| 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 | |