/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1997 Doug Rabson
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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 _SYS_MODULE_H_
#define _SYS_MODULE_H_

/*
 * Module metadata types
 */
#define MDT_DEPEND      1               /* argument is a module name */
#define MDT_MODULE      2               /* module declaration */
#define MDT_VERSION     3               /* module version(s) */
#define MDT_PNP_INFO    4               /* Plug and play hints record */

#define MDT_STRUCT_VERSION      1       /* version of metadata structure */
#define MDT_SETNAME     "modmetadata_set"

typedef enum modeventtype {
        MOD_LOAD,
        MOD_UNLOAD,
        MOD_SHUTDOWN,
        MOD_QUIESCE
} modeventtype_t;

typedef struct module *module_t;
typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);

/*
 * Struct for registering modules statically via SYSINIT.
 */
typedef struct moduledata {
        const char      *name;          /* module name */
        modeventhand_t  evhand;         /* event handler */
        void            *priv;          /* extra data */
} moduledata_t;

/*
 * A module can use this to report module specific data to the user via
 * kldstat(2).
 */
typedef union modspecific {
        int     intval;
        u_int   uintval;
        long    longval;
        u_long  ulongval;
} modspecific_t;

/*
 * Module dependency declaration
 */
struct mod_depend {
        int     md_ver_minimum;
        int     md_ver_preferred;
        int     md_ver_maximum;
};

/*
 * Module version declaration
 */
struct mod_version {
        int     mv_version;
};

struct mod_metadata {
        int             md_version;     /* structure version MDTV_* */
        int             md_type;        /* type of entry MDT_* */
        const void      *md_data;       /* specific data */
        const char      *md_cval;       /* common string label */
};

struct mod_pnp_match_info 
{
        const char *descr;      /* Description of the table */
        const char *bus;        /* Name of the bus for this table */
        const void *table;      /* Pointer to pnp table */
        int entry_len;          /* Length of each entry in the table (may be */
                                /*   longer than descr describes). */
        int num_entry;          /* Number of entries in the table */
};
#ifdef  _KERNEL

#include <sys/linker_set.h>

#define MODULE_METADATA_CONCAT(uniquifier)      _mod_metadata##uniquifier
#define MODULE_METADATA(uniquifier, type, data, cval)                   \
        static struct mod_metadata MODULE_METADATA_CONCAT(uniquifier) = {       \
                MDT_STRUCT_VERSION,                                     \
                type,                                                   \
                data,                                                   \
                cval                                                    \
        };                                                              \
        DATA_SET(modmetadata_set, MODULE_METADATA_CONCAT(uniquifier))

#define MODULE_DEPEND_CONCAT(module, mdepend)   _##module##_depend_on_##mdepend
#define MODULE_DEPEND(module, mdepend, vmin, vpref, vmax)               \
        static struct mod_depend MODULE_DEPEND_CONCAT(module, mdepend)  \
            __section(".data") = {                                      \
                vmin,                                                   \
                vpref,                                                  \
                vmax                                                    \
        };                                                              \
        MODULE_METADATA(MODULE_DEPEND_CONCAT(module, mdepend),          \
            MDT_DEPEND, &MODULE_DEPEND_CONCAT(module, mdepend),         \
            __XSTRING(mdepend))

/*
 * Every kernel has a 'kernel' module with the version set to
 * __FreeBSD_version.  We embed a MODULE_DEPEND() inside every module
 * that depends on the 'kernel' module.  It uses the current value of
 * __FreeBSD_version as the minimum and preferred versions.  For the
 * maximum version it rounds the version up to the end of its branch
 * (i.e. M99999 for M.x).  This allows a module built on M.x to work
 * on M.y systems where y >= x, but fail on M.z systems where z < x.
 */
#define MODULE_KERNEL_MAXVER    (roundup(__FreeBSD_version, 100000) - 1)

#define DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, maxver)      \
        MODULE_DEPEND(name, kernel, __FreeBSD_version,                  \
            __FreeBSD_version, maxver);                                 \
        MODULE_METADATA(_md_##name, MDT_MODULE, &data, __XSTRING(name));\
        SYSINIT(name##module, sub, order, module_register_init, &data); \
        struct __hack

#ifdef KLD_TIED
#define DECLARE_MODULE(name, data, sub, order)                          \
        DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, __FreeBSD_version)
#else
#define DECLARE_MODULE(name, data, sub, order)                                                  \
        DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, MODULE_KERNEL_MAXVER)
#endif

