/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2020, Red Hat Inc. All rights reserved.
 */

#ifndef _VDPA_SIM_H
#define _VDPA_SIM_H

#include <linux/iova.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <linux/virtio_byteorder.h>
#include <linux/vhost_iotlb.h>
#include <uapi/linux/virtio_config.h>

#define VDPASIM_FEATURES        ((1ULL << VIRTIO_F_ANY_LAYOUT) | \
                                 (1ULL << VIRTIO_F_VERSION_1)  | \
                                 (1ULL << VIRTIO_F_ACCESS_PLATFORM))

struct vdpasim;

struct vdpasim_virtqueue {
        struct vringh vring;
        struct vringh_kiov in_iov;
        struct vringh_kiov out_iov;
        unsigned short head;
        bool ready;
        u64 desc_addr;
        u64 device_addr;
        u64 driver_addr;
        u32 num;
        void *private;
        irqreturn_t (*cb)(void *data);
};

struct vdpasim_dev_attr {
        struct vdpa_mgmt_dev *mgmt_dev;
        const char *name;
        u64 supported_features;
        size_t alloc_size;
        size_t config_size;
        int nvqs;
        u32 id;
        u32 ngroups;
        u32 nas;

        void (*work_fn)(struct vdpasim *vdpasim);
        void (*get_config)(struct vdpasim *vdpasim, void *config);
        void (*set_config)(struct vdpasim *vdpasim, const void *config);
        int (*get_stats)(struct vdpasim *vdpasim, u16 idx,
                         struct sk_buff *msg,
                         struct netlink_ext_ack *extack);
        void (*free)(struct vdpasim *vdpasim);
};

/* State of each vdpasim device */
struct vdpasim {
        struct vdpa_device vdpa;
        struct vdpasim_virtqueue *vqs;
        struct kthread_worker *worker;
        struct kthread_work work;
        struct mm_struct *mm_bound;
        struct vdpasim_dev_attr dev_attr;
        /* mutex to synchronize virtqueue state */
        struct mutex mutex;
        /* virtio config according to device type */
        void *config;
        struct vhost_iotlb *iommu;
        bool *iommu_pt;
        u32 status;
        u32 generation;
        u64 features;
        u32 groups;
        bool running;
        bool pending_kick;
        /* spinlock to synchronize iommu table */
        spinlock_t iommu_lock;
};

struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *attr,
                               const struct vdpa_dev_set_config *config);
void vdpasim_schedule_work(struct vdpasim *vdpasim);

/* TODO: cross-endian support */
static inline bool vdpasim_is_little_endian(struct vdpasim *vdpasim)
{
        return virtio_legacy_is_little_endian() ||
                (vdpasim->features & (1ULL << VIRTIO_F_VERSION_1));
}

static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
{
        return __virtio16_to_cpu(vdpasim_is_little_endian(vdpasim), val);
}

static inline __virtio16 cpu_to_vdpasim16(struct vdpasim *vdpasim, u16 val)
{
        return __cpu_to_virtio16(vdpasim_is_little_endian(vdpasim), val);
}

static inline u32 vdpasim32_to_cpu(struct vdpasim *vdpasim, __virtio32 val)
{
        return __virtio32_to_cpu(vdpasim_is_little_endian(vdpasim), val);
}

static inline __virtio32 cpu_to_vdpasim32(struct vdpasim *vdpasim, u32 val)
{
        return __cpu_to_virtio32(vdpasim_is_little_endian(vdpasim), val);
}

static inline u64 vdpasim64_to_cpu(struct vdpasim *vdpasim, __virtio64 val)
{
        return __virtio64_to_cpu(vdpasim_is_little_endian(vdpasim), val);
}

static inline __virtio64 cpu_to_vdpasim64(struct vdpasim *vdpasim, u64 val)
{
        return __cpu_to_virtio64(vdpasim_is_little_endian(vdpasim), val);
}

#endif