/*      $OpenBSD: bus.h,v 1.33 2022/01/04 20:41:42 deraadt Exp $        */
/*      $NetBSD: bus.h,v 1.10 1996/12/02 22:19:32 cgd Exp $     */

/*
 * Copyright (c) 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#ifndef _MACHINE_BUS_H_
#define _MACHINE_BUS_H_

#ifdef _KERNEL

/*
 * Addresses (in bus space).
 */
typedef u_long bus_addr_t;
typedef u_long bus_size_t;

/*
 * Access methods for bus space.
 */
typedef struct alpha_bus_space *bus_space_tag_t;
typedef u_long bus_space_handle_t;

struct alpha_bus_space {
        /* cookie */
        void            *abs_cookie;

        /* mapping/unmapping */
        int             (*abs_map)(void *, bus_addr_t, bus_size_t,
                            int, bus_space_handle_t *);
        void            (*abs_unmap)(void *, bus_space_handle_t,
                            bus_size_t);
        int             (*abs_subregion)(void *, bus_space_handle_t,
                            bus_size_t, bus_size_t, bus_space_handle_t *);

        /* allocation/deallocation */
        int             (*abs_alloc)(void *, bus_addr_t, bus_addr_t,
                            bus_size_t, bus_size_t, bus_size_t, int,
                            bus_addr_t *, bus_space_handle_t *);
        void            (*abs_free)(void *, bus_space_handle_t,
                            bus_size_t);

        /* get kernel virtual address */
        void *          (*abs_vaddr)(void *, bus_space_handle_t);

        /* barrier */
        void            (*abs_barrier)(void *, bus_space_handle_t,
                            bus_size_t, bus_size_t, int);

        /* read (single) */
        u_int8_t        (*abs_r_1)(void *, bus_space_handle_t,
                            bus_size_t);
        u_int16_t       (*abs_r_2)(void *, bus_space_handle_t,
                            bus_size_t);
        u_int32_t       (*abs_r_4)(void *, bus_space_handle_t,
                            bus_size_t);
        u_int64_t       (*abs_r_8)(void *, bus_space_handle_t,
                            bus_size_t);

        /* read multiple */
        void            (*abs_rm_1)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);
        void            (*abs_rm_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int16_t *, bus_size_t);
        void            (*abs_rm_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int32_t *, bus_size_t);
        void            (*abs_rm_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int64_t *, bus_size_t);
                                        
        /* read region */
        void            (*abs_rr_1)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);
        void            (*abs_rr_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int16_t *, bus_size_t);
        void            (*abs_rr_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int32_t *, bus_size_t);
        void            (*abs_rr_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int64_t *, bus_size_t);
                                        
        /* write (single) */
        void            (*abs_w_1)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t);
        void            (*abs_w_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int16_t);
        void            (*abs_w_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int32_t);
        void            (*abs_w_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int64_t);

        /* write multiple */
        void            (*abs_wm_1)(void *, bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*abs_wm_2)(void *, bus_space_handle_t,
                            bus_size_t, const u_int16_t *, bus_size_t);
        void            (*abs_wm_4)(void *, bus_space_handle_t,
                            bus_size_t, const u_int32_t *, bus_size_t);
        void            (*abs_wm_8)(void *, bus_space_handle_t,
                            bus_size_t, const u_int64_t *, bus_size_t);
                                        
        /* write region */
        void            (*abs_wr_1)(void *, bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*abs_wr_2)(void *, bus_space_handle_t,
                            bus_size_t, const u_int16_t *, bus_size_t);
        void            (*abs_wr_4)(void *, bus_space_handle_t,
                            bus_size_t, const u_int32_t *, bus_size_t);
        void            (*abs_wr_8)(void *, bus_space_handle_t,
                            bus_size_t, const u_int64_t *, bus_size_t);

        /* set multiple */
        void            (*abs_sm_1)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t, bus_size_t);
        void            (*abs_sm_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int16_t, bus_size_t);
        void            (*abs_sm_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int32_t, bus_size_t);
        void            (*abs_sm_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int64_t, bus_size_t);

        /* set region */
        void            (*abs_sr_1)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t, bus_size_t);
        void            (*abs_sr_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int16_t, bus_size_t);
        void            (*abs_sr_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int32_t, bus_size_t);
        void            (*abs_sr_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int64_t, bus_size_t);