/*
 * The module declared with DECLARE_MODULE_TIED can only be loaded
 * into the kernel with exactly the same __FreeBSD_version.
 *
 * Use it for modules that use kernel interfaces that are not stable
 * even on STABLE/X branches.
 */
#define DECLARE_MODULE_TIED(name, data, sub, order)                     \
        DECLARE_MODULE_WITH_MAXVER(name, data, sub, order, __FreeBSD_version)

#define MODULE_VERSION_CONCAT(module, version)  _##module##_version
#define MODULE_VERSION(module, version)                                 \
        static struct mod_version MODULE_VERSION_CONCAT(module, version)\
            __section(".data") = {                                      \
                version                                                 \
        };                                                              \
        MODULE_METADATA(MODULE_VERSION_CONCAT(module, version), MDT_VERSION,\
            &MODULE_VERSION_CONCAT(module, version), __XSTRING(module))

/**
 * Generic macros to create pnp info hints that modules may export
 * to allow external tools to parse their internal device tables
 * to make an informed guess about what driver(s) to load.
 */
#define MODULE_PNP_INFO(d, b, unique, t, n)                             \
        static const struct mod_pnp_match_info _module_pnp_##b##_##unique = {   \
                .descr = d,                                             \
                .bus = #b,                                              \
                .table = t,                                             \
                .entry_len = sizeof((t)[0]),                            \
                .num_entry = n                                          \
        };                                                              \
        MODULE_METADATA(_md_##b##_pnpinfo_##unique, MDT_PNP_INFO,       \
            &_module_pnp_##b##_##unique, #b);
/**
 * descr is a string that describes each entry in the table. The general
 * form is the grammar (TYPE:pnp_name[/pnp_name];)*
 * where TYPE is one of the following:
 *      U8      uint8_t element
 *      V8      like U8 and 0xff means match any
 *      G16     uint16_t element, any value >= matches
 *      L16     uint16_t element, any value <= matches
 *      M16     uint16_t element, mask of which of the following fields to use.
 *      U16     uint16_t element
 *      V16     like U16 and 0xffff means match any
 *      U32     uint32_t element
 *      V32     like U32 and 0xffffffff means match any
 *      W32     Two 16-bit values with first pnp_name in LSW and second in MSW.
 *      Z       pointer to a string to match exactly
 *      D       pointer to a string to human readable description for device
 *      P       A pointer that should be ignored
 *      E       EISA PNP Identifier (in binary, but bus publishes string)
 *      T       Key for whole table. pnp_name=value. must be last, if present.
 *
 * The pnp_name "#" is reserved for other fields that should be ignored.
 * Otherwise pnp_name must match the name from the parent device's pnpinfo
 * output. The second pnp_name is used for the W32 type.
 */

extern struct sx modules_sx;

#define MOD_XLOCK       sx_xlock(&modules_sx)
#define MOD_SLOCK       sx_slock(&modules_sx)
#define MOD_XUNLOCK     sx_xunlock(&modules_sx)
#define MOD_SUNLOCK     sx_sunlock(&modules_sx)
#define MOD_LOCK_ASSERT sx_assert(&modules_sx, SX_LOCKED)
#define MOD_XLOCK_ASSERT        sx_assert(&modules_sx, SX_XLOCKED)

struct linker_file;

void    module_register_init(const void *);
int     module_register(const struct moduledata *, struct linker_file *);
module_t        module_lookupbyname(const char *);
module_t        module_lookupbyid(int);
int     module_quiesce(module_t);
void    module_reference(module_t);
void    module_release(module_t);
int     module_unload(module_t);
int     module_getid(module_t);
module_t        module_getfnext(module_t);
const char *    module_getname(module_t);
void    module_setspecific(module_t, modspecific_t *);
struct linker_file *module_file(module_t);

#ifdef  MOD_DEBUG
extern int mod_debug;
#define MOD_DEBUG_REFS  1

#define MOD_DPF(cat, args) do {                                         \
        if (mod_debug & MOD_DEBUG_##cat)                                \
                printf args;                                            \
} while (0)

#else   /* !MOD_DEBUG */

#define MOD_DPF(cat, args)
#endif
#endif  /* _KERNEL */

#define MAXMODNAMEV1V2  32
#define MAXMODNAMEV3    MAXPATHLEN
#define MAXMODNAME      MAXMODNAMEV3

struct module_stat {
        int             version;        /* set to sizeof(struct module_stat) */
        char            name[MAXMODNAME];
        int             refs;
        int             id;
        modspecific_t   data;
};

#ifndef _KERNEL

#include <sys/cdefs.h>

__BEGIN_DECLS
int     modnext(int _modid);
int     modfnext(int _modid);
int     modstat(int _modid, struct module_stat *_stat);
int     modfind(const char *_name);
__END_DECLS

#endif

#endif  /* !_SYS_MODULE_H_ */