/* $NetBSD: bus_space.c,v 1.18 2024/02/07 04:20:26 msaitoh Exp $ */

/*
 * Copyright (c) 2017 Ryo Shimizu
 * 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 ``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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: bus_space.c,v 1.18 2024/02/07 04:20:26 msaitoh Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>

#include <uvm/uvm_extern.h>

#include <aarch64/bus_funcs.h>
#include <aarch64/machdep.h>

#include <arm/cpufunc.h>

/* Prototypes for all the bus_space structure functions */
bs_protos(generic)
bs_protos(generic_dsb)

#if __AARCH64EB__
#define NSWAP(n)        n ## _swap
#else
#define NSWAP(n)        n
#endif

struct bus_space arm_generic_bs_tag = {
        .bs_cookie = &arm_generic_bs_tag,

        .bs_stride = 0,
        .bs_flags = 0,

        .bs_map = generic_bs_map,
        .bs_unmap = generic_bs_unmap,
        .bs_subregion = generic_bs_subregion,
        .bs_alloc = generic_bs_alloc,
        .bs_free = generic_bs_free,
        .bs_vaddr = generic_bs_vaddr,
        .bs_mmap = generic_bs_mmap,
        .bs_barrier = generic_bs_barrier,

        /* read */
        .bs_r_1 = generic_bs_r_1,
        .bs_r_2 = NSWAP(generic_bs_r_2),
        .bs_r_4 = NSWAP(generic_bs_r_4),
        .bs_r_8 = NSWAP(generic_bs_r_8),

        /* write */
        .bs_w_1 = generic_bs_w_1,
        .bs_w_2 = NSWAP(generic_bs_w_2),
        .bs_w_4 = NSWAP(generic_bs_w_4),
        .bs_w_8 = NSWAP(generic_bs_w_8),

        /* read region */
        .bs_rr_1 = generic_bs_rr_1,
        .bs_rr_2 = NSWAP(generic_bs_rr_2),
        .bs_rr_4 = NSWAP(generic_bs_rr_4),
        .bs_rr_8 = NSWAP(generic_bs_rr_8),

        /* write region */
        .bs_wr_1 = generic_bs_wr_1,
        .bs_wr_2 = NSWAP(generic_bs_wr_2),
        .bs_wr_4 = NSWAP(generic_bs_wr_4),
        .bs_wr_8 = NSWAP(generic_bs_wr_8),

        /* copy region */
        .bs_c_1 = generic_bs_c_1,
        .bs_c_2 = generic_bs_c_2,
        .bs_c_4 = generic_bs_c_4,
        .bs_c_8 = generic_bs_c_8,

        /* set region */
        .bs_sr_1 = generic_bs_sr_1,
        .bs_sr_2 = NSWAP(generic_bs_sr_2),
        .bs_sr_4 = NSWAP(generic_bs_sr_4),
        .bs_sr_8 = NSWAP(generic_bs_sr_8),

        /* read multi */
        .bs_rm_1 = generic_bs_rm_1,
        .bs_rm_2 = NSWAP(generic_bs_rm_2),
        .bs_rm_4 = NSWAP(generic_bs_rm_4),
        .bs_rm_8 = NSWAP(generic_bs_rm_8),

        /* write multi */
        .bs_wm_1 = generic_bs_wm_1,
        .bs_wm_2 = NSWAP(generic_bs_wm_2),
        .bs_wm_4 = NSWAP(generic_bs_wm_4),
        .bs_wm_8 = NSWAP(generic_bs_wm_8),

        /* set multi */
        .bs_sm_1 = generic_bs_sm_1,
        .bs_sm_2 = NSWAP(generic_bs_sm_2),
        .bs_sm_4 = NSWAP(generic_bs_sm_4),
        .bs_sm_8 = NSWAP(generic_bs_sm_8),

#ifdef __BUS_SPACE_HAS_STREAM_METHODS
        /* read stream */
        .bs_r_1_s = generic_bs_r_1,
        .bs_r_2_s = generic_bs_r_2,
        .bs_r_4_s = generic_bs_r_4,
        .bs_r_8_s = generic_bs_r_8,

        /* write stream */
        .bs_w_1_s = generic_bs_w_1,
        .bs_w_2_s = generic_bs_w_2,
        .bs_w_4_s = generic_bs_w_4,
        .bs_w_8_s = generic_bs_w_8,

