/*
   * 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
   */
  
  #ifndef __LINUX_IOMMU_H
  #define __LINUX_IOMMU_H

  #include <linux/errno.h>

  #define IOMMU_READ	(1)
  #define IOMMU_WRITE	(2)

  #define IOMMU_CACHE	(4) /* DMA cache coherency */

  struct iommu_ops;

  struct bus_type;

  struct device;

  struct iommu_domain;
  
  /* iommu fault flags */
  #define IOMMU_FAULT_READ	0x0
  #define IOMMU_FAULT_WRITE	0x1
  
  typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
  				struct device *, unsigned long, int);

  
  struct iommu_domain {

  	struct iommu_ops *ops;

  	void *priv;

  	iommu_fault_handler_t handler;

  };

  #define IOMMU_CAP_CACHE_COHERENCY	0x1

  #define IOMMU_CAP_INTR_REMAP		0x2	/* isolates device intrs */

  #ifdef CONFIG_IOMMU_API

  /**
   * struct iommu_ops - iommu ops and capabilities
   * @domain_init: init iommu domain
   * @domain_destroy: destroy iommu domain
   * @attach_dev: attach device to an iommu domain
   * @detach_dev: detach device from an iommu domain
   * @map: map a physically contiguous memory region to an iommu domain
   * @unmap: unmap a physically contiguous memory region from an iommu domain
   * @iova_to_phys: translate iova to physical address
   * @domain_has_cap: domain capabilities query
   * @commit: commit iommu domain
   * @pgsize_bitmap: bitmap of supported page sizes
   */

  struct iommu_ops {
  	int (*domain_init)(struct iommu_domain *domain);
  	void (*domain_destroy)(struct iommu_domain *domain);
  	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
  	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);

  	int (*map)(struct iommu_domain *domain, unsigned long iova,

  		   phys_addr_t paddr, size_t size, int prot);
  	size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
  		     size_t size);

  	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
  				    unsigned long iova);

  	int (*domain_has_cap)(struct iommu_domain *domain,
  			      unsigned long cap);

  	int (*device_group)(struct device *dev, unsigned int *groupid);

  	unsigned long pgsize_bitmap;

  };

  extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);

  extern bool iommu_present(struct bus_type *bus);

  extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);

  extern void iommu_domain_free(struct iommu_domain *domain);
  extern int iommu_attach_device(struct iommu_domain *domain,
  			       struct device *dev);
  extern void iommu_detach_device(struct iommu_domain *domain,
  				struct device *dev);

  extern int iommu_map(struct iommu_domain *domain, unsigned long iova,

  		     phys_addr_t paddr, size_t size, int prot);
  extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
  		       size_t size);

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

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

  extern void iommu_set_fault_handler(struct iommu_domain *domain,
  					iommu_fault_handler_t handler);

  extern int iommu_device_group(struct device *dev, unsigned int *groupid);

  
  /**
   * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
   * @domain: the iommu domain where the fault has happened
   * @dev: the device where the fault has happened
   * @iova: the faulting address
   * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
   *
   * This function should be called by the low-level IOMMU implementations
   * whenever IOMMU faults happen, to allow high-level users, that are
   * interested in such events, to know about them.
   *
   * This event may be useful for several possible use cases:
   * - mere logging of the event
   * - dynamic TLB/PTE loading
   * - if restarting of the faulting device is required
   *
   * Returns 0 on success and an appropriate error code otherwise (if dynamic
   * PTE/TLB loading will one day be supported, implementations will be able
   * to tell whether it succeeded or not according to this return value).

   *
   * Specifically, -ENOSYS is returned if a fault handler isn't installed
   * (though fault handlers can also return -ENOSYS, in case they want to
   * elicit the default behavior of the IOMMU drivers).

   */
  static inline int report_iommu_fault(struct iommu_domain *domain,
  		struct device *dev, unsigned long iova, int flags)
  {

  	int ret = -ENOSYS;

  	/*
  	 * if upper layers showed interest and installed a fault handler,
  	 * invoke it.
  	 */
  	if (domain->handler)
  		ret = domain->handler(domain, dev, iova, flags);

  	return ret;

  }

  #else /* CONFIG_IOMMU_API */

  struct iommu_ops {};

  static inline bool iommu_present(struct bus_type *bus)

  {
  	return false;
  }

  static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)

  {
  	return NULL;
  }
  
  static inline void iommu_domain_free(struct iommu_domain *domain)
  {
  }
  
  static inline int iommu_attach_device(struct iommu_domain *domain,
  				      struct device *dev)
  {
  	return -ENODEV;
  }
  
  static inline void iommu_detach_device(struct iommu_domain *domain,
  				       struct device *dev)
  {
  }

  static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
  			    phys_addr_t paddr, int gfp_order, int prot)
  {
  	return -ENODEV;
  }
  
  static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
  			      int gfp_order)
  {
  	return -ENODEV;
  }

  static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
  					     unsigned long iova)
  {
  	return 0;
  }

  static inline int domain_has_cap(struct iommu_domain *domain,
  				 unsigned long cap)
  {
  	return 0;
  }

  static inline void iommu_set_fault_handler(struct iommu_domain *domain,
  					iommu_fault_handler_t handler)
  {
  }

  static inline int iommu_device_group(struct device *dev, unsigned int *groupid)

  {
  	return -ENODEV;
  }

  #endif /* CONFIG_IOMMU_API */
  
  #endif /* __LINUX_IOMMU_H */