[PATCH 25/34] dma-direct: use phys_to_dma

[Christoph Hellwig]

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 <h...@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.mur...@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