/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Mediated device definition
 *
 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
 *     Author: Neo Jia <[email protected]>
 *             Kirti Wankhede <[email protected]>
 */

#ifndef MDEV_H
#define MDEV_H

#include <linux/device.h>
#include <linux/uuid.h>

struct mdev_type;

struct mdev_device {
    struct device dev;
    guid_t uuid;
    struct list_head next;
    struct mdev_type *type;
    struct device *iommu_device;
    bool active;
};

struct mdev_type {
    /* set by the driver before calling mdev_register parent: */
    const char *sysfs_name;
    const char *pretty_name;

    /* set by the core, can be used drivers */
    struct mdev_parent *parent;

    /* internal only */
    struct kobject kobj;
    struct kobject *devices_kobj;
};

/* embedded into the struct device that the mdev devices hang off */
struct mdev_parent {
    struct device *dev;
    struct mdev_driver *mdev_driver;
    struct kset *mdev_types_kset;
    /* Synchronize device creation/removal with parent unregistration */
    struct rw_semaphore unreg_sem;
    struct mdev_type **types;
    unsigned int nr_types;
    atomic_t available_instances;
};

static inline struct mdev_device *to_mdev_device(struct device *dev)
{
    return container_of(dev, struct mdev_device, dev);
}

/*
 * Called by the parent device driver to set the device which represents
 * this mdev in iommu protection scope. By default, the iommu device is
 * NULL, that indicates using vendor defined isolation.
 *
 * @dev: the mediated device that iommu will isolate.
 * @iommu_device: a pci device which represents the iommu for @dev.
 */
static inline void mdev_set_iommu_device(struct mdev_device *mdev,
                     struct device *iommu_device)
{
    mdev->iommu_device = iommu_device;
}

static inline struct device *mdev_get_iommu_device(struct mdev_device *mdev) {
    return mdev->iommu_device;
}


/**
 * struct mdev_driver - Mediated device driver
 * @device_api: string to return for the device_api sysfs
 * @max_instances: maximum number of instances supported (optional)
 * @probe: called when new device created
 * @remove: called when device removed
 * @get_available: Return the max number of instances that can be created
 * @show_description: Print a description of the mtype
 * @driver: device driver structure
 **/
struct mdev_driver {
    const char *device_api;
    unsigned int max_instances;
    int (*probe)(struct mdev_device *dev);
    void (*remove)(struct mdev_device *dev);
    unsigned int (*get_available)(struct mdev_type *mtype);
    ssize_t (*show_description)(struct mdev_type *mtype, char *buf);
    struct device_driver driver;
};

extern struct bus_type mdev_bus_type;

int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
        struct mdev_driver *mdev_driver, struct mdev_type **types,
        unsigned int nr_types);
void mdev_unregister_parent(struct mdev_parent *parent);

int mdev_register_driver(struct mdev_driver *drv);
void mdev_unregister_driver(struct mdev_driver *drv);

static inline struct device *mdev_dev(struct mdev_device *mdev)
{
    return &mdev->dev;
}

#endif /* MDEV_H */