Introduce a common structure to hold the per-device firmware data that
non-architectural IOMMU drivers generally need to keep track of.
Initially this is DT-specific to complement the existing of_iommu
support code, but will generalise further once other firmware methods
(e.g. ACPI IORT) come along.
Ultimately the aim is to promote the fwspec to a first-class member of
struct device, and handle the init/free automatically in the firmware
code. That way we can have API calls look for dev->fwspec->iommu_ops
before falling back to dev->bus->iommu_ops, and thus gracefully handle
those troublesome multi-IOMMU systems which we currently cannot. To
start with, though, make use of the existing archdata field and delegate
the init/free to drivers to allow an incremental conversion rather than
the impractical pain of trying to attempt everything in one go.
Suggested-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
v5: Fix shocking num_ids oversight.
drivers/iommu/of_iommu.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 15 ++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 1a65cc806898..bec51eb47b0d 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -219,3 +219,55 @@ static int __init of_iommu_init(void)
return 0;
}
postcore_initcall_sync(of_iommu_init);
+
+int iommu_fwspec_init(struct device *dev, struct device_node *iommu_np)
+{
+ struct iommu_fwspec *fwspec = dev->archdata.iommu;
+
+ if (fwspec)
+ return 0;
+
+ fwspec = kzalloc(sizeof(*fwspec), GFP_KERNEL);
+ if (!fwspec)
+ return -ENOMEM;
+
+ fwspec->iommu_np = of_node_get(iommu_np);
+ fwspec->iommu_ops = of_iommu_get_ops(iommu_np);
+ dev->archdata.iommu = fwspec;
+ return 0;
+}
+
+void iommu_fwspec_free(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev->archdata.iommu;
+
+ if (fwspec) {
+ of_node_put(fwspec->iommu_np);
+ kfree(fwspec);
+ }
+}
+
+int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
+{
+ struct iommu_fwspec *fwspec = dev->archdata.iommu;
+ size_t size;
+
+ if (!fwspec)
+ return -EINVAL;
+
+ size = offsetof(struct iommu_fwspec, ids[fwspec->num_ids + num_ids]);
+ fwspec = krealloc(dev->archdata.iommu, size, GFP_KERNEL);
+ if (!fwspec)
+ return -ENOMEM;
+
+ while (num_ids--)
+ fwspec->ids[fwspec->num_ids++] = *ids++;
+
+ dev->archdata.iommu = fwspec;
+ return 0;
+}
+
+inline struct iommu_fwspec *dev_iommu_fwspec(struct device *dev)
+{
+ return dev->archdata.iommu;
+}
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index e80b9c762a03..accdc0525f28 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -14,6 +14,14 @@ 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);
+struct iommu_fwspec {
+ const struct iommu_ops *iommu_ops;
+ struct device_node *iommu_np;
+ void *iommu_priv;
+ unsigned int num_ids;
+ u32 ids[];
+};
+
#else
static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
@@ -29,8 +37,15 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
return NULL;
}
+struct iommu_fwspec;
+
#endif /* CONFIG_OF_IOMMU */
+int iommu_fwspec_init(struct device *dev, struct device_node *iommu_np);
+void iommu_fwspec_free(struct device *dev);
+int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids);
+struct iommu_fwspec *dev_iommu_fwspec(struct device *dev);
+
void of_iommu_set_ops(struct device_node *np, const struct iommu_ops *ops);
const struct iommu_ops *of_iommu_get_ops(struct device_node *np);
--
2.8.1.dirty
--
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