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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E4754C001DB for ; Tue, 8 Aug 2023 16:12:41 +0000 (UTC) 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:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Wj1AcIWTlmDmKA0A/5rTRjcwAzhHxce7iEHPj091g70=; b=uztGKQlqWKicxh NwUKAFl4HFc+Rk7/nF3WHzq0qsdAgZh+62+1Hz/QJHgBzHU8/OjJGcoeFGus2fp49JYItdbq5uCU1 xUedQBryyxjMubvKLHxv3DjR97zpxR3igWMoCn2X8moiLx3zXsYOlr/im8R/QGwU0iM8+5sbu5a2s f6wP6E9M68lJkkHi9FStPvH4UjMzAKf6h4fTlwq+wT6dl1oC4aN/025gPP1uqbnTaGQWO4BqIIX3j 5Ecd6KNcluBWcjlfBEu0TXqgCspyFbHO0MRw7ubz7hRAnmdNO1wtOAhHXhUAzjevGxNcTpegcMuTD ptn1aNz6aVpdATvp+jOg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qTPJi-002ukf-1T; Tue, 08 Aug 2023 16:12:18 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qTPJf-002ujq-2g for linux-arm-kernel@lists.infradead.org; Tue, 08 Aug 2023 16:12:17 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 525AF61070; Tue, 8 Aug 2023 16:12:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9789FC433C8; Tue, 8 Aug 2023 16:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691511134; bh=3dtzfUCD+LNNd3R69riKgojTMmB3iwvo7xJjgLrGkV8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=q34GiRU8y8r2pRb0qHmcFZnOhscY+xDmlIhH4L0ZUdaIi96k4MWtFeaF6KVLQsIf5 m0QmQWwAZrGpPjOcunyJx/WxYukvd54B282f21cpE2jLkclk0ekzlUvBUBcJZmsLvq qdQO9uVszwltdLW8tltgXFkKVPceYj1CZze8+KlaywbUxg9fYeEbEXuAP+p0swyE8+ 1ejWJW9Y2WKOG8euvAgq4ji6Vu4W6ylOYb694tlUBBBD1240Wtqgmuvjy7Bb7fgaGc lKRcSMIF+6pIZ+GuYZ6P4rKeBks4z/XTR0AsBK/2Qo13ldQcq3kDbvV8EmbG9VGrSj RbTA3xdakPSaQ== Date: Tue, 8 Aug 2023 17:12:09 +0100 From: Will Deacon To: zhurui Cc: Nicolin Chen , linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Robin Murphy , Joerg Roedel , Lu Baolu , Jason Gunthorpe , Yicong Yang , Tomas Krcka , Jean-Philippe Brucker Subject: Re: [PATCH v2 1/1] iommu/arm-smmu-v3: Fix error case of range command Message-ID: <20230808161208.GA2890@willie-the-truck> References: <1690784482-30028-1-git-send-email-wangwudi@hisilicon.com> <20230801085504.GA26130@willie-the-truck> <27c895b8-1fb0-be88-8bc3-878d754684c8@huawei.com> <20230804165225.GF30679@willie-the-truck> <015b4573-9d74-451b-8028-a1050ade7019@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <015b4573-9d74-451b-8028-a1050ade7019@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230808_091215_955056_5D1DC5DC X-CRM114-Status: GOOD ( 24.49 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Aug 06, 2023 at 01:28:04PM +0800, zhurui wrote: > On 2023/8/5 2:30, Nicolin Chen wrote: > > On Fri, Aug 04, 2023 at 05:52:25PM +0100, Will Deacon wrote: > >> On Fri, Aug 04, 2023 at 05:31:20PM +0800, zhurui wrote: > >>> When tg != 0 but ttl, scale, num all 0 in a range tlbi command, it > >>> is reserved and will cause the CERROR_ILL error. This case means > >>> that the size to be invalidated is only one page size, and the > >>> range invalidation is meaningless here. So we set tg to 0 in this > >>> case to do an non-range invalidation instead. > > > >>> @@ -1930,6 +1927,12 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, > >>> num = (num_pages >> scale) & CMDQ_TLBI_RANGE_NUM_MAX; > >>> cmd->tlbi.num = num - 1; > >>> > >>> + /* Prevent error caused by one page tlbi with leaf 0 */ > >>> + if (scale == 0 && num == 1 && cmd->tlbi.leaf == 0) > >>> + cmd->tlbi.tg = 0; > >> > >> This should only be true for the last iteration, right (i.e. when num_pages > >> == 1)? In which case, I'd prefer to leave the old code as-is and just add: > >> > >> /* Single-page leaf invalidation requires a TG field of 0 */ > >> if (num_pages == 1 && !cmd->tlbi.leaf) > >> cmd->tlbi.tg = 0;To Will and Nicolin, > > Not only the last iteration, it's the result of __ffs function. For example, if > numpages is 33, then the value of __ffs(num_pages) is 0, so the value of scale > is also 0. The value of num depends on CMDQ_TLBI_RANGE_NUM_MAX. That is, the > maximum value of num is 31. Therefore, the final value of num is 1. > So, if consider CMDQ_TLBI_RANGE_NUM_MAX, there will be some case not the last > one page but the beginning pages. That's why I use scale and num as conditions, > not num_pages. Then I should reassign tg based on the result. Yes, thanks, you're quite right. I'm not sure what I was thinking! Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel