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 41static int 42drm_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 54static int 55drm_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 67static 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 74static int 75drm_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 87static int 88drm_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 100static 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 107void 108drm_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 118void 119drm_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 131void 132drm_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 144void 145drm_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 158int 159drm_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 191void 192drm_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 209void 210drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 211{ 212 213 rw_enter(&mgr->vom_lock, RW_READER); 214} 215 216void 217drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 218{ 219 220 rw_exit(&mgr->vom_lock); 221} 222 223struct drm_vma_offset_node * 224drm_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 (node->von_npages < npages) 237 return NULL; 238 if (node->von_npages - npages < startpage - node->von_startpage) 239 return NULL; 240 241 return node; 242} 243 244struct drm_vma_offset_node * 245drm_vma_offset_exact_lookup_locked(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 KASSERT(rw_lock_held(&mgr->vom_lock)); 252 253 node = rb_tree_find_node(&mgr->vom_nodes, &key); 254 if (node == NULL) 255 return NULL; 256 KASSERT(node->von_startpage == startpage); 257 if (node->von_npages != npages) 258 return NULL; 259 260 return node; 261} 262 263struct drm_vma_offset_node * 264drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, 265 unsigned long startpage, unsigned long npages) 266{ 267 struct drm_vma_offset_node *node; 268 269 rw_enter(&mgr->vom_lock, RW_READER); 270 node = drm_vma_offset_exact_lookup_locked(mgr, startpage, npages); 271 rw_exit(&mgr->vom_lock); 272 273 return node; 274} 275 276int 277drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *file) 278{ 279 struct drm_vma_offset_file *new, *old; 280 281 new = kmem_alloc(sizeof(*new), KM_NOSLEEP); 282 if (new == NULL) 283 return -ENOMEM; 284 new->vof_file = file; 285 286 rw_enter(&node->von_lock, RW_WRITER); 287 old = rb_tree_insert_node(&node->von_files, new); 288 rw_exit(&node->von_lock); 289 290 if (old != new) /* collision */ 291 kmem_free(new, sizeof(*new)); 292 293 return 0; 294} 295 296void 297drm_vma_node_revoke(struct drm_vma_offset_node *node, struct drm_file *file) 298{ 299 300 rw_enter(&node->von_lock, RW_WRITER); 301 struct drm_vma_offset_file *const found = 302 rb_tree_find_node(&node->von_files, file); 303 if (found != NULL) 304 rb_tree_remove_node(&node->von_files, found); 305 rw_exit(&node->von_lock); 306 if (found != NULL) 307 kmem_free(found, sizeof(*found)); 308} 309 310bool 311drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 312 struct drm_file *file) 313{ 314 315 rw_enter(&node->von_lock, RW_READER); 316 const bool allowed = 317 (rb_tree_find_node(&node->von_files, file) != NULL); 318 rw_exit(&node->von_lock); 319 320 return allowed; 321} 322 323int 324drm_vma_node_verify_access(struct drm_vma_offset_node *node, 325 struct drm_file *file) 326{ 327 328 if (!drm_vma_node_is_allowed(node, file)) 329 return -EACCES; 330 331 return 0; 332} 333