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      1 /*	$NetBSD: isadma_machdep.c,v 1.18 2023/12/20 15:34:45 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: isadma_machdep.c,v 1.18 2023/12/20 15:34:45 thorpej Exp $");
     35 
     36 #define ISA_DMA_STATS
     37 
     38 #include <sys/param.h>
     39 #include <sys/systm.h>
     40 #include <sys/syslog.h>
     41 #include <sys/device.h>
     42 #include <sys/proc.h>
     43 #include <sys/mbuf.h>
     44 
     45 #define _ARM32_BUS_DMA_PRIVATE
     46 #include <sys/bus.h>
     47 
     48 #include <dev/isa/isareg.h>
     49 #include <dev/isa/isavar.h>
     50 
     51 #include <uvm/uvm_extern.h>
     52 
     53 /*
     54  * ISA has a 24-bit address limitation, so at most it has a 16M
     55  * DMA range.  However, some platforms have a more limited range,
     56  * e.g. the Shark NC.  On these systems, we are provided with
     57  * a set of DMA ranges.  The pmap module is aware of these ranges
     58  * and places DMA-safe memory for them onto an alternate free list
     59  * so that they are protected from being used to service page faults,
     60  * etc. (unless we've run out of memory elsewhere).
     61  */
     62 extern struct arm32_dma_range *shark_isa_dma_ranges;
     63 extern int shark_isa_dma_nranges;
     64 
     65 /*
     66  * Entry points for ISA DMA.  These are mostly wrappers around
     67  * the generic functions that understand how to deal with bounce
     68  * buffers, if necessary.
     69  */
     70 struct arm32_bus_dma_tag isa_bus_dma_tag = {
     71 	_BUS_DMAMAP_FUNCS,
     72 	_BUS_DMAMEM_FUNCS,
     73 	_BUS_DMATAG_FUNCS,
     74 };
     75 
     76 /*
     77  * Initialize ISA DMA.
     78  */
     79 void
     80 isa_dma_init(void)
     81 {
     82 
     83 	isa_bus_dma_tag._ranges = shark_isa_dma_ranges;
     84 	isa_bus_dma_tag._nranges = shark_isa_dma_nranges;
     85 }
     86