1 files changed, 58 insertions, 0 deletions

diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
new file mode 100644
index 000000000000..a013ec9d0c54
--- /dev/null
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -0,0 +1,58 @@
+/* Glue code to lib/swiotlb-xen.c */
+
+#include <linux/dma-mapping.h>
+#include <xen/swiotlb-xen.h>
+
+#include <asm/xen/hypervisor.h>
+#include <xen/xen.h>
+
+int xen_swiotlb __read_mostly;
+
+static struct dma_map_ops xen_swiotlb_dma_ops = {
+        .mapping_error = xen_swiotlb_dma_mapping_error,
+        .alloc_coherent = xen_swiotlb_alloc_coherent,
+        .free_coherent = xen_swiotlb_free_coherent,
+        .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
+        .sync_single_for_device = xen_swiotlb_sync_single_for_device,
+        .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
+        .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
+        .map_sg = xen_swiotlb_map_sg_attrs,
+        .unmap_sg = xen_swiotlb_unmap_sg_attrs,
+        .map_page = xen_swiotlb_map_page,
+        .unmap_page = xen_swiotlb_unmap_page,
+        .dma_supported = xen_swiotlb_dma_supported,
+};
+
+/*
+ * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
+ *
+ * This returns non-zero if we are forced to use xen_swiotlb (by the boot
+ * option).
+ */
+int __init pci_xen_swiotlb_detect(void)
+{
+
+        /* If running as PV guest, either iommu=soft, or swiotlb=force will
+         * activate this IOMMU. If running as PV privileged, activate it
+         * irregardlesss.
+         */
+        if ((xen_initial_domain() || swiotlb || swiotlb_force) &&
+            (xen_pv_domain()))
+                xen_swiotlb = 1;
+
+        /* If we are running under Xen, we MUST disable the native SWIOTLB.
+         * Don't worry about swiotlb_force flag activating the native, as
+         * the 'swiotlb' flag is the only one turning it on. */
+        if (xen_pv_domain())
+                swiotlb = 0;
+
+        return xen_swiotlb;
+}
+
+void __init pci_xen_swiotlb_init(void)
+{
+        if (xen_swiotlb) {
+                xen_swiotlb_init(1);
+                dma_ops = &xen_swiotlb_dma_ops;
+        }
+}