iommu: Add DMA mapping operations
In order to support IOMMUs in non-bypass mode we need device ops
to map and unmap DMA memory. The map operation enters a mapping
for a region specified by CPU address and size into the translation
table of the IOMMU and returns a DMA address suitable for
programming the device to do DMA. The unmap operation removes
this mapping from the translation table of the IOMMU.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
diff --git a/drivers/iommu/iommu-uclass.c b/drivers/iommu/iommu-uclass.c
index ed917b3..f6b1457 100644
--- a/drivers/iommu/iommu-uclass.c
+++ b/drivers/iommu/iommu-uclass.c
@@ -7,6 +7,9 @@
#include <common.h>
#include <dm.h>
+#include <iommu.h>
+#include <phys2bus.h>
+#include <asm/io.h>
#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA))
int dev_iommu_enable(struct udevice *dev)
@@ -33,12 +36,37 @@
__func__, ret);
return ret;
}
+ dev->iommu = dev_iommu;
}
return 0;
}
#endif
+dma_addr_t dev_iommu_dma_map(struct udevice *dev, void *addr, size_t size)
+{
+ const struct iommu_ops *ops;
+
+ if (dev->iommu) {
+ ops = device_get_ops(dev->iommu);
+ if (ops && ops->map)
+ return ops->map(dev->iommu, addr, size);
+ }
+
+ return dev_phys_to_bus(dev, virt_to_phys(addr));
+}
+
+void dev_iommu_dma_unmap(struct udevice *dev, dma_addr_t addr, size_t size)
+{
+ const struct iommu_ops *ops;
+
+ if (dev->iommu) {
+ ops = device_get_ops(dev->iommu);
+ if (ops && ops->unmap)
+ ops->unmap(dev->iommu, addr, size);
+ }
+}
+
UCLASS_DRIVER(iommu) = {
.id = UCLASS_IOMMU,
.name = "iommu",
diff --git a/include/dm/device.h b/include/dm/device.h
index f3f953c..e946038 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -165,6 +165,7 @@
* automatically when the device is removed / unbound
* @dma_offset: Offset between the physical address space (CPU's) and the
* device's bus address space
+ * @iommu: IOMMU device associated with this device
*/
struct udevice {
const struct driver *driver;
@@ -194,6 +195,9 @@
#if CONFIG_IS_ENABLED(DM_DMA)
ulong dma_offset;
#endif
+#if CONFIG_IS_ENABLED(IOMMU)
+ struct udevice *iommu;
+#endif
};
static inline int dm_udevice_size(void)
diff --git a/include/iommu.h b/include/iommu.h
index 6c46adf..cf9719c 100644
--- a/include/iommu.h
+++ b/include/iommu.h
@@ -3,6 +3,27 @@
struct udevice;
+struct iommu_ops {
+ /**
+ * map() - map DMA memory
+ *
+ * @dev: device for which to map DMA memory
+ * @addr: CPU address of the memory
+ * @size: size of the memory
+ * @return DMA address for the device
+ */
+ dma_addr_t (*map)(struct udevice *dev, void *addr, size_t size);
+
+ /**
+ * unmap() - unmap DMA memory
+ *
+ * @dev: device for which to unmap DMA memory
+ * @addr: DMA address of the memory
+ * @size: size of the memory
+ */
+ void (*unmap)(struct udevice *dev, dma_addr_t addr, size_t size);
+};
+
#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \
CONFIG_IS_ENABLED(IOMMU)
int dev_iommu_enable(struct udevice *dev);
@@ -13,4 +34,7 @@
}
#endif
+dma_addr_t dev_iommu_dma_map(struct udevice *dev, void *addr, size_t size);
+void dev_iommu_dma_unmap(struct udevice *dev, dma_addr_t addr, size_t size);
+
#endif