/*      $OpenBSD: bus.h,v 1.37 2025/08/23 10:15:49 sf Exp $     */
/*      $NetBSD: bus.h,v 1.6 1996/11/10 03:19:25 thorpej Exp $  */

/*-
 * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright (c) 1996 Charles M. Hannum.  All rights reserved.
 * Copyright (c) 1996 Jason R. Thorpe.  All rights reserved.
 * Copyright (c) 1996 Christopher G. Demetriou.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou
 *      for the NetBSD Project.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 _MACHINE_BUS_H_
#define _MACHINE_BUS_H_

#include <sys/mutex.h>
#include <sys/tree.h>

#include <machine/pio.h>

/*
 * Bus address and size types
 */
typedef u_long bus_addr_t;
typedef u_long bus_size_t;

/*
 * Access methods for bus resources and address space.
 */
struct x86_bus_space_ops;
typedef const struct x86_bus_space_ops *bus_space_tag_t;
typedef u_long bus_space_handle_t;

int     bus_space_map(bus_space_tag_t t, bus_addr_t addr,
    bus_size_t size, int flags, bus_space_handle_t *bshp);
/* like map, but without extent map checking/allocation */ 
int     _bus_space_map(bus_space_tag_t t, bus_addr_t addr,
    bus_size_t size, int flags, bus_space_handle_t *bshp);

int     bus_space_alloc(bus_space_tag_t t, bus_addr_t rstart,
            bus_addr_t rend, bus_size_t size, bus_size_t align,
            bus_size_t boundary, int flags, bus_addr_t *addrp,
            bus_space_handle_t *bshp);
void    bus_space_free(bus_space_tag_t t, bus_space_handle_t bsh,  
            bus_size_t size);

/* 
 *      int bus_space_unmap(bus_space_tag_t t,
 *          bus_space_handle_t bsh, bus_size_t size);
 * 
 * Unmap a region of bus space.
 */
 
void    bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh,
            bus_size_t size);
void    _bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh,
            bus_size_t size, bus_addr_t *);

/* like bus_space_map(), but without extent map checking/allocation */
int     _bus_space_map(bus_space_tag_t t, bus_addr_t addr,
            bus_size_t size, int flags, bus_space_handle_t *bshp);

/*
 *      int bus_space_subregion(bus_space_tag_t t,
 *          bus_space_handle_t bsh, bus_size_t offset, bus_size_t size,
 *          bus_space_handle_t *nbshp);
 * 
 * Get a new handle for a subregion of an already-mapped area of bus space.
 */
 
int     bus_space_subregion(bus_space_tag_t t, bus_space_handle_t bsh,
            bus_size_t offset, bus_size_t size, bus_space_handle_t *nbshp);

struct x86_bus_space_ops {

/*
 *      u_intN_t bus_space_read_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset);
 *
 * Read a 1, 2, 4, or 8 byte quantity from bus space
 * described by tag/handle/offset.
 */
        u_int8_t        (*read_1)(bus_space_handle_t, bus_size_t);
        u_int16_t       (*read_2)(bus_space_handle_t, bus_size_t);
        u_int32_t       (*read_4)(bus_space_handle_t, bus_size_t);
        u_int64_t       (*read_8)(bus_space_handle_t, bus_size_t);

#define bus_space_read_1(_t, _h, _o) ((_t)->read_1((_h), (_o)))
#define bus_space_read_2(_t, _h, _o) ((_t)->read_2((_h), (_o)))
#define bus_space_read_4(_t, _h, _o) ((_t)->read_4((_h), (_o)))
#define bus_space_read_8(_t, _h, _o) ((_t)->read_8((_h), (_o)))

#define bus_space_read_raw_2(_t, _h, _o) ((_t)->read_2((_h), (_o)))
#define bus_space_read_raw_4(_t, _h, _o) ((_t)->read_4((_h), (_o)))
#define bus_space_read_raw_8(_t, _h, _o) ((_t)->read_8((_h), (_o)))

