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Commit a42a7a1f authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

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: default avatarGrant Likely <grant.likely@linaro.org>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
[will: added missing #include and missing ')']
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 4bb25789

drivers/iommu/of_iommu.c

+39 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/of_iommu.h

+2 −10
Original line number Diff line number Diff line
@@ -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;