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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 92C86C3F2CD for ; Mon, 23 Mar 2020 14:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EF7F2072E for ; Mon, 23 Mar 2020 14:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726141AbgCWO4u (ORCPT ); Mon, 23 Mar 2020 10:56:50 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:48127 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbgCWO4t (ORCPT ); Mon, 23 Mar 2020 10:56:49 -0400 Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=localhost.discworld.emantor.de) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jGOV7-0006Sg-Pz; Mon, 23 Mar 2020 15:56:25 +0100 Message-ID: <412a4da61063b8c8a72729f03c06480c5f1374fb.camel@pengutronix.de> Subject: Re: [PATCH v5 2/3] hw_random: cctrng: introduce Arm CryptoCell driver From: Rouven Czerwinski To: Hadar Gat , Matt Mackall , Herbert Xu , Rob Herring , Mark Rutland , Arnd Bergmann , Greg Kroah-Hartman , Krzysztof Kozlowski , Florian Fainelli , Alexander Sverdlin , Thomas Gleixner , Tomer Maimon , Randy Dunlap , Zaibo Xu , Daniel Thompson , Mauro Carvalho Chehab , "David S. Miller" , Jonathan Cameron Cc: linux-crypto@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Gilad Ben-Yossef , Ofir Drang Date: Mon, 23 Mar 2020 15:56:19 +0100 In-Reply-To: <1584891085-8963-3-git-send-email-hadar.gat@arm.com> References: <1584891085-8963-1-git-send-email-hadar.gat@arm.com> <1584891085-8963-3-git-send-email-hadar.gat@arm.com> Organization: Pengutronix e.K. Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: r.czerwinski@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-crypto@vger.kernel.org Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Hello Hadar, On Sun, 2020-03-22 at 17:31 +0200, Hadar Gat wrote: > Introduce low level Arm CryptoCell TRNG HW support. > > Signed-off-by: Hadar Gat > --- > drivers/char/hw_random/Kconfig | 12 + > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/cctrng.c | 735 > ++++++++++++++++++++++++++++++++++++++++ > drivers/char/hw_random/cctrng.h | 69 ++++ > 4 files changed, 817 insertions(+) > create mode 100644 drivers/char/hw_random/cctrng.c > create mode 100644 drivers/char/hw_random/cctrng.h > > [...] > +static int cctrng_probe(struct platform_device *pdev) > +{ > + struct resource *req_mem_cc_regs = NULL; > + struct cctrng_drvdata *drvdata; > + struct device *dev = &pdev->dev; > + int rc = 0; > + u32 val; > + int irq; > + > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); > + if (!drvdata) > + return -ENOMEM; > + > + drvdata->rng.name = devm_kstrdup(dev, dev_name(dev), > GFP_KERNEL); > + if (!drvdata->rng.name) > + return -ENOMEM; > + > + drvdata->rng.read = cctrng_read; > + drvdata->rng.priv = (unsigned long)drvdata; You are not initializing drvdata->rng.quality to a default value, which results in the TRNG not being used by the kernel by default. If its a perfect TRNG this should be set to 1024, i.e. 1024 bits of entropy per 1024 bits of input. Regards, Rouven Czerwinski