Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752055AbdFZJUH (ORCPT ); Mon, 26 Jun 2017 05:20:07 -0400 Received: from foss.arm.com ([217.140.101.70]:40824 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353AbdFZJTY (ORCPT ); Mon, 26 Jun 2017 05:19:24 -0400 From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux@armlinux.org.uk, sza@esh.hu, arnd@arndb.de, gregkh@linuxfoundation.org, akpm@linux-foundation.org, alexandre.torgue@st.com, robin.murphy@arm.com, kbuild-all@01.org, benjamin.gaignard@linaro.org, hch@lst.de, m.szyprowski@samsung.com, Joerg Roedel , Christian Borntraeger Subject: [PATCH v6 1/7] dma: Take into account dma_pfn_offset Date: Mon, 26 Jun 2017 10:18:55 +0100 Message-Id: <1498468741-12020-2-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1498468741-12020-1-git-send-email-vladimir.murzin@arm.com> References: <1498468741-12020-1-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: 2366 Lines: 67 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 | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/dma-noop.c b/lib/dma-noop.c index de26c8b..1f60c8a 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, @@ -43,11 +45,12 @@ static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nent struct scatterlist *sg; for_each_sg(sgl, sg, nents, i) { + dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset); void *va; 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) - offset; sg_dma_len(sg) = sg->length; } -- 2.0.0