        /* read region stream */
        .bs_rr_1_s = generic_bs_rr_1,
        .bs_rr_2_s = generic_bs_rr_2,
        .bs_rr_4_s = generic_bs_rr_4,
        .bs_rr_8_s = generic_bs_rr_8,

        /* write region stream */
        .bs_wr_1_s = generic_bs_wr_1,
        .bs_wr_2_s = generic_bs_wr_2,
        .bs_wr_4_s = generic_bs_wr_4,
        .bs_wr_8_s = generic_bs_wr_8,

        /* read multi stream */
        .bs_rm_1_s = generic_bs_rm_1,
        .bs_rm_2_s = generic_bs_rm_2,
        .bs_rm_4_s = generic_bs_rm_4,
        .bs_rm_8_s = generic_bs_rm_8,

        /* write multi stream */
        .bs_wm_1_s = generic_bs_wm_1,
        .bs_wm_2_s = generic_bs_wm_2,
        .bs_wm_4_s = generic_bs_wm_4,
        .bs_wm_8_s = generic_bs_wm_8,
#endif

#ifdef __BUS_SPACE_HAS_PROBING_METHODS
        /* peek */
        .bs_pe_1 = generic_bs_pe_1,
        .bs_pe_2 = generic_bs_pe_2,
        .bs_pe_4 = generic_bs_pe_4,
        .bs_pe_8 = generic_bs_pe_8,

        /* poke */
        .bs_po_1 = generic_bs_po_1,
        .bs_po_2 = generic_bs_po_2,
        .bs_po_4 = generic_bs_po_4,
        .bs_po_8 = generic_bs_po_8,
#endif
};

struct bus_space aarch64_generic_dsb_bs_tag = {
        .bs_cookie = &aarch64_generic_dsb_bs_tag,

        .bs_stride = 0,
        .bs_flags = 0,

        .bs_map = generic_bs_map,
        .bs_unmap = generic_bs_unmap,
        .bs_subregion = generic_bs_subregion,
        .bs_alloc = generic_bs_alloc,
        .bs_free = generic_bs_free,
        .bs_vaddr = generic_bs_vaddr,
        .bs_mmap = generic_bs_mmap,
        .bs_barrier = generic_bs_barrier,

        /* read */
        .bs_r_1 = generic_dsb_bs_r_1,
        .bs_r_2 = NSWAP(generic_dsb_bs_r_2),
        .bs_r_4 = NSWAP(generic_dsb_bs_r_4),
        .bs_r_8 = NSWAP(generic_dsb_bs_r_8),

        /* write */
        .bs_w_1 = generic_dsb_bs_w_1,
        .bs_w_2 = NSWAP(generic_dsb_bs_w_2),
        .bs_w_4 = NSWAP(generic_dsb_bs_w_4),
        .bs_w_8 = NSWAP(generic_dsb_bs_w_8),

        /* read region */
        .bs_rr_1 = generic_dsb_bs_rr_1,
        .bs_rr_2 = NSWAP(generic_dsb_bs_rr_2),
        .bs_rr_4 = NSWAP(generic_dsb_bs_rr_4),
        .bs_rr_8 = NSWAP(generic_dsb_bs_rr_8),

        /* write region */
        .bs_wr_1 = generic_dsb_bs_wr_1,
        .bs_wr_2 = NSWAP(generic_dsb_bs_wr_2),
        .bs_wr_4 = NSWAP(generic_dsb_bs_wr_4),
        .bs_wr_8 = NSWAP(generic_dsb_bs_wr_8),

        /* copy region */
        .bs_c_1 = generic_dsb_bs_c_1,
        .bs_c_2 = generic_dsb_bs_c_2,
        .bs_c_4 = generic_dsb_bs_c_4,
        .bs_c_8 = generic_dsb_bs_c_8,

        /* set region */
        .bs_sr_1 = generic_dsb_bs_sr_1,
        .bs_sr_2 = NSWAP(generic_dsb_bs_sr_2),
        .bs_sr_4 = NSWAP(generic_dsb_bs_sr_4),
        .bs_sr_8 = NSWAP(generic_dsb_bs_sr_8),

