[PATCH v4 5/6] xen: swiotlb: Switch to physical address mapping callbacks

[Leon Romanovsky <leon@xxxxxxxxxx>]

From: Leon Romanovsky <leonro@xxxxxxxxxx>

Combine resource and page mappings routines to one function
and remove .map_resource/.unmap_resource callbacks completely.

Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 drivers/xen/swiotlb-xen.c | 63 ++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 34 deletions(-)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index dd7747a2de879..48936179c940b 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -200,17 +200,32 @@ xen_swiotlb_free_coherent(struct device *dev, size_t 
size, void *vaddr,
  * physical address to use is returned.
  *
  * Once the device is given the dma address, the device owns this memory until
- * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed.
+ * either xen_swiotlb_unmap_phys or xen_swiotlb_dma_sync_single is performed.
  */
-static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
-                               unsigned long offset, size_t size,
-                               enum dma_data_direction dir,
+static dma_addr_t xen_swiotlb_map_phys(struct device *dev, phys_addr_t phys,
+                               size_t size, enum dma_data_direction dir,
                                unsigned long attrs)
 {
-       phys_addr_t map, phys = page_to_phys(page) + offset;
-       dma_addr_t dev_addr = xen_phys_to_dma(dev, phys);
+       dma_addr_t dev_addr;
+       phys_addr_t map;
 
        BUG_ON(dir == DMA_NONE);
+
+       if (attrs & DMA_ATTR_MMIO) {
+               if (unlikely(!dma_capable(dev, phys, size, false))) {
+                       dev_err_once(
+                               dev,
+                               "DMA addr %pad+%zu overflow (mask %llx, bus 
limit %llx).\n",
+                               &dma_addr, size, *dev->dma_mask,
+                               dev->bus_dma_limit);
+                       WARN_ON_ONCE(1);
+                       return DMA_MAPPING_ERROR;
+               }
+               return phys;
+       }
+
+       dev_addr = xen_phys_to_dma(dev, phys);
+
        /*
         * If the address happens to be in the device's DMA window,
         * we can safely return the device addr and not worry about bounce
@@ -257,13 +272,13 @@ static dma_addr_t xen_swiotlb_map_page(struct device 
*dev, struct page *page,
 
 /*
  * Unmap a single streaming mode DMA translation.  The dma_addr and size must
- * match what was provided for in a previous xen_swiotlb_map_page call.  All
+ * match what was provided for in a previous xen_swiotlb_map_phys call.  All
  * other usages are undefined.
  *
  * After this call, reads by the cpu to the buffer are guaranteed to see
  * whatever the device wrote there.
  */
-static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
+static void xen_swiotlb_unmap_phys(struct device *hwdev, dma_addr_t dev_addr,
                size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
        phys_addr_t paddr = xen_dma_to_phys(hwdev, dev_addr);
@@ -325,7 +340,7 @@ xen_swiotlb_sync_single_for_device(struct device *dev, 
dma_addr_t dma_addr,
 
 /*
  * Unmap a set of streaming mode DMA translations.  Again, cpu read rules
- * concerning calls here are the same as for swiotlb_unmap_page() above.
+ * concerning calls here are the same as for swiotlb_unmap_phys() above.
  */
 static void
 xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
@@ -337,7 +352,7 @@ xen_swiotlb_unmap_sg(struct device *hwdev, struct 
scatterlist *sgl, int nelems,
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i)
-               xen_swiotlb_unmap_page(hwdev, sg->dma_address, sg_dma_len(sg),
+               xen_swiotlb_unmap_phys(hwdev, sg->dma_address, sg_dma_len(sg),
                                dir, attrs);
 
 }
@@ -352,8 +367,8 @@ xen_swiotlb_map_sg(struct device *dev, struct scatterlist 
*sgl, int nelems,
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i) {
-               sg->dma_address = xen_swiotlb_map_page(dev, sg_page(sg),
-                               sg->offset, sg->length, dir, attrs);
+               sg->dma_address = xen_swiotlb_map_phys(dev, sg_phys(sg),
+                               sg->length, dir, attrs);
                if (sg->dma_address == DMA_MAPPING_ERROR)
                        goto out_unmap;
                sg_dma_len(sg) = sg->length;
@@ -392,25 +407,6 @@ xen_swiotlb_sync_sg_for_device(struct device *dev, struct 
scatterlist *sgl,
        }
 }
 
-static dma_addr_t xen_swiotlb_direct_map_resource(struct device *dev,
-                                                 phys_addr_t paddr,
-                                                 size_t size,
-                                                 enum dma_data_direction dir,
-                                                 unsigned long attrs)
-{
-       dma_addr_t dma_addr = paddr;
-
-       if (unlikely(!dma_capable(dev, dma_addr, size, false))) {
-               dev_err_once(dev,
-                            "DMA addr %pad+%zu overflow (mask %llx, bus limit 
%llx).\n",
-                            &dma_addr, size, *dev->dma_mask, 
dev->bus_dma_limit);
-               WARN_ON_ONCE(1);
-               return DMA_MAPPING_ERROR;
-       }
-
-       return dma_addr;
-}
-
 /*
  * Return whether the given device DMA address mask can be supported
  * properly.  For example, if your device can only drive the low 24-bits
@@ -437,13 +433,12 @@ const struct dma_map_ops xen_swiotlb_dma_ops = {
        .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
        .map_sg = xen_swiotlb_map_sg,
        .unmap_sg = xen_swiotlb_unmap_sg,
-       .map_page = xen_swiotlb_map_page,
-       .unmap_page = xen_swiotlb_unmap_page,
+       .map_phys = xen_swiotlb_map_phys,
+       .unmap_phys = xen_swiotlb_unmap_phys,
        .dma_supported = xen_swiotlb_dma_supported,
        .mmap = dma_common_mmap,
        .get_sgtable = dma_common_get_sgtable,
        .alloc_pages_op = dma_common_alloc_pages,
        .free_pages = dma_common_free_pages,
        .max_mapping_size = swiotlb_max_mapping_size,
-       .map_resource = xen_swiotlb_direct_map_resource,
 };
-- 
2.51.0