/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Block data types and constants.  Directly include this file only to
 * break include dependency loop.
 */
#ifndef __LINUX_BLK_TYPES_H
#define __LINUX_BLK_TYPES_H

#include <linux/types.h>
#include <linux/bvec.h>
#include <linux/device.h>
#include <linux/ktime.h>

struct bio_set;
struct bio;
struct bio_integrity_payload;
struct page;
struct io_context;
struct cgroup_subsys_state;
typedef void (bio_end_io_t) (struct bio *);
struct bio_crypt_ctx;

/*
 * The basic unit of block I/O is a sector. It is used in a number of contexts
 * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
 * bytes. Variables of type sector_t represent an offset or size that is a
 * multiple of 512 bytes. Hence these two constants.
 */
#ifndef SECTOR_SHIFT
#define SECTOR_SHIFT 9
#endif
#ifndef SECTOR_SIZE
#define SECTOR_SIZE (1 << SECTOR_SHIFT)
#endif

#define PAGE_SECTORS_SHIFT      (PAGE_SHIFT - SECTOR_SHIFT)
#define PAGE_SECTORS            (1 << PAGE_SECTORS_SHIFT)
#define SECTOR_MASK             (PAGE_SECTORS - 1)

struct block_device {
        sector_t                bd_start_sect;
        sector_t                bd_nr_sectors;
        struct disk_stats __percpu *bd_stats;
        unsigned long           bd_stamp;
        bool                    bd_read_only;   /* read-only policy */
        dev_t                   bd_dev;
        int                     bd_openers;
        struct inode *          bd_inode;       /* will die */
        struct super_block *    bd_super;
        void *                  bd_claiming;
        struct device           bd_device;
        void *                  bd_holder;
        int                     bd_holders;
        bool                    bd_write_holder;
        struct kobject          *bd_holder_dir;
        u8                      bd_partno;
        spinlock_t              bd_size_lock; /* for bd_inode->i_size updates */
        struct gendisk *        bd_disk;
        struct request_queue *  bd_queue;

        /* The counter of freeze processes */
        int                     bd_fsfreeze_count;
        /* Mutex for freeze */
        struct mutex            bd_fsfreeze_mutex;
        struct super_block      *bd_fsfreeze_sb;

        struct partition_meta_info *bd_meta_info;
#ifdef CONFIG_FAIL_MAKE_REQUEST
        bool                    bd_make_it_fail;
#endif
} __randomize_layout;

#define bdev_whole(_bdev) \
        ((_bdev)->bd_disk->part0)

#define dev_to_bdev(device) \
        container_of((device), struct block_device, bd_device)

#define bdev_kobj(_bdev) \
        (&((_bdev)->bd_device.kobj))

/*
 * Block error status values.  See block/blk-core:blk_errors for the details.
 * Alpha cannot write a byte atomically, so we need to use 32-bit value.
 */
#if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
typedef u32 __bitwise blk_status_t;
#else
typedef u8 __bitwise blk_status_t;
#endif
#define BLK_STS_OK 0
#define BLK_STS_NOTSUPP         ((__force blk_status_t)1)
#define BLK_STS_TIMEOUT         ((__force blk_status_t)2)
#define BLK_STS_NOSPC           ((__force blk_status_t)3)
#define BLK_STS_TRANSPORT       ((__force blk_status_t)4)
#define BLK_STS_TARGET          ((__force blk_status_t)5)
#define BLK_STS_NEXUS           ((__force blk_status_t)6)
#define BLK_STS_MEDIUM          ((__force blk_status_t)7)
#define BLK_STS_PROTECTION      ((__force blk_status_t)8)
#define BLK_STS_RESOURCE        ((__force blk_status_t)9)
#define BLK_STS_IOERR           ((__force blk_status_t)10)

/* hack for device mapper, don't use elsewhere: */
#define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11)

#define BLK_STS_AGAIN           ((__force blk_status_t)12)

/*
 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
 * device related resources are unavailable, but the driver can guarantee
 * that the queue will be rerun in the future once resources become
 * available again. This is typically the case for device specific
 * resources that are consumed for IO. If the driver fails allocating these
 * resources, we know that inflight (or pending) IO will free these
 * resource upon completion.
 *
 * This is different from BLK_STS_RESOURCE in that it explicitly references
 * a device specific resource. For resources of wider scope, allocation
 * failure can happen without having pending IO. This means that we can't
 * rely on request completions freeing these resources, as IO may not be in
 * flight. Examples of that are kernel memory allocations, DMA mappings, or
 * any other system wide resources.
 */
#define BLK_STS_DEV_RESOURCE    ((__force blk_status_t)13)