/*
 *      void bus_space_read_multi_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_intN_t *addr, size_t count);
 *
 * Read `count' 1, 2, 4, or 8 byte quantities from bus space
 * described by tag/handle/offset and copy into buffer provided.
 */

        void            (*read_multi_1)(bus_space_handle_t, bus_size_t,
                            u_int8_t *, bus_size_t);
        void            (*read_multi_2)(bus_space_handle_t, bus_size_t,
                            u_int16_t *, bus_size_t);
        void            (*read_multi_4)(bus_space_handle_t, bus_size_t,
                            u_int32_t *, bus_size_t);
        void            (*read_multi_8)(bus_space_handle_t, bus_size_t,
                            u_int64_t *, bus_size_t);

#define bus_space_read_multi_1(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_1((_h), (_o), (_a), (_c)))
#define bus_space_read_multi_2(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_2((_h), (_o), (_a), (_c)))
#define bus_space_read_multi_4(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_4((_h), (_o), (_a), (_c)))
#define bus_space_read_multi_8(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_read_raw_multi_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_int8_t *addr, size_t count);
 *
 * Read `count' bytes in 2, 4 or 8 byte wide quantities from bus space
 * described by tag/handle/offset and copy into buffer provided.  The buffer
 * must have proper alignment for the N byte wide entities.  Furthermore
 * possible byte-swapping should be done by these functions.
 */

#define bus_space_read_raw_multi_2(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_2((_h), (_o), (u_int16_t *)(_a), (_c) >> 1))
#define bus_space_read_raw_multi_4(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_4((_h), (_o), (u_int32_t *)(_a), (_c) >> 2))
#define bus_space_read_raw_multi_8(_t, _h, _o, _a, _c) \
        ((_t)->read_multi_8((_h), (_o), (u_int64_t *)(_a), (_c) >> 3))

/*
 *      void bus_space_read_region_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_intN_t *addr, size_t count);
 *
 * Read `count' 1, 2, 4, or 8 byte quantities from bus space
 * described by tag/handle and starting at `offset' and copy into
 * buffer provided.
 */

        void            (*read_region_1)(bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);
        void            (*read_region_2)(bus_space_handle_t,
                            bus_size_t, u_int16_t *, bus_size_t);
        void            (*read_region_4)(bus_space_handle_t,
                            bus_size_t, u_int32_t *, bus_size_t);
        void            (*read_region_8)(bus_space_handle_t,
                            bus_size_t, u_int64_t *, bus_size_t);

#define bus_space_read_region_1(_t, _h, _o, _a, _c) \
        ((_t)->read_region_1((_h), (_o), (_a), (_c)))
#define bus_space_read_region_2(_t, _h, _o, _a, _c) \
        ((_t)->read_region_2((_h), (_o), (_a), (_c)))
#define bus_space_read_region_4(_t, _h, _o, _a, _c) \
        ((_t)->read_region_4((_h), (_o), (_a), (_c)))
#define bus_space_read_region_8(_t, _h, _o, _a, _c) \
        ((_t)->read_region_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_read_raw_region_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_int8_t *addr, size_t count);
 *
 * Read `count' bytes in 2, 4 or 8 byte wide quantities from bus space
 * described by tag/handle and starting at `offset' and copy into
 * buffer provided.  The buffer must have proper alignment for the N byte
 * wide entities.  Furthermore possible byte-swapping should be done by
 * these functions.
 */

#define bus_space_read_raw_region_2(_t, _h, _o, _a, _c) \
        ((_t)->read_region_2((_h), (_o), (u_int16_t *)(_a), (_c) >> 1))
#define bus_space_read_raw_region_4(_t, _h, _o, _a, _c) \
        ((_t)->read_region_4((_h), (_o), (u_int32_t *)(_a), (_c) >> 2))
#define bus_space_read_raw_region_8(_t, _h, _o, _a, _c) \
        ((_t)->read_region_8((_h), (_o), (u_int64_t *)(_a), (_c) >> 3))

/*
 *      void bus_space_write_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_intN_t value);
 *
 * Write the 1, 2, 4, or 8 byte value `value' to bus space
 * described by tag/handle/offset.
 */

        void            (*write_1)(bus_space_handle_t, bus_size_t, u_int8_t);
        void            (*write_2)(bus_space_handle_t, bus_size_t, u_int16_t);
        void            (*write_4)(bus_space_handle_t, bus_size_t, u_int32_t);
        void            (*write_8)(bus_space_handle_t, bus_size_t, u_int64_t);

