From patchwork Mon Jul 26 17:56:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 12400429 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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 3DC60C4338F for ; Mon, 26 Jul 2021 17:59:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 00CDA60F6D for ; Mon, 26 Jul 2021 17:58:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 00CDA60F6D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vVXdQ1zksCfRUIBSKjBXsBIooUkZcHpG3GMegNoAE/c=; b=JWEq613VUA2lxN y6U93BdJo6i2WNsGf+rUiFik/LXlgU5XSZ4Uhaqt6vB1hXNZEZ0ZnTDGD/uVjMC9hAEKiXtOaT7XF uUP78nSDEG5R0jy0oMR5pZDzoxEnA2MWOfEJdM96rNCjmniuxNdCccDMzMex7l6+NtGet8aL5qLrM u9Qhjx0rIWSTM2MmnPsr7eWxBHdWbpdN/lqDecOZWBuC931CfUAcEzZcQtNJRfrsTOvtoZXm88QrP f97+hnafLZQvRSTR1l9Ee8ptj8IWYD5I5O8S4WszPAOjBPgE+P0v6t6a1YLPgKSX6HeBebSy7DbpN huTmTXqiXwzMIZ8Cb52g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m84qm-00C9Id-1a; Mon, 26 Jul 2021 17:57:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m84qY-00C9Fx-Mw for linux-arm-kernel@lists.infradead.org; Mon, 26 Jul 2021 17:57:00 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 039CC31B; Mon, 26 Jul 2021 10:56:55 -0700 (PDT) Received: from localhost.localdomain (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DFBFC3F66F; Mon, 26 Jul 2021 10:56:52 -0700 (PDT) From: Andre Przywara To: Matt Mackall , Herbert Xu , Mark Rutland , Lorenzo Pieralisi , Sudeep Holla Cc: linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Ard Biesheuvel , Mark Brown , Will Deacon , Ali Saidi , Jon Nettleton Subject: [PATCH v3 1/2] firmware: smccc: Register smccc_trng platform device Date: Mon, 26 Jul 2021 18:56:09 +0100 Message-Id: <20210726175610.3311-2-andre.przywara@arm.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20210726175610.3311-1-andre.przywara@arm.com> References: <20210726175610.3311-1-andre.przywara@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210726_105658_837224_E9F3E2A5 X-CRM114-Status: GOOD ( 14.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org At the moment we probe for the Random Number Generator SMCCC service, and use that in the core code (arch_get_random). However the hardware entropy can also be useful to access from userland, and be it to assess its quality. Register a platform device when the SMCCC TRNG service is detected, to allow a hw_random driver to hook onto this. The function registering the device is deliberately made in a way which allows expansion, so other services that could be exposed via a platform device (or some other interface), can be added here easily. Signed-off-by: Andre Przywara --- drivers/firmware/smccc/smccc.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index 9f937b125ab0..60ccf3e90d7d 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -9,6 +9,7 @@ #include #include #include +#include #include static u32 smccc_version = ARM_SMCCC_VERSION_1_0; @@ -42,3 +43,19 @@ u32 arm_smccc_get_version(void) return smccc_version; } EXPORT_SYMBOL_GPL(arm_smccc_get_version); + +static int __init smccc_devices_init(void) +{ + struct platform_device *pdev; + + if (smccc_trng_available) { + pdev = platform_device_register_simple("smccc_trng", -1, + NULL, 0); + if (IS_ERR(pdev)) + pr_err("smccc_trng: could not register device: %ld\n", + PTR_ERR(pdev)); + } + + return 0; +} +device_initcall(smccc_devices_init);