1 /* $NetBSD: drm_vma_manager.c,v 1.8 2021/12/19 11:57:27 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 __KERNEL_RCSID(0, "$NetBSD: drm_vma_manager.c,v 1.8 2021/12/19 11:57:27 riastradh 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 drm_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 133 drm_vma_node_init(struct drm_vma_offset_node *node) 134 { 135 static const struct drm_vma_offset_node zero_node; 136 137 *node = zero_node; 138 139 rw_init(&node->von_lock); 140 node->von_startpage = 0; 141 node->von_npages = 0; 142 rb_tree_init(&node->von_files, &drm_vma_file_rb_ops); 143 } 144 145 void 146 drm_vma_node_destroy(struct drm_vma_offset_node *node) 147 { 148 149 KASSERTMSG((RB_TREE_MIN(&node->von_files) == NULL), 150 "drm vma node %p not empty", node); 151 #if 0 152 rb_tree_destroy(&node->von_files); 153 #endif 154 KASSERT(node->von_startpage == 0); 155 KASSERT(node->von_npages == 0); 156 rw_destroy(&node->von_lock); 157 } 158 159 int 160 drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 161 struct drm_vma_offset_node *node, unsigned long npages) 162 { 163 vmem_size_t startpage; 164 struct drm_vma_offset_node *collision __diagused; 165 int error; 166 167 KASSERT(npages != 0); 168 169 if (0 < node->von_npages) 170 return 0; 171 172 error = vmem_alloc(mgr->vom_vmem, npages, VM_NOSLEEP|VM_BESTFIT, 173 &startpage); 174 if (error) { 175 if (error == ENOMEM) 176 error = ENOSPC; 177 /* XXX errno NetBSD->Linux */ 178 return -error; 179 } 180 181 node->von_startpage = startpage; 182 node->von_npages = npages; 183 184 rw_enter(&mgr->vom_lock, RW_WRITER); 185 collision = rb_tree_insert_node(&mgr->vom_nodes, node); 186 KASSERT(collision == node); 187 rw_exit(&mgr->vom_lock); 188 189 return 0; 190 } 191 192 void 193 drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 194 struct drm_vma_offset_node *node) 195 { 196 197 if (node->von_npages == 0) 198 return; 199 200 rw_enter(&mgr->vom_lock, RW_WRITER); 201 rb_tree_remove_node(&mgr->vom_nodes, node); 202 rw_exit(&mgr->vom_lock); 203 204 vmem_free(mgr->vom_vmem, node->von_startpage, node->von_npages); 205 206 node->von_npages = 0; 207 node->von_startpage = 0; 208 } 209 210 void 212 drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 213 { 214 215 rw_enter(&mgr->vom_lock, RW_READER); 216 } 217 218 void 219 drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 220 { 221 222 rw_exit(&mgr->vom_lock); 223 } 224 225 struct drm_vma_offset_node * 226 drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 227 unsigned long startpage, unsigned long npages) 228 { 229 const vmem_addr_t key = startpage; 230 struct drm_vma_offset_node *node; 231 232 KASSERT(rw_lock_held(&mgr->vom_lock)); 233 234 node = rb_tree_find_node_leq(&mgr->vom_nodes, &key); 235 if (node == NULL) 236 return NULL; 237 KASSERT(node->von_startpage <= startpage); 238 if (node->von_npages < npages) 239 return NULL; 240 if (node->von_npages - npages < startpage - node->von_startpage) 241 return NULL; 242 243 return node; 244 } 245 246 struct drm_vma_offset_node * 247 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 248 unsigned long startpage, unsigned long npages) 249 { 250 const vmem_addr_t key = startpage; 251 struct drm_vma_offset_node *node; 252 253 KASSERT(rw_lock_held(&mgr->vom_lock)); 254 255 node = rb_tree_find_node(&mgr->vom_nodes, &key); 256 if (node == NULL) 257 return NULL; 258 KASSERT(node->von_startpage == startpage); 259 if (node->von_npages != npages) 260 return NULL; 261 262 return node; 263 } 264 265 struct drm_vma_offset_node * 266 drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, 267 unsigned long startpage, unsigned long npages) 268 { 269 struct drm_vma_offset_node *node; 270 271 rw_enter(&mgr->vom_lock, RW_READER); 272 node = drm_vma_offset_exact_lookup_locked(mgr, startpage, npages); 273 rw_exit(&mgr->vom_lock); 274 275 return node; 276 } 277 278 int 280 drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *file) 281 { 282 struct drm_vma_offset_file *new, *old; 283 284 new = kmem_alloc(sizeof(*new), KM_NOSLEEP); 285 if (new == NULL) 286 return -ENOMEM; 287 new->vof_file = file; 288 289 rw_enter(&node->von_lock, RW_WRITER); 290 old = rb_tree_insert_node(&node->von_files, new); 291 rw_exit(&node->von_lock); 292 293 if (old != new) /* collision */ 294 kmem_free(new, sizeof(*new)); 295 296 return 0; 297 } 298 299 void 300 drm_vma_node_revoke(struct drm_vma_offset_node *node, struct drm_file *file) 301 { 302 303 rw_enter(&node->von_lock, RW_WRITER); 304 struct drm_vma_offset_file *const found = 305 rb_tree_find_node(&node->von_files, file); 306 if (found != NULL) 307 rb_tree_remove_node(&node->von_files, found); 308 rw_exit(&node->von_lock); 309 if (found != NULL) 310 kmem_free(found, sizeof(*found)); 311 } 312 313 bool 314 drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 315 struct drm_file *file) 316 { 317 318 rw_enter(&node->von_lock, RW_READER); 319 const bool allowed = 320 (rb_tree_find_node(&node->von_files, file) != NULL); 321 rw_exit(&node->von_lock); 322 323 return allowed; 324 } 325 326 int 327 drm_vma_node_verify_access(struct drm_vma_offset_node *node, 328 struct drm_file *file) 329 { 330 331 if (!drm_vma_node_is_allowed(node, file)) 332 return -EACCES; 333 334 return 0; 335 } 336
Indexes created Sat Sep 20 22:09:52 GMT 2025