1 /* $NetBSD: isadma_machdep.c,v 1.17 2022/09/27 06:36:41 skrll Exp $ */
2
3 #define ISA_DMA_STATS
4
5 /*-
6 * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
11 * NASA Ames Research Center.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: isadma_machdep.c,v 1.17 2022/09/27 06:36:41 skrll Exp $");
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 #define ISA_DMA_BOUNCE_THRESHOLD (16 * 1024 * 1024)
63
64 struct arm32_dma_range *footbridge_isa_dma_ranges;
65 int footbridge_isa_dma_nranges;
66
67 /*
68 * Entry points for ISA DMA. These are mostly wrappers around
69 * the generic functions that understand how to deal with bounce
70 * buffers, if necessary.
71 */
72 struct arm32_bus_dma_tag isa_bus_dma_tag = {
73 _BUS_DMAMAP_FUNCS,
74 _BUS_DMAMEM_FUNCS,
75 _BUS_DMATAG_FUNCS,
76 };
77
78 /*
79 * Initialize ISA DMA.
80 */
81 void
isa_dma_init(void)82 isa_dma_init(void)
83 {
84
85 isa_bus_dma_tag._ranges = footbridge_isa_dma_ranges;
86 isa_bus_dma_tag._nranges = footbridge_isa_dma_nranges;
87 }
88