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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 C4A64C433DF for ; Wed, 8 Jul 2020 11:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAAD22085B for ; Wed, 8 Jul 2020 11:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728902AbgGHLc4 (ORCPT ); Wed, 8 Jul 2020 07:32:56 -0400 Received: from foss.arm.com ([217.140.110.172]:34024 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728410AbgGHLcy (ORCPT ); Wed, 8 Jul 2020 07:32:54 -0400 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 1B3831045; Wed, 8 Jul 2020 04:32:54 -0700 (PDT) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C29C63F68F; Wed, 8 Jul 2020 04:32:52 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org Cc: hch@lst.de, iommu@lists.linux-foundation.org, jonathan.lemon@gmail.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, baolu.lu@linux.intel.com, dwmw2@infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/2] iommu/dma: Avoid SAC address trick for PCIe devices Date: Wed, 8 Jul 2020 12:32:42 +0100 Message-Id: X-Mailer: git-send-email 2.23.0.dirty In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As for the intel-iommu implementation, relegate the opportunistic attempt to allocate a SAC address to the domain of conventional PCI devices only, to avoid it increasingly causing far more performance issues than possible benefits on modern PCI Express systems. Signed-off-by: Robin Murphy --- drivers/iommu/dma-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 4959f5df21bd..0ff124f16ad4 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -426,7 +426,8 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end); /* Try to get PCI devices a SAC address */ - if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) + if (dma_limit > DMA_BIT_MASK(32) && + dev_is_pci(dev) && !pci_is_pcie(to_pci_dev(dev))) iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift, false); -- 2.23.0.dirty