/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _DM_PCACHE_H
#define _DM_PCACHE_H
#include <linux/device-mapper.h>

#include "../dm-core.h"

#define CACHE_DEV_TO_PCACHE(cache_dev)          (container_of(cache_dev, struct dm_pcache, cache_dev))
#define BACKING_DEV_TO_PCACHE(backing_dev)      (container_of(backing_dev, struct dm_pcache, backing_dev))
#define CACHE_TO_PCACHE(cache)                  (container_of(cache, struct dm_pcache, cache))

#define PCACHE_STATE_RUNNING                    1
#define PCACHE_STATE_STOPPING                   2

struct pcache_cache_dev;
struct pcache_backing_dev;
struct pcache_cache;
struct pcache_cache_options;
struct dm_pcache {
        struct dm_target *ti;
        struct pcache_cache_dev cache_dev;
        struct pcache_backing_dev backing_dev;
        struct pcache_cache cache;
        struct pcache_cache_options opts;

        spinlock_t                      defered_req_list_lock;
        struct list_head                defered_req_list;
        struct workqueue_struct         *task_wq;

        struct work_struct              defered_req_work;

        atomic_t                        state;
        atomic_t                        inflight_reqs;
        wait_queue_head_t               inflight_wq;
};

static inline bool pcache_is_stopping(struct dm_pcache *pcache)
{
        return (atomic_read(&pcache->state) == PCACHE_STATE_STOPPING);
}

#define pcache_dev_err(pcache, fmt, ...)                                                        \
        pcache_err("%s " fmt, pcache->ti->table->md->name, ##__VA_ARGS__)
#define pcache_dev_info(pcache, fmt, ...)                                                       \
        pcache_info("%s " fmt, pcache->ti->table->md->name, ##__VA_ARGS__)
#define pcache_dev_debug(pcache, fmt, ...)                                                      \
        pcache_debug("%s " fmt, pcache->ti->table->md->name, ##__VA_ARGS__)

struct pcache_request {
        struct dm_pcache        *pcache;
        struct bio              *bio;

        u64                     off;
        u32                     data_len;

        struct kref             ref;
        int                     ret;

        struct list_head        list_node;
};

void pcache_req_get(struct pcache_request *pcache_req);
void pcache_req_put(struct pcache_request *pcache_req, int ret);

void pcache_defer_reqs_kick(struct dm_pcache *pcache);

#endif /* _DM_PCACHE_H */