From patchwork Wed Aug 11 12:21:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12431109 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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 98380C4338F for ; Wed, 11 Aug 2021 12:30:51 +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 5FBE96105A for ; Wed, 11 Aug 2021 12:30:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5FBE96105A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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=HujBylYcXtKWEalM/lW4Njx0JaL/A71Fb3tKfdTOyKo=; b=O30cKRrRpXcl6g waARHNNhPFFz9R6hluerXqk9fVjAGligPp+JzYZCETq8TRmer6FNMAOFAcTLARpaj7KPKlupQighk nva5jBeffublXW8u2m9SN84+PnG68K2EpMXM28QYiZ01tmQSuwb3XlgpTyb0f3FNSHduRJPpOKHrG jlUoWU5O6M4V8q1LIQKzUtHvhAjHBcoq0wmJBVYFpNCZ3D5yezDvfhLXlgUQGdX/k/8VJ0TZYz7rw pjdaG/czpx4CHPddBQrtQoG4CoAcEKKnYdSB2TyAEeKYtkNwxbPBiMFiSBgKy02luB137WYaVkFrH egqbjdDVFFvK3+75QPXQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDnLg-0072KK-W8; Wed, 11 Aug 2021 12:28:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDnFT-006yYv-NJ for linux-arm-kernel@lists.infradead.org; Wed, 11 Aug 2021 12:22:21 +0000 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 2B85A13D5; Wed, 11 Aug 2021 05:22:19 -0700 (PDT) Received: from 010265703453.arm.com (unknown [10.57.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 705EC3F718; Wed, 11 Aug 2021 05:22:17 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, suravee.suthikulpanit@amd.com, baolu.lu@linux.intel.com, john.garry@huawei.com, dianders@chromium.org, rajatja@google.com, chenxiang66@hisilicon.com Subject: [PATCH v4 14/24] iommu: Indicate queued flushes via gather data Date: Wed, 11 Aug 2021 13:21:28 +0100 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210811_052219_950260_7E8956A7 X-CRM114-Status: GOOD ( 17.77 ) 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 Since iommu_iotlb_gather exists to help drivers optimise flushing for a given unmap request, it is also the logical place to indicate whether the unmap is strict or not, and thus help them further optimise for whether to expect a sync or a flush_all subsequently. As part of that, it also seems fair to make the flush queue code take responsibility for enforcing the really subtle ordering requirement it brings, so that we don't need to worry about forgetting that if new drivers want to add flush queue support, and can consolidate the existing versions. While we're adding to the kerneldoc, also fill in some info for @freelist which was overlooked previously. Signed-off-by: Robin Murphy --- v3: New --- drivers/iommu/dma-iommu.c | 1 + drivers/iommu/iova.c | 7 +++++++ include/linux/iommu.h | 8 +++++++- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index e28396cea6eb..d63b30a7dc82 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -474,6 +474,7 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr, dma_addr -= iova_off; size = iova_align(iovad, size + iova_off); iommu_iotlb_gather_init(&iotlb_gather); + iotlb_gather.queued = cookie->fq_domain; unmapped = iommu_unmap_fast(domain, dma_addr, size, &iotlb_gather); WARN_ON(unmapped != size); diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index b6cf5f16123b..2ad73fb2e94e 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -637,6 +637,13 @@ void queue_iova(struct iova_domain *iovad, unsigned long flags; unsigned idx; + /* + * Order against the IOMMU driver's pagetable update from unmapping + * @pte, to guarantee that iova_domain_flush() observes that if called + * from a different CPU before we release the lock below. + */ + smp_wmb(); + spin_lock_irqsave(&fq->lock, flags); /* diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 141779d76035..f7679f6684b1 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -161,16 +161,22 @@ enum iommu_dev_features { * @start: IOVA representing the start of the range to be flushed * @end: IOVA representing the end of the range to be flushed (inclusive) * @pgsize: The interval at which to perform the flush + * @freelist: Removed pages to free after sync + * @queued: Indicates that the flush will be queued * * This structure is intended to be updated by multiple calls to the * ->unmap() function in struct iommu_ops before eventually being passed - * into ->iotlb_sync(). + * into ->iotlb_sync(). Drivers can add pages to @freelist to be freed after + * ->iotlb_sync() or ->iotlb_flush_all() have cleared all cached references to + * them. @queued is set to indicate when ->iotlb_flush_all() will be called + * later instead of ->iotlb_sync(), so drivers may optimise accordingly. */ struct iommu_iotlb_gather { unsigned long start; unsigned long end; size_t pgsize; struct page *freelist; + bool queued; }; /**