From patchwork Sun Aug 27 07:41:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 718547 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 897E8C83F13 for ; Sun, 27 Aug 2023 07:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230313AbjH0Hnu (ORCPT ); Sun, 27 Aug 2023 03:43:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230101AbjH0HmP (ORCPT ); Sun, 27 Aug 2023 03:42:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A977AFA; Sun, 27 Aug 2023 00:42:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 42E1E61CA0; Sun, 27 Aug 2023 07:42:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9ECECC433C8; Sun, 27 Aug 2023 07:42:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693122131; bh=ZZzrW8bCe0Cteehk6ZqBfbcWjR/I+i/gq8lRg9vf2WA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tql1LjTU7g8mlHtwTYYEgppjz13KzJg8CbOAzJOH+03SYjSO9+Iz7BtC4MuNdrnTs e33fCxrt6+lclkxrvnRTpzFpQfvp9ec/armE5l2HHPMWdYEqNO5ikL1EfhpPOreD7x ARgZ67Ge+TESVhsXvDq1k1cWEhBcjLjlYfmtvQu4D6gMxK6XFQnjurO7X0dQpc8I8M OWIOQ/IH1TFpCkoo3g1D5B2caUkVGW4I1OlBoPNAtlYQk2CjSIYpejIvpeR4hAbmlV SxqqwBxdivqNicLDA85awptDjZ6Sv0xF+++OOam1n2XRBJPLosQvoGbYwLSxGtXZOh 2ZkGjZSLo45wQ== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" Subject: [PATCH v2 14/14] tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw() Date: Sun, 27 Aug 2023 09:41:47 +0200 Message-ID: <20230827074147.2287-15-jirislaby@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230827074147.2287-1-jirislaby@kernel.org> References: <20230827074147.2287-1-jirislaby@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The code is duplicated to perform the copy twice -- to handle buffer wrap-around. Instead of the duplication, roll this into the loop. (And add some blank lines around to have the code a bit more readable.) Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/n_tty.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index edf59f6fc669..6c9a408d67cd 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -1528,19 +1528,18 @@ n_tty_receive_buf_real_raw(const struct tty_struct *tty, const u8 *cp, size_t count) { struct n_tty_data *ldata = tty->disc_data; - size_t n, head; - - head = MASK(ldata->read_head); - n = min(count, N_TTY_BUF_SIZE - head); - memcpy(read_buf_addr(ldata, head), cp, n); - ldata->read_head += n; - cp += n; - count -= n; - - head = MASK(ldata->read_head); - n = min(count, N_TTY_BUF_SIZE - head); - memcpy(read_buf_addr(ldata, head), cp, n); - ldata->read_head += n; + + /* handle buffer wrap-around by a loop */ + for (unsigned int i = 0; i < 2; i++) { + size_t head = MASK(ldata->read_head); + size_t n = min(count, N_TTY_BUF_SIZE - head); + + memcpy(read_buf_addr(ldata, head), cp, n); + + ldata->read_head += n; + cp += n; + count -= n; + } } static void