#define bus_space_write_1(_t, _h, _o, _v) \
        ((_t)->write_1((_h), (_o), (_v)))
#define bus_space_write_2(_t, _h, _o, _v) \
        ((_t)->write_2((_h), (_o), (_v)))
#define bus_space_write_4(_t, _h, _o, _v) \
        ((_t)->write_4((_h), (_o), (_v)))
#define bus_space_write_8(_t, _h, _o, _v) \
        ((_t)->write_8((_h), (_o), (_v)))

#define bus_space_write_raw_2(_t, _h, _o, _v) \
        ((_t)->write_2((_h), (_o), (_v)))
#define bus_space_write_raw_4(_t, _h, _o, _v) \
        ((_t)->write_4((_h), (_o), (_v)))
#define bus_space_write_raw_8(_t, _h, _o, _v) \
        ((_t)->write_8((_h), (_o), (_v)))

/*
 *      void bus_space_write_multi_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          const u_intN_t *addr, size_t count);
 *
 * Write `count' 1, 2, 4, or 8 byte quantities from the buffer
 * provided to bus space described by tag/handle/offset.
 */

        void            (*write_multi_1)(bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*write_multi_2)(bus_space_handle_t,
                            bus_size_t, const u_int16_t *, bus_size_t);
        void            (*write_multi_4)(bus_space_handle_t,
                            bus_size_t, const u_int32_t *, bus_size_t);
        void            (*write_multi_8)(bus_space_handle_t,
                            bus_size_t, const u_int64_t *, bus_size_t);

#define bus_space_write_multi_1(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_1((_h), (_o), (_a), (_c)))
#define bus_space_write_multi_2(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_2((_h), (_o), (_a), (_c)))
#define bus_space_write_multi_4(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_4((_h), (_o), (_a), (_c)))
#define bus_space_write_multi_8(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_write_raw_multi_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          const u_int8_t *addr, size_t count);
 *
 * Write `count' bytes in 2, 4 or 8 byte wide quantities from the buffer
 * provided to bus space described by tag/handle/offset.  The buffer
 * must have proper alignment for the N byte wide entities.  Furthermore
 * possible byte-swapping should be done by these functions.
 */

#define bus_space_write_raw_multi_2(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_2((_h), (_o), (const u_int16_t *)(_a), (_c) >> 1))
#define bus_space_write_raw_multi_4(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_4((_h), (_o), (const u_int32_t *)(_a), (_c) >> 2))
#define bus_space_write_raw_multi_8(_t, _h, _o, _a, _c) \
        ((_t)->write_multi_8((_h), (_o), (const u_int64_t *)(_a), (_c) >> 3))

/*
 *      void bus_space_write_region_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          const u_intN_t *addr, size_t count);
 *
 * Write `count' 1, 2, 4, or 8 byte quantities from the buffer provided
 * to bus space described by tag/handle starting at `offset'.
 */

        void            (*write_region_1)(bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*write_region_2)(bus_space_handle_t,
                            bus_size_t, const u_int16_t *, bus_size_t);
        void            (*write_region_4)(bus_space_handle_t,
                            bus_size_t, const u_int32_t *, bus_size_t);
        void            (*write_region_8)(bus_space_handle_t,
                            bus_size_t, const u_int64_t *, bus_size_t);

#define bus_space_write_region_1(_t, _h, _o, _a, _c) \
        ((_t)->write_region_1((_h), (_o), (_a), (_c)))
#define bus_space_write_region_2(_t, _h, _o, _a, _c) \
        ((_t)->write_region_2((_h), (_o), (_a), (_c)))
#define bus_space_write_region_4(_t, _h, _o, _a, _c) \
        ((_t)->write_region_4((_h), (_o), (_a), (_c)))
#define bus_space_write_region_8(_t, _h, _o, _a, _c) \
        ((_t)->write_region_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_write_raw_region_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          const u_int8_t *addr, size_t count);
 *
 * Write `count' bytes in 2, 4 or 8 byte wide quantities to bus space
 * described by tag/handle and starting at `offset' from the
 * buffer provided.  The buffer must have proper alignment for the N byte
 * wide entities.  Furthermore possible byte-swapping should be done by
 * these functions.
 */

