swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device

Call xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu,
xen_dma_sync_single_for_device from swiotlb-xen to ensure cpu/device
coherency of the pages used for DMA, including the ones belonging to the
swiotlb buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 31 insertions, 8 deletions

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 189b8db5c983..4221cb52387d 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -378,8 +378,13 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
          * buffering it.
          */
         if (dma_capable(dev, dev_addr, size) &&
-            !range_straddles_page_boundary(phys, size) && !swiotlb_force)
+            !range_straddles_page_boundary(phys, size) && !swiotlb_force) {
+                /* we are not interested in the dma_addr returned by
+                 * xen_dma_map_page, only in the potential cache flushes executed
+                 * by the function. */
+                xen_dma_map_page(dev, page, offset, size, dir, attrs);
                 return dev_addr;
+        }
 
         /*
          * Oh well, have to allocate and map a bounce buffer.
@@ -388,6 +393,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
         if (map == SWIOTLB_MAP_ERROR)
                 return DMA_ERROR_CODE;
 
+        xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
+                                        map & ~PAGE_MASK, size, dir, attrs);
         dev_addr = xen_phys_to_bus(map);
 
         /*
@@ -410,12 +417,15 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
  * whatever the device wrote there.
  */
 static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
-                             size_t size, enum dma_data_direction dir)
+                             size_t size, enum dma_data_direction dir,
+                                 struct dma_attrs *attrs)
 {
         phys_addr_t paddr = xen_bus_to_phys(dev_addr);
 
         BUG_ON(dir == DMA_NONE);
 
+        xen_dma_unmap_page(hwdev, paddr, size, dir, attrs);
+
         /* NOTE: We use dev_addr here, not paddr! */
         if (is_xen_swiotlb_buffer(dev_addr)) {
                 swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
@@ -438,7 +448,7 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
                             size_t size, enum dma_data_direction dir,
                             struct dma_attrs *attrs)
 {
-        xen_unmap_single(hwdev, dev_addr, size, dir);
+        xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);
 
@@ -461,11 +471,15 @@ xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
 
         BUG_ON(dir == DMA_NONE);
 
+        if (target == SYNC_FOR_CPU)
+                xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);
+
         /* NOTE: We use dev_addr here, not paddr! */
-        if (is_xen_swiotlb_buffer(dev_addr)) {
+        if (is_xen_swiotlb_buffer(dev_addr))
                 swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
-                return;
-        }
+
+        if (target == SYNC_FOR_DEVICE)
+                xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);
 
         if (dir != DMA_FROM_DEVICE)
                 return;
@@ -536,8 +550,17 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
                                 return DMA_ERROR_CODE;
                         }
                         sg->dma_address = xen_phys_to_bus(map);
-                } else
+                } else {
+                        /* we are not interested in the dma_addr returned by
+                         * xen_dma_map_page, only in the potential cache flushes executed
+                         * by the function. */
+                        xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
+                                                paddr & ~PAGE_MASK,
+                                                sg->length,
+                                                dir,
+                                                attrs);
                         sg->dma_address = dev_addr;
+                }
                 sg_dma_len(sg) = sg->length;
         }
         return nelems;
@@ -559,7 +582,7 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
         BUG_ON(dir == DMA_NONE);
 
         for_each_sg(sgl, sg, nelems, i)
-                xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir);
+                xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);
 
 }
 EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs);