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

#define IOMMU_READ      (1)
#define IOMMU_WRITE     (2)
#define IOMMU_CACHE     (4) /* DMA cache coherency */

struct iommu_ops;
struct iommu_group;
struct bus_type;
struct device;
struct iommu_domain;
struct notifier_block;

/* 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, void *);

struct iommu_domain_geometry {
        dma_addr_t aperture_start; /* First address that can be mapped    */
        dma_addr_t aperture_end;   /* Last address that can be mapped     */
        bool force_aperture;       /* DMA only allowed in mappable range? */
};

struct iommu_domain {
        struct iommu_ops *ops;
        void *priv;
        iommu_fault_handler_t handler;
        void *handler_token;
        struct iommu_domain_geometry geometry;
};

#define IOMMU_CAP_CACHE_COHERENCY       0x1
#define IOMMU_CAP_INTR_REMAP            0x2     /* isolates device intrs */

enum iommu_attr {
        DOMAIN_ATTR_MAX,
        DOMAIN_ATTR_GEOMETRY,
};

#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
 * @add_device: add device to iommu grouping
 * @remove_device: remove device from iommu grouping
 * @domain_get_attr: Query domain attributes
 * @domain_set_attr: Change domain attributes
 * @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 (*add_device)(struct device *dev);
        void (*remove_device)(struct device *dev);
        int (*device_group)(struct device *dev, unsigned int *groupid);
        int (*domain_get_attr)(struct iommu_domain *domain,
                               enum iommu_attr attr, void *data);
        int (*domain_set_attr)(struct iommu_domain *domain,
                               enum iommu_attr attr, void *data);
        unsigned long pgsize_bitmap;
};

#define IOMMU_GROUP_NOTIFY_ADD_DEVICE           1 /* Device added */
#define IOMMU_GROUP_NOTIFY_DEL_DEVICE           2 /* Pre Device removed */
#define IOMMU_GROUP_NOTIFY_BIND_DRIVER          3 /* Pre Driver bind */
#define IOMMU_GROUP_NOTIFY_BOUND_DRIVER         4 /* Post Driver bind */
#define IOMMU_GROUP_NOTIFY_UNBIND_DRIVER        5 /* Pre Driver unbind */
#define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER       6 /* Post Driver unbind */

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, void *token);

extern int iommu_attach_group(struct iommu_domain *domain,
                              struct iommu_group *group);
extern void iommu_detach_group(struct iommu_domain *domain,
                               struct iommu_group *group);
extern struct iommu_group *iommu_group_alloc(void);
extern void *iommu_group_get_iommudata(struct iommu_group *group);
extern void iommu_group_set_iommudata(struct iommu_group *group,
                                      void *iommu_data,
                                      void (*release)(void *iommu_data));
extern int iommu_group_set_name(struct iommu_group *group, const char *name);
extern int iommu_group_add_device(struct iommu_group *group,
                                  struct device *dev);
extern void iommu_group_remove_device(struct device *dev);
extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
                                    int (*fn)(struct device *, void *));
extern struct iommu_group *iommu_group_get(struct device *dev);
extern void iommu_group_put(struct iommu_group *group);
extern int iommu_group_register_notifier(struct iommu_group *group,
                                         struct notifier_block *nb);
extern int iommu_group_unregister_notifier(struct iommu_group *group,
                                           struct notifier_block *nb);
extern int iommu_group_id(struct iommu_group *group);

extern int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr,
                                 void *data);
extern int iommu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr,
                                 void *data);

/**
 * 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,
                                                domain->handler_token);

        return ret;
}

#else /* CONFIG_IOMMU_API */

struct iommu_ops {};
struct iommu_group {};

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, void *token)
{
}

static inline int iommu_attach_group(struct iommu_domain *domain,
                                     struct iommu_group *group)
{
        return -ENODEV;
}

static inline void iommu_detach_group(struct iommu_domain *domain,
                                      struct iommu_group *group)
{
}

static inline struct iommu_group *iommu_group_alloc(void)
{
        return ERR_PTR(-ENODEV);
}

static inline void *iommu_group_get_iommudata(struct iommu_group *group)
{
        return NULL;
}

static inline void iommu_group_set_iommudata(struct iommu_group *group,
                                             void *iommu_data,
                                             void (*release)(void *iommu_data))
{
}

static inline int iommu_group_set_name(struct iommu_group *group,
                                       const char *name)
{
        return -ENODEV;
}

static inline int iommu_group_add_device(struct iommu_group *group,
                                         struct device *dev)
{
        return -ENODEV;
}

static inline void iommu_group_remove_device(struct device *dev)
{
}

static inline int iommu_group_for_each_dev(struct iommu_group *group,
                                           void *data,
                                           int (*fn)(struct device *, void *))
{
        return -ENODEV;
}

static inline struct iommu_group *iommu_group_get(struct device *dev)
{
        return NULL;
}

static inline void iommu_group_put(struct iommu_group *group)
{
}

static inline int iommu_group_register_notifier(struct iommu_group *group,
                                                struct notifier_block *nb)
{
        return -ENODEV;
}

static inline int iommu_group_unregister_notifier(struct iommu_group *group,
                                                  struct notifier_block *nb)
{
        return 0;
}

static inline int iommu_group_id(struct iommu_group *group)
{
        return -ENODEV;
}

static inline int iommu_domain_get_attr(struct iommu_domain *domain,
                                        enum iommu_attr attr, void *data)
{
        return -EINVAL;
}

static inline int iommu_domain_set_attr(struct iommu_domain *domain,
                                        enum iommu_attr attr, void *data)
{
        return -EINVAL;
}

#endif /* CONFIG_IOMMU_API */

#endif /* __LINUX_IOMMU_H */