From patchwork Tue Jan 28 11:00:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kaiser X-Patchwork-Id: 11354107 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 456B41398 for ; Tue, 28 Jan 2020 11:02:17 +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 0929824684 for ; Tue, 28 Jan 2020 11:02:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="heBu98gp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0929824684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaiser.cx Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ys1ucTuhIvccs4jMIf0gtT1TV11fIdWOFn3ROy06Qpg=; b=heBu98gp9xU71f 3idb6HMXJ/ak+F3WQNBfcKorE2AHDQpldAAVDzj4uGzJxVQvDvs4+jqUIF2Zy0G7NMxEwkld0pYpU mSUUbpEieCBfkSxIqXzyuYsVoD/02EeF/fMG07F6dvGqtQzFS57CU4Yr1jzZ99H65Buvp0fC7nfYw kFHwsVERlgVCyvdSCaO2zXVKzrodruJZkpFQEcLd4uycHOb0CGlDQjjVDsp8nORWoecMhths9PtzF ZuAIeWjp1AtFMiDtIun4G9KgtNPeb3aENL4hGm9uzwMWUCzYX8M1mNOBJmsCV6UG/6ZA/goR58FS+ 8ZEIXU6N0M0cKTRmVKQQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iwOdJ-0006bq-IO; Tue, 28 Jan 2020 11:02:13 +0000 Received: from viti.kaiser.cx ([2a01:238:43fe:e600:cd0c:bd4a:7a3:8e9f]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iwOck-00068V-El for linux-arm-kernel@lists.infradead.org; Tue, 28 Jan 2020 11:01:39 +0000 Received: from dslb-088-068-095-017.088.068.pools.vodafone-ip.de ([88.68.95.17] helo=martin-debian-1.paytec.ch) by viti.kaiser.cx with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1iwOcf-0008Dy-Ji; Tue, 28 Jan 2020 12:01:33 +0100 From: Martin Kaiser To: Herbert Xu , PrasannaKumar Muralidharan , NXP Linux Team Subject: [PATCH 2/6] hwrng: imx-rngc - use automatic seeding Date: Tue, 28 Jan 2020 12:00:58 +0100 Message-Id: <20200128110102.11522-3-martin@kaiser.cx> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200128110102.11522-1-martin@kaiser.cx> References: <20200128110102.11522-1-martin@kaiser.cx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200128_030138_681115_E21985FC X-CRM114-Status: GOOD ( 11.81 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Martin Kaiser , linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org The rngc requires a new seed for its prng after generating 2^20 160-bit words of random data. At the moment, we seed the prng only once during initalisation. Set the rngc to auto seed mode so that it kicks off the internal reseeding operation when a new seed is required. Keep the manual calculation of the initial seed when the device is probed and switch to automatic seeding afterwards. Signed-off-by: Martin Kaiser Reviewed-by: PrasannaKumar Muralidharan --- drivers/char/hw_random/imx-rngc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c index 0576801944fd..903894518c8d 100644 --- a/drivers/char/hw_random/imx-rngc.c +++ b/drivers/char/hw_random/imx-rngc.c @@ -31,6 +31,7 @@ #define RNGC_CTRL_MASK_ERROR 0x00000040 #define RNGC_CTRL_MASK_DONE 0x00000020 +#define RNGC_CTRL_AUTO_SEED 0x00000010 #define RNGC_STATUS_ERROR 0x00010000 #define RNGC_STATUS_FIFO_LEVEL_MASK 0x00000f00 @@ -167,7 +168,7 @@ static irqreturn_t imx_rngc_irq(int irq, void *priv) static int imx_rngc_init(struct hwrng *rng) { struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng); - u32 cmd; + u32 cmd, ctrl; int ret; /* clear error */ @@ -192,7 +193,18 @@ static int imx_rngc_init(struct hwrng *rng) } while (rngc->err_reg == RNGC_ERROR_STATUS_STAT_ERR); - return rngc->err_reg ? -EIO : 0; + if (rngc->err_reg) + return -EIO; + + /* + * enable automatic seeding, the rngc creates a new seed automatically + * after serving 2^20 random 160-bit words + */ + ctrl = readl(rngc->base + RNGC_CONTROL); + ctrl |= RNGC_CTRL_AUTO_SEED; + writel(ctrl, rngc->base + RNGC_CONTROL); + + return 0; } static int imx_rngc_probe(struct platform_device *pdev)