xref: /openbsd-src/sys/arch/alpha/dev/sgmap_common.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /* $OpenBSD: sgmap_common.c,v 1.2 2001/07/05 10:00:25 art Exp $ */
2 /* $NetBSD: sgmap_common.c,v 1.13 2000/06/29 09:02:57 mrg Exp $ */
3 
4 /*-
5  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
10  * NASA Ames Research Center.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the NetBSD
23  *	Foundation, Inc. and its contributors.
24  * 4. Neither the name of The NetBSD Foundation nor the names of its
25  *    contributors may be used to endorse or promote products derived
26  *    from this software without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38  * POSSIBILITY OF SUCH DAMAGE.
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/proc.h>
46 
47 #include <vm/vm.h>
48 #include <uvm/uvm_extern.h>
49 
50 #include <machine/bus.h>
51 
52 #include <alpha/dev/sgmapvar.h>
53 
54 /*
55  * Some systems will prefetch the next page during a memory -> device DMA.
56  * This can cause machine checks if there is not a spill page after the
57  * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE).
58  */
59 vaddr_t		alpha_sgmap_prefetch_spill_page_va;
60 bus_addr_t	alpha_sgmap_prefetch_spill_page_pa;
61 
62 void
63 alpha_sgmap_init(t, sgmap, name, wbase, sgvabase, sgvasize, ptesize, ptva,
64     minptalign)
65 	bus_dma_tag_t t;
66 	struct alpha_sgmap *sgmap;
67 	const char *name;
68 	bus_addr_t wbase;
69 	bus_addr_t sgvabase;
70 	bus_size_t sgvasize;
71 	size_t ptesize;
72 	void *ptva;
73 	bus_size_t minptalign;
74 {
75 	bus_dma_segment_t seg;
76 	size_t ptsize;
77 	int rseg;
78 
79 	if (sgvasize & PGOFSET) {
80 		printf("size botch for sgmap `%s'\n", name);
81 		goto die;
82 	}
83 
84 	sgmap->aps_wbase = wbase;
85 	sgmap->aps_sgvabase = sgvabase;
86 	sgmap->aps_sgvasize = sgvasize;
87 
88 	if (ptva != NULL) {
89 		/*
90 		 * We already have a page table; this may be a system
91 		 * where the page table resides in bridge-resident SRAM.
92 		 */
93 		sgmap->aps_pt = ptva;
94 		sgmap->aps_ptpa = 0;
95 	} else {
96 		/*
97 		 * Compute the page table size and allocate it.  At minimum,
98 		 * this must be aligned to the page table size.  However,
99 		 * some platforms have more strict alignment reqirements.
100 		 */
101 		ptsize = (sgvasize / NBPG) * ptesize;
102 		if (minptalign != 0) {
103 			if (minptalign < ptsize)
104 				minptalign = ptsize;
105 		} else
106 			minptalign = ptsize;
107 		if (bus_dmamem_alloc(t, ptsize, minptalign, 0, &seg, 1, &rseg,
108 		    BUS_DMA_NOWAIT)) {
109 			panic("unable to allocate page table for sgmap `%s'\n",
110 			    name);
111 			goto die;
112 		}
113 		sgmap->aps_ptpa = seg.ds_addr;
114 		sgmap->aps_pt = (caddr_t)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa);
115 	}
116 
117 	/*
118 	 * Create the extent map used to manage the virtual address
119 	 * space.
120 	 */
121 	sgmap->aps_ex = extent_create((char *)name, sgvabase, sgvasize - 1,
122 	    M_DEVBUF, NULL, 0, EX_NOWAIT|EX_NOCOALESCE);
123 	if (sgmap->aps_ex == NULL) {
124 		printf("unable to create extent map for sgmap `%s'\n",
125 		    name);
126 		goto die;
127 	}
128 
129 	/*
130 	 * Allocate a spill page if that hasn't already been done.
131 	 */
132 	if (alpha_sgmap_prefetch_spill_page_va == 0) {
133 		if (bus_dmamem_alloc(t, NBPG, 0, 0, &seg, 1, &rseg,
134 		    BUS_DMA_NOWAIT)) {
135 			printf("unable to allocate spill page for sgmap `%s'\n",
136 			    name);
137 			goto die;
138 		}
139 		alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr;
140 		alpha_sgmap_prefetch_spill_page_va =
141 		    ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa);
142 		bzero((caddr_t)alpha_sgmap_prefetch_spill_page_va, NBPG);
143 	}
144 
145 	return;
146  die:
147 	panic("alpha_sgmap_init");
148 }
149 
150 int
151 alpha_sgmap_alloc(map, origlen, sgmap, flags)
152 	bus_dmamap_t map;
153 	bus_size_t origlen;
154 	struct alpha_sgmap *sgmap;
155 	int flags;
156 {
157 	int error;
158 	bus_size_t len = origlen, boundary, alignment;
159 
160 #ifdef DIAGNOSTIC
161 	if (map->_dm_flags & DMAMAP_HAS_SGMAP)
162 		panic("alpha_sgmap_alloc: already have sgva space");
163 #endif
164 	/*
165 	 * Add a range for spill page.
166 	 */
167 	len += NBPG;
168 
169 	/*
170 	 * And add an additional amount in case of ALLOCNOW.
171 	 */
172 	if (flags & BUS_DMA_ALLOCNOW)
173 		len += NBPG;
174 
175 	map->_dm_sgvalen = round_page(len);
176 
177 	/*
178 	 * ARGH! If the addition of spill pages bumped us over our
179 	 * boundary, we have to 2x the boundary limit.
180 	 */
181 	boundary = map->_dm_boundary;
182 	if (boundary && boundary < map->_dm_sgvalen) {
183 		alignment = boundary;
184 		do {
185 			boundary <<= 1;
186 		} while (boundary < map->_dm_sgvalen);
187 	} else
188 		alignment = NBPG;
189 #if 0
190 	printf("len %x -> %x, _dm_sgvalen %x _dm_boundary %x boundary %x -> ",
191 	    origlen, len, map->_dm_sgvalen, map->_dm_boundary, boundary);
192 #endif
193 
194 	error = extent_alloc(sgmap->aps_ex, map->_dm_sgvalen, alignment, 0,
195 	    boundary, (flags & BUS_DMA_NOWAIT) ? EX_NOWAIT : EX_WAITOK,
196 	    &map->_dm_sgva);
197 #if 0
198 	printf("error %d _dm_sgva %x\n", error, map->_dm_sgva);
199 #endif
200 
201 	if (error == 0)
202 		map->_dm_flags |= DMAMAP_HAS_SGMAP;
203 	else
204 		map->_dm_flags &= ~DMAMAP_HAS_SGMAP;
205 
206 	return (error);
207 }
208 
209 void
210 alpha_sgmap_free(map, sgmap)
211 	bus_dmamap_t map;
212 	struct alpha_sgmap *sgmap;
213 {
214 
215 #ifdef DIAGNOSTIC
216 	if ((map->_dm_flags & DMAMAP_HAS_SGMAP) == 0)
217 		panic("alpha_sgmap_free: no sgva space to free");
218 #endif
219 
220 	if (extent_free(sgmap->aps_ex, map->_dm_sgva, map->_dm_sgvalen,
221 	    EX_NOWAIT))
222 		panic("alpha_sgmap_free");
223 
224 	map->_dm_flags &= ~DMAMAP_HAS_SGMAP;
225 }
226