/*
 * BLK_STS_ZONE_RESOURCE is returned from the driver to the block layer if zone
 * related resources are unavailable, but the driver can guarantee the queue
 * will be rerun in the future once the resources become available again.
 *
 * This is different from BLK_STS_DEV_RESOURCE in that it explicitly references
 * a zone specific resource and IO to a different zone on the same device could
 * still be served. Examples of that are zones that are write-locked, but a read
 * to the same zone could be served.
 */
#define BLK_STS_ZONE_RESOURCE   ((__force blk_status_t)14)

/*
 * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion
 * path if the device returns a status indicating that too many zone resources
 * are currently open. The same command should be successful if resubmitted
 * after the number of open zones decreases below the device's limits, which is
 * reported in the request_queue's max_open_zones.
 */
#define BLK_STS_ZONE_OPEN_RESOURCE      ((__force blk_status_t)15)

/*
 * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion
 * path if the device returns a status indicating that too many zone resources
 * are currently active. The same command should be successful if resubmitted
 * after the number of active zones decreases below the device's limits, which
 * is reported in the request_queue's max_active_zones.
 */
#define BLK_STS_ZONE_ACTIVE_RESOURCE    ((__force blk_status_t)16)

/**
 * blk_path_error - returns true if error may be path related
 * @error: status the request was completed with
 *
 * Description:
 *     This classifies block error status into non-retryable errors and ones
 *     that may be successful if retried on a failover path.
 *
 * Return:
 *     %false - retrying failover path will not help
 *     %true  - may succeed if retried
 */
static inline bool blk_path_error(blk_status_t error)
{
        switch (error) {
        case BLK_STS_NOTSUPP:
        case BLK_STS_NOSPC:
        case BLK_STS_TARGET:
        case BLK_STS_NEXUS:
        case BLK_STS_MEDIUM:
        case BLK_STS_PROTECTION:
                return false;
        }

        /* Anything else could be a path failure, so should be retried */
        return true;
}

/*
 * From most significant bit:
 * 1 bit: reserved for other usage, see below
 * 12 bits: original size of bio
 * 51 bits: issue time of bio
 */
#define BIO_ISSUE_RES_BITS      1
#define BIO_ISSUE_SIZE_BITS     12
#define BIO_ISSUE_RES_SHIFT     (64 - BIO_ISSUE_RES_BITS)
#define BIO_ISSUE_SIZE_SHIFT    (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
#define BIO_ISSUE_TIME_MASK     ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
#define BIO_ISSUE_SIZE_MASK     \
        (((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
#define BIO_ISSUE_RES_MASK      (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))

/* Reserved bit for blk-throtl */
#define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)

struct bio_issue {
        u64 value;
};

static inline u64 __bio_issue_time(u64 time)
{
        return time & BIO_ISSUE_TIME_MASK;
}

static inline u64 bio_issue_time(struct bio_issue *issue)
{
        return __bio_issue_time(issue->value);
}

static inline sector_t bio_issue_size(struct bio_issue *issue)
{
        return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
}

static inline void bio_issue_init(struct bio_issue *issue,
                                       sector_t size)
{
        size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
        issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
                        (ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
                        ((u64)size << BIO_ISSUE_SIZE_SHIFT));
}

typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE           -1U

/*
 * main unit of I/O for the block layer and lower layers (ie drivers and
 * stacking drivers)
 */
struct bio {
        struct bio              *bi_next;       /* request queue link */
        struct block_device     *bi_bdev;
        unsigned int            bi_opf;         /* bottom bits req flags,
                                                 * top bits REQ_OP. Use
                                                 * accessors.
                                                 */
        unsigned short          bi_flags;       /* BIO_* below */
        unsigned short          bi_ioprio;
        unsigned short          bi_write_hint;
        blk_status_t            bi_status;
        atomic_t                __bi_remaining;

        struct bvec_iter        bi_iter;

        blk_qc_t                bi_cookie;
        bio_end_io_t            *bi_end_io;
        void                    *bi_private;
#ifdef CONFIG_BLK_CGROUP
        /*
         * Represents the association of the css and request_queue for the bio.
         * If a bio goes direct to device, it will not have a blkg as it will
         * not have a request_queue associated with it.  The reference is put
         * on release of the bio.
         */
        struct blkcg_gq         *bi_blkg;
        struct bio_issue        bi_issue;
#ifdef CONFIG_BLK_CGROUP_IOCOST
        u64                     bi_iocost_cost;
#endif
#endif