        /* read multi */
        .bs_rm_1 = generic_dsb_bs_rm_1,
        .bs_rm_2 = NSWAP(generic_dsb_bs_rm_2),
        .bs_rm_4 = NSWAP(generic_dsb_bs_rm_4),
        .bs_rm_8 = NSWAP(generic_dsb_bs_rm_8),

        /* write multi */
        .bs_wm_1 = generic_dsb_bs_wm_1,
        .bs_wm_2 = NSWAP(generic_dsb_bs_wm_2),
        .bs_wm_4 = NSWAP(generic_dsb_bs_wm_4),
        .bs_wm_8 = NSWAP(generic_dsb_bs_wm_8),

        /* set multi */
        .bs_sm_1 = generic_dsb_bs_sm_1,
        .bs_sm_2 = NSWAP(generic_dsb_bs_sm_2),
        .bs_sm_4 = NSWAP(generic_dsb_bs_sm_4),
        .bs_sm_8 = NSWAP(generic_dsb_bs_sm_8),

#ifdef __BUS_SPACE_HAS_STREAM_METHODS
        /* read stream */
        .bs_r_1_s = generic_dsb_bs_r_1,
        .bs_r_2_s = generic_dsb_bs_r_2,
        .bs_r_4_s = generic_dsb_bs_r_4,
        .bs_r_8_s = generic_dsb_bs_r_8,

        /* write stream */
        .bs_w_1_s = generic_dsb_bs_w_1,
        .bs_w_2_s = generic_dsb_bs_w_2,
        .bs_w_4_s = generic_dsb_bs_w_4,
        .bs_w_8_s = generic_dsb_bs_w_8,

        /* read region stream */
        .bs_rr_1_s = generic_dsb_bs_rr_1,
        .bs_rr_2_s = generic_dsb_bs_rr_2,
        .bs_rr_4_s = generic_dsb_bs_rr_4,
        .bs_rr_8_s = generic_dsb_bs_rr_8,

        /* write region stream */
        .bs_wr_1_s = generic_dsb_bs_wr_1,
        .bs_wr_2_s = generic_dsb_bs_wr_2,
        .bs_wr_4_s = generic_dsb_bs_wr_4,
        .bs_wr_8_s = generic_dsb_bs_wr_8,

        /* read multi stream */
        .bs_rm_1_s = generic_dsb_bs_rm_1,
        .bs_rm_2_s = generic_dsb_bs_rm_2,
        .bs_rm_4_s = generic_dsb_bs_rm_4,
        .bs_rm_8_s = generic_dsb_bs_rm_8,

        /* write multi stream */
        .bs_wm_1_s = generic_dsb_bs_wm_1,
        .bs_wm_2_s = generic_dsb_bs_wm_2,
        .bs_wm_4_s = generic_dsb_bs_wm_4,
        .bs_wm_8_s = generic_dsb_bs_wm_8,
#endif

#ifdef __BUS_SPACE_HAS_PROBING_METHODS
        /* peek */
        .bs_pe_1 = generic_bs_pe_1,
        .bs_pe_2 = generic_bs_pe_2,
        .bs_pe_4 = generic_bs_pe_4,
        .bs_pe_8 = generic_bs_pe_8,

        /* poke */
        .bs_po_1 = generic_bs_po_1,
        .bs_po_2 = generic_bs_po_2,
        .bs_po_4 = generic_bs_po_4,
        .bs_po_8 = generic_bs_po_8,
#endif
};

struct bus_space arm_generic_a4x_bs_tag = {
        .bs_cookie = &arm_generic_a4x_bs_tag,

        .bs_stride = 2,
        .bs_flags = 0,

        .bs_map = generic_bs_map,
        .bs_unmap = generic_bs_unmap,
        .bs_subregion = generic_bs_subregion,
        .bs_alloc = generic_bs_alloc,
        .bs_free = generic_bs_free,
        .bs_vaddr = generic_bs_vaddr,
        .bs_mmap = generic_bs_mmap,
        .bs_barrier = generic_bs_barrier,

        /* read */
        .bs_r_1 = generic_bs_r_1,
        .bs_r_2 = NSWAP(generic_bs_r_2),
        .bs_r_4 = NSWAP(generic_bs_r_4),
        .bs_r_8 = NSWAP(generic_bs_r_8),

