1 /* $NetBSD: drm_vma_manager.h,v 1.3 2021/12/18 23:45:46 riastradh Exp $ */ 2 3 #ifndef __DRM_VMA_MANAGER_H__ 4 #define __DRM_VMA_MANAGER_H__ 5 6 /* 7 * Copyright (c) 2013 David Herrmann <dh.herrmann (at) gmail.com> 8 * 9 * Permission is hereby granted, free of charge, to any person obtaining a 10 * copy of this software and associated documentation files (the "Software"), 11 * to deal in the Software without restriction, including without limitation 12 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 13 * and/or sell copies of the Software, and to permit persons to whom the 14 * Software is furnished to do so, subject to the following conditions: 15 * 16 * The above copyright notice and this permission notice shall be included in 17 * all copies or substantial portions of the Software. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 22 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 23 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 25 * OTHER DEALINGS IN THE SOFTWARE. 26 */ 27 28 #include <drm/drm_mm.h> 29 #include <linux/mm.h> 30 #include <linux/rbtree.h> 31 #include <linux/spinlock.h> 32 #include <linux/types.h> 33 34 /* We make up offsets for buffer objects so we can recognize them at 35 * mmap time. pgoff in mmap is an unsigned long, so we need to make sure 36 * that the faked up offset will fit 37 */ 38 #if BITS_PER_LONG == 64 39 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) 40 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 256) 41 #else 42 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) 43 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) 44 #endif 45 46 struct drm_file; 47 48 struct drm_vma_offset_file { 49 struct rb_node vm_rb; 50 struct drm_file *vm_tag; 51 unsigned long vm_count; 52 }; 53 54 struct drm_vma_offset_node { 55 rwlock_t vm_lock; 56 struct drm_mm_node vm_node; 57 struct rb_root vm_files; 58 bool readonly:1; 59 }; 60 61 struct drm_vma_offset_manager { 62 rwlock_t vm_lock; 63 struct drm_mm vm_addr_space_mm; 64 }; 65 66 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 67 unsigned long page_offset, unsigned long size); 68 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 69 70 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 71 unsigned long start, 72 unsigned long pages); 73 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 74 struct drm_vma_offset_node *node, unsigned long pages); 75 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 76 struct drm_vma_offset_node *node); 77 78 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); 79 void drm_vma_node_revoke(struct drm_vma_offset_node *node, 80 struct drm_file *tag); 81 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 82 struct drm_file *tag); 83 84 /** 85 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address 86 * @mgr: Manager object 87 * @start: Start address (page-based, not byte-based) 88 * @pages: Size of object (page-based) 89 * 90 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. 91 * It only returns the exact object with the given start address. 92 * 93 * RETURNS: 94 * Node at exact start address @start. 95 */ 96 static inline struct drm_vma_offset_node * 97 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 98 unsigned long start, 99 unsigned long pages) 100 { 101 struct drm_vma_offset_node *node; 102 103 node = drm_vma_offset_lookup_locked(mgr, start, pages); 104 return (node && node->vm_node.start == start) ? node : NULL; 105 } 106 107 /** 108 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 109 * @mgr: Manager object 110 * 111 * Lock VMA manager for extended lookups. Only locked VMA function calls 112 * are allowed while holding this lock. All other contexts are blocked from VMA 113 * until the lock is released via drm_vma_offset_unlock_lookup(). 114 * 115 * Use this if you need to take a reference to the objects returned by 116 * drm_vma_offset_lookup_locked() before releasing this lock again. 117 * 118 * This lock must not be used for anything else than extended lookups. You must 119 * not call any other VMA helpers while holding this lock. 120 * 121 * Note: You're in atomic-context while holding this lock! 122 */ 123 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 124 { 125 read_lock(&mgr->vm_lock); 126 } 127 128 /** 129 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 130 * @mgr: Manager object 131 * 132 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 133 */ 134 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 135 { 136 read_unlock(&mgr->vm_lock); 137 } 138 139 /** 140 * drm_vma_node_reset() - Initialize or reset node object 141 * @node: Node to initialize or reset 142 * 143 * Reset a node to its initial state. This must be called before using it with 144 * any VMA offset manager. 145 * 146 * This must not be called on an already allocated node, or you will leak 147 * memory. 148 */ 149 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 150 { 151 memset(node, 0, sizeof(*node)); 152 node->vm_files = RB_ROOT; 153 rwlock_init(&node->vm_lock); 154 } 155 156 /** 157 * drm_vma_node_start() - Return start address for page-based addressing 158 * @node: Node to inspect 159 * 160 * Return the start address of the given node. This can be used as offset into 161 * the linear VM space that is provided by the VMA offset manager. Note that 162 * this can only be used for page-based addressing. If you need a proper offset 163 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 164 * drm_vma_node_offset_addr() helper instead. 165 * 166 * RETURNS: 167 * Start address of @node for page-based addressing. 0 if the node does not 168 * have an offset allocated. 169 */ 170 static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node) 171 { 172 return node->vm_node.start; 173 } 174 175 /** 176 * drm_vma_node_size() - Return size (page-based) 177 * @node: Node to inspect 178 * 179 * Return the size as number of pages for the given node. This is the same size 180 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 181 * node, this is 0. 182 * 183 * RETURNS: 184 * Size of @node as number of pages. 0 if the node does not have an offset 185 * allocated. 186 */ 187 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 188 { 189 return node->vm_node.size; 190 } 191 192 /** 193 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 194 * @node: Linked offset node 195 * 196 * Same as drm_vma_node_start() but returns the address as a valid offset that 197 * can be used for user-space mappings during mmap(). 198 * This must not be called on unlinked nodes. 199 * 200 * RETURNS: 201 * Offset of @node for byte-based addressing. 0 if the node does not have an 202 * object allocated. 203 */ 204 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 205 { 206 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 207 } 208 209 /** 210 * drm_vma_node_unmap() - Unmap offset node 211 * @node: Offset node 212 * @file_mapping: Address space to unmap @node from 213 * 214 * Unmap all userspace mappings for a given offset node. The mappings must be 215 * associated with the @file_mapping address-space. If no offset exists 216 * nothing is done. 217 * 218 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 219 * is not called on this node concurrently. 220 */ 221 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 222 struct address_space *file_mapping) 223 { 224 if (drm_mm_node_allocated(&node->vm_node)) 225 unmap_mapping_range(file_mapping, 226 drm_vma_node_offset_addr(node), 227 drm_vma_node_size(node) << PAGE_SHIFT, 1); 228 } 229 230 /** 231 * drm_vma_node_verify_access() - Access verification helper for TTM 232 * @node: Offset node 233 * @tag: Tag of file to check 234 * 235 * This checks whether @tag is granted access to @node. It is the same as 236 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 237 * verify_access() callbacks. 238 * 239 * RETURNS: 240 * 0 if access is granted, -EACCES otherwise. 241 */ 242 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 243 struct drm_file *tag) 244 { 245 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; 246 } 247 248 #endif /* __DRM_VMA_MANAGER_H__ */ 249
Indexes created Wed Sep 24 05:09:52 GMT 2025