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Commit 7eba1d51 authored by Will Deacon's avatar Will Deacon
Browse files

iommu: provide helper function to configure an IOMMU for an of master 



The generic IOMMU device-tree bindings can be used to add arbitrary OF
masters to an IOMMU with a compliant binding.

This patch introduces of_iommu_configure, which does exactly that.

Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarJoerg Roedel <jroedel@suse.de>
Acked-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent d0f60a44

drivers/iommu/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ if IOMMU_SUPPORT 


config OF_IOMMU

       def_bool y

       depends on OF

       depends on OF && IOMMU_API



config FSL_PAMU

	bool "Freescale IOMMU support"

drivers/iommu/of_iommu.c

+33 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
 */



#include <linux/export.h>

#include <linux/iommu.h>

#include <linux/limits.h>

#include <linux/of.h>

#include <linux/of_iommu.h>
@@ -93,6 +94,38 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, 
}

EXPORT_SYMBOL_GPL(of_get_dma_window);



struct iommu_ops *of_iommu_configure(struct device *dev)

{

	struct of_phandle_args iommu_spec;

	struct device_node *np;

	struct iommu_ops *ops = NULL;

	int idx = 0;



	/*

	 * We don't currently walk up the tree looking for a parent IOMMU.

	 * See the `Notes:' section of

	 * Documentation/devicetree/bindings/iommu/iommu.txt

	 */

	while (!of_parse_phandle_with_args(dev->of_node, "iommus",

					   "#iommu-cells", idx,

					   &iommu_spec)) {

		np = iommu_spec.np;

		ops = of_iommu_get_ops(np);



		if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec))

			goto err_put_node;



		of_node_put(np);

		idx++;

	}



	return ops;



err_put_node:

	of_node_put(np);

	return NULL;

}



void __init of_iommu_init(void)

{

	struct device_node *np;

include/linux/of_iommu.h

+6 −0
Original line number Diff line number Diff line 
#ifndef __OF_IOMMU_H

#define __OF_IOMMU_H



#include <linux/device.h>

#include <linux/iommu.h>

#include <linux/of.h>
@@ -11,6 +12,7 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix, 
			     size_t *size);



extern void of_iommu_init(void);

extern struct iommu_ops *of_iommu_configure(struct device *dev);



#else
@@ -22,6 +24,10 @@ static inline int of_get_dma_window(struct device_node *dn, const char *prefix, 
}



static inline void of_iommu_init(void) { }

static inline struct iommu_ops *of_iommu_configure(struct device *dev)

{

	return NULL;

}



#endif	/* CONFIG_OF_IOMMU */