/*      $NetBSD: dmovervar.h,v 1.11 2024/09/08 09:36:50 rillig Exp $    */

/*
 * Copyright (c) 2002, 2003 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _DMOVER_DMOVERVAR_H_
#define _DMOVER_DMOVERVAR_H_

#include <sys/lock.h>
#include <sys/queue.h>

/*
 * Types of buffers the dmover-api can handle.
 */
typedef enum {
        DMOVER_BUF_NONE                 = 0,
        DMOVER_BUF_LINEAR               = 1,
        DMOVER_BUF_UIO                  = 2
} dmover_buffer_type;

typedef struct {
        void *l_addr;
        size_t l_len;
} dmover_buf_linear;

typedef union {
        dmover_buf_linear dmbuf_linear;
        struct uio *dmbuf_uio;
} dmover_buffer;

/*
 * dmover_algdesc:
 *
 *      This structure describes a dmover algorithm.
 *
 *      All members of this structure are public.
 */
struct dmover_algdesc {
        const char *dad_name;           /* algorithm name */
        void *dad_data;                 /* opaque algorithm description */
        int dad_ninputs;                /* number of inputs */
};

/*
 * dmover_assignment:
 *
 *      This structure contains the information necessary to assign
 *      a request to a back-end.
 *
 *      All members of this structure are public.
 */
struct dmover_assignment {
        struct dmover_backend *das_backend;
        const struct dmover_algdesc *das_algdesc;
};

/*
 * dmover_session:
 *
 *      State for a dmover session.
 */
struct dmover_session {
        /*
         * PUBLIC MEMBERS
         */
        void    *dses_cookie;           /* for client */
        int     dses_ninputs;           /* number of inputs for function */

        /*
         * PRIVATE MEMBERS
         */
        LIST_ENTRY(dmover_session) __dses_list;

        /*
         * XXX Assignment is static when a session is
         * XXX created, for now.
         */
        struct dmover_assignment __dses_assignment;

        /* List of active requests on this session. */
        TAILQ_HEAD(, dmover_request) __dses_pendreqs;
        int     __dses_npendreqs;
};

#define dmover_session_insque(dses, dreq)                               \
do {                                                                    \
        TAILQ_INSERT_TAIL(&(dses)->__dses_pendreqs, (dreq), dreq_sesq); \
        (dses)->__dses_npendreqs++;                                     \
} while (/*CONSTCOND*/0)

#define dmover_session_remque(dses, dreq)                               \
do {                                                                    \
        TAILQ_REMOVE(&(dses)->__dses_pendreqs, (dreq), dreq_sesq);      \
        (dses)->__dses_npendreqs--;                                     \
} while (/*CONSTCOND*/0)

/*
 * dmover_request:
 *
 *      A data dmover request.
 */
struct dmover_request {
        /*
         * PUBLIC MEMBERS
         */

        /* Links on session and back-end queues. */
        TAILQ_ENTRY(dmover_request) dreq_sesq;
        TAILQ_ENTRY(dmover_request) dreq_dmbq;

        /* Pointer to our session. */
        struct dmover_session *dreq_session;

        /* Our current back-end assignment. */
        struct dmover_assignment *dreq_assignment;

        /* Function to call when processing is complete. */
        void    (*dreq_callback)(struct dmover_request *);
        void    *dreq_cookie;   /* for client */

        volatile int dreq_flags; /* flags; see below */
        int     dreq_error;        /* valid if DMOVER_REQ_ERROR is set */

        /*
         * General purpose immediate value.  Can be used as an
         * input, output, or both, depending on the function.
         */
        uint8_t dreq_immediate[8];

        /* Output buffer. */
        dmover_buffer_type dreq_outbuf_type;
        dmover_buffer dreq_outbuf;

        /* Input buffer. */
        dmover_buffer_type dreq_inbuf_type;
        dmover_buffer *dreq_inbuf;
};

/* dreq_flags */
#define DMOVER_REQ_DONE         0x0001  /* request is completed */
#define DMOVER_REQ_ERROR        0x0002  /* error occurred */
#define DMOVER_REQ_RUNNING      0x0004  /* request is being executed */
#define DMOVER_REQ_WAIT         0x0008  /* wait for completion */

#define __DMOVER_REQ_INBUF_FREE 0x01000000 /* need to free input buffer */

#define __DMOVER_REQ_FLAGS_PRESERVE                                     \
        (DMOVER_REQ_WAIT | __DMOVER_REQ_INBUF_FREE)