#define bus_space_write_raw_region_2(_t, _h, _o, _a, _c) \
        ((_t)->write_region_2((_h), (_o), (const u_int16_t *)(_a), (_c) >> 1))
#define bus_space_write_raw_region_4(_t, _h, _o, _a, _c) \
        ((_t)->write_region_4((_h), (_o), (const u_int32_t *)(_a), (_c) >> 2))
#define bus_space_write_raw_region_8(_t, _h, _o, _a, _c) \
        ((_t)->write_region_8((_h), (_o), (const u_int64_t *)(_a), (_c) >> 3))

/*
 *      void bus_space_set_multi_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_intN_t val, size_t count);
 *
 * Write the 1, 2, 4, or 8 byte value `val' to bus space described
 * by tag/handle/offset `count' times.
 */

        void            (*set_multi_1)(bus_space_handle_t,
                            bus_size_t, u_int8_t, size_t);
        void            (*set_multi_2)(bus_space_handle_t,
                            bus_size_t, u_int16_t, size_t);
        void            (*set_multi_4)(bus_space_handle_t,
                            bus_size_t, u_int32_t, size_t);
        void            (*set_multi_8)(bus_space_handle_t,
                            bus_size_t, u_int64_t, size_t);

#define bus_space_set_multi_1(_t, _h, _o, _a, _c) \
        ((_t)->set_multi_1((_h), (_o), (_a), (_c)))
#define bus_space_set_multi_2(_t, _h, _o, _a, _c) \
        ((_t)->set_multi_2((_h), (_o), (_a), (_c)))
#define bus_space_set_multi_4(_t, _h, _o, _a, _c) \
        ((_t)->set_multi_4((_h), (_o), (_a), (_c)))
#define bus_space_set_multi_8(_t, _h, _o, _a, _c) \
        ((_t)->set_multi_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_set_region_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh, bus_size_t offset,
 *          u_intN_t val, size_t count);
 *
 * Write `count' 1, 2, 4, or 8 byte value `val' to bus space described
 * by tag/handle starting at `offset'.
 */

        void            (*set_region_1)(bus_space_handle_t,
                            bus_size_t, u_int8_t, size_t);
        void            (*set_region_2)(bus_space_handle_t,
                            bus_size_t, u_int16_t, size_t);
        void            (*set_region_4)(bus_space_handle_t,
                            bus_size_t, u_int32_t, size_t);
        void            (*set_region_8)(bus_space_handle_t,
                            bus_size_t, u_int64_t, size_t);

#define bus_space_set_region_1(_t, _h, _o, _a, _c) \
        ((_t)->set_region_1((_h), (_o), (_a), (_c)))
#define bus_space_set_region_2(_t, _h, _o, _a, _c) \
        ((_t)->set_region_2((_h), (_o), (_a), (_c)))
#define bus_space_set_region_4(_t, _h, _o, _a, _c) \
        ((_t)->set_region_4((_h), (_o), (_a), (_c)))
#define bus_space_set_region_8(_t, _h, _o, _a, _c) \
        ((_t)->set_region_8((_h), (_o), (_a), (_c)))

/*
 *      void bus_space_copy_N(bus_space_tag_t tag,
 *          bus_space_handle_t bsh1, bus_size_t off1,
 *          bus_space_handle_t bsh2, bus_size_t off2,
 *          size_t count);
 *
 * Copy `count' 1, 2, 4, or 8 byte values from bus space starting
 * at tag/bsh1/off1 to bus space starting at tag/bsh2/off2.
 */

        void            (*copy_1)(bus_space_handle_t,
                            bus_size_t, bus_space_handle_t, bus_size_t, size_t);
        void            (*copy_2)(bus_space_handle_t,
                            bus_size_t, bus_space_handle_t, bus_size_t, size_t);
        void            (*copy_4)(bus_space_handle_t,
                            bus_size_t, bus_space_handle_t, bus_size_t, size_t);
        void            (*copy_8)(bus_space_handle_t,
                            bus_size_t, bus_space_handle_t, bus_size_t, size_t);

#define bus_space_copy_1(_t, _h1, _o1, _h2, _o2, _c) \
        ((_t)->copy_1((_h1), (_o1), (_h2), (_o2), (_c)))
#define bus_space_copy_2(_t, _h1, _o1, _h2, _o2, _c) \
        ((_t)->copy_2((_h1), (_o1), (_h2), (_o2), (_c)))
#define bus_space_copy_4(_t, _h1, _o1, _h2, _o2, _c) \
        ((_t)->copy_4((_h1), (_o1), (_h2), (_o2), (_c)))
#define bus_space_copy_8(_t, _h1, _o1, _h2, _o2, _c) \
        ((_t)->copy_8((_h1), (_o1), (_h2), (_o2), (_c)))

