/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Internal header file _only_ for device mapper core
 *
 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef DM_CORE_INTERNAL_H
#define DM_CORE_INTERNAL_H

#include <linux/kthread.h>
#include <linux/ktime.h>
#include <linux/blk-mq.h>
#include <linux/blk-crypto-profile.h>
#include <linux/jump_label.h>

#include <trace/events/block.h>

#include "dm.h"
#include "dm-ima.h"

#define DM_RESERVED_MAX_IOS             1024
#define DM_MAX_TARGETS                  1048576
#define DM_MAX_TARGET_PARAMS            1024

struct dm_io;

struct dm_kobject_holder {
        struct kobject kobj;
        struct completion completion;
};

/*
 * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
 * DM targets must _not_ deference a mapped_device or dm_table to directly
 * access their members!
 */

/*
 * For mempools pre-allocation at the table loading time.
 */
struct dm_md_mempools {
        struct bio_set bs;
        struct bio_set io_bs;
};

struct mapped_device {
        struct mutex suspend_lock;

        struct mutex table_devices_lock;
        struct list_head table_devices;

        /*
         * The current mapping (struct dm_table *).
         * Use dm_get_live_table{_fast} or take suspend_lock for
         * dereference.
         */
        void __rcu *map;

        unsigned long flags;

        /* Protect queue and type against concurrent access. */
        struct mutex type_lock;
        enum dm_queue_mode type;

        int numa_node_id;
        struct request_queue *queue;

        atomic_t holders;
        atomic_t open_count;

        struct dm_target *immutable_target;
        struct target_type *immutable_target_type;

        char name[16];
        struct gendisk *disk;
        struct dax_device *dax_dev;

        wait_queue_head_t wait;
        unsigned long __percpu *pending_io;

        /* forced geometry settings */
        struct hd_geometry geometry;

        /*
         * Processing queue (flush)
         */
        struct workqueue_struct *wq;

        /*
         * A list of ios that arrived while we were suspended.
         */
        struct work_struct work;
        spinlock_t deferred_lock;
        struct bio_list deferred;

        /*
         * requeue work context is needed for cloning one new bio
         * to represent the dm_io to be requeued, since each
         * dm_io may point to the original bio from FS.
         */
        struct work_struct requeue_work;
        struct dm_io *requeue_list;

        void *interface_ptr;

        /*
         * Event handling.
         */
        wait_queue_head_t eventq;
        atomic_t event_nr;
        atomic_t uevent_seq;
        struct list_head uevent_list;
        spinlock_t uevent_lock; /* Protect access to uevent_list */

        /* for blk-mq request-based DM support */
        bool init_tio_pdu:1;
        struct blk_mq_tag_set *tag_set;

        struct dm_stats stats;

        /* the number of internal suspends */
        unsigned int internal_suspend_count;

        int swap_bios;
        struct semaphore swap_bios_semaphore;
        struct mutex swap_bios_lock;

        /*
         * io objects are allocated from here.
         */
        struct dm_md_mempools *mempools;

        /* kobject and completion */
        struct dm_kobject_holder kobj_holder;

        struct srcu_struct io_barrier;

#ifdef CONFIG_BLK_DEV_ZONED
        void *zone_revalidate_map;
        struct task_struct *revalidate_map_task;
#endif

#ifdef CONFIG_IMA
        struct dm_ima_measurements ima;
#endif
};

/*
 * Bits for the flags field of struct mapped_device.
 */
#define DMF_BLOCK_IO_FOR_SUSPEND 0
#define DMF_SUSPENDED 1
#define DMF_FROZEN 2
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
#define DMF_DEFERRED_REMOVE 6
#define DMF_SUSPENDED_INTERNALLY 7
#define DMF_POST_SUSPENDING 8
#define DMF_EMULATE_ZONE_APPEND 9
#define DMF_QUEUE_STOPPED 10

static inline sector_t dm_get_size(struct mapped_device *md)
{
        return get_capacity(md->disk);
}

static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
{
        return &md->stats;
}