/*
 * dmover_backend:
 *
 *      Glue between the dmover-api middle layer and the dmover
 *      backends.
 *
 *      All members of this structure are public.
 */
struct dmover_backend {
        TAILQ_ENTRY(dmover_backend) dmb_list;

        const char *dmb_name;           /* name of back-end */
        u_int dmb_speed;                /* est. KB/s throughput */

        void    *dmb_cookie;            /* for back-end */

        /* List of algorithms this back-ends supports. */
        const struct dmover_algdesc *dmb_algdescs;
        int dmb_nalgdescs;

        /* Back-end functions. */
        void    (*dmb_process)(struct dmover_backend *);

        /* List of sessions currently on this back-end. */
        LIST_HEAD(, dmover_session) dmb_sessions;
        int     dmb_nsessions;          /* current number of sessions */

        /* List of active requests on this back-end. */
        TAILQ_HEAD(, dmover_request) dmb_pendreqs;
        int     dmb_npendreqs;
};

#define dmover_backend_insque(dmb, dreq)                                \
do {                                                                    \
        TAILQ_INSERT_TAIL(&(dmb)->dmb_pendreqs, (dreq), dreq_dmbq);     \
        (dmb)->dmb_npendreqs++;                                         \
} while (/*CONSTCOND*/0)

#define dmover_backend_remque(dmb, dreq)                                \
do {                                                                    \
        TAILQ_REMOVE(&(dmb)->dmb_pendreqs, (dreq), dreq_dmbq);          \
        (dmb)->dmb_npendreqs--;                                         \
} while (/*CONSTCOND*/0)

/*
 * Well-known data mover functions.  Using these for the function name
 * saves space.
 */
extern const char dmover_funcname_zero[];
#define DMOVER_FUNC_ZERO                dmover_funcname_zero

extern const char dmover_funcname_fill8[];
#define DMOVER_FUNC_FILL8               dmover_funcname_fill8

extern const char dmover_funcname_copy[];
#define DMOVER_FUNC_COPY                dmover_funcname_copy

extern const char dmover_funcname_iscsi_crc32c[];
#define DMOVER_FUNC_ISCSI_CRC32C        dmover_funcname_iscsi_crc32c

extern const char dmover_funcname_xor2[];
#define DMOVER_FUNC_XOR2                dmover_funcname_xor2

extern const char dmover_funcname_xor3[];
#define DMOVER_FUNC_XOR3                dmover_funcname_xor3

extern const char dmover_funcname_xor4[];
#define DMOVER_FUNC_XOR4                dmover_funcname_xor4

extern const char dmover_funcname_xor5[];
#define DMOVER_FUNC_XOR5                dmover_funcname_xor5

extern const char dmover_funcname_xor6[];
#define DMOVER_FUNC_XOR6                dmover_funcname_xor6

extern const char dmover_funcname_xor7[];
#define DMOVER_FUNC_XOR7                dmover_funcname_xor7

extern const char dmover_funcname_xor8[];
#define DMOVER_FUNC_XOR8                dmover_funcname_xor8

extern const char dmover_funcname_xor9[];
#define DMOVER_FUNC_XOR9                dmover_funcname_xor9

extern const char dmover_funcname_xor10[];
#define DMOVER_FUNC_XOR10               dmover_funcname_xor10

extern const char dmover_funcname_xor11[];
#define DMOVER_FUNC_XOR11               dmover_funcname_xor11

extern const char dmover_funcname_xor12[];
#define DMOVER_FUNC_XOR12               dmover_funcname_xor12

extern const char dmover_funcname_xor13[];
#define DMOVER_FUNC_XOR13               dmover_funcname_xor13

extern const char dmover_funcname_xor14[];
#define DMOVER_FUNC_XOR14               dmover_funcname_xor14

extern const char dmover_funcname_xor15[];
#define DMOVER_FUNC_XOR15               dmover_funcname_xor15

extern const char dmover_funcname_xor16[];
#define DMOVER_FUNC_XOR16               dmover_funcname_xor16

/* Back-end management functions. */
void    dmover_backend_register(struct dmover_backend *);
void    dmover_backend_unregister(struct dmover_backend *);
int     dmover_backend_alloc(struct dmover_session *, const char *);
void    dmover_backend_release(struct dmover_session *);

/* Session management functions. */
void    dmover_session_initialize(void);
int     dmover_session_create(const char *, struct dmover_session **);
void    dmover_session_destroy(struct dmover_session *);

/* Request management functions. */
void    dmover_request_initialize(void);
struct dmover_request *dmover_request_alloc(struct dmover_session *,
            dmover_buffer *);
void    dmover_request_free(struct dmover_request *);

/* Processing engine functions. */
void    dmover_process_initialize(void);
void    dmover_process(struct dmover_request *);
void    dmover_done(struct dmover_request *);

/* Utility functions. */
const struct dmover_algdesc *
            dmover_algdesc_lookup(const struct dmover_algdesc *, int,
            const char *);

#endif /* _DMOVER_DMOVERVAR_H_ */