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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 CAE2EC2D0DB for ; Mon, 20 Jan 2020 11:14:13 +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 9C4522087E for ; Mon, 20 Jan 2020 11:14:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="scu0nuWn"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="uJYsc9Wm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C4522087E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=bN/gaOLQHUwRJxTppQ8hlHIu+MwE2OfM9djelFojiTM=; b=scu0nuWnmdIMdbo2EA/qisOnN gZEHSaT6A8Brrj5nBQJJb06glIFQET08XKqeaE/MGrZtf9cdzhB7/SZjmZgkIO1CBIq7flcEw5zRg Fvdwv+oY1r9jcjhxIH0XSFCFCRTTYvaYFmmwFExIOKFKLAWArxDbvm3wduhIE9dV3Cy5i2gRbiN8X 3k3hPbb5u4gPQBdu8mKdMzGqM/gobBQb1mx8zPVfHVYtHMhDvcUHAJNDEPMfQAkwMnIxWNmlONcgZ 9hVPWR72G99NqJfzVbFT0X9lxcL6PLTbb/fi8t/OQFq2edk0XR5Pd2ePKnTQ5oh9eFO+u1aio/kc8 V/42BOT1w==; 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 1itV0X-0006F1-4j; Mon, 20 Jan 2020 11:14:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1itV0Q-0006EW-M0 for linux-arm-kernel@lists.infradead.org; Mon, 20 Jan 2020 11:14:11 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2F20520674; Mon, 20 Jan 2020 11:14:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579518846; bh=HAHcS1egkuTL8fOWbZRIsOSuG2XkQ6V9uDzuweE93QQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=uJYsc9WmWttZ+T1kL7mR5Z6VCb/q84SaSkiINgfXZ6OV7rcxaibik2M43q1wTZSJQ TYMzZKu8bfz1hmjiv7WfQtooviE5zNFKmfR4a/aYEulIO+03vjfQ7kkxscNFiaBZ3K pyZvvW7e3AJuHqLg27h6GfLQHdY9Eh6XgujCHPtk= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1itV0O-000FHR-G6; Mon, 20 Jan 2020 11:14:04 +0000 MIME-Version: 1.0 Date: Mon, 20 Jan 2020 12:14:04 +0100 From: Marc Zyngier To: Vladimir Murzin Subject: Re: [PATCH] ARM: virt: Relax arch timer version check during early boot In-Reply-To: References: <1579097798-106243-1-git-send-email-vladimir.murzin@arm.com> Message-ID: X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.8 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: vladimir.murzin@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200120_031406_741001_D374C0B7 X-CRM114-Status: GOOD ( 14.87 ) 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: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Vladimir, On 2020-01-20 11:46, Vladimir Murzin wrote: > + Marc > + kvmarm@lists.cs.columbia.edu > > On 1/15/20 2:16 PM, Vladimir Murzin wrote: >> Updates to the Generic Timer architecture allow ID_PFR1.GenTimer to >> have values other than 0 or 1. At the moment, Linux is quite strict in >> the way it handles this field at early boot and will not configure >> arch timer if it doesn't find the value 1. >> >> Since here use ubfx for arch timer version extraction (hyb-stub build >> with -march=armv7-a, so it is safe) >> >> To help backports (even though the code was correct at the time of >> writing) >> Fixes: 8ec58be9f3ff ("ARM: virt: arch_timers: enable access to >> physical timers") >> Signed-off-by: Vladimir Murzin I'm not opposed to such a change, but it'd be good to document what other values are expected here, as the current (Rev E_a) ARM ARM only mentions values 0 and 1. Thanks, M. >> --- >> arch/arm/kernel/hyp-stub.S | 7 +++---- >> 1 file changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S >> index ae50203..6607fa8 100644 >> --- a/arch/arm/kernel/hyp-stub.S >> +++ b/arch/arm/kernel/hyp-stub.S >> @@ -146,10 +146,9 @@ ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE >> #if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) >> @ make CNTP_* and CNTPCT accessible from PL1 >> mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 >> - lsr r7, #16 >> - and r7, #0xf >> - cmp r7, #1 >> - bne 1f >> + ubfx r7, r7, #16, #4 >> + teq r7, #0 >> + beq 1f >> mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL >> orr r7, r7, #3 @ PL1PCEN | PL1PCTEN >> mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL >> -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel