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      1 /* $NetBSD: fdt_dma_machdep.c,v 1.1 2020/07/16 11:49:38 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2020 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: fdt_dma_machdep.c,v 1.1 2020/07/16 11:49:38 jmcneill Exp $");
     31 
     32 #define	_MIPS_BUS_DMA_PRIVATE
     33 
     34 #include <sys/param.h>
     35 #include <sys/bus.h>
     36 #include <sys/kmem.h>
     37 
     38 #include <dev/fdt/fdtvar.h>
     39 
     40 static struct mips_bus_dma_tag fdtbus_dma_tag = {
     41 	._cookie = NULL,
     42 	._wbase = 0,
     43 	._bounce_alloc_lo = 0,
     44 	._bounce_alloc_hi = 0,
     45 	._dmamap_ops = _BUS_DMAMAP_OPS_INITIALIZER,
     46 	._dmamem_ops = _BUS_DMAMEM_OPS_INITIALIZER,
     47 	._dmatag_ops = _BUS_DMATAG_OPS_INITIALIZER,
     48 };
     49 
     50 bus_dma_tag_t
     51 fdtbus_dma_tag_create(int phandle, const struct fdt_dma_range *ranges,
     52     u_int nranges)
     53 {
     54 	bus_dma_tag_t newtag;
     55 	bus_addr_t min_addr, max_addr;
     56 	int error;
     57 
     58 	if (nranges == 0)
     59 		return &fdtbus_dma_tag;
     60 
     61 	KASSERT(nranges == 1);
     62 	KASSERT(ranges[0].dr_sysbase == ranges[0].dr_busbase);
     63 
     64 	min_addr = ranges[0].dr_sysbase;
     65 	max_addr = min_addr + ranges[0].dr_len - 1;
     66 	error = bus_dmatag_subregion(&fdtbus_dma_tag, min_addr, max_addr,
     67 	    &newtag, 0);
     68 	KASSERT(error == 0);
     69 
     70 	return newtag;
     71 }
     72