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 DDC6FC6FA99 for ; Wed, 8 Mar 2023 03:43:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229614AbjCHDnE (ORCPT ); Tue, 7 Mar 2023 22:43:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229542AbjCHDm6 (ORCPT ); Tue, 7 Mar 2023 22:42:58 -0500 Received: from SHSQR01.spreadtrum.com (mx1.unisoc.com [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4899A8EA6 for ; Tue, 7 Mar 2023 19:42:19 -0800 (PST) Received: from SHSend.spreadtrum.com (bjmbx02.spreadtrum.com [10.0.64.8]) by SHSQR01.spreadtrum.com with ESMTP id 3283g5Qb087717; Wed, 8 Mar 2023 11:42:05 +0800 (+08) (envelope-from Chunyan.Zhang@unisoc.com) Received: from ubt.spreadtrum.com (10.0.74.87) by BJMBX02.spreadtrum.com (10.0.64.8) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Wed, 8 Mar 2023 11:42:02 +0800 From: Chunyan Zhang To: Joerg Roedel , Will Deacon , "Robin Murphy" CC: , Baolu Lu , Baolin Wang , Orson Zhai , "Chunyan Zhang" , Chunyan Zhang , LKML Subject: [PATCH V2] iommu: sprd: release dma buffer to avoid memory leak Date: Wed, 8 Mar 2023 11:41:58 +0800 Message-ID: <20230308034158.509458-1-chunyan.zhang@unisoc.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.0.74.87] X-ClientProxiedBy: SHCAS01.spreadtrum.com (10.0.1.201) To BJMBX02.spreadtrum.com (10.0.64.8) X-MAIL: SHSQR01.spreadtrum.com 3283g5Qb087717 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Release page table DMA buffer when the IOMMU domain is not used: - Domain freed. - IOMMU is attaching to a new domain. Since one sprd IOMMU servers only one client device, if the IOMMU has been attached to other domain, it has to be detached first, that's saying the DMA buffer should be released, otherwise that would cause memory leak issue. Signed-off-by: Chunyan Zhang --- V2: * Added some comment in sprd_iommu_attach_device() for the reason of calling sprd_iommu_cleanup(). V1: https://lkml.org/lkml/2023/2/10/198 --- drivers/iommu/sprd-iommu.c | 46 ++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c index ae94d74b73f4..fb2f96df3bca 100644 --- a/drivers/iommu/sprd-iommu.c +++ b/drivers/iommu/sprd-iommu.c @@ -62,6 +62,7 @@ enum sprd_iommu_version { * @eb: gate clock which controls IOMMU access */ struct sprd_iommu_device { + struct sprd_iommu_domain *dom; enum sprd_iommu_version ver; u32 *prot_page_va; dma_addr_t prot_page_pa; @@ -151,13 +152,6 @@ static struct iommu_domain *sprd_iommu_domain_alloc(unsigned int domain_type) return &dom->domain; } -static void sprd_iommu_domain_free(struct iommu_domain *domain) -{ - struct sprd_iommu_domain *dom = to_sprd_domain(domain); - - kfree(dom); -} - static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom) { struct sprd_iommu_device *sdev = dom->sdev; @@ -230,6 +224,29 @@ static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en) sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val); } +static void sprd_iommu_cleanup(struct sprd_iommu_device *sdev) +{ + struct sprd_iommu_domain *dom = sdev->dom; + size_t pgt_size = sprd_iommu_pgt_size(&dom->domain); + + dma_free_coherent(sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa); + dom->sdev = NULL; + sdev->dom = NULL; + sprd_iommu_hw_en(sdev, false); +} + +static void sprd_iommu_domain_free(struct iommu_domain *domain) +{ + struct sprd_iommu_domain *dom = to_sprd_domain(domain); + struct sprd_iommu_device *sdev = dom->sdev; + + /* Free DMA buffer first if the domain has been attached */ + if (sdev) + sprd_iommu_cleanup(sdev); + + kfree(dom); +} + static int sprd_iommu_attach_device(struct iommu_domain *domain, struct device *dev) { @@ -237,14 +254,29 @@ static int sprd_iommu_attach_device(struct iommu_domain *domain, struct sprd_iommu_domain *dom = to_sprd_domain(domain); size_t pgt_size = sprd_iommu_pgt_size(domain); + /* Return directly if the domain attached to IOMMU already */ if (dom->sdev) return -EINVAL; + /* The IOMMU already attached to a domain */ + if (sdev->dom) { + if (sdev->dom == dom) + return 0; + + /* + * Clean up the previous domain, one sprd IOMMU servers only + * one client device, if the IOMMU has been attached to other + * domain, it has to be detached first. + */ + sprd_iommu_cleanup(sdev); + } + dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL); if (!dom->pgt_va) return -ENOMEM; dom->sdev = sdev; + sdev->dom = dom; sprd_iommu_first_ppn(dom); sprd_iommu_first_vpn(dom); -- 2.25.1