        /* copy */
        void            (*abs_c_1)(void *, bus_space_handle_t, bus_size_t,
                            bus_space_handle_t, bus_size_t, bus_size_t);
        void            (*abs_c_2)(void *, bus_space_handle_t, bus_size_t,
                            bus_space_handle_t, bus_size_t, bus_size_t);
        void            (*abs_c_4)(void *, bus_space_handle_t, bus_size_t,
                            bus_space_handle_t, bus_size_t, bus_size_t);
        void            (*abs_c_8)(void *, bus_space_handle_t, bus_size_t,
                            bus_space_handle_t, bus_size_t, bus_size_t);

        /* OpenBSD extensions follows */

        /* read multiple raw */
        void            (*abs_rrm_2)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);
        void            (*abs_rrm_4)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);
        void            (*abs_rrm_8)(void *, bus_space_handle_t,
                            bus_size_t, u_int8_t *, bus_size_t);

        /* write multiple raw */
        void            (*abs_wrm_2)(void *, bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*abs_wrm_4)(void *, bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
        void            (*abs_wrm_8)(void *, bus_space_handle_t,
                            bus_size_t, const u_int8_t *, bus_size_t);
};


/*
 * Utility macros; INTERNAL USE ONLY.
 */
#define __abs_c(a,b)            __CONCAT(a,b)
#define __abs_opname(op,size)   __abs_c(__abs_c(__abs_c(abs_,op),_),size)

#define __abs_rs(sz, t, h, o)                                           \
        (*(t)->__abs_opname(r,sz))((t)->abs_cookie, h, o)
#define __abs_ws(sz, t, h, o, v)                                        \
        (*(t)->__abs_opname(w,sz))((t)->abs_cookie, h, o, v)
#define __abs_nonsingle(type, sz, t, h, o, a, c)                        \
        (*(t)->__abs_opname(type,sz))((t)->abs_cookie, h, o, a, c)
#ifndef DEBUG
#define __abs_aligned_nonsingle(type, sz, t, h, o, a, c)                \
        __abs_nonsingle(type, sz, (t), (h), (o), (a), (c))

#else
#define __abs_aligned_nonsingle(type, sz, t, h, o, a, c)                \
    do {                                                                \
        if (((unsigned long)a & (sz - 1)) != 0)                         \
                panic("bus non-single %d-byte unaligned (to %p) at %s:%d", \
                    sz, a, __FILE__, __LINE__);                         \
        (*(t)->__abs_opname(type,sz))((t)->abs_cookie, h, o, a, c);     \
    } while (0)
#endif
#define __abs_set(type, sz, t, h, o, v, c)                              \
        (*(t)->__abs_opname(type,sz))((t)->abs_cookie, h, o, v, c)
#define __abs_copy(sz, t, h1, o1, h2, o2, cnt)                  \
        (*(t)->__abs_opname(c,sz))((t)->abs_cookie, h1, o1, h2, o2, cnt)

/*
 * Mapping and unmapping operations.
 */
#define bus_space_map(t, a, s, c, hp)                                   \
        (*(t)->abs_map)((t)->abs_cookie, (a), (s), (c), (hp))
#define alpha_bus_space_map_noacct bus_space_map
#define bus_space_unmap(t, h, s)                                        \
        (*(t)->abs_unmap)((t)->abs_cookie, (h), (s))
#define alpha_bus_space_unmap_noacct bus_space_unmap
#define bus_space_subregion(t, h, o, s, hp)                             \
        (*(t)->abs_subregion)((t)->abs_cookie, (h), (o), (s), (hp))

#define BUS_SPACE_MAP_CACHEABLE         0x01
#define BUS_SPACE_MAP_LINEAR            0x02
#define BUS_SPACE_MAP_PREFETCHABLE      0x04

/*
 * Allocation and deallocation operations.
 */
#define bus_space_alloc(t, rs, re, s, a, b, c, ap, hp)                  \
        (*(t)->abs_alloc)((t)->abs_cookie, (rs), (re), (s), (a), (b),   \
            (c), (ap), (hp))
#define bus_space_free(t, h, s)                                         \
        (*(t)->abs_free)((t)->abs_cookie, (h), (s))

