xref: /netbsd/sys/arch/alpha/common/sgmap_common.c (revision c4a72b64)
1 /* $NetBSD: sgmap_common.c,v 1.19 2002/09/27 15:35:36 provos Exp $ */
2 
3 /*-
4  * Copyright (c) 1997, 1998, 2001 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  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
41 
42 __KERNEL_RCSID(0, "$NetBSD: sgmap_common.c,v 1.19 2002/09/27 15:35:36 provos Exp $");
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/malloc.h>
48 #include <sys/proc.h>
49 
50 #include <uvm/uvm_extern.h>
51 
52 #define	_ALPHA_BUS_DMA_PRIVATE
53 #include <machine/bus.h>
54 
55 #include <alpha/common/sgmapvar.h>
56 
57 /*
58  * Some systems will prefetch the next page during a memory -> device DMA.
59  * This can cause machine checks if there is not a spill page after the
60  * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE).
61  */
62 vaddr_t		alpha_sgmap_prefetch_spill_page_va;
63 bus_addr_t	alpha_sgmap_prefetch_spill_page_pa;
64 
65 void
66 alpha_sgmap_init(bus_dma_tag_t t, struct alpha_sgmap *sgmap, const char *name,
67     bus_addr_t wbase, bus_addr_t sgvabase, bus_size_t sgvasize, size_t ptesize,
68     void *ptva, bus_size_t minptalign)
69 {
70 	bus_dma_segment_t seg;
71 	size_t ptsize;
72 	int rseg;
73 
74 	if (sgvasize & PGOFSET) {
75 		printf("size botch for sgmap `%s'\n", name);
76 		goto die;
77 	}
78 
79 	sgmap->aps_wbase = wbase;
80 	sgmap->aps_sgvabase = sgvabase;
81 	sgmap->aps_sgvasize = sgvasize;
82 
83 	if (ptva != NULL) {
84 		/*
85 		 * We already have a page table; this may be a system
86 		 * where the page table resides in bridge-resident SRAM.
87 		 */
88 		sgmap->aps_pt = ptva;
89 		sgmap->aps_ptpa = 0;
90 	} else {
91 		/*
92 		 * Compute the page table size and allocate it.  At minimum,
93 		 * this must be aligned to the page table size.  However,
94 		 * some platforms have more strict alignment reqirements.
95 		 */
96 		ptsize = (sgvasize / NBPG) * ptesize;
97 		if (minptalign != 0) {
98 			if (minptalign < ptsize)
99 				minptalign = ptsize;
100 		} else
101 			minptalign = ptsize;
102 		if (bus_dmamem_alloc(t, ptsize, minptalign, 0, &seg, 1, &rseg,
103 		    BUS_DMA_NOWAIT)) {
104 			panic("unable to allocate page table for sgmap `%s'",
105 			    name);
106 			goto die;
107 		}
108 		sgmap->aps_ptpa = seg.ds_addr;
109 		sgmap->aps_pt = (caddr_t)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa);
110 	}
111 
112 	/*
113 	 * Create the extent map used to manage the virtual address
114 	 * space.
115 	 */
116 	sgmap->aps_ex = extent_create((char *)name, sgvabase, sgvasize - 1,
117 	    M_DMAMAP, NULL, 0, EX_NOWAIT|EX_NOCOALESCE);
118 	if (sgmap->aps_ex == NULL) {
119 		printf("unable to create extent map for sgmap `%s'\n",
120 		    name);
121 		goto die;
122 	}
123 
124 	/*
125 	 * Allocate a spill page if that hasn't already been done.
126 	 */
127 	if (alpha_sgmap_prefetch_spill_page_va == 0) {
128 		if (bus_dmamem_alloc(t, NBPG, 0, 0, &seg, 1, &rseg,
129 		    BUS_DMA_NOWAIT)) {
130 			printf("unable to allocate spill page for sgmap `%s'\n",
131 			    name);
132 			goto die;
133 		}
134 		alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr;
135 		alpha_sgmap_prefetch_spill_page_va =
136 		    ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa);
137 		memset((caddr_t)alpha_sgmap_prefetch_spill_page_va, 0, NBPG);
138 	}
139 
140 	return;
141  die:
142 	panic("alpha_sgmap_init");
143 }
144 
145 int
146 alpha_sgmap_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments,
147     bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
148 {
149 	bus_dmamap_t map;
150 	int error;
151 
152 	error = _bus_dmamap_create(t, size, nsegments, maxsegsz,
153 	    boundary, flags, &map);
154 	if (error)
155 		return (error);
156 
157 	/* XXX BUS_DMA_ALLOCNOW */
158 
159 	if (error == 0)
160 		*dmamp = map;
161 	else
162 		alpha_sgmap_dmamap_destroy(t, map);
163 
164 	return (error);
165 }
166 
167 void
168 alpha_sgmap_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
169 {
170 
171 	KASSERT(map->dm_mapsize == 0);
172 
173 	_bus_dmamap_destroy(t, map);
174 }
175