From patchwork Fri Dec 29 08:18:37 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10136913 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A608D600C5 for ; Fri, 29 Dec 2017 08:58:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 96F742DAA4 for ; Fri, 29 Dec 2017 08:58:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8BEDF2DEEE; Fri, 29 Dec 2017 08:58:40 +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=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 04F0B2DAA4 for ; 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Fri, 29 Dec 2017 08:58:32 +0000 Received: from 77.117.237.29.wireless.dyn.drei.com ([77.117.237.29] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.89 #1 (Red Hat Linux)) id 1eUpvC-0002UP-A1; Fri, 29 Dec 2017 08:21:42 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 33/67] dma-direct: reject too small dma masks Date: Fri, 29 Dec 2017 09:18:37 +0100 Message-Id: <20171229081911.2802-34-hch@lst.de> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171229081911.2802-1-hch@lst.de> References: <20171229081911.2802-1-hch@lst.de> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Guan Xuetao , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org, linux-hexagon@vger.kernel.org, x86@kernel.org, linux-snps-arc@lists.infradead.org, adi-buildroot-devel@lists.sourceforge.net, linux-m68k@lists.linux-m68k.org, patches@groups.riscv.org, linux-metag@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Michal Simek , linux-parisc@vger.kernel.org, linux-cris-kernel@axis.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Christoph Hellwig --- include/linux/dma-direct.h | 1 + lib/dma-direct.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 4788bf0bf683..bcdb1a3e4b1f 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -42,5 +42,6 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs); void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs); +int dma_direct_supported(struct device *dev, u64 mask); #endif /* _LINUX_DMA_DIRECT_H */ diff --git a/lib/dma-direct.c b/lib/dma-direct.c index 2e9b9494610c..5bb289483efc 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -123,6 +123,24 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, return nents; } +int dma_direct_supported(struct device *dev, u64 mask) +{ +#ifdef CONFIG_ZONE_DMA + if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) + return 0; +#else + /* + * Because 32-bit DMA masks are so common we expect every architecture + * to be able to satisfy them - either by not supporting more physical + * memory, or by providing a ZONE_DMA32. If neither is the case, the + * architecture needs to use an IOMMU instead of the direct mapping. + */ + if (mask < DMA_BIT_MASK(32)) + return 0; +#endif + return 1; +} + static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) { return dma_addr == DIRECT_MAPPING_ERROR; @@ -133,6 +151,7 @@ const struct dma_map_ops dma_direct_ops = { .free = dma_direct_free, .map_page = dma_direct_map_page, .map_sg = dma_direct_map_sg, + .dma_supported = dma_direct_supported, .mapping_error = dma_direct_mapping_error, .is_phys = true, };