xen-swiotlb: implement ->mapping_error

DMA_ERROR_CODE is going to go away, so don't rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index a0f006daab48c716652186b4838ffc52d2c1b087..c3a04b2d7532402d7ed5fc5e163b74a5a3e0c2be 100644 (file)
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -67,6 +67,8 @@ static unsigned long dma_alloc_coherent_mask(struct device *dev,
 }
 #endif
 
+#define XEN_SWIOTLB_ERROR_CODE (~(dma_addr_t)0x0)
+
 static char *xen_io_tlb_start, *xen_io_tlb_end;
 static unsigned long xen_io_tlb_nslabs;
 /*
@@ -410,7 +412,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
        map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
                                     attrs);
        if (map == SWIOTLB_MAP_ERROR)
-               return DMA_ERROR_CODE;
+               return XEN_SWIOTLB_ERROR_CODE;
 
        dev_addr = xen_phys_to_bus(map);
        xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
@@ -425,7 +427,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
        attrs |= DMA_ATTR_SKIP_CPU_SYNC;
        swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
 
-       return DMA_ERROR_CODE;
+       return XEN_SWIOTLB_ERROR_CODE;
 }
 
 /*
@@ -715,6 +717,11 @@ xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
        return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
 }
 
+static int xen_swiotlb_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+       return dma_addr == XEN_SWIOTLB_ERROR_CODE;
+}
+
 const struct dma_map_ops xen_swiotlb_dma_ops = {
        .alloc = xen_swiotlb_alloc_coherent,
        .free = xen_swiotlb_free_coherent,
@@ -730,4 +737,5 @@ const struct dma_map_ops xen_swiotlb_dma_ops = {
        .set_dma_mask = xen_swiotlb_set_dma_mask,
        .mmap = xen_swiotlb_dma_mmap,
        .get_sgtable = xen_swiotlb_get_sgtable,
+       .mapping_error  = xen_swiotlb_mapping_error,
 };