[PATCH v3 3/3] arm,smmu: add support for generic DT bindings. Implement add_device and dt_xlate.

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

From: Brian Woods <brian.woods@xxxxxxxxxx>

Now that all arm iommu drivers support generic bindings we can remove
the workaround from iommu_add_dt_device().

Note that if both legacy bindings and generic bindings are present in
device tree, the legacy bindings are the ones that are used.

Signed-off-by: Brian Woods <brian.woods@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
---
Changes in v3:
- split patch
- make find_smmu return non-const so that we can use it in 
arm_smmu_dt_add_device_generic
- use dt_phandle_args
- update commit message
---
 xen/drivers/passthrough/arm/smmu.c    | 40 ++++++++++++++++++++++++++-
 xen/drivers/passthrough/device_tree.c | 17 +-----------
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu.c 
b/xen/drivers/passthrough/arm/smmu.c
index 9687762283..620ba5a4b5 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -254,6 +254,8 @@ struct iommu_group
        atomic_t ref;
 };
 
+static struct arm_smmu_device *find_smmu(const struct device *dev);
+
 static struct iommu_group *iommu_group_alloc(void)
 {
        struct iommu_group *group = xzalloc(struct iommu_group);
@@ -843,6 +845,40 @@ static int register_smmu_master(struct arm_smmu_device 
*smmu,
                                             fwspec);
 }
 
+static int arm_smmu_dt_add_device_generic(u8 devfn, struct device *dev)
+{
+       struct arm_smmu_device *smmu;
+       struct iommu_fwspec *fwspec;
+
+       fwspec = dev_iommu_fwspec_get(dev);
+       if (fwspec == NULL)
+               return -ENXIO;
+
+       smmu = find_smmu(fwspec->iommu_dev);
+       if (smmu == NULL)
+               return -ENXIO;
+
+       return arm_smmu_dt_add_device_legacy(smmu, dev, fwspec);
+}
+
+static int arm_smmu_dt_xlate_generic(struct device *dev,
+                                   const struct dt_phandle_args *spec)
+{
+       uint32_t mask, fwid = 0;
+
+       if (spec->args_count > 0)
+               fwid |= (SMR_ID_MASK & spec->args[0]) << SMR_ID_SHIFT;
+
+       if (spec->args_count > 1)
+               fwid |= (SMR_MASK_MASK & spec->args[1]) << SMR_MASK_SHIFT;
+       else if (!of_property_read_u32(spec->np, "stream-match-mask", &mask))
+               fwid |= (SMR_MASK_MASK & mask) << SMR_MASK_SHIFT;
+
+       return iommu_fwspec_add_ids(dev,
+                                   &fwid,
+                                   1);
+}
+
 static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
 {
        struct arm_smmu_device *smmu;
@@ -2766,6 +2802,7 @@ static void arm_smmu_iommu_domain_teardown(struct domain 
*d)
 static const struct iommu_ops arm_smmu_iommu_ops = {
     .init = arm_smmu_iommu_domain_init,
     .hwdom_init = arm_smmu_iommu_hwdom_init,
+    .add_device = arm_smmu_dt_add_device_generic,
     .teardown = arm_smmu_iommu_domain_teardown,
     .iotlb_flush = arm_smmu_iotlb_flush,
     .iotlb_flush_all = arm_smmu_iotlb_flush_all,
@@ -2773,9 +2810,10 @@ static const struct iommu_ops arm_smmu_iommu_ops = {
     .reassign_device = arm_smmu_reassign_dev,
     .map_page = arm_iommu_map_page,
     .unmap_page = arm_iommu_unmap_page,
+    .dt_xlate = arm_smmu_dt_xlate_generic,
 };
 
-static __init const struct arm_smmu_device *find_smmu(const struct device *dev)
+static struct arm_smmu_device *find_smmu(const struct device *dev)
 {
        struct arm_smmu_device *smmu;
        bool found = false;
diff --git a/xen/drivers/passthrough/device_tree.c 
b/xen/drivers/passthrough/device_tree.c
index a51ae3c9c3..ae07f272e1 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -162,22 +162,7 @@ int iommu_add_dt_device(struct dt_device_node *np)
          * these callback implemented.
          */
         if ( !ops->add_device || !ops->dt_xlate )
-        {
-            /*
-             * Some Device Trees may expose both legacy SMMU and generic
-             * IOMMU bindings together. However, the SMMU driver is only
-             * supporting the former and will protect them during the
-             * initialization. So we need to skip them and not return
-             * error here.
-             *
-             * XXX: This can be dropped when the SMMU is able to deal
-             * with generic bindings.
-             */
-            if ( dt_device_is_protected(np) )
-                return 0;
-            else
-                return -EINVAL;
-        }
+            return -EINVAL;
 
         if ( !dt_device_is_available(iommu_spec.np) )
             break;
-- 
2.17.1