From a42a7a1fb5f1f9004b023594609dc22da02fc08b Mon Sep 17 00:00:00 2001
From: Robin Murphy <Robin.Murphy@arm.com>
Date: Fri, 5 Dec 2014 13:41:02 +0000
Subject: [PATCH] iommu: store DT-probed IOMMU data privately
Since the data pointer in the DT node is public and may be overwritten
by conflicting code, move the DT-probed IOMMU ops to a private list
where they will be safe.
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: added missing #include and missing ')']
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
drivers/iommu/of_iommu.c | 39 +++++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 12 ++----------
2 files changed, 41 insertions(+), 10 deletions(-)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 73236d3cc955..af1dc6a1c0a1 100644
--- 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/slab.h>
static const struct of_device_id __iommu_of_table_sentinel
__used __section(__iommu_of_table_end);
@@ -94,6 +95,44 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
}
EXPORT_SYMBOL_GPL(of_get_dma_window);
+struct of_iommu_node {
+ struct list_head list;
+ struct device_node *np;
+ struct iommu_ops *ops;
+};
+static LIST_HEAD(of_iommu_list);
+static DEFINE_SPINLOCK(of_iommu_lock);
+
+void of_iommu_set_ops(struct device_node *np, struct iommu_ops *ops)
+{
+ struct of_iommu_node *iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+
+ if (WARN_ON(!iommu))
+ return;
+
+ INIT_LIST_HEAD(&iommu->list);
+ iommu->np = np;
+ iommu->ops = ops;
+ spin_lock(&of_iommu_lock);
+ list_add_tail(&iommu->list, &of_iommu_list);
+ spin_unlock(&of_iommu_lock);
+}
+
+struct iommu_ops *of_iommu_get_ops(struct device_node *np)
+{
+ struct of_iommu_node *node;
+ struct iommu_ops *ops = NULL;
+
+ spin_lock(&of_iommu_lock);
+ list_for_each_entry(node, &of_iommu_list, list)
+ if (node->np == np) {
+ ops = node->ops;
+ break;
+ }
+ spin_unlock(&of_iommu_lock);
+ return ops;
+}
+
struct iommu_ops *of_iommu_configure(struct device *dev)
{
struct of_phandle_args iommu_spec;
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index d03abbb11c34..16c75547d725 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -31,16 +31,8 @@ static inline struct iommu_ops *of_iommu_configure(struct device *dev)
#endif /* CONFIG_OF_IOMMU */
-static inline void of_iommu_set_ops(struct device_node *np,
- const struct iommu_ops *ops)
-{
- np->data = (struct iommu_ops *)ops;
-}
-
-static inline struct iommu_ops *of_iommu_get_ops(struct device_node *np)
-{
- return np->data;
-}
+void of_iommu_set_ops(struct device_node *np, struct iommu_ops *ops);
+struct iommu_ops *of_iommu_get_ops(struct device_node *np);
extern struct of_device_id __iommu_of_table;
--
2.34.1