dma-mapping: move dma configuration to bus infrastructure

ACPI/OF support for configuration of DMA is a bus specific aspect, and
thus should be configured by the bus.  Introduces a 'dma_configure' bus
method so that busses can control their DMA capabilities.

Also update the PCI, Platform, ACPI and host1x buses to use the new
method.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>  # PCI parts
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[hch: simplified host1x_dma_configure based on a comment from Thierry,
      rewrote changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 8075ddc70a17..638d42e93772 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1130,6 +1130,22 @@ int platform_pm_restore(struct device *dev)
 
 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 
+int platform_dma_configure(struct device *dev)
+{
+        enum dev_dma_attr attr;
+        int ret = 0;
+
+        if (dev->of_node) {
+                ret = of_dma_configure(dev, dev->of_node);
+        } else if (has_acpi_companion(dev)) {
+                attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
+                if (attr != DEV_DMA_NOT_SUPPORTED)
+                        ret = acpi_dma_configure(dev, attr);
+        }
+
+        return ret;
+}
+
 static const struct dev_pm_ops platform_dev_pm_ops = {
         .runtime_suspend = pm_generic_runtime_suspend,
         .runtime_resume = pm_generic_runtime_resume,
@@ -1141,6 +1157,7 @@ struct bus_type platform_bus_type = {
         .dev_groups     = platform_dev_groups,
         .match          = platform_match,
         .uevent         = platform_uevent,
+        .dma_configure  = platform_dma_configure,
         .pm             = &platform_dev_pm_ops,
         .force_dma      = true,
 };