#ifdef CONFIG_BLK_INLINE_ENCRYPTION
        struct bio_crypt_ctx    *bi_crypt_context;
#endif

        union {
#if defined(CONFIG_BLK_DEV_INTEGRITY)
                struct bio_integrity_payload *bi_integrity; /* data integrity */
#endif
        };

        unsigned short          bi_vcnt;        /* how many bio_vec's */

        /*
         * Everything starting with bi_max_vecs will be preserved by bio_reset()
         */

        unsigned short          bi_max_vecs;    /* max bvl_vecs we can hold */

        atomic_t                __bi_cnt;       /* pin count */

        struct bio_vec          *bi_io_vec;     /* the actual vec list */

        struct bio_set          *bi_pool;

        /*
         * We can inline a number of vecs at the end of the bio, to avoid
         * double allocations for a small number of bio_vecs. This member
         * MUST obviously be kept at the very end of the bio.
         */
        struct bio_vec          bi_inline_vecs[];
};

#define BIO_RESET_BYTES         offsetof(struct bio, bi_max_vecs)
#define BIO_MAX_SECTORS         (UINT_MAX >> SECTOR_SHIFT)

/*
 * bio flags
 */
enum {
        BIO_NO_PAGE_REF,        /* don't put release vec pages */
        BIO_CLONED,             /* doesn't own data */
        BIO_BOUNCED,            /* bio is a bounce bio */
        BIO_WORKINGSET,         /* contains userspace workingset pages */
        BIO_QUIET,              /* Make BIO Quiet */
        BIO_CHAIN,              /* chained bio, ->bi_remaining in effect */
        BIO_REFFED,             /* bio has elevated ->bi_cnt */
        BIO_THROTTLED,          /* This bio has already been subjected to
                                 * throttling rules. Don't do it again. */
        BIO_TRACE_COMPLETION,   /* bio_endio() should trace the final completion
                                 * of this bio. */
        BIO_CGROUP_ACCT,        /* has been accounted to a cgroup */
        BIO_TRACKED,            /* set if bio goes through the rq_qos path */
        BIO_REMAPPED,
        BIO_ZONE_WRITE_LOCKED,  /* Owns a zoned device zone write lock */
        BIO_PERCPU_CACHE,       /* can participate in per-cpu alloc cache */
        BIO_FLAG_LAST
};

typedef __u32 __bitwise blk_mq_req_flags_t;

/*
 * Operations and flags common to the bio and request structures.
 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
 *
 * The least significant bit of the operation number indicates the data
 * transfer direction:
 *
 *   - if the least significant bit is set transfers are TO the device
 *   - if the least significant bit is not set transfers are FROM the device
 *
 * If a operation does not transfer data the least significant bit has no
 * meaning.
 */
#define REQ_OP_BITS     8
#define REQ_OP_MASK     ((1 << REQ_OP_BITS) - 1)
#define REQ_FLAG_BITS   24

enum req_opf {
        /* read sectors from the device */
        REQ_OP_READ             = 0,
        /* write sectors to the device */
        REQ_OP_WRITE            = 1,
        /* flush the volatile write cache */
        REQ_OP_FLUSH            = 2,
        /* discard sectors */
        REQ_OP_DISCARD          = 3,
        /* securely erase sectors */
        REQ_OP_SECURE_ERASE     = 5,
        /* write the same sector many times */
        REQ_OP_WRITE_SAME       = 7,
        /* write the zero filled sector many times */
        REQ_OP_WRITE_ZEROES     = 9,
        /* Open a zone */
        REQ_OP_ZONE_OPEN        = 10,
        /* Close a zone */
        REQ_OP_ZONE_CLOSE       = 11,
        /* Transition a zone to full */
        REQ_OP_ZONE_FINISH      = 12,
        /* write data at the current zone write pointer */
        REQ_OP_ZONE_APPEND      = 13,
        /* reset a zone write pointer */
        REQ_OP_ZONE_RESET       = 15,
        /* reset all the zone present on the device */
        REQ_OP_ZONE_RESET_ALL   = 17,

        /* Driver private requests */
        REQ_OP_DRV_IN           = 34,
        REQ_OP_DRV_OUT          = 35,

        REQ_OP_LAST,
};

enum req_flag_bits {
        __REQ_FAILFAST_DEV =    /* no driver retries of device errors */
                REQ_OP_BITS,
        __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
        __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
        __REQ_SYNC,             /* request is sync (sync write or read) */
        __REQ_META,             /* metadata io request */
        __REQ_PRIO,             /* boost priority in cfq */
        __REQ_NOMERGE,          /* don't touch this for merging */
        __REQ_IDLE,             /* anticipate more IO after this one */
        __REQ_INTEGRITY,        /* I/O includes block integrity payload */
        __REQ_FUA,              /* forced unit access */
        __REQ_PREFLUSH,         /* request for cache flush */
        __REQ_RAHEAD,           /* read ahead, can fail anytime */
        __REQ_BACKGROUND,       /* background IO */
        __REQ_NOWAIT,           /* Don't wait if request will block */
        /*
         * When a shared kthread needs to issue a bio for a cgroup, doing
         * so synchronously can lead to priority inversions as the kthread
         * can be trapped waiting for that cgroup.  CGROUP_PUNT flag makes
         * submit_bio() punt the actual issuing to a dedicated per-blkcg
         * work item to avoid such priority inversions.
         */
        __REQ_CGROUP_PUNT,