/*
 *      void *bus_space_vaddr(bus_space_tag_t, bus_space_handle_t);
 *
 * Get the kernel virtual address for the mapped bus space.
 * Only allowed for regions mapped with BUS_SPACE_MAP_LINEAR.
 */
        void *          (*vaddr)(bus_space_handle_t);

#define bus_space_vaddr(_t, _h) \
        ((_t)->vaddr((_h)))

/*      
 *      paddr_t bus_space_mmap(bus_space_tag_t t, bus_addr_t base,
 *          off_t offset, int prot, int flags);
 * 
 * Mmap an area of bus space.
 */
 
        paddr_t         (*mmap)(bus_addr_t, off_t, int, int);

#define bus_space_mmap(_t, _a, _o, _p, _f) \
        ((_t)->mmap((_a), (_o), (_p), (_f)))
};

/*
 * Bus read/write barrier methods.
 */
#define BUS_SPACE_BARRIER_READ  0x01            /* force read barrier */
#define BUS_SPACE_BARRIER_WRITE 0x02            /* force write barrier */

static inline void
bus_space_barrier(bus_space_tag_t space, bus_space_handle_t
    handle, bus_size_t offset, bus_size_t length, int flags)
{
        switch (flags) {
        case (BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE):
                __asm volatile("mfence" ::: "memory");
                break;
        case BUS_SPACE_BARRIER_WRITE:
                __asm volatile("sfence" ::: "memory");
                break;
        default:
                __asm volatile("lfence" ::: "memory");
                break;
        }
}

#define BUS_SPACE_MAP_CACHEABLE         0x0001
#define BUS_SPACE_MAP_LINEAR            0x0002
#define BUS_SPACE_MAP_PREFETCHABLE      0x0008

/*
 * Values for the x86 bus space tag, not to be used directly by MI code.
 */

/* space is i/o space */
extern const struct x86_bus_space_ops *x86_bus_space_io_ops;
#define X86_BUS_SPACE_IO        (x86_bus_space_io_ops)

/* space is mem space */
extern const struct x86_bus_space_ops *x86_bus_space_mem_ops;
#define X86_BUS_SPACE_MEM       (x86_bus_space_mem_ops)

/*
 * bus_dma
 */

/*
 * Flags used in various bus DMA methods.
 */
#define BUS_DMA_WAITOK          0x0000  /* safe to sleep (pseudo-flag) */
#define BUS_DMA_NOWAIT          0x0001  /* not safe to sleep */
#define BUS_DMA_ALLOCNOW        0x0002  /* perform resource allocation now */
#define BUS_DMA_COHERENT        0x0004  /* hint: map memory DMA coherent */
#define BUS_DMA_BUS1            0x0010  /* placeholders for bus functions... */
#define BUS_DMA_BUS2            0x0020
#define BUS_DMA_32BIT           0x0040
#define BUS_DMA_24BIT           0x0080  /* isadma map */
#define BUS_DMA_STREAMING       0x0100  /* hint: sequential, unidirectional */
#define BUS_DMA_READ            0x0200  /* mapping is device -> memory only */
#define BUS_DMA_WRITE           0x0400  /* mapping is memory -> device only */
#define BUS_DMA_NOCACHE         0x0800  /* map memory uncached */
#define BUS_DMA_ZERO            0x1000  /* zero memory in dmamem_alloc */
#define BUS_DMA_64BIT           0x2000  /* device handles 64bit dva */

/* Forwards needed by prototypes below. */
struct mbuf;
struct proc;
struct uio;

/*
 * Operations performed by bus_dmamap_sync().
 */
#define BUS_DMASYNC_PREREAD     0x01
#define BUS_DMASYNC_POSTREAD    0x02
#define BUS_DMASYNC_PREWRITE    0x04
#define BUS_DMASYNC_POSTWRITE   0x08

typedef struct bus_dma_tag              *bus_dma_tag_t;
typedef struct bus_dmamap               *bus_dmamap_t;

