/* Copyright (c) 2013 Coraid, Inc.  See COPYING for GPL terms. */
#include <linux/blk-mq.h>

#define VERSION "85"
#define AOE_MAJOR 152
#define DEVICE_NAME "aoe"

/* set AOE_PARTITIONS to 1 to use whole-disks only
 * default is 16, which is 15 partitions plus the whole disk
 */
#ifndef AOE_PARTITIONS
#define AOE_PARTITIONS (16)
#endif

#define WHITESPACE " \t\v\f\n,"

enum {
        AOECMD_ATA,
        AOECMD_CFG,
        AOECMD_VEND_MIN = 0xf0,

        AOEFL_RSP = (1<<3),
        AOEFL_ERR = (1<<2),

        AOEAFL_EXT = (1<<6),
        AOEAFL_DEV = (1<<4),
        AOEAFL_ASYNC = (1<<1),
        AOEAFL_WRITE = (1<<0),

        AOECCMD_READ = 0,
        AOECCMD_TEST,
        AOECCMD_PTEST,
        AOECCMD_SET,
        AOECCMD_FSET,

        AOE_HVER = 0x10,
};

struct aoe_hdr {
        unsigned char dst[6];
        unsigned char src[6];
        __be16 type;
        unsigned char verfl;
        unsigned char err;
        __be16 major;
        unsigned char minor;
        unsigned char cmd;
        __be32 tag;
};

struct aoe_atahdr {
        unsigned char aflags;
        unsigned char errfeat;
        unsigned char scnt;
        unsigned char cmdstat;
        unsigned char lba0;
        unsigned char lba1;
        unsigned char lba2;
        unsigned char lba3;
        unsigned char lba4;
        unsigned char lba5;
        unsigned char res[2];
};

struct aoe_cfghdr {
        __be16 bufcnt;
        __be16 fwver;
        unsigned char scnt;
        unsigned char aoeccmd;
        unsigned char cslen[2];
};

enum {
        DEVFL_UP = 1,   /* device is installed in system and ready for AoE->ATA commands */
        DEVFL_TKILL = (1<<1),   /* flag for timer to know when to kill self */
        DEVFL_EXT = (1<<2),     /* device accepts lba48 commands */
        DEVFL_GDALLOC = (1<<3), /* need to alloc gendisk */
        DEVFL_GD_NOW = (1<<4),  /* allocating gendisk */
        DEVFL_KICKME = (1<<5),  /* slow polling network card catch */
        DEVFL_NEWSIZE = (1<<6), /* need to update dev size in block layer */
        DEVFL_FREEING = (1<<7), /* set when device is being cleaned up */
        DEVFL_FREED = (1<<8),   /* device has been cleaned up */
        DEVFL_DEAD = (1<<9),    /* device has timed out of aoe_deadsecs */
};

enum {
        DEFAULTBCNT = 2 * 512,  /* 2 sectors */
        MIN_BUFS = 16,
        NTARGETS = 4,
        NAOEIFS = 8,
        NSKBPOOLMAX = 256,
        NFACTIVE = 61,

        TIMERTICK = HZ / 10,
        RTTSCALE = 8,
        RTTDSCALE = 3,
        RTTAVG_INIT = USEC_PER_SEC / 4 << RTTSCALE,
        RTTDEV_INIT = RTTAVG_INIT / 4,

        HARD_SCORN_SECS = 10,   /* try another remote port after this */
        MAX_TAINT = 1000,       /* cap on aoetgt taint */
};

struct aoe_req {
        unsigned long nr_bios;
};

struct buf {
        ulong nframesout;
        struct bio *bio;
        struct bvec_iter iter;
        struct request *rq;
};

enum frame_flags {
        FFL_PROBE = 1,
};

struct frame {
        struct list_head head;
        u32 tag;
        ktime_t sent;                   /* high-res time packet was sent */
        ulong waited;
        ulong waited_total;
        struct aoetgt *t;               /* parent target I belong to */
        struct sk_buff *skb;            /* command skb freed on module exit */
        struct sk_buff *r_skb;          /* response skb for async processing */
        struct buf *buf;
        struct bvec_iter iter;
        char flags;
};

struct aoeif {
        struct net_device *nd;
        ulong lost;
        int bcnt;
};