/*
 * Get kernel virtual address for ranges mapped BUS_SPACE_MAP_LINEAR.
 */
#define bus_space_vaddr(t, h)                                           \
        (*(t)->abs_vaddr)((t)->abs_cookie, (h))

/*
 * Bus barrier operations.
 */
#define bus_space_barrier(t, h, o, l, f)                                \
        (*(t)->abs_barrier)((t)->abs_cookie, (h), (o), (l), (f))

#define BUS_SPACE_BARRIER_READ  0x01
#define BUS_SPACE_BARRIER_WRITE 0x02


/*
 * Bus read (single) operations.
 */
#define bus_space_read_1(t, h, o)       __abs_rs(1,(t),(h),(o))
#define bus_space_read_2(t, h, o)       __abs_rs(2,(t),(h),(o))
#define bus_space_read_4(t, h, o)       __abs_rs(4,(t),(h),(o))
#define bus_space_read_8(t, h, o)       __abs_rs(8,(t),(h),(o))


/*
 * Bus read (single) operations.
 */
#define bus_space_read_raw_1(t, h, o)   __abs_rs(1,(t),(h),(o))
#define bus_space_read_raw_2(t, h, o)   __abs_rs(2,(t),(h),(o))
#define bus_space_read_raw_4(t, h, o)   __abs_rs(4,(t),(h),(o))
#define bus_space_read_raw_8(t, h, o)   __abs_rs(8,(t),(h),(o))


/*
 * Bus read multiple operations.
 */
#define bus_space_read_multi_1(t, h, o, a, c)                           \
        __abs_nonsingle(rm,1,(t),(h),(o),(a),(c))
#define bus_space_read_multi_2(t, h, o, a, c)                           \
        __abs_aligned_nonsingle(rm,2,(t),(h),(o),(a),(c))
#define bus_space_read_multi_4(t, h, o, a, c)                           \
        __abs_aligned_nonsingle(rm,4,(t),(h),(o),(a),(c))
#define bus_space_read_multi_8(t, h, o, a, c)                           \
        __abs_aligned_nonsingle(rm,8,(t),(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)                       \
        __abs_nonsingle(rrm,2,(t),(h),(o),(a),(c))
#define bus_space_read_raw_multi_4(t, h, o, a, c)                       \
        __abs_nonsingle(rrm,4,(t),(h),(o),(a),(c))
#define bus_space_read_raw_multi_8(t, h, o, a, c)                       \
        __abs_nonsingle(rrm,8,(t),(h),(o),(a),(c))

/*
 * Bus read region operations.
 */
#define bus_space_read_region_1(t, h, o, a, c)                          \
        __abs_nonsingle(rr,1,(t),(h),(o),(a),(c))
#define bus_space_read_region_2(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(rr,2,(t),(h),(o),(a),(c))
#define bus_space_read_region_4(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(rr,4,(t),(h),(o),(a),(c))
#define bus_space_read_region_8(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(rr,8,(t),(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' 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_read_raw_region_2(t, h, o, a, c)                      \
    bus_space_read_region_2((t), (h), (o), (u_int16_t *)(a), (c) >> 1)
#define bus_space_read_raw_region_4(t, h, o, a, c)                      \
    bus_space_read_region_4((t), (h), (o), (u_int32_t *)(a), (c) >> 2)

/*
 * Bus write (single) operations.
 */
#define bus_space_write_1(t, h, o, v)   __abs_ws(1,(t),(h),(o),(v))
#define bus_space_write_2(t, h, o, v)   __abs_ws(2,(t),(h),(o),(v))
#define bus_space_write_4(t, h, o, v)   __abs_ws(4,(t),(h),(o),(v))
#define bus_space_write_8(t, h, o, v)   __abs_ws(8,(t),(h),(o),(v))


/*
 * Bus write raw (single) operations.
 */
#define bus_space_write_raw_1(t, h, o, v)       __abs_ws(1,(t),(h),(o),(v))
#define bus_space_write_raw_2(t, h, o, v)       __abs_ws(2,(t),(h),(o),(v))
#define bus_space_write_raw_4(t, h, o, v)       __abs_ws(4,(t),(h),(o),(v))
#define bus_space_write_raw_8(t, h, o, v)       __abs_ws(8,(t),(h),(o),(v))


