xref: /netbsd-src/sys/arch/alpha/common/sgmap_common.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /* $NetBSD: sgmap_common.c,v 1.13 2000/06/29 09:02:57 mrg Exp $ */
2 
3 /*-
4  * Copyright (c) 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  * 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 1.13 2000/06/29 09:02:57 mrg 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 #include <machine/bus.h>
53 
54 #include <alpha/common/sgmapvar.h>
55 
56 /*
57  * Some systems will prefetch the next page during a memory -> device DMA.
58  * This can cause machine checks if there is not a spill page after the
59  * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE).
60  */
61 vaddr_t		alpha_sgmap_prefetch_spill_page_va;
62 bus_addr_t	alpha_sgmap_prefetch_spill_page_pa;
63 
64 void
65 alpha_sgmap_init(t, sgmap, name, wbase, sgvabase, sgvasize, ptesize, ptva,
66     minptalign)
67 	bus_dma_tag_t t;
68 	struct alpha_sgmap *sgmap;
69 	const char *name;
70 	bus_addr_t wbase;
71 	bus_addr_t sgvabase;
72 	bus_size_t sgvasize;
73 	size_t ptesize;
74 	void *ptva;
75 	bus_size_t minptalign;
76 {
77 	bus_dma_segment_t seg;
78 	size_t ptsize;
79 	int rseg;
80 
81 	if (sgvasize & PGOFSET) {
82 		printf("size botch for sgmap `%s'\n", name);
83 		goto die;
84 	}
85 
86 	sgmap->aps_wbase = wbase;
87 	sgmap->aps_sgvabase = sgvabase;
88 	sgmap->aps_sgvasize = sgvasize;
89 
90 	if (ptva != NULL) {
91 		/*
92 		 * We already have a page table; this may be a system
93 		 * where the page table resides in bridge-resident SRAM.
94 		 */
95 		sgmap->aps_pt = ptva;
96 		sgmap->aps_ptpa = 0;
97 	} else {
98 		/*
99 		 * Compute the page table size and allocate it.  At minimum,
100 		 * this must be aligned to the page table size.  However,
101 		 * some platforms have more strict alignment reqirements.
102 		 */
103 		ptsize = (sgvasize / NBPG) * ptesize;
104 		if (minptalign != 0) {
105 			if (minptalign < ptsize)
106 				minptalign = ptsize;
107 		} else
108 			minptalign = ptsize;
109 		if (bus_dmamem_alloc(t, ptsize, minptalign, 0, &seg, 1, &rseg,
110 		    BUS_DMA_NOWAIT)) {
111 			panic("unable to allocate page table for sgmap `%s'\n",
112 			    name);
113 			goto die;
114 		}
115 		sgmap->aps_ptpa = seg.ds_addr;
116 		sgmap->aps_pt = (caddr_t)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa);
117 	}
118 
119 	/*
120 	 * Create the extent map used to manage the virtual address
121 	 * space.
122 	 */
123 	sgmap->aps_ex = extent_create((char *)name, sgvabase, sgvasize - 1,
124 	    M_DMAMAP, NULL, 0, EX_NOWAIT|EX_NOCOALESCE);
125 	if (sgmap->aps_ex == NULL) {
126 		printf("unable to create extent map for sgmap `%s'\n",
127 		    name);
128 		goto die;
129 	}
130 
131 	/*
132 	 * Allocate a spill page if that hasn't already been done.
133 	 */
134 	if (alpha_sgmap_prefetch_spill_page_va == 0) {
135 		if (bus_dmamem_alloc(t, NBPG, 0, 0, &seg, 1, &rseg,
136 		    BUS_DMA_NOWAIT)) {
137 			printf("unable to allocate spill page for sgmap `%s'\n",
138 			    name);
139 			goto die;
140 		}
141 		alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr;
142 		alpha_sgmap_prefetch_spill_page_va =
143 		    ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa);
144 		bzero((caddr_t)alpha_sgmap_prefetch_spill_page_va, NBPG);
145 	}
146 
147 	return;
148  die:
149 	panic("alpha_sgmap_init");
150 }
151 
152 int
153 alpha_sgmap_alloc(map, origlen, sgmap, flags)
154 	bus_dmamap_t map;
155 	bus_size_t origlen;
156 	struct alpha_sgmap *sgmap;
157 	int flags;
158 {
159 	int error;
160 	bus_size_t len = origlen, boundary, alignment;
161 
162 #ifdef DIAGNOSTIC
163 	if (map->_dm_flags & DMAMAP_HAS_SGMAP)
164 		panic("alpha_sgmap_alloc: already have sgva space");
165 #endif
166 	/*
167 	 * Add a range for spill page.
168 	 */
169 	len += NBPG;
170 
171 	/*
172 	 * And add an additional amount in case of ALLOCNOW.
173 	 */
174 	if (flags & BUS_DMA_ALLOCNOW)
175 		len += NBPG;
176 
177 	map->_dm_sgvalen = round_page(len);
178 
179 	/*
180 	 * ARGH! If the addition of spill pages bumped us over our
181 	 * boundary, we have to 2x the boundary limit.
182 	 */
183 	boundary = map->_dm_boundary;
184 	if (boundary && boundary < map->_dm_sgvalen) {
185 		alignment = boundary;
186 		do {
187 			boundary <<= 1;
188 		} while (boundary < map->_dm_sgvalen);
189 	} else
190 		alignment = NBPG;
191 #if 0
192 	printf("len %x -> %x, _dm_sgvalen %x _dm_boundary %x boundary %x -> ",
193 	    origlen, len, map->_dm_sgvalen, map->_dm_boundary, boundary);
194 #endif
195 
196 	error = extent_alloc(sgmap->aps_ex, map->_dm_sgvalen, alignment,
197 	    boundary, (flags & BUS_DMA_NOWAIT) ? EX_NOWAIT : EX_WAITOK,
198 	    &map->_dm_sgva);
199 #if 0
200 	printf("error %d _dm_sgva %x\n", error, map->_dm_sgva);
201 #endif
202 
203 	if (error == 0)
204 		map->_dm_flags |= DMAMAP_HAS_SGMAP;
205 	else
206 		map->_dm_flags &= ~DMAMAP_HAS_SGMAP;
207 
208 	return (error);
209 }
210 
211 void
212 alpha_sgmap_free(map, sgmap)
213 	bus_dmamap_t map;
214 	struct alpha_sgmap *sgmap;
215 {
216 
217 #ifdef DIAGNOSTIC
218 	if ((map->_dm_flags & DMAMAP_HAS_SGMAP) == 0)
219 		panic("alpha_sgmap_free: no sgva space to free");
220 #endif
221 
222 	if (extent_free(sgmap->aps_ex, map->_dm_sgva, map->_dm_sgvalen,
223 	    EX_NOWAIT))
224 		panic("alpha_sgmap_free");
225 
226 	map->_dm_flags &= ~DMAMAP_HAS_SGMAP;
227 }
228