1 | /* $NetBSD: drm_vma_manager.c,v 1.5 2016/11/19 17:19:59 maya 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 | __KERNEL_RCSID(0, "$NetBSD: drm_vma_manager.c,v 1.5 2016/11/19 17:19:59 maya Exp $" ); |
34 | |
35 | #include <sys/kmem.h> |
36 | #include <sys/rbtree.h> |
37 | #include <sys/vmem.h> |
38 | |
39 | #include <drm/drm_vma_manager.h> |
40 | |
41 | static int |
42 | drm_vma_node_compare(void *cookie __unused, const void *va, const void *vb) |
43 | { |
44 | const struct drm_vma_offset_node *const na = va; |
45 | const struct drm_vma_offset_node *const nb = vb; |
46 | |
47 | if (na->von_startpage < nb->von_startpage) |
48 | return -1; |
49 | if (na->von_startpage > nb->von_startpage) |
50 | return +1; |
51 | return 0; |
52 | } |
53 | |
54 | static int |
55 | drm_vma_node_compare_key(void *cookie __unused, const void *vn, const void *vk) |
56 | { |
57 | const struct drm_vma_offset_node *const n = vn; |
58 | const vmem_addr_t *const k = vk; |
59 | |
60 | if (n->von_startpage < *k) |
61 | return -1; |
62 | if (n->von_startpage > *k) |
63 | return +1; |
64 | return 0; |
65 | } |
66 | |
67 | static const rb_tree_ops_t drm_vma_node_rb_ops = { |
68 | .rbto_compare_nodes = &drm_vma_node_compare, |
69 | .rbto_compare_key = &drm_vma_node_compare_key, |
70 | .rbto_node_offset = offsetof(struct drm_vma_offset_node, von_rb_node), |
71 | .rbto_context = NULL, |
72 | }; |
73 | |
74 | static int |
75 | drm_vma_file_compare(void *cookie __unused, const void *va, const void *vb) |
76 | { |
77 | const struct drm_vma_offset_file *const fa = va; |
78 | const struct drm_vma_offset_file *const fb = vb; |
79 | |
80 | if (fa->vof_file < fb->vof_file) |
81 | return -1; |
82 | if (fa->vof_file > fb->vof_file) |
83 | return +1; |
84 | return 0; |
85 | } |
86 | |
87 | static int |
88 | drm_vma_file_compare_key(void *cookie __unused, const void *vf, const void *vk) |
89 | { |
90 | const struct drm_vma_offset_file *const f = vf; |
91 | const struct file *const k = vk; |
92 | |
93 | if (f->vof_file < k) |
94 | return -1; |
95 | if (f->vof_file > k) |
96 | return +1; |
97 | return 0; |
98 | } |
99 | |
100 | static const rb_tree_ops_t drm_vma_file_rb_ops = { |
101 | .rbto_compare_nodes = &drm_vma_file_compare, |
102 | .rbto_compare_key = &drm_vma_file_compare_key, |
103 | .rbto_node_offset = offsetof(struct drm_vma_offset_file, vof_rb_node), |
104 | .rbto_context = NULL, |
105 | }; |
106 | |
107 | void |
108 | drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, |
109 | unsigned long startpage, unsigned long npages) |
110 | { |
111 | |
112 | rw_init(&mgr->vom_lock); |
113 | rb_tree_init(&mgr->vom_nodes, &drm_vma_node_rb_ops); |
114 | mgr->vom_vmem = vmem_create("drm_vma" , startpage, npages, 1, |
115 | NULL, NULL, NULL, 0, VM_SLEEP, IPL_NONE); |
116 | } |
117 | |
118 | void |
119 | drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr) |
120 | { |
121 | |
122 | vmem_destroy(mgr->vom_vmem); |
123 | KASSERTMSG((RB_TREE_MIN(&mgr->vom_nodes) == NULL), |
124 | "drm vma offset manager %p not empty" , mgr); |
125 | #if 0 |
126 | rb_tree_destroy(&mgr->vom_nodes); |
127 | #endif |
128 | rw_destroy(&mgr->vom_lock); |
129 | } |
130 | |
131 | void |
132 | drm_vma_node_init(struct drm_vma_offset_node *node) |
133 | { |
134 | static const struct drm_vma_offset_node zero_node; |
135 | |
136 | *node = zero_node; |
137 | |
138 | rw_init(&node->von_lock); |
139 | node->von_startpage = 0; |
140 | node->von_npages = 0; |
141 | rb_tree_init(&node->von_files, &drm_vma_file_rb_ops); |
142 | } |
143 | |
144 | void |
145 | drm_vma_node_destroy(struct drm_vma_offset_node *node) |
146 | { |
147 | |
148 | KASSERTMSG((RB_TREE_MIN(&node->von_files) == NULL), |
149 | "drm vma node %p not empty" , node); |
150 | #if 0 |
151 | rb_tree_destroy(&node->von_files); |
152 | #endif |
153 | KASSERT(node->von_startpage == 0); |
154 | KASSERT(node->von_npages == 0); |
155 | rw_destroy(&node->von_lock); |
156 | } |
157 | |
158 | int |
159 | drm_vma_offset_add(struct drm_vma_offset_manager *mgr, |
160 | struct drm_vma_offset_node *node, unsigned long npages) |
161 | { |
162 | vmem_size_t startpage; |
163 | struct drm_vma_offset_node *collision __diagused; |
164 | int error; |
165 | |
166 | KASSERT(npages != 0); |
167 | |
168 | if (0 < node->von_npages) |