/*
 * Bus write multiple operations.
 */
#define bus_space_write_multi_1(t, h, o, a, c)                          \
        __abs_nonsingle(wm,1,(t),(h),(o),(a),(c))
#define bus_space_write_multi_2(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(wm,2,(t),(h),(o),(a),(c))
#define bus_space_write_multi_4(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(wm,4,(t),(h),(o),(a),(c))
#define bus_space_write_multi_8(t, h, o, a, c)                          \
        __abs_aligned_nonsingle(wm,8,(t),(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,
 *          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)                      \
        __abs_nonsingle(wrm,2,(t),(h),(o),(a),(c))
#define bus_space_write_raw_multi_4(t, h, o, a, c)                      \
        __abs_nonsingle(wrm,4,(t),(h),(o),(a),(c))
#define bus_space_write_raw_multi_8(t, h, o, a, c)                      \
        __abs_nonsingle(wrm,8,(t),(h),(o),(a),(c))

/*
 * Bus write region operations.
 */
#define bus_space_write_region_1(t, h, o, a, c)                         \
        __abs_nonsingle(wr,1,(t),(h),(o),(a),(c))
#define bus_space_write_region_2(t, h, o, a, c)                         \
        __abs_aligned_nonsingle(wr,2,(t),(h),(o),(a),(c))
#define bus_space_write_region_4(t, h, o, a, c)                         \
        __abs_aligned_nonsingle(wr,4,(t),(h),(o),(a),(c))
#define bus_space_write_region_8(t, h, o, a, c)                         \
        __abs_aligned_nonsingle(wr,8,(t),(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)                     \
    bus_space_write_region_2((t), (h), (o), (const u_int16_t *)(a), (c) >> 1)
#define bus_space_write_raw_region_4(t, h, o, a, c)                     \
    bus_space_write_region_4((t), (h), (o), (const u_int32_t *)(a), (c) >> 2)

/*
 * Set multiple operations.
 */
#define bus_space_set_multi_1(t, h, o, v, c)                            \
        __abs_set(sm,1,(t),(h),(o),(v),(c))
#define bus_space_set_multi_2(t, h, o, v, c)                            \
        __abs_set(sm,2,(t),(h),(o),(v),(c))
#define bus_space_set_multi_4(t, h, o, v, c)                            \
        __abs_set(sm,4,(t),(h),(o),(v),(c))
#define bus_space_set_multi_8(t, h, o, v, c)                            \
        __abs_set(sm,8,(t),(h),(o),(v),(c))


/*
 * Set region operations.
 */
#define bus_space_set_region_1(t, h, o, v, c)                           \
        __abs_set(sr,1,(t),(h),(o),(v),(c))
#define bus_space_set_region_2(t, h, o, v, c)                           \
        __abs_set(sr,2,(t),(h),(o),(v),(c))
#define bus_space_set_region_4(t, h, o, v, c)                           \
        __abs_set(sr,4,(t),(h),(o),(v),(c))
#define bus_space_set_region_8(t, h, o, v, c)                           \
        __abs_set(sr,8,(t),(h),(o),(v),(c))


/*
 * Copy operations.
 */
#define bus_space_copy_1(t, h1, o1, h2, o2, c)                          \
        __abs_copy(1, t, h1, o1, h2, o2, c)
#define bus_space_copy_2(t, h1, o1, h2, o2, c)                          \
        __abs_copy(2, t, h1, o1, h2, o2, c)
#define bus_space_copy_4(t, h1, o1, h2, o2, c)                          \
        __abs_copy(4, t, h1, o1, h2, o2, c)
#define bus_space_copy_8(t, h1, o1, h2, o2, c)                          \
        __abs_copy(8, t, h1, o1, h2, o2, c)

/*
 * Bus DMA methods.
 */

/*
 * 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_BUS3            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_ZERO            0x1000  /* zero memory in dmamem_alloc */
#define BUS_DMA_64BIT           0x2000  /* device handles 64bit dva */

/*
 * Private flags stored in the DMA map.
 */
#define DMAMAP_NO_COALESCE      0x40000000      /* don't coalesce adjacent
                                                   segments */