/*
 *      bus_dma_segment_t
 *
 *      Describes a single contiguous DMA transaction.  Values
 *      are suitable for programming into DMA registers.
 */
struct bus_dma_segment {
        bus_addr_t      ds_addr;        /* DMA address */
        bus_size_t      ds_len;         /* length of transfer */
        vaddr_t         _ds_va;         /* mapped loaded data */
        vaddr_t         _ds_bounce_va;  /* mapped bounced data */

        /*
         * Ugh. need this so can pass alignment down from bus_dmamem_alloc
         * to scatter gather maps. only the first one is used so the rest is
         * wasted space. bus_dma could do with fixing the api for this.
         */
         bus_size_t     _ds_boundary;   /* don't cross */
         bus_size_t     _ds_align;      /* align to me */
};
typedef struct bus_dma_segment  bus_dma_segment_t;

/*
 *      bus_dma_tag_t
 *
 *      A machine-dependent opaque type describing the implementation of
 *      DMA for a given bus.
 */

struct bus_dma_tag {
        void    *_cookie;               /* cookie used in the guts */

        /*
         * DMA mapping methods.
         */
        int     (*_dmamap_create)(bus_dma_tag_t, bus_size_t, int,
                    bus_size_t, bus_size_t, int, bus_dmamap_t *);
        void    (*_dmamap_destroy)(bus_dma_tag_t, bus_dmamap_t);
        int     (*_dmamap_load)(bus_dma_tag_t, bus_dmamap_t, void *,
                    bus_size_t, struct proc *, int);
        int     (*_dmamap_load_mbuf)(bus_dma_tag_t, bus_dmamap_t,
                    struct mbuf *, int);
        int     (*_dmamap_load_uio)(bus_dma_tag_t, bus_dmamap_t,
                    struct uio *, int);
        int     (*_dmamap_load_raw)(bus_dma_tag_t, bus_dmamap_t,
                    bus_dma_segment_t *, int, bus_size_t, int);
        void    (*_dmamap_unload)(bus_dma_tag_t, bus_dmamap_t);
        void    (*_dmamap_sync)(bus_dma_tag_t, bus_dmamap_t,
                    bus_addr_t, bus_size_t, int);

        /*
         * DMA memory utility functions.
         */
        int     (*_dmamem_alloc)(bus_dma_tag_t, bus_size_t, bus_size_t,
                    bus_size_t, bus_dma_segment_t *, int, int *, int);
        int     (*_dmamem_alloc_range)(bus_dma_tag_t, bus_size_t, bus_size_t,
                    bus_size_t, bus_dma_segment_t *, int, int *, int,
                    bus_addr_t, bus_addr_t);
        void    (*_dmamem_free)(bus_dma_tag_t,
                    bus_dma_segment_t *, int);
        int     (*_dmamem_map)(bus_dma_tag_t, bus_dma_segment_t *,
                    int, size_t, caddr_t *, int);
        void    (*_dmamem_unmap)(bus_dma_tag_t, caddr_t, size_t);
        paddr_t (*_dmamem_mmap)(bus_dma_tag_t, bus_dma_segment_t *,
                    int, off_t, int, int);
};

#define bus_dmamap_create(t, s, n, m, b, f, p)                  \
        (*(t)->_dmamap_create)((t), (s), (n), (m), (b), (f), (p))
#define bus_dmamap_destroy(t, p)                                \
        (*(t)->_dmamap_destroy)((t), (p))
#define bus_dmamap_load(t, m, b, s, p, f)                       \
        (*(t)->_dmamap_load)((t), (m), (b), (s), (p), (f))
#define bus_dmamap_load_mbuf(t, m, b, f)                        \
        (*(t)->_dmamap_load_mbuf)((t), (m), (b), (f))
#define bus_dmamap_load_uio(t, m, u, f)                         \
        (*(t)->_dmamap_load_uio)((t), (m), (u), (f))
#define bus_dmamap_load_raw(t, m, sg, n, s, f)                  \
        (*(t)->_dmamap_load_raw)((t), (m), (sg), (n), (s), (f))
#define bus_dmamap_unload(t, p)                                 \
        (*(t)->_dmamap_unload)((t), (p))
#define bus_dmamap_sync(t, p, o, l, ops)                        \
        (*(t)->_dmamap_sync)((t), (p), (o), (l), (ops))

