From patchwork Mon Aug 5 09:11:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11076345 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 577E613AC for ; Mon, 5 Aug 2019 09:13:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 459CC1FE82 for ; Mon, 5 Aug 2019 09:13:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 373E9286A4; Mon, 5 Aug 2019 09:13:15 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable 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 C5CD91FE82 for ; Mon, 5 Aug 2019 09:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728077AbfHEJMR (ORCPT ); Mon, 5 Aug 2019 05:12:17 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:34434 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728067AbfHEJMQ (ORCPT ); Mon, 5 Aug 2019 05:12:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=urEmUUgdHQK/RXisjgziTewBbi9Y6Q1gTs0AWjfkJa4=; b=t/QmNF9K0u3YouJ4rprzdwLiu3 pq0Ju27OXGFCUDZNcHEg1LqwhycGIlPuO9U6/SIVaWFJ3jJJq32TokI9y+h6Y7nhet9HM9ZQF/6Bi 43+BNkAzi4O31w4OniYVzgQ+zBiJ5QxviAimO5OFhNLV5sHoBI2AyB2LMVuj7S0/TbTPB5tlQhODs hPdLd+WCQj4Cckuo2FZHSP27KP/5vA+VqCt+emHHWH/89phj6Iu0X+UgrEdmFrZ+ZpB4dsa6VcnIm GFA3VknvjrcVZbn0/OIVzey1wxfRVSmbi/SwzhAkTswnvvqZz9QHC67atngF7ukZiGzmNlg+BGbKK TtYIr4tQ==; Received: from [195.167.85.94] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1huZ2I-0004x8-6E; Mon, 05 Aug 2019 09:12:11 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org, Marek Szyprowski Cc: Takashi Iwai , Robin Murphy , Michal Simek , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/7] dma-mapping: add a dma_can_mmap helper Date: Mon, 5 Aug 2019 12:11:55 +0300 Message-Id: <20190805091159.7826-4-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190805091159.7826-1-hch@lst.de> References: <20190805091159.7826-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a helper to check if DMA allocations for a specific device can be mapped to userspace using dma_mmap_*. Signed-off-by: Christoph Hellwig --- include/linux/dma-mapping.h | 5 +++++ kernel/dma/mapping.c | 23 +++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f7d1eea32c78..17271857be5d 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -462,6 +462,7 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs); +bool dma_can_mmap(struct device *dev); int dma_supported(struct device *dev, u64 mask); int dma_set_mask(struct device *dev, u64 mask); int dma_set_coherent_mask(struct device *dev, u64 mask); @@ -552,6 +553,10 @@ static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, { return -ENXIO; } +static inline bool dma_can_mmap(struct device *dev) +{ + return false; +} static inline int dma_supported(struct device *dev, u64 mask) { return 0; diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index cdb157cd70e7..ab6aa355e1a0 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -203,6 +203,29 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, #endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ } +/** + * dma_can_mmap - check if a given device supports dma_mmap_* + * @dev: device to check + * + * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to + * map DMA allocations to userspace. + */ +bool dma_can_mmap(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (IS_ENABLED(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)) + return false; + + if (dma_is_direct(ops)) { + return dev_is_dma_coherent(dev) || + IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN); + } + + return ops->mmap != NULL; +} +EXPORT_SYMBOL_GPL(dma_can_mmap); + /** * dma_mmap_attrs - map a coherent DMA allocation into user space * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices