7lJCpFJ6NtqOzmKL9SsIa/kENxhClB+hgl1Q= Subject: patch "ihex: Simplify next record offset calculation" added to driver-core-testing To: andrew.smirnov@gmail.com, akpm@linux-foundation.org, cphealy@gmail.com, dwmw2@infradead.org, gregkh@linuxfoundation.org, kyle@kernel.org, linux-kernel@vger.kernel.org, yamada.masahiro@socionext.com From: Date: Tue, 22 Jan 2019 10:24:40 +0100 Message-ID: <1548149080187105@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a note to let you know that I've just added the patch titled ihex: Simplify next record offset calculation to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the driver-core-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 9fb4ab4d3dd665a62da9c176a89e7c7feaf5d9e4 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Thu, 20 Dec 2018 23:28:39 -0800 Subject: ihex: Simplify next record offset calculation Next record calucaltion can be reduced to a much more tivial ALIGN operation as follows: 1. Splitting 5 into 2 + 3 we get next = ((be16_to_cpu(rec->len) + 2 + 3) & ~3) - 2 (1) 2. Using ALIGN macro we reduce (1) to: ALIGN(be16_to_cpu(rec->len) + 2, 4) - 2 (2) 3. Subsituting 'next' in original next record calucation we get: (void *)&rec->data[ALIGN(be16_to_cpu(rec->len) + 2, 4) - 2] (3) 4. Converting array index to pointer arithmetic we convert (3) into: (void *)rec + sizeof(*rec) + ALIGN(be16_to_cpu(rec->len) + 2, 4) - 2 (4) 5. Subsituting sizeof(*rec) with its value, 6, and substracting 2, in (4) we get: (void *)rec + ALIGN(be16_to_cpu(rec->len) + 2, 4) + 4 (5) 6. Since ALIGN(X, 4) + 4 == ALIGN(X + 4, 4), (5) can be converted to: (void *)rec + ALIGN(be16_to_cpu(rec->len) + 6, 4) (6) 5. Subsituting 6 in (6) to sizeof(*rec) we get: (void *)rec + ALIGN(be16_to_cpu(rec->len) + sizeof(*rec), 4) (7) Using expression (7) should make it more clear that next record is located by adding full size of the current record (payload + auxiliary data) aligned to 4 bytes, to the location of the current one. No functional change intended. Cc: Chris Healy Cc: Kyle McMartin Cc: Andrew Morton Cc: Masahiro Yamada Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: linux-kernel Signed-off-by: Andrey Smirnov Signed-off-by: Greg Kroah-Hartman --- include/linux/ihex.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/include/linux/ihex.h b/include/linux/ihex.h index 9130f307a420..98cb5ce0b0a0 100644 --- a/include/linux/ihex.h +++ b/include/linux/ihex.h @@ -21,14 +21,18 @@ struct ihex_binrec { uint8_t data[0]; } __attribute__((packed)); +static inline uint16_t ihex_binrec_size(const struct ihex_binrec *p) +{ + return be16_to_cpu(p->len) + sizeof(*p); +} + /* Find the next record, taking into account the 4-byte alignment */ static inline const struct ihex_binrec * __ihex_next_binrec(const struct ihex_binrec *rec) { - int next = ((be16_to_cpu(rec->len) + 5) & ~3) - 2; - rec = (void *)&rec->data[next]; + const void *p = rec; - return rec; + return p + ALIGN(ihex_binrec_size(rec), 4); } static inline const struct ihex_binrec * -- 2.20.1