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 | |
52 | struct 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 | |
59 | static struct { |
60 | kmutex_t lock; |
61 | pserialize_t psz; |
62 | struct pv_track *list; |
63 | } pv_unmanaged __cacheline_aligned; |
64 | |
65 | void |
66 | pmap_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 | |
74 | void |
75 | pmap_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 | |
99 | void |
100 | pmap_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); |
129 | out: mutex_exit(&pv_unmanaged.lock); |
130 | |
131 | npages = size >> PAGE_SHIFT; |
132 | kmem_free(pvt, offsetof(struct pv_track, pvt_pages[npages])); |
133 | } |
134 | |
135 | struct pmap_page * |
136 | pmap_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 | |