To allow for more customized device tree bindings that point to IOMMUs,
allow manual specification of iommu_spec to of_dma_configure.

The initial use case for this is with Host1x, where the driver manages
a set of device tree-defined IOMMU contexts that are dynamically
allocated to various users. These contexts don't correspond to
platform devices and are instead attached to dummy devices on a custom
software bus.

Signed-off-by: Mikko Perttunen <mperttu...@nvidia.com>
---
 drivers/iommu/of_iommu.c  | 12 ++++++++----
 drivers/of/device.c       |  9 +++++----
 include/linux/of_device.h | 34 +++++++++++++++++++++++++++-------
 include/linux/of_iommu.h  |  6 ++++--
 4 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index e505b9130a1c..3fefa6c63863 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -87,8 +87,7 @@ int of_get_dma_window(struct device_node *dn, const char 
*prefix, int index,
 }
 EXPORT_SYMBOL_GPL(of_get_dma_window);
 
-static int of_iommu_xlate(struct device *dev,
-                         struct of_phandle_args *iommu_spec)
+int of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec)
 {
        const struct iommu_ops *ops;
        struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
@@ -117,6 +116,7 @@ static int of_iommu_xlate(struct device *dev,
        module_put(ops->owner);
        return ret;
 }
+EXPORT_SYMBOL_GPL(of_iommu_xlate);
 
 static int of_iommu_configure_dev_id(struct device_node *master_np,
                                     struct device *dev,
@@ -177,7 +177,8 @@ static int of_iommu_configure_device(struct device_node 
*master_np,
 
 const struct iommu_ops *of_iommu_configure(struct device *dev,
                                           struct device_node *master_np,
-                                          const u32 *id)
+                                          const u32 *id,
+                                          struct of_phandle_args *iommu_spec)
 {
        const struct iommu_ops *ops = NULL;
        struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
@@ -209,7 +210,10 @@ const struct iommu_ops *of_iommu_configure(struct device 
*dev,
                err = pci_for_each_dma_alias(to_pci_dev(dev),
                                             of_pci_iommu_init, &info);
        } else {
-               err = of_iommu_configure_device(master_np, dev, id);
+               if (iommu_spec)
+                       err = of_iommu_xlate(dev, iommu_spec);
+               else
+                       err = of_iommu_configure_device(master_np, dev, id);
 
                fwspec = dev_iommu_fwspec_get(dev);
                if (!err && fwspec)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index aedfaaafd3e7..84ada2110c5b 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -88,8 +88,9 @@ int of_device_add(struct platform_device *ofdev)
  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  * to fix up DMA configuration.
  */
-int of_dma_configure_id(struct device *dev, struct device_node *np,
-                       bool force_dma, const u32 *id)
+int __of_dma_configure(struct device *dev, struct device_node *np,
+                       bool force_dma, const u32 *id,
+                       struct of_phandle_args *iommu_spec)
 {
        const struct iommu_ops *iommu;
        const struct bus_dma_region *map = NULL;
@@ -170,7 +171,7 @@ int of_dma_configure_id(struct device *dev, struct 
device_node *np,
        dev_dbg(dev, "device is%sdma coherent\n",
                coherent ? " " : " not ");
 
-       iommu = of_iommu_configure(dev, np, id);
+       iommu = of_iommu_configure(dev, np, id, iommu_spec);
        if (PTR_ERR(iommu) == -EPROBE_DEFER) {
                kfree(map);
                return -EPROBE_DEFER;
@@ -184,7 +185,7 @@ int of_dma_configure_id(struct device *dev, struct 
device_node *np,
        dev->dma_range_map = map;
        return 0;
 }
-EXPORT_SYMBOL_GPL(of_dma_configure_id);
+EXPORT_SYMBOL_GPL(__of_dma_configure);
 
 int of_device_register(struct platform_device *pdev)
 {
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 07ca187fc5e4..40cc3e788cb9 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -55,14 +55,27 @@ static inline struct device_node 
*of_cpu_device_node_get(int cpu)
        return of_node_get(cpu_dev->of_node);
 }
 
-int of_dma_configure_id(struct device *dev,
+int __of_dma_configure(struct device *dev,
                     struct device_node *np,
-                    bool force_dma, const u32 *id);
+                    bool force_dma, const u32 *id,
+                    struct of_phandle_args *iommu_spec);
 static inline int of_dma_configure(struct device *dev,
                                   struct device_node *np,
                                   bool force_dma)
 {
-       return of_dma_configure_id(dev, np, force_dma, NULL);
+       return __of_dma_configure(dev, np, force_dma, NULL, NULL);
+}
+static inline int of_dma_configure_id(struct device *dev,
+                                     struct device_node *np,
+                                     bool force_dma, const u32 *id)
+{
+       return __of_dma_configure(dev, np, force_dma, id, NULL);
+}
+static inline int
+of_dma_configure_iommu_spec(struct device *dev, struct device_node *np,
+                           bool force_dma, struct of_phandle_args *iommu_spec)
+{
+       return __of_dma_configure(dev, np, force_dma, NULL, iommu_spec);
 }
 #else /* CONFIG_OF */
 
@@ -112,18 +125,25 @@ static inline struct device_node 
*of_cpu_device_node_get(int cpu)
        return NULL;
 }
 
-static inline int of_dma_configure_id(struct device *dev,
+static inline int of_dma_configure(struct device *dev,
                                   struct device_node *np,
                                   bool force_dma)
 {
        return 0;
 }
-static inline int of_dma_configure(struct device *dev,
-                                  struct device_node *np,
-                                  bool force_dma)
+
+static inline int of_dma_configure_id(struct device *dev,
+                                     struct device_node *np,
+                                     bool force_dma, const u32 *id)
 {
        return 0;
 }
+
+static inline int
+of_dma_configure_iommu_spec(struct device *dev, struct device_node *np,
+                           bool force_dma, struct of_phandle_args *iommu_spec)
+{      return 0;
+}
 #endif /* CONFIG_OF */
 
 #endif /* _LINUX_OF_DEVICE_H */
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index 16f4b3e87f20..e8d1e6d32d77 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -14,7 +14,8 @@ extern int of_get_dma_window(struct device_node *dn, const 
char *prefix,
 
 extern const struct iommu_ops *of_iommu_configure(struct device *dev,
                                        struct device_node *master_np,
-                                       const u32 *id);
+                                       const u32 *id,
+                                       struct of_phandle_args *iommu_spec);
 
 #else
 
@@ -27,7 +28,8 @@ static inline int of_get_dma_window(struct device_node *dn, 
const char *prefix,
 
 static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
                                         struct device_node *master_np,
-                                        const u32 *id)
+                                        const u32 *id,
+                                        struct of_phandle_args *iommu_spec);
 {
        return NULL;
 }
-- 
2.30.0

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