/* SPDX-License-Identifier: GPL-2.0 */
/*
 * virtio_pmem.h: virtio pmem Driver
 *
 * Discovers persistent memory range information
 * from host and provides a virtio based flushing
 * interface.
 **/

#ifndef _LINUX_VIRTIO_PMEM_H
#define _LINUX_VIRTIO_PMEM_H

#include <linux/module.h>
#include <uapi/linux/virtio_pmem.h>
#include <linux/libnvdimm.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>

struct virtio_pmem_request {
        struct virtio_pmem_req req;
        struct virtio_pmem_resp resp;

        /* Wait queue to process deferred work after ack from host */
        wait_queue_head_t host_acked;
        bool done;

        /* Wait queue to process deferred work after virt queue buffer avail */
        wait_queue_head_t wq_buf;
        bool wq_buf_avail;
        struct list_head list;
};

struct virtio_pmem {
        struct virtio_device *vdev;

        /* Virtio pmem request queue */
        struct virtqueue *req_vq;

        /* Serialize flush requests to the device. */
        struct mutex flush_lock;

        /* nvdimm bus registers virtio pmem device */
        struct nvdimm_bus *nvdimm_bus;
        struct nvdimm_bus_descriptor nd_desc;

        /* List to store deferred work if virtqueue is full */
        struct list_head req_list;

        /* Synchronize virtqueue data */
        spinlock_t pmem_lock;

        /* Memory region information */
        __u64 start;
        __u64 size;
};

void virtio_pmem_host_ack(struct virtqueue *vq);
int async_pmem_flush(struct nd_region *nd_region, struct bio *bio);
#endif