From patchwork Mon Mar 14 07:31:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12779664 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 41DA8C433EF for ; Mon, 14 Mar 2022 07:34:43 +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:MIME-Version: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=qTKbad27hb0xSQibGJebDkRP8euvmvd2ehT2YoUFzpg=; b=GRoUST5b2cX2EO OtIxIUgW742cwp1x4Ly89/F8W4204A90CtvC80FKUBdRO0MzqD+hV0LObfKqZQb3AmfYXawi10lRx SEEuHemD+/aAAbmA3JMx5iXvDqpdrxGNM2ley6MipkDgn7NCksGdoNfIwVinMiVBnJhQ2nE0J6gUw zrP8GBlC1S58oofSxtn5Rn3QLfsH1Sn1eC2CDzJZkqQOu5yc9IFBv7WExkX/lyDECf8p3TZ/FQNF+ nuIDuYeQnhzX0zkeBBrbKosahf46RvOclQScCKRMU9gIbIyo7T28xEhuQgCjieZ8BLOHh0ATABU/p kq0ksVitjtVygA702Mxg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nTfCt-0045q1-KY; Mon, 14 Mar 2022 07:33:31 +0000 Received: from [46.140.54.162] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nTfBE-0044YU-6n; Mon, 14 Mar 2022 07:31:48 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Cc: x86@kernel.org, Anshuman Khandual , Tom Lendacky , Konrad Rzeszutek Wilk , Stefano Stabellini , Boris Ostrovsky , Juergen Gross , Joerg Roedel , David Woodhouse , Lu Baolu , Robin Murphy , linux-arm-kernel@lists.infradead.org, xen-devel@lists.xenproject.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-hyperv@vger.kernel.org, tboot-devel@lists.sourceforge.net, linux-pci@vger.kernel.org, Stefano Stabellini Subject: [PATCH 05/15] arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region Date: Mon, 14 Mar 2022 08:31:19 +0100 Message-Id: <20220314073129.1862284-6-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220314073129.1862284-1-hch@lst.de> References: <20220314073129.1862284-1-hch@lst.de> MIME-Version: 1.0 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Stefano Stabellini It used to be that Linux enabled swiotlb-xen when running a dom0 on ARM. Since f5079a9a2a31 "xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped", Linux detects whether to enable or disable swiotlb-xen based on the new feature flags: XENFEAT_direct_mapped and XENFEAT_not_direct_mapped. However, there is still a leftover xen_initial_domain() check in xen_create_contiguous_region. Remove the check as xen_create_contiguous_region is only called by swiotlb-xen during initialization. If xen_create_contiguous_region is called, we know Linux is running 1:1 mapped so there is no need for additional checks. Also update the in-code comment. Signed-off-by: Stefano Stabellini Signed-off-by: Christoph Hellwig --- arch/arm/xen/mm.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index a7e54a087b802..28c2070602535 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -122,10 +122,7 @@ int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle) { - if (!xen_initial_domain()) - return -EINVAL; - - /* we assume that dom0 is mapped 1:1 for now */ + /* the domain is 1:1 mapped to use swiotlb-xen */ *dma_handle = pstart; return 0; }