        /* write */
        .bs_w_1 = generic_bs_w_1,
        .bs_w_2 = NSWAP(generic_bs_w_2),
        .bs_w_4 = NSWAP(generic_bs_w_4),
        .bs_w_8 = NSWAP(generic_bs_w_8),

        /* read region */
        .bs_rr_1 = generic_bs_rr_1,
        .bs_rr_2 = NSWAP(generic_bs_rr_2),
        .bs_rr_4 = NSWAP(generic_bs_rr_4),
        .bs_rr_8 = NSWAP(generic_bs_rr_8),

        /* write region */
        .bs_wr_1 = generic_bs_wr_1,
        .bs_wr_2 = NSWAP(generic_bs_wr_2),
        .bs_wr_4 = NSWAP(generic_bs_wr_4),
        .bs_wr_8 = NSWAP(generic_bs_wr_8),

        /* copy region */
        .bs_c_1 = generic_bs_c_1,
        .bs_c_2 = generic_bs_c_2,
        .bs_c_4 = generic_bs_c_4,
        .bs_c_8 = generic_bs_c_8,

        /* set region */
        .bs_sr_1 = generic_bs_sr_1,
        .bs_sr_2 = NSWAP(generic_bs_sr_2),
        .bs_sr_4 = NSWAP(generic_bs_sr_4),
        .bs_sr_8 = NSWAP(generic_bs_sr_8),

        /* read multi */
        .bs_rm_1 = generic_bs_rm_1,
        .bs_rm_2 = NSWAP(generic_bs_rm_2),
        .bs_rm_4 = NSWAP(generic_bs_rm_4),
        .bs_rm_8 = NSWAP(generic_bs_rm_8),

        /* write multi */
        .bs_wm_1 = generic_bs_wm_1,
        .bs_wm_2 = NSWAP(generic_bs_wm_2),
        .bs_wm_4 = NSWAP(generic_bs_wm_4),
        .bs_wm_8 = NSWAP(generic_bs_wm_8),

        /* set multi */
        .bs_sm_1 = generic_bs_sm_1,
        .bs_sm_2 = NSWAP(generic_bs_sm_2),
        .bs_sm_4 = NSWAP(generic_bs_sm_4),
        .bs_sm_8 = NSWAP(generic_bs_sm_8),

#ifdef __BUS_SPACE_HAS_STREAM_METHODS
        /* read stream */
        .bs_r_1_s = generic_bs_r_1,
        .bs_r_2_s = generic_bs_r_2,
        .bs_r_4_s = generic_bs_r_4,
        .bs_r_8_s = generic_bs_r_8,

        /* write stream */
        .bs_w_1_s = generic_bs_w_1,
        .bs_w_2_s = generic_bs_w_2,
        .bs_w_4_s = generic_bs_w_4,
        .bs_w_8_s = generic_bs_w_8,

        /* read region stream */
        .bs_rr_1_s = generic_bs_rr_1,
        .bs_rr_2_s = generic_bs_rr_2,
        .bs_rr_4_s = generic_bs_rr_4,
        .bs_rr_8_s = generic_bs_rr_8,

        /* write region stream */
        .bs_wr_1_s = generic_bs_wr_1,
        .bs_wr_2_s = generic_bs_wr_2,
        .bs_wr_4_s = generic_bs_wr_4,
        .bs_wr_8_s = generic_bs_wr_8,

        /* read multi stream */
        .bs_rm_1_s = generic_bs_rm_1,
        .bs_rm_2_s = generic_bs_rm_2,
        .bs_rm_4_s = generic_bs_rm_4,
        .bs_rm_8_s = generic_bs_rm_8,

        /* write multi stream */
        .bs_wm_1_s = generic_bs_wm_1,
        .bs_wm_2_s = generic_bs_wm_2,
        .bs_wm_4_s = generic_bs_wm_4,
        .bs_wm_8_s = generic_bs_wm_8,
#endif

#ifdef __BUS_SPACE_HAS_PROBING_METHODS
        /* peek */
        .bs_pe_1 = generic_bs_pe_1,
        .bs_pe_2 = generic_bs_pe_2,
        .bs_pe_4 = generic_bs_pe_4,
        .bs_pe_8 = generic_bs_pe_8,

