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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 1B44BC49ED7 for ; Tue, 10 Sep 2019 14:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2966208E4 for ; Tue, 10 Sep 2019 14:44:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fu4g8oru" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393523AbfIJOo5 (ORCPT ); Tue, 10 Sep 2019 10:44:57 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:33679 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387874AbfIJOo4 (ORCPT ); Tue, 10 Sep 2019 10:44:56 -0400 Received: by mail-wr1-f67.google.com with SMTP id u16so20876245wrr.0; Tue, 10 Sep 2019 07:44:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=K5duO6IbkJ8p2e8p4z12GaGcHnnxC09bJLQvbWViWok=; b=fu4g8oruUidKGWMGKAQilbHJ3zZ7QI7stPHT9LX/emhpA0g/uhNnCIfSzvekCRxVHx Wnrh4cBhFQ05o5vH8hUWdGFnFKzPPI9fi/iv6vHcJlFrQ1nMCaJ5BpIulyKguP3lhglr 9e74K100oZ8+JWH98eeNglVWTOWnCXBZMme6/Lw6ruC2MmV+R72Ou/j9luMFFmINvC1f 0GiPVVVtqRaVbXqxLF3HVhEllIaskwiqn2821fB3L4wcOj8TsZS0O0kHENJXS4uCTrJQ YxZ3oWIPlmC3d7SH/UJsQs1IRCIUc/CdG9PM4XnY07ShLokUiUoQhY2q4EV9Sjn6/cVT TbNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=K5duO6IbkJ8p2e8p4z12GaGcHnnxC09bJLQvbWViWok=; b=PISmjsUgPwc5MVWmHYBw9C7tQTavaRAU4dy6mixx8KKOFw50pPrHEumzOvVQtCEJA9 X3/icrjdE1aUEpPWcEd+VpuZ3BnTD1BRf8HMp2YYWxFMThosNW/zgV8kAC06YuyzI6+p O17jqfpRHzkUBJNihHAp6G5cPGOYjuDvGsGCJUGIGeSB23tRCA9AaaEcrw9wRjAdj9kO okdvS+vSuJBj2zGUTt+DVoMfgoE8q3WDgDoDl8MMmiVCMhXDvjqbzUyfkNPgIt9CbsvX x7iPbvhU6MMEgEEuDPg9BHMMOFA9NqwQngGs8M8puQ33gakMe6+3tgA3K5A1oYGf4eq3 hjeA== X-Gm-Message-State: APjAAAUGVGM//3oNS5sG3aD3wK/HwgB80WMjlj96GZRy3OyDxtzK9bDJ yCyL4C/FXPnUv8GsIuyHyTo= X-Google-Smtp-Source: APXvYqy8oCF9jzlFwjhls5MC+bV0p4KcSxaCpKbMvnhXuGJ9mOg6cetjGtTvTEefF3ROADm+FtzlQA== X-Received: by 2002:a5d:45c3:: with SMTP id b3mr27792792wrs.207.1568126694371; Tue, 10 Sep 2019 07:44:54 -0700 (PDT) Received: from pali ([2a02:2b88:2:1::5cc6:2f]) by smtp.gmail.com with ESMTPSA id a192sm5705205wma.1.2019.09.10.07.44.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 10 Sep 2019 07:44:53 -0700 (PDT) Date: Tue, 10 Sep 2019 16:44:52 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Sebastian Reichel Cc: Adam Ford , Tony Lindgren , Mark Rutland , devicetree , Paul Walmsley , Aaro Koskinen , Russell King , Linux Kernel Mailing List , Tero Kristo , Rob Herring , =?utf-8?Q?Beno=C3=AEt?= Cousson , Linux-OMAP , Adam Ford , arm-soc Subject: Re: [RFC] ARM: omap3: Enable HWMODS for HW Random Number Generator Message-ID: <20190910144452.vmhmls3xhh6hd5xw@pali> References: <20190828150037.2640-1-aford173@gmail.com> <20190905230443.GA52127@atomide.com> <20190910143732.3g3q4acvnx2pqvjx@earth.universe> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190910143732.3g3q4acvnx2pqvjx@earth.universe> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 10 September 2019 15:37:32 Sebastian Reichel wrote: > Hi, > > On Tue, Sep 10, 2019 at 08:56:49AM -0500, Adam Ford wrote: > > On Thu, Sep 5, 2019 at 6:04 PM Tony Lindgren wrote: > > > Oh and this needs to default to status = "disabled" for > > > HS devices like n900 as it needs to use the omap3-rom-rng. > > > > I don't know enough about the HS version of the OMAP3, but what's the > > main difference between omap3-rom-rng and this one? > > The OMAP HS chips have the bus firewall configured to block direct > access to some cryptography related devices. The kernel will crash > with a bus error, if you try to read/write the registers for > protected devices. And if you try to read it more times, SOC would be rebooted for security reasons. > The omap3-rom-rng avoids this by communicating > with the security middleware component instead of directly accessing > the RNG hardware. And that component is loaded by signed bootloader into "secure" area not accessible by "non-secure" work (like kernel) and communication is done via arm smc instruction. -- Pali Rohár pali.rohar@gmail.com