From: Vladimir Murzin vladimir.murzin@arm.com
[ Upstream commit 25f1e18870881f3366a5abec27b651983ce9032c ]
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 jroedel@suse.de Cc: Christian Borntraeger borntraeger@de.ibm.com Reported-by: Benjamin Gaignard benjamin.gaignard@linaro.org Tested-by: Benjamin Gaignard benjamin.gaignard@linaro.org Tested-by: Andras Szemzo sza@esh.hu Tested-by: Alexandre TORGUE alexandre.torgue@st.com Reviewed-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- 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 3d766e78fbe2..9a7b5ed7ceac 100644 --- a/lib/dma-noop.c +++ b/lib/dma-noop.c @@ -7,6 +7,7 @@ #include <linux/mm.h> #include <linux/dma-mapping.h> #include <linux/scatterlist.h> +#include <linux/pfn.h>
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; }