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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C8753C4332F for ; Wed, 15 Sep 2021 15:21:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0BF560FC0 for ; Wed, 15 Sep 2021 15:21:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238071AbhIOPW7 (ORCPT ); Wed, 15 Sep 2021 11:22:59 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:9736 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234118AbhIOPWz (ORCPT ); Wed, 15 Sep 2021 11:22:55 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4H8kS11stHzW1dR; Wed, 15 Sep 2021 23:20:33 +0800 (CST) Received: from dggpeml100016.china.huawei.com (7.185.36.216) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Wed, 15 Sep 2021 23:21:34 +0800 Received: from DESKTOP-27KDQMV.china.huawei.com (10.174.148.223) by dggpeml100016.china.huawei.com (7.185.36.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Wed, 15 Sep 2021 23:21:33 +0800 From: "Longpeng(Mike)" To: , , , CC: , , , "Longpeng(Mike)" Subject: [PATCH v1 2/2] iommu/vt-d: avoid duplicated removing in __domain_mapping Date: Wed, 15 Sep 2021 23:21:29 +0800 Message-ID: <20210915152129.1254-3-longpeng2@huawei.com> X-Mailer: git-send-email 2.25.0.windows.1 In-Reply-To: <20210915152129.1254-1-longpeng2@huawei.com> References: <20210915152129.1254-1-longpeng2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpeml100016.china.huawei.com (7.185.36.216) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __domain_mapping() always removes the pages in the range from 'iov_pfn' to 'end_pfn', but the 'end_pfn' is always the last pfn of the range that the caller wants to map. This would introduce too many duplicated removing and leads the map operation take too long, for example: Map iova=0x100000,nr_pages=0x7d61800 iov_pfn: 0x100000, end_pfn: 0x7e617ff iov_pfn: 0x140000, end_pfn: 0x7e617ff iov_pfn: 0x180000, end_pfn: 0x7e617ff iov_pfn: 0x1c0000, end_pfn: 0x7e617ff iov_pfn: 0x200000, end_pfn: 0x7e617ff ... it takes about 50ms in total. We can reduce the cost by recalculate the 'end_pfn' and limit it to the boundary of the end of the pte page. Map iova=0x100000,nr_pages=0x7d61800 iov_pfn: 0x100000, end_pfn: 0x13ffff iov_pfn: 0x140000, end_pfn: 0x17ffff iov_pfn: 0x180000, end_pfn: 0x1bffff iov_pfn: 0x1c0000, end_pfn: 0x1fffff iov_pfn: 0x200000, end_pfn: 0x23ffff ... it only need 9ms now. Signed-off-by: Longpeng(Mike) --- drivers/iommu/intel/iommu.c | 12 +++++++----- include/linux/intel-iommu.h | 6 ++++++ 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index d75f59a..87cbf34 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2354,12 +2354,18 @@ static void switch_to_super_page(struct dmar_domain *domain, return -ENOMEM; first_pte = pte; + lvl_pages = lvl_to_nr_pages(largepage_lvl); + BUG_ON(nr_pages < lvl_pages); + /* It is large page*/ if (largepage_lvl > 1) { unsigned long end_pfn; + unsigned long pages_to_remove; pteval |= DMA_PTE_LARGE_PAGE; - end_pfn = ((iov_pfn + nr_pages) & level_mask(largepage_lvl)) - 1; + pages_to_remove = min_t(unsigned long, nr_pages, + nr_pte_to_next_page(pte) * lvl_pages); + end_pfn = iov_pfn + pages_to_remove - 1; switch_to_super_page(domain, iov_pfn, end_pfn, largepage_lvl); } else { pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE; @@ -2381,10 +2387,6 @@ static void switch_to_super_page(struct dmar_domain *domain, WARN_ON(1); } - lvl_pages = lvl_to_nr_pages(largepage_lvl); - - BUG_ON(nr_pages < lvl_pages); - nr_pages -= lvl_pages; iov_pfn += lvl_pages; phys_pfn += lvl_pages; diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index a590b00..4bff70c 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -713,6 +713,12 @@ static inline bool first_pte_in_page(struct dma_pte *pte) return !((unsigned long)pte & ~VTD_PAGE_MASK); } +static inline int nr_pte_to_next_page(struct dma_pte *pte) +{ + return first_pte_in_page(pte) ? BIT_ULL(VTD_STRIDE_SHIFT) : + (struct dma_pte *)VTD_PAGE_ALIGN((unsigned long)pte) - pte; +} + extern struct dmar_drhd_unit * dmar_find_matched_drhd_unit(struct pci_dev *dev); extern int dmar_find_matched_atsr_unit(struct pci_dev *dev); -- 1.8.3.1