rust: kernel: platform: Add Device.set_dma_masks()

Allows drivers to configure the DMA masks for a device. Implemented
here, not in device, because it requires a mutable platform device
reference this way (device::Device is a safely clonable reference).

Signed-off-by: Asahi Lina <lina@asahilina.net>

Author: hoshinolina

rust/bindings/bindings_helper.h

@@ -16,6 +16,7 @@
 #include <linux/blk_types.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/errname.h>
 #include <linux/ethtool.h>
 #include <linux/firmware.h>

rust/helpers/device.c

@@ -1,10 +1,26 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/device.h>
+#include <linux/dma-mapping.h>
+
+void *rust_helper_dev_get_drvdata(struct device *dev)
+{
+	return dev_get_drvdata(dev);
+}
 
 int rust_helper_devm_add_action(struct device *dev,
 				void (*action)(void *),
 				void *data)
 {
 	return devm_add_action(dev, action, data);
 }
+
+const char *rust_helper_dev_name(const struct device *dev)
+{
+	return dev_name(dev);
+}
+
+int rust_helper_dma_set_mask_and_coherent(struct device *dev, u64 mask)
+{
+	return dma_set_mask_and_coherent(dev, mask);
+}

rust/kernel/platform.rs

@@ -216,6 +216,12 @@ impl Device {
         unsafe { container_of!(self.dev.as_raw(), bindings::platform_device, dev) }.cast_mut()
     }
 
+    /// Sets the DMA masks (normal and coherent) for a platform device.
+    pub fn set_dma_masks(&mut self, mask: u64) -> Result {
+        // SAFETY: `self.ptr` is valid by the type invariant.
+        to_result(unsafe { bindings::dma_set_mask_and_coherent(&mut (*self.ptr).dev, mask) })
+    }
+
     /// Gets a system resources of a platform device.
     pub fn get_resource(&mut self, rtype: IoResource, num: usize) -> Result<Resource> {
         // SAFETY: `self.ptr` is valid by the type invariant.