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

/*
 * 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

/*
 *      alpha_bus_t
 *
 *      Busses supported by NetBSD/alpha, used by internal
 *      utility functions.  NOT TO BE USED BY MACHINE-INDEPENDENT
 *      CODE!
 */
typedef enum {
        ALPHA_BUS_TURBOCHANNEL,
        ALPHA_BUS_PCI,
        ALPHA_BUS_EISA,
        ALPHA_BUS_ISA,
        ALPHA_BUS_TLSB,
} alpha_bus_t;

typedef struct alpha_bus_dma_tag        *bus_dma_tag_t;
typedef struct alpha_bus_dmamap         *bus_dmamap_t;

/*
 *      bus_dma_segment_t
 *
 *      Describes a single contiguous DMA transaction.  Values
 *      are suitable for programming into DMA registers.
 */
struct alpha_bus_dma_segment {
        bus_addr_t      ds_addr;        /* DMA address */
        bus_size_t      ds_len;         /* length of transfer */
};
typedef struct alpha_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 alpha_bus_dma_tag {
        void    *_cookie;               /* cookie used in the guts */
        bus_addr_t _wbase;              /* DMA window base */

        /*
         * The following two members are used to chain DMA windows
         * together.  If, during the course of a map load, the
         * resulting physical memory address is too large to
         * be addressed by the window, the next window will be
         * attempted.  These would be chained together like so:
         *
         *      direct -> sgmap -> NULL
         *  or
         *      sgmap -> NULL
         *  or
         *      direct -> NULL
         *
         * If the window size is 0, it will not be checked (e.g.
         * TurboChannel DMA).
         */
        bus_size_t _wsize;
        struct alpha_bus_dma_tag *_next_window;

        /*
         * Some chipsets have a built-in boundary constraint, independent
         * of what the device requests.  This allows that boundary to
         * be specified.  If the device has a more restrictive constraint,
         * the map will use that, otherwise this boundary will be used.
         * This value is ignored if 0.
         */
        bus_size_t _boundary;

        /*
         * A chipset may have more than one SGMAP window, so SGMAP
         * windows also get a pointer to their SGMAP state.
         */
        struct alpha_sgmap *_sgmap;

        /*
         * Internal-use only utility methods.  NOT TO BE USED BY
         * MACHINE-INDEPENDENT CODE!
         */
        bus_dma_tag_t (*_get_tag)(bus_dma_tag_t, alpha_bus_t);

        /*
         * 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);
        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 alphabus_dma_get_tag(t, b)                              \
        (*(t)->_get_tag)(t, b)

#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)                                 \
        (void)(t),                                              \
        (*(p)->_dm_window->_dmamap_unload)((p)->_dm_window, (p))
#define bus_dmamap_sync(t, p, a, s, op)                         \
        (void)(t),                                              \
        (*(p)->_dm_window->_dmamap_sync)((p)->_dm_window, (p), (a), (s), (op))
#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_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 alpha_bus_dmamap {
        /*
         * PRIVATE MEMBERS: not for use by machine-independent code.
         */
        bus_size_t      _dm_size;       /* largest DMA transfer mappable */
        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 */
        int             _dm_flags;      /* misc. flags */

        /*
         * Private cookie to be used by the DMA back-end.
         */
        void            *_dm_cookie;
        size_t          _dm_cookiesize; /* size allocated for _dm_cookie */

        /*
         * The DMA window that we ended up being mapped in.
         */
        bus_dma_tag_t   _dm_window;

        /*
         * 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 */
};

#ifdef _ALPHA_BUS_DMA_PRIVATE
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_direct(bus_dma_tag_t, bus_dmamap_t,
            void *, bus_size_t, struct proc *, int);
int     _bus_dmamap_load_mbuf_direct(bus_dma_tag_t,
            bus_dmamap_t, struct mbuf *, int);
int     _bus_dmamap_load_uio_direct(bus_dma_tag_t,
            bus_dmamap_t, struct uio *, int);
int     _bus_dmamap_load_raw_direct(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);
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,
            paddr_t low, paddr_t high);
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);
#endif /* _ALPHA_BUS_DMA_PRIVATE */

#endif /* _KERNEL */

#endif /* _MACHINE_BUS_H_ */