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    Subject[PATCH 24/33] dma-direct: use phys_to_dma
    Date
    This means it uses whatever linear remapping scheme that the architecture
    provides is used in the generic dma_direct ops.

    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
    ---
    lib/dma-direct.c | 18 +++++++-----------
    1 file changed, 7 insertions(+), 11 deletions(-)

    diff --git a/lib/dma-direct.c b/lib/dma-direct.c
    index 0ec3262a3148..12ea9653781b 100644
    --- a/lib/dma-direct.c
    +++ b/lib/dma-direct.c
    @@ -1,12 +1,11 @@
    // SPDX-License-Identifier: GPL-2.0
    /*
    - * lib/dma-noop.c
    - *
    - * DMA operations that map to physical addresses without flushing memory.
    + * DMA operations that map physical memory directly without using an IOMMU or
    + * flushing caches.
    */
    #include <linux/export.h>
    #include <linux/mm.h>
    -#include <linux/dma-mapping.h>
    +#include <linux/dma-direct.h>
    #include <linux/scatterlist.h>
    #include <linux/pfn.h>

    @@ -17,7 +16,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size,

    ret = (void *)__get_free_pages(gfp, get_order(size));
    if (ret)
    - *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset);
    + *dma_handle = phys_to_dma(dev, virt_to_phys(ret));

    return ret;
    }
    @@ -32,7 +31,7 @@ static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
    unsigned long offset, size_t size, enum dma_data_direction dir,
    unsigned long attrs)
    {
    - return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset);
    + return phys_to_dma(dev, page_to_phys(page)) + offset;
    }

    static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
    @@ -42,12 +41,9 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
    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) - offset;
    +
    + sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg));
    sg_dma_len(sg) = sg->length;
    }

    --
    2.14.2
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