xref: /netbsd-src/sys/arch/alpha/common/sgmap_common.c (revision 26bc586398db6f1e94fe6ee2140a168d49b06ea2)
1 /* $NetBSD: sgmap_common.c,v 1.29 2021/07/18 05:12:27 thorpej 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  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
34 
35 __KERNEL_RCSID(0, "$NetBSD: sgmap_common.c,v 1.29 2021/07/18 05:12:27 thorpej Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/proc.h>
41 
42 #include <uvm/uvm_extern.h>
43 
44 #define	_ALPHA_BUS_DMA_PRIVATE
45 #include <sys/bus.h>
46 
47 #include <alpha/common/sgmapvar.h>
48 
49 /*
50  * Some systems will prefetch the next page during a memory -> device DMA.
51  * This can cause machine checks if there is not a spill page after the
52  * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE).
53  */
54 vaddr_t		alpha_sgmap_prefetch_spill_page_va;
55 bus_addr_t	alpha_sgmap_prefetch_spill_page_pa;
56 
57 void
alpha_sgmap_init(bus_dma_tag_t t,struct alpha_sgmap * sgmap,const char * name,bus_addr_t wbase,bus_addr_t sgvabase,bus_size_t sgvasize,size_t ptesize,void * ptva,bus_size_t minptalign)58 alpha_sgmap_init(bus_dma_tag_t t, struct alpha_sgmap *sgmap, const char *name,
59     bus_addr_t wbase, bus_addr_t sgvabase, bus_size_t sgvasize, size_t ptesize,
60     void *ptva, bus_size_t minptalign)
61 {
62 	bus_dma_segment_t seg;
63 	size_t ptsize;
64 	int rseg;
65 
66 	if (sgvasize & PGOFSET) {
67 		printf("size botch for sgmap `%s'\n", name);
68 		goto die;
69 	}
70 
71 	/*
72 	 * If we don't yet have a minimum SGVA alignment, default
73 	 * to the system page size.
74 	 */
75 	if (t->_sgmap_minalign < PAGE_SIZE) {
76 		t->_sgmap_minalign = PAGE_SIZE;
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 / PAGE_SIZE) * 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 = (void *)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa);
110 	}
111 
112 	/*
113 	 * Create the arena used to manage the virtual address
114 	 * space.
115 	 *
116 	 * XXX Consider using a quantum cache up to MAXPHYS+PAGE_SIZE
117 	 * XXX (extra page to handle the spill page).  For now, we don't,
118 	 * XXX because we are using constrained allocations everywhere.
119 	 */
120 	sgmap->aps_arena = vmem_create(name, sgvabase, sgvasize,
121 				       PAGE_SIZE,	/* quantum */
122 				       NULL,		/* importfn */
123 				       NULL,		/* releasefn */
124 				       NULL,		/* source */
125 				       0,		/* qcache_max */
126 				       VM_SLEEP,
127 				       IPL_VM);
128 	KASSERT(sgmap->aps_arena != NULL);
129 
130 	/*
131 	 * Allocate a spill page if that hasn't already been done.
132 	 */
133 	if (alpha_sgmap_prefetch_spill_page_va == 0) {
134 		if (bus_dmamem_alloc(t, PAGE_SIZE, 0, 0, &seg, 1, &rseg,
135 		    BUS_DMA_NOWAIT)) {
136 			printf("unable to allocate spill page for sgmap `%s'\n",
137 			    name);
138 			goto die;
139 		}
140 		alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr;
141 		alpha_sgmap_prefetch_spill_page_va =
142 		    ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa);
143 		memset((void *)alpha_sgmap_prefetch_spill_page_va, 0,
144 		    PAGE_SIZE);
145 	}
146 
147 	return;
148  die:
149 	panic("alpha_sgmap_init");
150 }
151 
152 int
alpha_sgmap_dmamap_create(bus_dma_tag_t t,bus_size_t size,int nsegments,bus_size_t maxsegsz,bus_size_t boundary,int flags,bus_dmamap_t * dmamp)153 alpha_sgmap_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments,
154     bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
155 {
156 	bus_dmamap_t map;
157 	int error;
158 
159 	error = _bus_dmamap_create(t, size, nsegments, maxsegsz,
160 	    boundary, flags, &map);
161 	if (error)
162 		return (error);
163 
164 	/* XXX BUS_DMA_ALLOCNOW */
165 
166 	if (error == 0)
167 		*dmamp = map;
168 	else
169 		alpha_sgmap_dmamap_destroy(t, map);
170 
171 	return (error);
172 }
173 
174 void
alpha_sgmap_dmamap_destroy(bus_dma_tag_t t,bus_dmamap_t map)175 alpha_sgmap_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
176 {
177 
178 	KASSERT(map->dm_mapsize == 0);
179 
180 	_bus_dmamap_destroy(t, map);
181 }
182