#define bus_dmamem_alloc(t, s, a, b, sg, n, r, f)               \
        (*(t)->_dmamem_alloc)((t), (s), (a), (b), (sg), (n), (r), (f))
#define bus_dmamem_alloc_range(t, s, a, b, sg, n, r, f, l, h)   \
        (*(t)->_dmamem_alloc_range)((t), (s), (a), (b), (sg),   \
                (n), (r), (f), (l), (h))
#define bus_dmamem_free(t, sg, n)                               \
        (*(t)->_dmamem_free)((t), (sg), (n))
#define bus_dmamem_map(t, sg, n, s, k, f)                       \
        (*(t)->_dmamem_map)((t), (sg), (n), (s), (k), (f))
#define bus_dmamem_unmap(t, k, s)                               \
        (*(t)->_dmamem_unmap)((t), (k), (s))
#define bus_dmamem_mmap(t, sg, n, o, p, f)                      \
        (*(t)->_dmamem_mmap)((t), (sg), (n), (o), (p), (f))

/*
 *      bus_dmamap_t
 *
 *      Describes a DMA mapping.
 */
struct bus_dmamap {
        /*
         * PRIVATE MEMBERS: not for use by machine-independent code.
         */
        bus_size_t      _dm_size;       /* largest DMA transfer mappable */
        int             _dm_flags;      /* misc. flags */
        int             _dm_segcnt;     /* number of segs this map can map */
        bus_size_t      _dm_maxsegsz;   /* largest possible segment */
        bus_size_t      _dm_boundary;   /* don't cross this */

        void            *_dm_cookie;    /* cookie for bus-specific functions */

        struct vm_page **_dm_pages;     /* replacement pages */
        vaddr_t         _dm_pgva;       /* those above -- mapped */
        int             _dm_npages;     /* number of pages allocated */
        int             _dm_nused;      /* number of pages replaced */

        /*
         * PUBLIC MEMBERS: these are used by machine-independent code.
         */
        bus_size_t      dm_mapsize;     /* size of the mapping */
        int             dm_nsegs;       /* # valid segments in mapping */
        bus_dma_segment_t dm_segs[1];   /* segments; variable length */
};

int     _bus_dmamap_create(bus_dma_tag_t, bus_size_t, int, bus_size_t,
            bus_size_t, int, bus_dmamap_t *);
void    _bus_dmamap_destroy(bus_dma_tag_t, bus_dmamap_t);
int     _bus_dmamap_load(bus_dma_tag_t, bus_dmamap_t, void *,
            bus_size_t, struct proc *, int);
int     _bus_dmamap_load_mbuf(bus_dma_tag_t, bus_dmamap_t,
            struct mbuf *, int);
int     _bus_dmamap_load_uio(bus_dma_tag_t, bus_dmamap_t,
            struct uio *, int);
int     _bus_dmamap_load_raw(bus_dma_tag_t, bus_dmamap_t,
            bus_dma_segment_t *, int, bus_size_t, int);
void    _bus_dmamap_unload(bus_dma_tag_t, bus_dmamap_t);
void    _bus_dmamap_sync(bus_dma_tag_t, bus_dmamap_t, bus_addr_t,
            bus_size_t, int);

int     _bus_dmamem_alloc(bus_dma_tag_t tag, bus_size_t size,
            bus_size_t alignment, bus_size_t boundary,
            bus_dma_segment_t *segs, int nsegs, int *rsegs, int flags);
void    _bus_dmamem_free(bus_dma_tag_t tag, bus_dma_segment_t *segs,
            int nsegs);
int     _bus_dmamem_map(bus_dma_tag_t tag, bus_dma_segment_t *segs,
            int nsegs, size_t size, caddr_t *kvap, int flags);
void    _bus_dmamem_unmap(bus_dma_tag_t tag, caddr_t kva,
            size_t size);
paddr_t _bus_dmamem_mmap(bus_dma_tag_t tag, bus_dma_segment_t *segs,
            int nsegs, off_t off, int prot, int flags);

int     _bus_dmamem_alloc_range(bus_dma_tag_t tag, bus_size_t size,
            bus_size_t alignment, bus_size_t boundary,
            bus_dma_segment_t *segs, int nsegs, int *rsegs, int flags,
            bus_addr_t low, bus_addr_t high);

#endif /* _MACHINE_BUS_H_ */