add frontend implementation for the IOMMU API

/*

 * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.

 * Author: Joerg Roedel <joerg.roedel@amd.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published

 * by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 */

#include <linux/bug.h>

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/iommu.h>

static struct iommu_ops *iommu_ops;

void register_iommu(struct iommu_ops *ops)

{

	if (iommu_ops)

		BUG();

	iommu_ops = ops;

}

bool iommu_found()

{

	return iommu_ops != NULL;

}

EXPORT_SYMBOL_GPL(iommu_found);

struct iommu_domain *iommu_domain_alloc(void)

{

	struct iommu_domain *domain;

	int ret;

	domain = kmalloc(sizeof(*domain), GFP_KERNEL);

	if (!domain)

		return NULL;

	ret = iommu_ops->domain_init(domain);

	if (ret)

		goto out_free;

	return domain;

out_free:

	kfree(domain);

	return NULL;

}

EXPORT_SYMBOL_GPL(iommu_domain_alloc);

void iommu_domain_free(struct iommu_domain *domain)

{

	iommu_ops->domain_destroy(domain);

	kfree(domain);

}

EXPORT_SYMBOL_GPL(iommu_domain_free);

int iommu_attach_device(struct iommu_domain *domain, struct device *dev)

{

	return iommu_ops->attach_dev(domain, dev);

}

EXPORT_SYMBOL_GPL(iommu_attach_device);

void iommu_detach_device(struct iommu_domain *domain, struct device *dev)

{

	iommu_ops->detach_dev(domain, dev);

}

EXPORT_SYMBOL_GPL(iommu_detach_device);

int iommu_map_range(struct iommu_domain *domain, unsigned long iova,

		    phys_addr_t paddr, size_t size, int prot)

{

	return iommu_ops->map(domain, iova, paddr, size, prot);

}

EXPORT_SYMBOL_GPL(iommu_map_range);

void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova,

		      size_t size)

{

	iommu_ops->unmap(domain, iova, size);

}

EXPORT_SYMBOL_GPL(iommu_unmap_range);

phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,

			       unsigned long iova)

{

	return iommu_ops->iova_to_phys(domain, iova);

}

EXPORT_SYMBOL_GPL(iommu_iova_to_phys);