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 D85B3C433EF for ; Mon, 14 Mar 2022 15:34:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242544AbiCNPfd (ORCPT ); Mon, 14 Mar 2022 11:35:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240734AbiCNPfZ (ORCPT ); Mon, 14 Mar 2022 11:35:25 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC2911EC5C for ; Mon, 14 Mar 2022 08:34:14 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1nTmhd-0006ou-Cw; Mon, 14 Mar 2022 16:33:45 +0100 Message-ID: <7f1e4cbd-2d02-2345-493b-68ded3357f26@pengutronix.de> Date: Mon, 14 Mar 2022 16:33:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [EXT] Re: [PATCH v5 4/5] crypto: caam - add in-kernel interface for blob generator Content-Language: en-US To: Pankaj Gupta , Jarkko Sakkinen Cc: David Gstir , Aymen Sghaier , Mimi Zohar , David Howells , "keyrings@vger.kernel.org" , Matthias Schiffer , Herbert Xu , Horia Geanta , Richard Weinberger , James Morris , Eric Biggers , James Bottomley , "Serge E. Hallyn" , "tharvey@gateworks.com" , Franck Lenormand , Jan Luebbe , Sumit Garg , "linux-kernel@vger.kernel.org" , "linux-security-module@vger.kernel.org" , "linux-crypto@vger.kernel.org" , "kernel@pengutronix.de" , "linux-integrity@vger.kernel.org" , "David S. Miller" References: <20220222195819.2313913-1-a.fatoum@pengutronix.de> <20220222195819.2313913-5-a.fatoum@pengutronix.de> From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Pankaj, On 25.02.22 13:20, Pankaj Gupta wrote: >>>> +static u32 *caam_blob_alloc_desc(size_t keymod_len) { >>>> + size_t len; >>>> + >>>> + /* header + (key mod immediate) + 2x pointers + op */ >>>> + len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 + >>>> + CAAM_PTR_SZ_MAX) + 4; >>> >>> Nit: the amount of magic numbers is overwhelming here. I neither >>> understand the statement nor how that comment should help me to >> understand it. >> >> header = 4 >> (key mod immediate) = (4 + ALIGN(keymod_len, 4)) >> 2x pointer = 2 * (4 + 4 + CAAM_PTR_SZ_MAX) >> op = 4 > > Instead of the function caam_blob_alloc_desc(), it will be great if the caller functions caam_encap_blob()/caam_encap_blob (), could add local array: > uint32_t desc[CAAM_DESC_BYTES_MAX]; I just looked into this and placing desc on stack is not possible as it is used for DMA inside caam_jr_enqueue(). Cheers, Ahmad -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |