Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934868AbdCJJYU (ORCPT ); Fri, 10 Mar 2017 04:24:20 -0500 Received: from foss.arm.com ([217.140.101.70]:53502 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934852AbdCJJYR (ORCPT ); Fri, 10 Mar 2017 04:24:17 -0500 From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Cc: kbuild-all@01.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, akpm@linux-foundation.org, robin.murphy@arm.com, benjamin.gaignard@linaro.org, alexandre.torgue@st.com, sza@esh.hu, Joerg Roedel , Christian Borntraeger Subject: [PATCH v3 1/7] dma: Take into account dma_pfn_offset Date: Fri, 10 Mar 2017 09:23:53 +0000 Message-Id: <1489137839-549-2-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1489137839-549-1-git-send-email-vladimir.murzin@arm.com> References: <1489137839-549-1-git-send-email-vladimir.murzin@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2258 Lines: 62 Even though dma-noop-ops assumes 1:1 memory mapping DMA memory range can be different to RAM. For example, ARM STM32F4 MCU offers the possibility to remap SDRAM from 0xc000_0000 to 0x0 to get CPU performance boost, but DMA continue to see SDRAM at 0xc000_0000. This difference in mapping is handled via device-tree "dma-range" property which leads to dev->dma_pfn_offset is set nonzero. To handle such cases take dma_pfn_offset into account. Cc: Joerg Roedel Cc: Christian Borntraeger Reported-by: Benjamin Gaignard Tested-by: Benjamin Gaignard Tested-by: Andras Szemzo Tested-by: Alexandre TORGUE Reviewed-by: Robin Murphy Signed-off-by: Vladimir Murzin --- lib/dma-noop.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/lib/dma-noop.c b/lib/dma-noop.c index de26c8b..ff4ef5e 100644 --- a/lib/dma-noop.c +++ b/lib/dma-noop.c @@ -7,6 +7,7 @@ #include #include #include +#include static void *dma_noop_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, @@ -16,7 +17,8 @@ static void *dma_noop_alloc(struct device *dev, size_t size, ret = (void *)__get_free_pages(gfp, get_order(size)); if (ret) - *dma_handle = virt_to_phys(ret); + *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset); + return ret; } @@ -32,7 +34,7 @@ static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page, enum dma_data_direction dir, unsigned long attrs) { - return page_to_phys(page) + offset; + return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset); } static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents, @@ -47,7 +49,7 @@ static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nent BUG_ON(!sg_page(sg)); va = sg_virt(sg); - sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va); + sg_dma_address(sg) = (dma_addr_t)(virt_to_phys(va) - PFN_PHYS(dev->dma_pfn_offset)); sg_dma_len(sg) = sg->length; } -- 2.0.0