From patchwork Wed Aug 4 17:15:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12419489 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 3DB77C4338F for ; Wed, 4 Aug 2021 17:23:44 +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 01A556023B for ; Wed, 4 Aug 2021 17:23:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 01A556023B 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=gYAEYPHISS2uKL /pfeE/Ub3klBfpLALwakzoOm7MAJ8eNeD8Uxx6PiJw49neEZVqWkONkn+ccbmIheh1wgs2o2syehU 0Qa9NXTPznkjeUZfWm3bH1/gw0dQ/5o1qS6tXJqVJ7FMEVfQzEYKWO0hn9QB1zc9OQKmmLzsCXqR0 gkxeJ5LY9y75qfz+asnE3VGFZ4io+toO9wI0VpOLvdAlfMzOk97fVjmQtXcOtAURniGP7tIetEUhn 6/XGynQ1A2uIwtX/vB/i0yIb82yR3aYsRIQ6ghEWMQmV+QG1c8n+kIR36KlBXpJcRfqUE7seZKDSK QJPsJI8TrKyj24KKd2CQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mBKas-006wZ9-Vi; Wed, 04 Aug 2021 17:22:15 +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 1mBKVS-006tSU-Er for linux-arm-kernel@lists.infradead.org; Wed, 04 Aug 2021 17:16:40 +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 00BED1424; Wed, 4 Aug 2021 10:16:38 -0700 (PDT) Received: from 010265703453.arm.com (unknown [10.57.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 48A5A3F66F; Wed, 4 Aug 2021 10:16:36 -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 v3 14/25] iommu: Indicate queued flushes via gather data Date: Wed, 4 Aug 2021 18:15:42 +0100 Message-Id: <8f7cd9a8114e3b3f44231849a3b46e7c75cec25e.1628094601.git.robin.murphy@arm.com> 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-20210804_101638_647087_7996716B X-CRM114-Status: GOOD ( 18.13 ) 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; }; /**