From patchwork Wed Jan 30 16:40:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 10789007 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2D38913BF for ; Wed, 30 Jan 2019 16:40:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 17ECF2FF3B for ; Wed, 30 Jan 2019 16:40:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 162D82FF74; Wed, 30 Jan 2019 16:40:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A562B2FF3B for ; Wed, 30 Jan 2019 16:40:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732090AbfA3Qke (ORCPT ); Wed, 30 Jan 2019 11:40:34 -0500 Received: from 8bytes.org ([81.169.241.247]:36028 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732089AbfA3QkK (ORCPT ); Wed, 30 Jan 2019 11:40:10 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 0102E69F; Wed, 30 Jan 2019 17:40:08 +0100 (CET) From: Joerg Roedel To: "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk , Christoph Hellwig Cc: Jens Axboe , virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jfehlig@suse.com, jon.grimm@amd.com, brijesh.singh@amd.com, joro@8bytes.org, jroedel@suse.de, Thomas.Lendacky@amd.com Subject: [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Date: Wed, 30 Jan 2019 17:40:04 +0100 Message-Id: <20190130164007.26497-3-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190130164007.26497-1-joro@8bytes.org> References: <20190130164007.26497-1-joro@8bytes.org> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Joerg Roedel This function will be used from dma_direct code to determine the maximum segment size of a dma mapping. Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Christoph Hellwig Signed-off-by: Joerg Roedel --- include/linux/swiotlb.h | 6 ++++++ kernel/dma/swiotlb.c | 9 +++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 1c22d96e1742..e9e786b4b598 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -63,6 +63,7 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev, extern int swiotlb_dma_supported(struct device *hwdev, u64 mask); size_t swiotlb_max_mapping_size(struct device *dev); +bool is_swiotlb_active(void); #ifdef CONFIG_SWIOTLB extern enum swiotlb_force swiotlb_force; @@ -100,6 +101,11 @@ static inline size_t swiotlb_max_mapping_size(struct device *dev) { return SIZE_MAX; } + +static inline bool is_swiotlb_active(void) +{ + return false; +} #endif /* CONFIG_SWIOTLB */ extern void swiotlb_print_info(void); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 9cb21259cb0b..c873f9cc2146 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -667,3 +667,12 @@ size_t swiotlb_max_mapping_size(struct device *dev) { return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; } + +bool is_swiotlb_active(void) +{ + /* + * When SWIOTLB is initialized, even if io_tlb_start points to physical + * address zero, io_tlb_end surely doesn't. + */ + return io_tlb_end != 0; +}