xref: /netbsd/sys/arch/alpha/jensenio/jensenio_dma.c (revision bf9ec67e)
1 /* $NetBSD: jensenio_dma.c,v 1.1 2000/07/12 20:36:09 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 2000 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * DMA support for the Jensen system.
41  *
42  * The Jensen uses direct-mapped DMA with a window base of 0, i.e.
43  * a page of phyical memory has the same PCI address as CPU address.
44  * There is no support for SGMAPs on the Jensen.  This means that for
45  * ISA DMA, we must employ bounce buffers for DMA transactions over
46  * 16MB ISA limit (due to ISA's 24-bit address space limitation).
47  *
48  * Furthermore, the H_BUS will not respond to DMA transactions between
49  * 512KB and 1MB.  This is to allow for the ISA `hole'.  However, the
50  * ISA `hole' typically exists only between 640KB and 1MB.  We must
51  * therefore bounce transactions that fall within this region, as well.
52  * XXX Should we prevent having managed memory in this region, instead?
53  */
54 
55 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
56 
57 __KERNEL_RCSID(0, "$NetBSD: jensenio_dma.c,v 1.1 2000/07/12 20:36:09 thorpej Exp $");
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/kernel.h>
62 #include <sys/device.h>
63 #include <sys/malloc.h>
64 #include <sys/mbuf.h>
65 
66 #define _ALPHA_BUS_DMA_PRIVATE
67 #include <machine/bus.h>
68 
69 #include <dev/eisa/eisavar.h>
70 
71 #include <dev/isa/isavar.h>
72 
73 #include <alpha/jensenio/jenseniovar.h>
74 
75 bus_dma_tag_t jensenio_dma_get_tag(bus_dma_tag_t, alpha_bus_t);
76 
77 void
78 jensenio_dma_init(struct jensenio_config *jcp)
79 {
80 	bus_dma_tag_t t;
81 
82 	/*
83 	 * Initialize the DMA tag used for EISA DMA.
84 	 */
85 	t = &jcp->jc_dmat_eisa;
86 	t->_cookie = jcp;
87 	t->_wbase = 0;
88 	t->_wsize = 0x100000000UL;
89 	t->_next_window = NULL;
90 	t->_boundary = 0;
91 	t->_sgmap = NULL;
92 	t->_get_tag = jensenio_dma_get_tag;
93 	t->_dmamap_create = _bus_dmamap_create;
94 	t->_dmamap_destroy = _bus_dmamap_destroy;
95 	t->_dmamap_load = _bus_dmamap_load_direct;
96 	t->_dmamap_load_mbuf = _bus_dmamap_load_mbuf_direct;
97 	t->_dmamap_load_uio = _bus_dmamap_load_uio_direct;
98 	t->_dmamap_load_raw = _bus_dmamap_load_raw_direct;
99 	t->_dmamap_unload = _bus_dmamap_unload;
100 	t->_dmamap_sync = _bus_dmamap_sync;
101 
102 	t->_dmamem_alloc = _bus_dmamem_alloc;
103 	t->_dmamem_free = _bus_dmamem_free;
104 	t->_dmamem_map = _bus_dmamem_map;
105 	t->_dmamem_unmap = _bus_dmamem_unmap;
106 	t->_dmamem_mmap = _bus_dmamem_mmap;
107 
108 	/*
109 	 * Initialize the DMA tag used for ISA DMA.
110 	 */
111 	t = &jcp->jc_dmat_isa;
112 	t->_cookie = jcp;
113 	t->_wbase = 0;
114 	t->_wsize = 0x1000000;
115 	t->_next_window = NULL;
116 	t->_boundary = 0;
117 	t->_sgmap = NULL;
118 	t->_get_tag = jensenio_dma_get_tag;
119 	t->_dmamap_create = isadma_bounce_dmamap_create;
120 	t->_dmamap_destroy = isadma_bounce_dmamap_destroy;
121 	t->_dmamap_load = isadma_bounce_dmamap_load;
122 	t->_dmamap_load_mbuf = isadma_bounce_dmamap_load_mbuf;
123 	t->_dmamap_load_uio = isadma_bounce_dmamap_load_uio;
124 	t->_dmamap_load_raw = isadma_bounce_dmamap_load_raw;
125 	t->_dmamap_unload = isadma_bounce_dmamap_unload;
126 	t->_dmamap_sync = isadma_bounce_dmamap_sync;
127 
128 	t->_dmamem_alloc = isadma_bounce_dmamem_alloc;
129 	t->_dmamem_free = _bus_dmamem_free;
130 	t->_dmamem_map = _bus_dmamem_map;
131 	t->_dmamem_unmap = _bus_dmamem_unmap;
132 	t->_dmamem_mmap = _bus_dmamem_mmap;
133 
134 	/* XXX XXX BEGIN XXX XXX */
135 	{							/* XXX */
136 		extern paddr_t alpha_XXX_dmamap_or;		/* XXX */
137 		alpha_XXX_dmamap_or = 0;			/* XXX */
138 	}
139 }
140 
141 /*
142  * Return the bus dma tag to be used fo rthe specified bus type.
143  * INTERNAL USE ONLY!
144  */
145 bus_dma_tag_t
146 jensenio_dma_get_tag(bus_dma_tag_t t, alpha_bus_t bustype)
147 {
148 	struct jensenio_config *jcp = t->_cookie;
149 
150 	switch (bustype) {
151 	case ALPHA_BUS_EISA:
152 		/*
153 		 * Busses capable of 32-bit DMA get the EISA DMA tag.
154 		 */
155 		return (&jcp->jc_dmat_eisa);
156 
157 	case ALPHA_BUS_ISA:
158 		/*
159 		 * Lame 24-bit busses have to bounce.
160 		 */
161 		return (&jcp->jc_dmat_isa);
162 
163 	default:
164 		panic("jensenio_dma_get_tag: shouldn't be here, really...");
165 	}
166 }
167