DECLARE_STATIC_KEY_FALSE(stats_enabled);
DECLARE_STATIC_KEY_FALSE(swap_bios_enabled);
DECLARE_STATIC_KEY_FALSE(zoned_enabled);

static inline bool dm_emulate_zone_append(struct mapped_device *md)
{
        if (blk_queue_is_zoned(md->queue))
                return test_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
        return false;
}

#define DM_TABLE_MAX_DEPTH 16

struct dm_table {
        struct mapped_device *md;
        enum dm_queue_mode type;

        /* btree table */
        unsigned int depth;
        unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
        sector_t *index[DM_TABLE_MAX_DEPTH];

        unsigned int num_targets;
        unsigned int num_allocated;
        sector_t *highs;
        struct dm_target *targets;

        struct target_type *immutable_target_type;

        bool integrity_supported:1;
        bool singleton:1;
        /* set if all the targets in the table have "flush_bypasses_map" set */
        bool flush_bypasses_map:1;

        /*
         * Indicates the rw permissions for the new logical device.  This
         * should be a combination of BLK_OPEN_READ and BLK_OPEN_WRITE.
         */
        blk_mode_t mode;

        /* a list of devices used by this table */
        struct list_head devices;

        /* events get handed up using this callback */
        void (*event_fn)(void *data);
        void *event_context;

        struct dm_md_mempools *mempools;

#ifdef CONFIG_BLK_INLINE_ENCRYPTION
        struct blk_crypto_profile *crypto_profile;
#endif
};

static inline struct dm_target *dm_table_get_target(struct dm_table *t,
                                                    unsigned int index)
{
        BUG_ON(index >= t->num_targets);
        return t->targets + index;
}

/*
 * One of these is allocated per clone bio.
 */
#define DM_TIO_MAGIC 28714
struct dm_target_io {
        unsigned short magic;
        blk_short_t flags;
        unsigned int target_bio_nr;
        struct dm_io *io;
        struct dm_target *ti;
        unsigned int *len_ptr;
        sector_t old_sector;
        struct bio clone;
};
#define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
#define DM_IO_BIO_OFFSET \
        (offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))

/*
 * dm_target_io flags
 */
enum {
        DM_TIO_INSIDE_DM_IO,
        DM_TIO_IS_DUPLICATE_BIO
};

static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)
{
        return (tio->flags & (1U << bit)) != 0;
}

static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)
{
        tio->flags |= (1U << bit);
}

static inline bool dm_tio_is_normal(struct dm_target_io *tio)
{
        return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
                !dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
}

/*
 * One of these is allocated per original bio.
 * It contains the first clone used for that original.
 */
#define DM_IO_MAGIC 19577
struct dm_io {
        unsigned short magic;
        blk_short_t flags;
        spinlock_t lock;
        unsigned long start_time;
        void *data;
        struct dm_io *next;
        struct dm_stats_aux stats_aux;
        blk_status_t status;
        bool requeue_flush_with_data;
        atomic_t io_count;
        struct mapped_device *md;

        /* The three fields represent mapped part of original bio */
        struct bio *orig_bio;
        unsigned int sector_offset; /* offset to end of orig_bio */
        unsigned int sectors;

        /* last member of dm_target_io is 'struct bio' */
        struct dm_target_io tio;
};

/*
 * dm_io flags
 */
enum {
        DM_IO_ACCOUNTED,
        DM_IO_WAS_SPLIT,
        DM_IO_BLK_STAT
};

static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)
{
        return (io->flags & (1U << bit)) != 0;
}

static inline void dm_io_set_flag(struct dm_io *io, unsigned int bit)
{
        io->flags |= (1U << bit);
}

void dm_io_rewind(struct dm_io *io, struct bio_set *bs);

static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
{
        return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
}

unsigned int __dm_get_module_param(unsigned int *module_param, unsigned int def, unsigned int max);

static inline bool dm_message_test_buffer_overflow(char *result, unsigned int maxlen)
{
        return !maxlen || strlen(result) + 1 >= maxlen;
}

extern atomic_t dm_global_event_nr;
extern wait_queue_head_t dm_global_eventq;
void dm_issue_global_event(void);

#endif