struct aoetgt {
        unsigned char addr[6];
        ushort nframes;         /* cap on frames to use */
        struct aoedev *d;                       /* parent device I belong to */
        struct list_head ffree;                 /* list of free frames */
        struct aoeif ifs[NAOEIFS];
        struct aoeif *ifp;      /* current aoeif in use */
        ushort nout;            /* number of AoE commands outstanding */
        ushort maxout;          /* current value for max outstanding */
        ushort next_cwnd;       /* incr maxout after decrementing to zero */
        ushort ssthresh;        /* slow start threshold */
        ulong falloc;           /* number of allocated frames */
        int taint;              /* how much we want to avoid this aoetgt */
        int minbcnt;
        int wpkts, rpkts;
        char nout_probes;
};

struct aoedev {
        struct aoedev *next;
        ulong sysminor;
        ulong aoemajor;
        u32 rttavg;             /* scaled AoE round trip time average */
        u32 rttdev;             /* scaled round trip time mean deviation */
        u16 aoeminor;
        u16 flags;
        u16 nopen;              /* (bd_openers isn't available without sleeping) */
        u16 fw_ver;             /* version of blade's firmware */
        u16 lasttag;            /* last tag sent */
        u16 useme;
        ulong ref;
        struct work_struct work;/* disk create work struct */
        struct gendisk *gd;
        struct dentry *debugfs;
        struct request_queue *blkq;
        struct list_head rq_list;
        struct blk_mq_tag_set tag_set;
        struct hd_geometry geo;
        sector_t ssize;
        struct timer_list timer;
        spinlock_t lock;
        struct sk_buff_head skbpool;
        mempool_t *bufpool;     /* for deadlock-free Buf allocation */
        struct {                /* pointers to work in progress */
                struct buf *buf;
                struct bio *nxbio;
                struct request *rq;
        } ip;
        ulong maxbcnt;
        struct list_head factive[NFACTIVE];     /* hash of active frames */
        struct list_head rexmitq; /* deferred retransmissions */
        struct aoetgt **targets;
        ulong ntargets;         /* number of allocated aoetgt pointers */
        struct aoetgt **tgt;    /* target in use when working */
        ulong kicked;
        char ident[512];
};

/* kthread tracking */
struct ktstate {
        struct completion rendez;
        struct task_struct *task;
        wait_queue_head_t *waitq;
        int (*fn) (int);
        char name[12];
        spinlock_t *lock;
        int id;
        int active;
};

int aoeblk_init(void);
void aoeblk_exit(void);
void aoeblk_gdalloc(void *);
void aoedisk_rm_debugfs(struct aoedev *d);

int aoechr_init(void);
void aoechr_exit(void);
void aoechr_error(char *);

void aoecmd_work(struct aoedev *d);
void aoecmd_cfg(ushort aoemajor, unsigned char aoeminor);
struct sk_buff *aoecmd_ata_rsp(struct sk_buff *);
void aoecmd_cfg_rsp(struct sk_buff *);
void aoecmd_sleepwork(struct work_struct *);
void aoecmd_wreset(struct aoetgt *t);
void aoecmd_cleanslate(struct aoedev *);
void aoecmd_exit(void);
int aoecmd_init(void);
struct sk_buff *aoecmd_ata_id(struct aoedev *);
void aoe_freetframe(struct frame *);
void aoe_flush_iocq(void);
void aoe_flush_iocq_by_index(int);
void aoe_end_request(struct aoedev *, struct request *, int);
int aoe_ktstart(struct ktstate *k);
void aoe_ktstop(struct ktstate *k);

int aoedev_init(void);
void aoedev_exit(void);
struct aoedev *aoedev_by_aoeaddr(ulong maj, int min, int do_alloc);
void aoedev_downdev(struct aoedev *d);
int aoedev_flush(const char __user *str, size_t size);
void aoe_failbuf(struct aoedev *, struct buf *);
void aoedev_put(struct aoedev *);

int aoenet_init(void);
void aoenet_exit(void);
void aoenet_xmit(struct sk_buff_head *);
int is_aoe_netif(struct net_device *ifp);
int set_aoe_iflist(const char __user *str, size_t size);

extern struct workqueue_struct *aoe_wq;