Merge tag 'tegra-for-4.8-i2c' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra...

[cascardo/linux.git] / drivers / iommu / of_iommu.c

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 57f23ea..5b82862 100644 (file)
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -22,6 +22,7 @@
 #include <linux/limits.h>
 #include <linux/of.h>
 #include <linux/of_iommu.h>
+#include <linux/of_pci.h>
 #include <linux/slab.h>
 
 static const struct of_device_id __iommu_of_table_sentinel
@@ -134,6 +135,47 @@ const struct iommu_ops *of_iommu_get_ops(struct device_node *np)
        return ops;
 }
 
+static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
+{
+       struct of_phandle_args *iommu_spec = data;
+
+       iommu_spec->args[0] = alias;
+       return iommu_spec->np == pdev->bus->dev.of_node;
+}
+
+static const struct iommu_ops
+*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)
+{
+       const struct iommu_ops *ops;
+       struct of_phandle_args iommu_spec;
+
+       /*
+        * Start by tracing the RID alias down the PCI topology as
+        * far as the host bridge whose OF node we have...
+        * (we're not even attempting to handle multi-alias devices yet)
+        */
+       iommu_spec.args_count = 1;
+       iommu_spec.np = bridge_np;
+       pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec);
+       /*
+        * ...then find out what that becomes once it escapes the PCI
+        * bus into the system beyond, and which IOMMU it ends up at.
+        */
+       iommu_spec.np = NULL;
+       if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
+                          "iommu-map-mask", &iommu_spec.np, iommu_spec.args))
+               return NULL;
+
+       ops = of_iommu_get_ops(iommu_spec.np);
+       if (!ops || !ops->of_xlate ||
+           iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) ||
+           ops->of_xlate(&pdev->dev, &iommu_spec))
+               ops = NULL;
+
+       of_node_put(iommu_spec.np);
+       return ops;
+}
+
 const struct iommu_ops *of_iommu_configure(struct device *dev,
                                           struct device_node *master_np)
 {
@@ -142,12 +184,8 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
        const struct iommu_ops *ops = NULL;
        int idx = 0;
 
-       /*
-        * We can't do much for PCI devices without knowing how
-        * device IDs are wired up from the PCI bus to the IOMMU.
-        */
        if (dev_is_pci(dev))
-               return NULL;
+               return of_pci_iommu_configure(to_pci_dev(dev), master_np);
 
        /*
         * We don't currently walk up the tree looking for a parent IOMMU.
@@ -160,7 +198,9 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
                np = iommu_spec.np;
                ops = of_iommu_get_ops(np);
 
-               if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec))
+               if (!ops || !ops->of_xlate ||
+                   iommu_fwspec_init(dev, &np->fwnode, ops) ||
+                   ops->of_xlate(dev, &iommu_spec))
                        goto err_put_node;
 
                of_node_put(np);