        /* poke */
        .bs_po_1 = generic_bs_po_1,
        .bs_po_2 = generic_bs_po_2,
        .bs_po_4 = generic_bs_po_4,
        .bs_po_8 = generic_bs_po_8,
#endif
};

struct bus_space aarch64_generic_a4x_dsb_bs_tag = {
        .bs_cookie = &aarch64_generic_a4x_dsb_bs_tag,

        .bs_stride = 2,
        .bs_flags = 0,

        .bs_map = generic_bs_map,
        .bs_unmap = generic_bs_unmap,
        .bs_subregion = generic_bs_subregion,
        .bs_alloc = generic_bs_alloc,
        .bs_free = generic_bs_free,
        .bs_vaddr = generic_bs_vaddr,
        .bs_mmap = generic_bs_mmap,
        .bs_barrier = generic_bs_barrier,

        /* read */
        .bs_r_1 = generic_dsb_bs_r_1,
        .bs_r_2 = NSWAP(generic_dsb_bs_r_2),
        .bs_r_4 = NSWAP(generic_dsb_bs_r_4),
        .bs_r_8 = NSWAP(generic_dsb_bs_r_8),

        /* write */
        .bs_w_1 = generic_dsb_bs_w_1,
        .bs_w_2 = NSWAP(generic_dsb_bs_w_2),
        .bs_w_4 = NSWAP(generic_dsb_bs_w_4),
        .bs_w_8 = NSWAP(generic_dsb_bs_w_8),

        /* read region */
        .bs_rr_1 = generic_dsb_bs_rr_1,
        .bs_rr_2 = NSWAP(generic_dsb_bs_rr_2),
        .bs_rr_4 = NSWAP(generic_dsb_bs_rr_4),
        .bs_rr_8 = NSWAP(generic_dsb_bs_rr_8),

        /* write region */
        .bs_wr_1 = generic_dsb_bs_wr_1,
        .bs_wr_2 = NSWAP(generic_dsb_bs_wr_2),
        .bs_wr_4 = NSWAP(generic_dsb_bs_wr_4),
        .bs_wr_8 = NSWAP(generic_dsb_bs_wr_8),

        /* copy region */
        .bs_c_1 = generic_dsb_bs_c_1,
        .bs_c_2 = generic_dsb_bs_c_2,
        .bs_c_4 = generic_dsb_bs_c_4,
        .bs_c_8 = generic_dsb_bs_c_8,

        /* set region */
        .bs_sr_1 = generic_dsb_bs_sr_1,
        .bs_sr_2 = NSWAP(generic_dsb_bs_sr_2),
        .bs_sr_4 = NSWAP(generic_dsb_bs_sr_4),
        .bs_sr_8 = NSWAP(generic_dsb_bs_sr_8),

        /* read multi */
        .bs_rm_1 = generic_dsb_bs_rm_1,
        .bs_rm_2 = NSWAP(generic_dsb_bs_rm_2),
        .bs_rm_4 = NSWAP(generic_dsb_bs_rm_4),
        .bs_rm_8 = NSWAP(generic_dsb_bs_rm_8),

        /* write multi */
        .bs_wm_1 = generic_dsb_bs_wm_1,
        .bs_wm_2 = NSWAP(generic_dsb_bs_wm_2),
        .bs_wm_4 = NSWAP(generic_dsb_bs_wm_4),
        .bs_wm_8 = NSWAP(generic_dsb_bs_wm_8),

        /* set multi */
        .bs_sm_1 = generic_dsb_bs_sm_1,
        .bs_sm_2 = NSWAP(generic_dsb_bs_sm_2),
        .bs_sm_4 = NSWAP(generic_dsb_bs_sm_4),
        .bs_sm_8 = NSWAP(generic_dsb_bs_sm_8),

#ifdef __BUS_SPACE_HAS_STREAM_METHODS
        /* read stream */
        .bs_r_1_s = generic_dsb_bs_r_1,
        .bs_r_2_s = generic_dsb_bs_r_2,
        .bs_r_4_s = generic_dsb_bs_r_4,
        .bs_r_8_s = generic_dsb_bs_r_8,

        /* write stream */
        .bs_w_1_s = generic_dsb_bs_w_1,
        .bs_w_2_s = generic_dsb_bs_w_2,
        .bs_w_4_s = generic_dsb_bs_w_4,
        .bs_w_8_s = generic_dsb_bs_w_8,

