1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 51b7061ff7c0..f3deb6af42ad 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -7,9 +7,11 @@
  * This file is released under the GPLv2.
  */
 
+#include <linux/acpi.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -340,3 +342,42 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
         vunmap(cpu_addr);
 }
 #endif
+
+/*
+ * Common configuration to enable DMA API use for a device
+ */
+#include <linux/pci.h>
+
+int dma_configure(struct device *dev)
+{
+        struct device *bridge = NULL, *dma_dev = dev;
+        enum dev_dma_attr attr;
+        int ret = 0;
+
+        if (dev_is_pci(dev)) {
+                bridge = pci_get_host_bridge_device(to_pci_dev(dev));
+                dma_dev = bridge;
+                if (IS_ENABLED(CONFIG_OF) && dma_dev->parent &&
+                    dma_dev->parent->of_node)
+                        dma_dev = dma_dev->parent;
+        }
+
+        if (dma_dev->of_node) {
+                ret = of_dma_configure(dev, dma_dev->of_node);
+        } else if (has_acpi_companion(dma_dev)) {
+                attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode));
+                if (attr != DEV_DMA_NOT_SUPPORTED)
+                        ret = acpi_dma_configure(dev, attr);
+        }
+
+        if (bridge)
+                pci_put_host_bridge_device(bridge);
+
+        return ret;
+}
+
+void dma_deconfigure(struct device *dev)
+{
+        of_dma_deconfigure(dev);
+        acpi_dma_deconfigure(dev);
+}