1/* $NetBSD: pmap_pvt.c,v 1.3 2016/02/07 18:41:25 riastradh Exp $ */
2
3/*-
4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__RCSID("$NetBSD: pmap_pvt.c,v 1.3 2016/02/07 18:41:25 riastradh Exp $");
34
35#include <sys/kmem.h>
36#include <sys/pserialize.h>
37
38#include <uvm/uvm.h>
39#include <uvm/pmap/pmap_pvt.h>
40
41/*
42 * unmanaged pv-tracked ranges
43 *
44 * This is a linear list for now because the only user are the DRM
45 * graphics drivers, with a single tracked range per device, for the
46 * graphics aperture, so there are expected to be few of them.
47 *
48 * This is used only after the VM system is initialized well enough
49 * that we can use kmem_alloc.
50 */
51
52struct pv_track {
53 paddr_t pvt_start;
54 psize_t pvt_size;
55 struct pv_track *pvt_next;
56 struct pmap_page pvt_pages[];
57};
58
59static struct {
60 kmutex_t lock;
61 pserialize_t psz;
62 struct pv_track *list;
63} pv_unmanaged __cacheline_aligned;
64
65void
66pmap_pv_init(void)
67{
68
69 mutex_init(&pv_unmanaged.lock, MUTEX_DEFAULT, IPL_NONE);
70 pv_unmanaged.psz = pserialize_create();
71 pv_unmanaged.list = NULL;
72}
73
74void
75pmap_pv_track(paddr_t start, psize_t size)
76{
77 struct pv_track *pvt;
78 size_t npages;
79
80 KASSERT(start == trunc_page(start));
81 KASSERT(size == trunc_page(size));
82
83 /* We may sleep for allocation. */
84 ASSERT_SLEEPABLE();
85
86 npages = size >> PAGE_SHIFT;
87 pvt = kmem_zalloc(offsetof(struct pv_track, pvt_pages[npages]),
88 KM_SLEEP);
89 pvt->pvt_start = start;
90 pvt->pvt_size = size;
91
92 mutex_enter(&pv_unmanaged.lock);
93 pvt->pvt_next = pv_unmanaged.list;
94 membar_producer();
95 pv_unmanaged.list = pvt;
96 mutex_exit(&pv_unmanaged.lock);
97}
98
99void
100pmap_pv_untrack(paddr_t start, psize_t size)
101{
102 struct pv_track **pvtp, *pvt;
103 size_t npages;
104
105 KASSERT(start == trunc_page(start));
106 KASSERT(size == trunc_page(size));
107
108 /* We may sleep for pserialize_perform. */
109 ASSERT_SLEEPABLE();
110
111 mutex_enter(&pv_unmanaged.lock);
112 for (pvtp = &pv_unmanaged.list;
113 (pvt = *pvtp) != NULL;
114 pvtp = &pvt->pvt_next) {
115 if (pvt->pvt_start != start)
116 continue;
117 if (pvt->pvt_size != size)
118 panic("pmap_pv_untrack: pv-tracking at 0x%"PRIxPADDR
119 ": 0x%"PRIxPSIZE" bytes, not 0x%"PRIxPSIZE" bytes",
120 pvt->pvt_start, pvt->pvt_size, size);
121 *pvtp = pvt->pvt_next;
122 pserialize_perform(pv_unmanaged.psz);
123 pvt->pvt_next = NULL;
124 goto out;
125 }
126 panic("pmap_pv_untrack: pages not pv-tracked at 0x%"PRIxPADDR
127 " (0x%"PRIxPSIZE" bytes)",
128 start, size);
129out: mutex_exit(&pv_unmanaged.lock);
130
131 npages = size >> PAGE_SHIFT;
132 kmem_free(pvt, offsetof(struct pv_track, pvt_pages[npages]));
133}
134
135struct pmap_page *
136pmap_pv_tracked(paddr_t pa)
137{
138 struct pv_track *pvt;
139 size_t pgno;
140 int s;
141
142 KASSERT(pa == trunc_page(pa));
143
144 s = pserialize_read_enter();
145 for (pvt = pv_unmanaged.list; pvt != NULL; pvt = pvt->pvt_next) {
146 membar_datadep_consumer();
147 if ((pvt->pvt_start <= pa) &&
148 ((pa - pvt->pvt_start) < pvt->pvt_size))
149 break;
150 }
151 pserialize_read_exit(s);
152
153 if (pvt == NULL)
154 return NULL;
155 KASSERT(pvt->pvt_start <= pa);
156 KASSERT((pa - pvt->pvt_start) < pvt->pvt_size);
157 pgno = (pa - pvt->pvt_start) >> PAGE_SHIFT;
158 return &pvt->pvt_pages[pgno];
159}
160
161