        /* command specific flags for REQ_OP_WRITE_ZEROES: */
        __REQ_NOUNMAP,          /* do not free blocks when zeroing */

        __REQ_POLLED,           /* caller polls for completion using bio_poll */

        /* for driver use */
        __REQ_DRV,
        __REQ_SWAP,             /* swapping request. */
        __REQ_NR_BITS,          /* stops here */
};

#define REQ_FAILFAST_DEV        (1ULL << __REQ_FAILFAST_DEV)
#define REQ_FAILFAST_TRANSPORT  (1ULL << __REQ_FAILFAST_TRANSPORT)
#define REQ_FAILFAST_DRIVER     (1ULL << __REQ_FAILFAST_DRIVER)
#define REQ_SYNC                (1ULL << __REQ_SYNC)
#define REQ_META                (1ULL << __REQ_META)
#define REQ_PRIO                (1ULL << __REQ_PRIO)
#define REQ_NOMERGE             (1ULL << __REQ_NOMERGE)
#define REQ_IDLE                (1ULL << __REQ_IDLE)
#define REQ_INTEGRITY           (1ULL << __REQ_INTEGRITY)
#define REQ_FUA                 (1ULL << __REQ_FUA)
#define REQ_PREFLUSH            (1ULL << __REQ_PREFLUSH)
#define REQ_RAHEAD              (1ULL << __REQ_RAHEAD)
#define REQ_BACKGROUND          (1ULL << __REQ_BACKGROUND)
#define REQ_NOWAIT              (1ULL << __REQ_NOWAIT)
#define REQ_CGROUP_PUNT         (1ULL << __REQ_CGROUP_PUNT)

#define REQ_NOUNMAP             (1ULL << __REQ_NOUNMAP)
#define REQ_POLLED              (1ULL << __REQ_POLLED)

#define REQ_DRV                 (1ULL << __REQ_DRV)
#define REQ_SWAP                (1ULL << __REQ_SWAP)

#define REQ_FAILFAST_MASK \
        (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)

#define REQ_NOMERGE_FLAGS \
        (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)

enum stat_group {
        STAT_READ,
        STAT_WRITE,
        STAT_DISCARD,
        STAT_FLUSH,

        NR_STAT_GROUPS
};

#define bio_op(bio) \
        ((bio)->bi_opf & REQ_OP_MASK)

/* obsolete, don't use in new code */
static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
                unsigned op_flags)
{
        bio->bi_opf = op | op_flags;
}

static inline bool op_is_write(unsigned int op)
{
        return (op & 1);
}

/*
 * Check if the bio or request is one that needs special treatment in the
 * flush state machine.
 */
static inline bool op_is_flush(unsigned int op)
{
        return op & (REQ_FUA | REQ_PREFLUSH);
}

/*
 * Reads are always treated as synchronous, as are requests with the FUA or
 * PREFLUSH flag.  Other operations may be marked as synchronous using the
 * REQ_SYNC flag.
 */
static inline bool op_is_sync(unsigned int op)
{
        return (op & REQ_OP_MASK) == REQ_OP_READ ||
                (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
}

static inline bool op_is_discard(unsigned int op)
{
        return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
}

/*
 * Check if a bio or request operation is a zone management operation, with
 * the exception of REQ_OP_ZONE_RESET_ALL which is treated as a special case
 * due to its different handling in the block layer and device response in
 * case of command failure.
 */
static inline bool op_is_zone_mgmt(enum req_opf op)
{
        switch (op & REQ_OP_MASK) {
        case REQ_OP_ZONE_RESET:
        case REQ_OP_ZONE_OPEN:
        case REQ_OP_ZONE_CLOSE:
        case REQ_OP_ZONE_FINISH:
                return true;
        default:
                return false;
        }
}

static inline int op_stat_group(unsigned int op)
{
        if (op_is_discard(op))
                return STAT_DISCARD;
        return op_is_write(op);
}

struct blk_rq_stat {
        u64 mean;
        u64 min;
        u64 max;
        u32 nr_samples;
        u64 batch;
};

#endif /* __LINUX_BLK_TYPES_H */