        /* read region stream */
        .bs_rr_1_s = generic_dsb_bs_rr_1,
        .bs_rr_2_s = generic_dsb_bs_rr_2,
        .bs_rr_4_s = generic_dsb_bs_rr_4,
        .bs_rr_8_s = generic_dsb_bs_rr_8,

        /* write region stream */
        .bs_wr_1_s = generic_dsb_bs_wr_1,
        .bs_wr_2_s = generic_dsb_bs_wr_2,
        .bs_wr_4_s = generic_dsb_bs_wr_4,
        .bs_wr_8_s = generic_dsb_bs_wr_8,

        /* read multi stream */
        .bs_rm_1_s = generic_dsb_bs_rm_1,
        .bs_rm_2_s = generic_dsb_bs_rm_2,
        .bs_rm_4_s = generic_dsb_bs_rm_4,
        .bs_rm_8_s = generic_dsb_bs_rm_8,

        /* write multi stream */
        .bs_wm_1_s = generic_dsb_bs_wm_1,
        .bs_wm_2_s = generic_dsb_bs_wm_2,
        .bs_wm_4_s = generic_dsb_bs_wm_4,
        .bs_wm_8_s = generic_dsb_bs_wm_8,
#endif

#ifdef __BUS_SPACE_HAS_PROBING_METHODS
        /* peek */
        .bs_pe_1 = generic_bs_pe_1,
        .bs_pe_2 = generic_bs_pe_2,
        .bs_pe_4 = generic_bs_pe_4,
        .bs_pe_8 = generic_bs_pe_8,

        /* poke */
        .bs_po_1 = generic_bs_po_1,
        .bs_po_2 = generic_bs_po_2,
        .bs_po_4 = generic_bs_po_4,
        .bs_po_8 = generic_bs_po_8,
#endif
};

int
generic_bs_map(void *t, bus_addr_t bpa, bus_size_t size, int flag,
    bus_space_handle_t *bshp)
{
        const struct pmap_devmap *pd;
        paddr_t startpa, endpa, pa;
        vaddr_t va;
        int pmapflags;

        if ((pd = pmap_devmap_find_pa(bpa, size)) != NULL) {
                *bshp = pd->pd_va + (bpa - pd->pd_pa);
                return 0;
        }

        startpa = trunc_page(bpa);
        endpa = round_page(bpa + size);

        /* XXX use extent manager to check duplicate mapping */

        va = uvm_km_alloc(kernel_map, endpa - startpa, 0,
            UVM_KMF_VAONLY | UVM_KMF_NOWAIT);
        if (va == 0)
                return ENOMEM;

        *bshp = (bus_space_handle_t)(va + (bpa - startpa));

        if ((flag & BUS_SPACE_MAP_PREFETCHABLE) != 0)
                pmapflags = PMAP_WRITE_COMBINE;
        else if ((flag & BUS_SPACE_MAP_CACHEABLE) != 0)
                pmapflags = PMAP_WRITE_BACK;
        else if ((flag & BUS_SPACE_MAP_NONPOSTED) != 0)
                pmapflags = PMAP_DEV_NP;
        else
                pmapflags = PMAP_DEV;

        for (pa = startpa; pa < endpa; pa += PAGE_SIZE, va += PAGE_SIZE) {
                pmap_kenter_pa(va, pa, VM_PROT_READ | VM_PROT_WRITE, pmapflags);
        }
        pmap_update(pmap_kernel());

        return 0;
}

void
generic_bs_unmap(void *t, bus_space_handle_t bsh, bus_size_t size)
{
        vaddr_t va;
        vsize_t sz;

        if (pmap_devmap_find_va(bsh, size) != NULL)
                return;

        va = trunc_page(bsh);
        sz = round_page(bsh + size) - va;

        pmap_kremove(va, sz);
        pmap_update(pmap_kernel());
        uvm_km_free(kernel_map, va, sz, UVM_KMF_VAONLY);
}


int
generic_bs_subregion(void *t, bus_space_handle_t bsh, bus_size_t offset,
    bus_size_t size, bus_space_handle_t *nbshp)
{
        *nbshp = bsh + (offset << ((struct bus_space *)t)->bs_stride);
        return 0;
}

void
generic_bs_barrier(void *t, bus_space_handle_t bsh, bus_size_t offset,
    bus_size_t len, int flags)
{
        flags &= BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE;

