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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2EB3AC6FD1D for ; Thu, 30 Mar 2023 14:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231733AbjC3Ocf (ORCPT ); Thu, 30 Mar 2023 10:32:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231340AbjC3Oce (ORCPT ); Thu, 30 Mar 2023 10:32:34 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B39AD187 for ; Thu, 30 Mar 2023 07:32:32 -0700 (PDT) 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 9203B12FC; Thu, 30 Mar 2023 07:33:16 -0700 (PDT) Received: from [10.1.35.23] (e122027.cambridge.arm.com [10.1.35.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DB1073F663; Thu, 30 Mar 2023 07:32:30 -0700 (PDT) Message-ID: <864ef90a-c235-1e72-7941-6766541bb199@arm.com> Date: Thu, 30 Mar 2023 15:32:29 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v2] iommu/rockchip: Add missing set_platform_dma_ops callback Content-Language: en-GB To: Jason Gunthorpe , John Keeping Cc: Heiko Stuebner , Joerg Roedel , Will Deacon , Robin Murphy , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org References: <20230324111127.221640-1-steven.price@arm.com> From: Steven Price In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/03/2023 16:26, Jason Gunthorpe wrote: > On Mon, Mar 27, 2023 at 03:35:04PM +0100, John Keeping wrote: >> On Fri, Mar 24, 2023 at 11:11:27AM +0000, Steven Price wrote: >>> Similar to exynos, we need a set_platform_dma_ops() callback for proper >>> operation on ARM 32 bit after recent changes in the IOMMU framework >>> (detach ops removal). But also the use of a NULL domain is confusing. >>> >>> Rework the code to have a singleton rk_identity_domain which is assigned >>> to domain when using an identity mapping rather than "detaching". This >>> makes the code easier to reason about. >>> >>> Signed-off-by: Steven Price >>> --- >>> Changes since v1[1]: >>> >>> * Reworked the code to avoid a NULL domain, instead a singleton >>> rk_identity_domain is used instead. The 'detach' language is no >>> longer used. >>> >>> [1] https://lore.kernel.org/r/20230315164152.333251-1-steven.price%40arm.com >>> >>> drivers/iommu/rockchip-iommu.c | 50 ++++++++++++++++++++++++++-------- >>> 1 file changed, 39 insertions(+), 11 deletions(-) >>> >>> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c >>> index f30db22ea5d7..437541004994 100644 >>> --- a/drivers/iommu/rockchip-iommu.c >>> +++ b/drivers/iommu/rockchip-iommu.c >> [snip] >>> +static struct iommu_domain rk_identity_domain = { >>> + .type = IOMMU_DOMAIN_IDENTITY, >>> + .ops = &rk_identity_ops, >>> +}; >>> + >>> +#ifdef CONFIG_ARM >> >> Is this #ifdef needed? I can't see anything ARM-specific about this >> function or .set_platform_dma_ops. > > set_platform_dma_ops is never called on ARM64. I have to admit this was somewhat cargo-culted from the exynos-iommu change. This is only needed for Arm, but I'm not sure if there's any real harm including it for other arches. >> Not shown in the patch are the pm_runtime hooks. Do they need to >> change like this? > > Most likely yes Good spot - I'll send a v3 with this fixed. Thanks, Steve