169 | return 0; |
170 | |
171 | error = vmem_alloc(mgr->vom_vmem, npages, VM_NOSLEEP|VM_BESTFIT, |
172 | &startpage); |
173 | if (error) { |
174 | if (error == ENOMEM) |
175 | error = ENOSPC; |
176 | /* XXX errno NetBSD->Linux */ |
177 | return -error; |
178 | } |
179 | |
180 | node->von_startpage = startpage; |
181 | node->von_npages = npages; |
182 | |
183 | rw_enter(&mgr->vom_lock, RW_WRITER); |
184 | collision = rb_tree_insert_node(&mgr->vom_nodes, node); |
185 | KASSERT(collision == node); |
186 | rw_exit(&mgr->vom_lock); |
187 | |
188 | return 0; |
189 | } |
190 | |
191 | void |
192 | drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, |
193 | struct drm_vma_offset_node *node) |
194 | { |
195 | |
196 | if (node->von_npages == 0) |
197 | return; |
198 | |
199 | rw_enter(&mgr->vom_lock, RW_WRITER); |
200 | rb_tree_remove_node(&mgr->vom_nodes, node); |
201 | rw_exit(&mgr->vom_lock); |
202 | |
203 | vmem_free(mgr->vom_vmem, node->von_startpage, node->von_npages); |
204 | |
205 | node->von_npages = 0; |
206 | node->von_startpage = 0; |
207 | } |
208 | |
209 | void |
210 | drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) |
211 | { |
212 | |
213 | rw_enter(&mgr->vom_lock, RW_READER); |
214 | } |
215 | |
216 | void |
217 | drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) |
218 | { |
219 | |
220 | rw_exit(&mgr->vom_lock); |
221 | } |
222 | |
223 | struct drm_vma_offset_node * |
224 | drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, |
225 | unsigned long startpage, unsigned long npages) |
226 | { |
227 | const vmem_addr_t key = startpage; |
228 | struct drm_vma_offset_node *node; |
229 | |
230 | KASSERT(rw_lock_held(&mgr->vom_lock)); |
231 | |
232 | node = rb_tree_find_node_leq(&mgr->vom_nodes, &key); |
233 | if (node == NULL) |
234 | return NULL; |
235 | KASSERT(node->von_startpage <= startpage); |
236 | if (npages < node->von_npages) |
237 | return NULL; |
238 | if (node->von_npages - npages < startpage - node->von_startpage) |
239 | return NULL; |
240 | |
241 | return node; |
242 | } |
243 | |
244 | struct drm_vma_offset_node * |
245 | drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, |
246 | unsigned long startpage, unsigned long npages) |
247 | { |
248 | const vmem_addr_t key = startpage; |
249 | struct drm_vma_offset_node *node; |
250 | |
251 | rw_enter(&mgr->vom_lock, RW_READER); |
252 | |
253 | node = rb_tree_find_node(&mgr->vom_nodes, &key); |
254 | if (node == NULL) |
255 | goto out; |
256 | KASSERT(node->von_startpage == startpage); |
257 | if (node->von_npages != npages) { |
258 | node = NULL; |
259 | goto out; |
260 | } |
261 | |
262 | out: rw_exit(&mgr->vom_lock); |
263 | return node; |
264 | } |
265 | |
266 | int |
267 | drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *file) |
268 | { |
269 | struct drm_vma_offset_file *new, *old; |
270 | |
271 | new = kmem_alloc(sizeof(*new), KM_NOSLEEP); |
272 | if (new == NULL) |
273 | return -ENOMEM; |
274 | new->vof_file = file; |
275 | |
276 | rw_enter(&node->von_lock, RW_WRITER); |
277 | old = rb_tree_insert_node(&node->von_files, new); |
278 | rw_exit(&node->von_lock); |
279 | |
280 | if (old != new) /* collision */ |
281 | kmem_free(new, sizeof(*new)); |
282 | |
283 | return 0; |
284 | } |
285 | |
286 | void |
287 | drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *file) |
288 | { |
289 | |
290 | rw_enter(&node->von_lock, RW_WRITER); |
291 | struct drm_vma_offset_file *const found = |
292 | rb_tree_find_node(&node->von_files, file); |
293 | if (found != NULL) |
294 | rb_tree_remove_node(&node->von_files, found); |
295 | rw_exit(&node->von_lock); |
296 | if (found != NULL) |
297 | kmem_free(found, sizeof(*found)); |
298 | } |
299 | |
300 | bool |
301 | drm_vma_node_is_allowed(struct drm_vma_offset_node *node, struct file *file) |
302 | { |
303 | |
304 | rw_enter(&node->von_lock, RW_READER); |
305 | const bool allowed = |
306 | (rb_tree_find_node(&node->von_files, file) != NULL); |
307 | rw_exit(&node->von_lock); |
308 | |
309 | return allowed; |
310 | } |
311 | |
312 | int |
313 | drm_vma_node_verify_access(struct drm_vma_offset_node *node, struct file *file) |
314 | { |
315 | |
316 | if (!drm_vma_node_is_allowed(node, file)) |
317 | return -EACCES; |
318 | |
319 | return 0; |
320 | } |
321 | |