The generic IOMMU device-tree bindings can be used to add arbitrary OF
masters to an IOMMU with a compliant binding.
This patch introduces of_iommu_configure, which does exactly that.
Signed-off-by: Will Deacon <will.dea...@arm.com>
---
drivers/iommu/Kconfig | 2 +-
drivers/iommu/of_iommu.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 6 ++++++
3 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index dd5112265cc9..6d13f962f156 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -15,7 +15,7 @@ if IOMMU_SUPPORT
config OF_IOMMU
def_bool y
- depends on OF
+ depends on OF && IOMMU_API
config FSL_PAMU
bool "Freescale IOMMU support"
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index f9209666157c..a7d3b3a13b83 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -19,6 +19,7 @@
#include <linux/export.h>
#include <linux/limits.h>
+#include <linux/iommu.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
@@ -90,6 +91,41 @@ int of_get_dma_window(struct device_node *dn, const char
*prefix, int index,
}
EXPORT_SYMBOL_GPL(of_get_dma_window);
+int of_iommu_configure(struct device *dev)
+{
+ struct of_phandle_args iommu_spec;
+ struct bus_type *bus = dev->bus;
+ const struct iommu_ops *ops = bus->iommu_ops;
+ int ret = -EINVAL, idx = 0;
+
+ if (!iommu_present(bus))
+ return -ENODEV;
+
+ /*
+ * We don't currently walk up the tree looking for a parent IOMMU.
+ * See the `Notes:' section of
+ * Documentation/devicetree/bindings/iommu/iommu.txt
+ */
+ while (!of_parse_phandle_with_args(dev->of_node, "iommus",
+ "#iommu-cells", idx,
+ &iommu_spec)) {
+ void *data = of_iommu_get_data(iommu_spec.np);
+
+ of_node_put(iommu_spec.np);
+ if (!ops->add_device_master_ids)
+ return -ENODEV;
+
+ ret = ops->add_device_master_ids(dev, iommu_spec.args_count,
+ iommu_spec.args, data);
+ if (ret)
+ break;
+
+ idx++;
+ }
+
+ return ret;
+}
+
void __init of_iommu_init(void)
{
struct device_node *np;
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index 29f2f3f88d6a..85c6d1152624 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -1,6 +1,7 @@
#ifndef __OF_IOMMU_H
#define __OF_IOMMU_H
+#include <linux/device.h>
#include <linux/of.h>
#ifdef CONFIG_OF_IOMMU
@@ -10,6 +11,7 @@ extern int of_get_dma_window(struct device_node *dn, const
char *prefix,
size_t *size);
extern void of_iommu_init(void);
+extern int of_iommu_configure(struct device *dev);
#else
@@ -21,6 +23,10 @@ static inline int of_get_dma_window(struct device_node *dn,
const char *prefix,
}
static inline void of_iommu_init(void) { }
+static inline int of_iommu_configure(struct device *dev)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_OF_IOMMU */
--
2.1.0
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