1 /* $NetBSD: jensenio_dma.c,v 1.10 2021/08/17 22:00:27 andvar Exp $ */
2
3 /*-
4 * Copyright (c) 2000, 2020 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.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * DMA support for the Jensen system.
34 *
35 * The Jensen uses direct-mapped DMA with a window base of 0, i.e.
36 * a page of physical memory has the same PCI address as CPU address.
37 * There is no support for SGMAPs on the Jensen. This means that for
38 * ISA DMA, we must employ bounce buffers for DMA transactions over
39 * 16MB ISA limit (due to ISA's 24-bit address space limitation).
40 *
41 * Furthermore, the H_BUS will not respond to DMA transactions between
42 * 512KB and 1MB. This is to allow for the ISA `hole'. However, the
43 * ISA `hole' typically exists only between 640KB and 1MB. We must
44 * therefore bounce transactions that fall within this region, as well.
45 * XXX Should we prevent having managed memory in this region, instead?
46 */
47
48 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
49
50 __KERNEL_RCSID(0, "$NetBSD: jensenio_dma.c,v 1.10 2021/08/17 22:00:27 andvar Exp $");
51
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
55 #include <sys/device.h>
56 #include <sys/mbuf.h>
57
58 #define _ALPHA_BUS_DMA_PRIVATE
59 #include <sys/bus.h>
60
61 #include <dev/eisa/eisavar.h>
62
63 #include <dev/isa/isavar.h>
64
65 #include <alpha/jensenio/jenseniovar.h>
66
67 #include <machine/alpha.h>
68
69 static bus_dma_tag_t jensenio_dma_get_tag(bus_dma_tag_t, alpha_bus_t);
70
71 void
jensenio_page_physload(unsigned long const start_pfn,unsigned long const end_pfn)72 jensenio_page_physload(unsigned long const start_pfn,
73 unsigned long const end_pfn)
74 {
75 /*
76 * The Jensen does not have SGMAP DMA. For this reason, we
77 * need to protect the first 16MB of RAM from random allocations
78 * in order to give ISA DMA a snowball's chance of working.
79 */
80 alpha_page_physload_sheltered(start_pfn, end_pfn,
81 0, alpha_btop(0x1000000));
82 }
83
84 void
jensenio_dma_init(struct jensenio_config * jcp)85 jensenio_dma_init(struct jensenio_config *jcp)
86 {
87 bus_dma_tag_t t;
88
89 /*
90 * Initialize the DMA tag used for EISA DMA.
91 */
92 t = &jcp->jc_dmat_eisa;
93 t->_cookie = jcp;
94 t->_wbase = 0;
95 t->_wsize = 0x100000000UL;
96 t->_next_window = NULL;
97 t->_boundary = 0;
98 t->_sgmap = NULL;
99 t->_get_tag = jensenio_dma_get_tag;
100 t->_dmamap_create = _bus_dmamap_create;
101 t->_dmamap_destroy = _bus_dmamap_destroy;
102 t->_dmamap_load = _bus_dmamap_load_direct;
103 t->_dmamap_load_mbuf = _bus_dmamap_load_mbuf_direct;
104 t->_dmamap_load_uio = _bus_dmamap_load_uio_direct;
105 t->_dmamap_load_raw = _bus_dmamap_load_raw_direct;
106 t->_dmamap_unload = _bus_dmamap_unload;
107 t->_dmamap_sync = _bus_dmamap_sync;
108
109 t->_dmamem_alloc = _bus_dmamem_alloc;
110 t->_dmamem_free = _bus_dmamem_free;
111 t->_dmamem_map = _bus_dmamem_map;
112 t->_dmamem_unmap = _bus_dmamem_unmap;
113 t->_dmamem_mmap = _bus_dmamem_mmap;
114
115 /*
116 * Initialize the DMA tag used for ISA DMA.
117 */
118 t = &jcp->jc_dmat_isa;
119 t->_cookie = jcp;
120 t->_wbase = 0;
121 t->_wsize = 0x1000000;
122 t->_next_window = NULL;
123 t->_boundary = 0;
124 t->_sgmap = NULL;
125 t->_get_tag = jensenio_dma_get_tag;
126 t->_dmamap_create = isadma_bounce_dmamap_create;
127 t->_dmamap_destroy = isadma_bounce_dmamap_destroy;
128 t->_dmamap_load = isadma_bounce_dmamap_load;
129 t->_dmamap_load_mbuf = isadma_bounce_dmamap_load_mbuf;
130 t->_dmamap_load_uio = isadma_bounce_dmamap_load_uio;
131 t->_dmamap_load_raw = isadma_bounce_dmamap_load_raw;
132 t->_dmamap_unload = isadma_bounce_dmamap_unload;
133 t->_dmamap_sync = isadma_bounce_dmamap_sync;
134
135 t->_dmamem_alloc = isadma_bounce_dmamem_alloc;
136 t->_dmamem_free = _bus_dmamem_free;
137 t->_dmamem_map = _bus_dmamem_map;
138 t->_dmamem_unmap = _bus_dmamem_unmap;
139 t->_dmamem_mmap = _bus_dmamem_mmap;
140 }
141
142 /*
143 * Return the bus dma tag to be used for the specified bus type.
144 * INTERNAL USE ONLY!
145 */
146 static bus_dma_tag_t
jensenio_dma_get_tag(bus_dma_tag_t t,alpha_bus_t bustype)147 jensenio_dma_get_tag(bus_dma_tag_t t, alpha_bus_t bustype)
148 {
149 struct jensenio_config *jcp = t->_cookie;
150
151 switch (bustype) {
152 case ALPHA_BUS_EISA:
153 /*
154 * Busses capable of 32-bit DMA get the EISA DMA tag.
155 */
156 return (&jcp->jc_dmat_eisa);
157
158 case ALPHA_BUS_ISA:
159 /*
160 * Lame 24-bit busses have to bounce.
161 */
162 return (&jcp->jc_dmat_isa);
163
164 default:
165 panic("jensenio_dma_get_tag: shouldn't be here, really...");
166 }
167 }
168