/*
   * 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/device.h>

  #include <linux/kernel.h>

  #include <linux/bug.h>
  #include <linux/types.h>

  #include <linux/module.h>
  #include <linux/slab.h>

  #include <linux/errno.h>
  #include <linux/iommu.h>

  static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops)
  {
  }

  /**
   * bus_set_iommu - set iommu-callbacks for the bus
   * @bus: bus.
   * @ops: the callbacks provided by the iommu-driver
   *
   * This function is called by an iommu driver to set the iommu methods
   * used for a particular bus. Drivers for devices on that bus can use
   * the iommu-api after these ops are registered.
   * This special function is needed because IOMMUs are usually devices on
   * the bus itself, so the iommu drivers are not initialized when the bus
   * is set up. With this function the iommu-driver can set the iommu-ops
   * afterwards.
   */
  int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)

  {

  	if (bus->iommu_ops != NULL)
  		return -EBUSY;

  	bus->iommu_ops = ops;
  
  	/* Do IOMMU specific setup for this bus-type */
  	iommu_bus_init(bus, ops);

  	return 0;

  }

  EXPORT_SYMBOL_GPL(bus_set_iommu);

  bool iommu_present(struct bus_type *bus)

  {

  	return bus->iommu_ops != NULL;

  }

  EXPORT_SYMBOL_GPL(iommu_present);

  /**
   * iommu_set_fault_handler() - set a fault handler for an iommu domain
   * @domain: iommu domain
   * @handler: fault handler

   *
   * This function should be used by IOMMU users which want to be notified
   * whenever an IOMMU fault happens.
   *
   * The fault handler itself should return 0 on success, and an appropriate
   * error code otherwise.

   */
  void iommu_set_fault_handler(struct iommu_domain *domain,
  					iommu_fault_handler_t handler)
  {
  	BUG_ON(!domain);
  
  	domain->handler = handler;
  }

  EXPORT_SYMBOL_GPL(iommu_set_fault_handler);

  struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)

  {
  	struct iommu_domain *domain;
  	int ret;

  	if (bus == NULL || bus->iommu_ops == NULL)

  		return NULL;

  	domain = kmalloc(sizeof(*domain), GFP_KERNEL);
  	if (!domain)
  		return NULL;

  	domain->ops = bus->iommu_ops;

  	ret = domain->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)
  {

  	if (likely(domain->ops->domain_destroy != NULL))
  		domain->ops->domain_destroy(domain);

  	kfree(domain);
  }
  EXPORT_SYMBOL_GPL(iommu_domain_free);
  
  int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
  {

  	if (unlikely(domain->ops->attach_dev == NULL))
  		return -ENODEV;
  
  	return domain->ops->attach_dev(domain, dev);

  }
  EXPORT_SYMBOL_GPL(iommu_attach_device);
  
  void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
  {

  	if (unlikely(domain->ops->detach_dev == NULL))
  		return;
  
  	domain->ops->detach_dev(domain, dev);

  }
  EXPORT_SYMBOL_GPL(iommu_detach_device);

  phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
  			       unsigned long iova)
  {

  	if (unlikely(domain->ops->iova_to_phys == NULL))
  		return 0;
  
  	return domain->ops->iova_to_phys(domain, iova);

  }
  EXPORT_SYMBOL_GPL(iommu_iova_to_phys);

  
  int iommu_domain_has_cap(struct iommu_domain *domain,
  			 unsigned long cap)
  {

  	if (unlikely(domain->ops->domain_has_cap == NULL))
  		return 0;
  
  	return domain->ops->domain_has_cap(domain, cap);

  }
  EXPORT_SYMBOL_GPL(iommu_domain_has_cap);

  
  int iommu_map(struct iommu_domain *domain, unsigned long iova,
  	      phys_addr_t paddr, int gfp_order, int prot)
  {

  	size_t size;

  	if (unlikely(domain->ops->map == NULL))
  		return -ENODEV;

  	size         = PAGE_SIZE << gfp_order;

  	BUG_ON(!IS_ALIGNED(iova | paddr, size));

  	return domain->ops->map(domain, iova, paddr, gfp_order, prot);

  }
  EXPORT_SYMBOL_GPL(iommu_map);
  
  int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
  {

  	size_t size;

  	if (unlikely(domain->ops->unmap == NULL))
  		return -ENODEV;

  	size         = PAGE_SIZE << gfp_order;

  	BUG_ON(!IS_ALIGNED(iova, size));

  	return domain->ops->unmap(domain, iova, gfp_order);

  }
  EXPORT_SYMBOL_GPL(iommu_unmap);