1 #ifndef __DRM_VMA_MANAGER_H__ 2 #define __DRM_VMA_MANAGER_H__ 3 4 /* 5 * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com> 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the "Software"), 9 * to deal in the Software without restriction, including without limitation 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 * and/or sell copies of the Software, and to permit persons to whom the 12 * Software is furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 23 * OTHER DEALINGS IN THE SOFTWARE. 24 */ 25 26 #include <drm/drm_mm.h> 27 #include <linux/fs.h> 28 #include <linux/mm.h> 29 #include <linux/module.h> 30 #include <linux/rbtree.h> 31 #include <linux/spinlock.h> 32 #include <linux/types.h> 33 34 struct drm_vma_offset_file { 35 struct rb_node vm_rb; 36 struct file *vm_filp; 37 unsigned long vm_count; 38 }; 39 40 struct drm_vma_offset_node { 41 rwlock_t vm_lock; 42 struct drm_mm_node vm_node; 43 struct rb_node vm_rb; 44 struct rb_root vm_files; 45 }; 46 47 struct drm_vma_offset_manager { 48 rwlock_t vm_lock; 49 struct rb_root vm_addr_space_rb; 50 struct drm_mm vm_addr_space_mm; 51 }; 52 53 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 54 unsigned long page_offset, unsigned long size); 55 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 56 57 struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr, 58 unsigned long start, 59 unsigned long pages); 60 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 61 unsigned long start, 62 unsigned long pages); 63 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 64 struct drm_vma_offset_node *node, unsigned long pages); 65 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 66 struct drm_vma_offset_node *node); 67 68 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct file *filp); 69 void drm_vma_node_revoke(struct drm_vma_offset_node *node, struct file *filp); 70 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 71 struct file *filp); 72 73 /** 74 * drm_vma_offset_exact_lookup() - Look up node by exact address 75 * @mgr: Manager object 76 * @start: Start address (page-based, not byte-based) 77 * @pages: Size of object (page-based) 78 * 79 * Same as drm_vma_offset_lookup() but does not allow any offset into the node. 80 * It only returns the exact object with the given start address. 81 * 82 * RETURNS: 83 * Node at exact start address @start. 84 */ 85 static inline struct drm_vma_offset_node * 86 drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, 87 unsigned long start, 88 unsigned long pages) 89 { 90 struct drm_vma_offset_node *node; 91 92 node = drm_vma_offset_lookup(mgr, start, pages); 93 return (node && node->vm_node.start == start) ? node : NULL; 94 } 95 96 /** 97 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 98 * @mgr: Manager object 99 * 100 * Lock VMA manager for extended lookups. Only *_locked() VMA function calls 101 * are allowed while holding this lock. All other contexts are blocked from VMA 102 * until the lock is released via drm_vma_offset_unlock_lookup(). 103 * 104 * Use this if you need to take a reference to the objects returned by 105 * drm_vma_offset_lookup_locked() before releasing this lock again. 106 * 107 * This lock must not be used for anything else than extended lookups. You must 108 * not call any other VMA helpers while holding this lock. 109 * 110 * Note: You're in atomic-context while holding this lock! 111 * 112 * Example: 113 * drm_vma_offset_lock_lookup(mgr); 114 * node = drm_vma_offset_lookup_locked(mgr); 115 * if (node) 116 * kref_get_unless_zero(container_of(node, sth, entr)); 117 * drm_vma_offset_unlock_lookup(mgr); 118 */ 119 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 120 { 121 read_lock(&mgr->vm_lock); 122 } 123 124 /** 125 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 126 * @mgr: Manager object 127 * 128 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 129 */ 130 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 131 { 132 read_unlock(&mgr->vm_lock); 133 } 134 135 /** 136 * drm_vma_node_reset() - Initialize or reset node object 137 * @node: Node to initialize or reset 138 * 139 * Reset a node to its initial state. This must be called before using it with 140 * any VMA offset manager. 141 * 142 * This must not be called on an already allocated node, or you will leak 143 * memory. 144 */ 145 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 146 { 147 memset(node, 0, sizeof(*node)); 148 node->vm_files = RB_ROOT; 149 rwlock_init(&node->vm_lock); 150 } 151 152 /** 153 * drm_vma_node_start() - Return start address for page-based addressing 154 * @node: Node to inspect 155 * 156 * Return the start address of the given node. This can be used as offset into 157 * the linear VM space that is provided by the VMA offset manager. Note that 158 * this can only be used for page-based addressing. If you need a proper offset 159 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 160 * drm_vma_node_offset_addr() helper instead. 161 * 162 * RETURNS: 163 * Start address of @node for page-based addressing. 0 if the node does not 164 * have an offset allocated. 165 */ 166 static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) 167 { 168 return node->vm_node.start; 169 } 170 171 /** 172 * drm_vma_node_size() - Return size (page-based) 173 * @node: Node to inspect 174 * 175 * Return the size as number of pages for the given node. This is the same size 176 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 177 * node, this is 0. 178 * 179 * RETURNS: 180 * Size of @node as number of pages. 0 if the node does not have an offset 181 * allocated. 182 */ 183 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 184 { 185 return node->vm_node.size; 186 } 187 188 /** 189 * drm_vma_node_has_offset() - Check whether node is added to offset manager 190 * @node: Node to be checked 191 * 192 * RETURNS: 193 * true iff the node was previously allocated an offset and added to 194 * an vma offset manager. 195 */ 196 static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) 197 { 198 return drm_mm_node_allocated(&node->vm_node); 199 } 200 201 /** 202 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 203 * @node: Linked offset node 204 * 205 * Same as drm_vma_node_start() but returns the address as a valid offset that 206 * can be used for user-space mappings during mmap(). 207 * This must not be called on unlinked nodes. 208 * 209 * RETURNS: 210 * Offset of @node for byte-based addressing. 0 if the node does not have an 211 * object allocated. 212 */ 213 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 214 { 215 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 216 } 217 218 /** 219 * drm_vma_node_unmap() - Unmap offset node 220 * @node: Offset node 221 * @file_mapping: Address space to unmap @node from 222 * 223 * Unmap all userspace mappings for a given offset node. The mappings must be 224 * associated with the @file_mapping address-space. If no offset exists 225 * nothing is done. 226 * 227 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 228 * is not called on this node concurrently. 229 */ 230 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 231 struct address_space *file_mapping) 232 { 233 if (drm_vma_node_has_offset(node)) 234 unmap_mapping_range(file_mapping, 235 drm_vma_node_offset_addr(node), 236 drm_vma_node_size(node) << PAGE_SHIFT, 1); 237 } 238 239 /** 240 * drm_vma_node_verify_access() - Access verification helper for TTM 241 * @node: Offset node 242 * @filp: Open-file 243 * 244 * This checks whether @filp is granted access to @node. It is the same as 245 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 246 * verify_access() callbacks. 247 * 248 * RETURNS: 249 * 0 if access is granted, -EACCES otherwise. 250 */ 251 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 252 struct file *filp) 253 { 254 return drm_vma_node_is_allowed(node, filp) ? 0 : -EACCES; 255 } 256 257 #endif /* __DRM_VMA_MANAGER_H__ */ 258