        /*
         * For default mappings, which are mapped with nGnRE memory
         * regions, all loads and stores are issued in program order
         * (non-reordered).
         *
         * For strongly ordered mappings, which are mapped with nGnRnE
         * regions, all loads and stores are issued in program order
         * (non-reordered) and will complete at the endpoint, thus
         * not requiring any barrier.
         *
         * For BUS_SPACE_MAP_PREFETCHABLE mappings, which are mapped
         * as normal memory with the non-cacheable cacheability attr-
         * ibute, loads and stores may be issued out of order, and
         * writes may be buffered, potentially requiring any of the
         * read, write, and read/write barriers.
         *
         * For BUS_SPACE_MAP_CACHEABLE mappings, which are mapped as
         * normal memory with the write-back cacheability attribute
         * (just like normal memory), the same potential for any of
         * the barriers exists.
         *
         * We can't easily tell here how the region was mapped (without
         * consulting the page tables), so just issue the barrier
         * unconditionally.  Chances are either it's necessary or the
         * cost is small in comparison to device register I/O.
         *
         * The bus_space(9) man page is not clear whether barriers
         * should enforce ordering or completion. To be safe, use dsb
         * (ensure completion) here instead of dmb (ordering).
         */
        switch (flags) {
        case BUS_SPACE_BARRIER_READ:
                dsb(ld);
                break;
        case BUS_SPACE_BARRIER_WRITE:
                dsb(st);
                break;
        case BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE:
                dsb(sy);
                break;
        }
}

void *
generic_bs_vaddr(void *t, bus_space_handle_t bsh)
{
        return (void *)bsh;
}

paddr_t
generic_bs_mmap(void *t, bus_addr_t bpa, off_t offset, int prot, int flags)
{
        paddr_t bus_flags = 0;

        if ((flags & BUS_SPACE_MAP_CACHEABLE) != 0)
                bus_flags |= ARM_MMAP_WRITEBACK;
        else if ((flags & BUS_SPACE_MAP_PREFETCHABLE) != 0)
                bus_flags |= ARM_MMAP_WRITECOMBINE;
        else
                bus_flags |= ARM_MMAP_DEVICE;

        return (atop(bpa + (offset << ((struct bus_space *)t)->bs_stride)) |
            bus_flags);
}

int
generic_bs_alloc(void *t, bus_addr_t rstart, bus_addr_t rend,
    bus_size_t size, bus_size_t alignment, bus_size_t boundary, int flags,
    bus_addr_t *bpap, bus_space_handle_t *bshp)
{
        panic("%s(): not implemented\n", __func__);
}

void
generic_bs_free(void *t, bus_space_handle_t bsh, bus_size_t size)
{
        panic("%s(): not implemented\n", __func__);
}

#ifdef __BUS_SPACE_HAS_PROBING_METHODS
int
generic_bs_pe_1(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint8_t *datap)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                *datap = generic_dsb_bs_r_1(t, bsh, offset);
                dsb(ld);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_pe_2(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint16_t *datap)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                *datap = NSWAP(generic_dsb_bs_r_2)(t, bsh, offset);
                dsb(ld);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_pe_4(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint32_t *datap)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                *datap = NSWAP(generic_dsb_bs_r_4)(t, bsh, offset);
                dsb(ld);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_pe_8(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint64_t *datap)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                *datap = NSWAP(generic_dsb_bs_r_8)(t, bsh, offset);
                dsb(ld);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_po_1(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint8_t data)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                generic_dsb_bs_w_1(t, bsh, offset, data);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_po_2(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint16_t data)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                NSWAP(generic_dsb_bs_w_2)(t, bsh, offset, data);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_po_4(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint32_t data)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                NSWAP(generic_dsb_bs_w_4)(t, bsh, offset, data);
                cpu_unset_onfault();
        }
        return error;
}

int
generic_bs_po_8(void *t, bus_space_handle_t bsh, bus_size_t offset,
    uint64_t data)
{
        struct faultbuf fb;
        int error;

        if ((error = cpu_set_onfault(&fb)) == 0) {
                NSWAP(generic_dsb_bs_w_8)(t, bsh, offset, data);
                cpu_unset_onfault();
        }
        return error;
}
#endif /* __BUS_SPACE_HAS_PROBING_METHODS */