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/mm.h> 28 #include <linux/rbtree.h> 29 #include <linux/spinlock.h> 30 #include <linux/types.h> 31 32 /* We make up offsets for buffer objects so we can recognize them at 33 * mmap time. pgoff in mmap is an unsigned long, so we need to make sure 34 * that the faked up offset will fit 35 */ 36 #if BITS_PER_LONG == 64 37 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) 38 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 256) 39 #else 40 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) 41 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) 42 #endif 43 44 struct drm_file; 45 46 struct drm_vma_offset_file { 47 struct rb_node vm_rb; 48 struct drm_file *vm_tag; 49 unsigned long vm_count; 50 }; 51 52 struct drm_vma_offset_node { 53 rwlock_t vm_lock; 54 struct drm_mm_node vm_node; 55 struct rb_root vm_files; 56 void *driver_private; 57 }; 58 59 struct drm_vma_offset_manager { 60 rwlock_t vm_lock; 61 struct drm_mm vm_addr_space_mm; 62 }; 63 64 void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, 65 unsigned long page_offset, unsigned long size); 66 void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); 67 68 struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, 69 unsigned long start, 70 unsigned long pages); 71 int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, 72 struct drm_vma_offset_node *node, unsigned long pages); 73 void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, 74 struct drm_vma_offset_node *node); 75 76 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag); 77 int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag); 78 void drm_vma_node_revoke(struct drm_vma_offset_node *node, 79 struct drm_file *tag); 80 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node, 81 struct drm_file *tag); 82 83 /** 84 * drm_vma_offset_exact_lookup_locked() - Look up node by exact address 85 * @mgr: Manager object 86 * @start: Start address (page-based, not byte-based) 87 * @pages: Size of object (page-based) 88 * 89 * Same as drm_vma_offset_lookup_locked() but does not allow any offset into the node. 90 * It only returns the exact object with the given start address. 91 * 92 * RETURNS: 93 * Node at exact start address @start. 94 */ 95 static inline struct drm_vma_offset_node * drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager * mgr,unsigned long start,unsigned long pages)96 drm_vma_offset_exact_lookup_locked(struct drm_vma_offset_manager *mgr, 97 unsigned long start, 98 unsigned long pages) 99 { 100 struct drm_vma_offset_node *node; 101 102 node = drm_vma_offset_lookup_locked(mgr, start, pages); 103 return (node && node->vm_node.start == start) ? node : NULL; 104 } 105 106 /** 107 * drm_vma_offset_lock_lookup() - Lock lookup for extended private use 108 * @mgr: Manager object 109 * 110 * Lock VMA manager for extended lookups. Only locked VMA function calls 111 * are allowed while holding this lock. All other contexts are blocked from VMA 112 * until the lock is released via drm_vma_offset_unlock_lookup(). 113 * 114 * Use this if you need to take a reference to the objects returned by 115 * drm_vma_offset_lookup_locked() before releasing this lock again. 116 * 117 * This lock must not be used for anything else than extended lookups. You must 118 * not call any other VMA helpers while holding this lock. 119 * 120 * Note: You're in atomic-context while holding this lock! 121 */ drm_vma_offset_lock_lookup(struct drm_vma_offset_manager * mgr)122 static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) 123 { 124 read_lock(&mgr->vm_lock); 125 } 126 127 /** 128 * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use 129 * @mgr: Manager object 130 * 131 * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. 132 */ drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager * mgr)133 static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) 134 { 135 read_unlock(&mgr->vm_lock); 136 } 137 138 /** 139 * drm_vma_node_reset() - Initialize or reset node object 140 * @node: Node to initialize or reset 141 * 142 * Reset a node to its initial state. This must be called before using it with 143 * any VMA offset manager. 144 * 145 * This must not be called on an already allocated node, or you will leak 146 * memory. 147 */ drm_vma_node_reset(struct drm_vma_offset_node * node)148 static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) 149 { 150 memset(node, 0, sizeof(*node)); 151 node->vm_files = RB_ROOT; 152 rwlock_init(&node->vm_lock); 153 } 154 155 /** 156 * drm_vma_node_start() - Return start address for page-based addressing 157 * @node: Node to inspect 158 * 159 * Return the start address of the given node. This can be used as offset into 160 * the linear VM space that is provided by the VMA offset manager. Note that 161 * this can only be used for page-based addressing. If you need a proper offset 162 * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the 163 * drm_vma_node_offset_addr() helper instead. 164 * 165 * RETURNS: 166 * Start address of @node for page-based addressing. 0 if the node does not 167 * have an offset allocated. 168 */ drm_vma_node_start(const struct drm_vma_offset_node * node)169 static inline unsigned long drm_vma_node_start(const struct drm_vma_offset_node *node) 170 { 171 return node->vm_node.start; 172 } 173 174 /** 175 * drm_vma_node_size() - Return size (page-based) 176 * @node: Node to inspect 177 * 178 * Return the size as number of pages for the given node. This is the same size 179 * that was passed to drm_vma_offset_add(). If no offset is allocated for the 180 * node, this is 0. 181 * 182 * RETURNS: 183 * Size of @node as number of pages. 0 if the node does not have an offset 184 * allocated. 185 */ drm_vma_node_size(struct drm_vma_offset_node * node)186 static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) 187 { 188 return node->vm_node.size; 189 } 190 191 /** 192 * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps 193 * @node: Linked offset node 194 * 195 * Same as drm_vma_node_start() but returns the address as a valid offset that 196 * can be used for user-space mappings during mmap(). 197 * This must not be called on unlinked nodes. 198 * 199 * RETURNS: 200 * Offset of @node for byte-based addressing. 0 if the node does not have an 201 * object allocated. 202 */ drm_vma_node_offset_addr(struct drm_vma_offset_node * node)203 static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) 204 { 205 return ((__u64)node->vm_node.start) << PAGE_SHIFT; 206 } 207 208 /** 209 * drm_vma_node_unmap() - Unmap offset node 210 * @node: Offset node 211 * @file_mapping: Address space to unmap @node from 212 * 213 * Unmap all userspace mappings for a given offset node. The mappings must be 214 * associated with the @file_mapping address-space. If no offset exists 215 * nothing is done. 216 * 217 * This call is unlocked. The caller must guarantee that drm_vma_offset_remove() 218 * is not called on this node concurrently. 219 */ drm_vma_node_unmap(struct drm_vma_offset_node * node,struct address_space * file_mapping)220 static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node, 221 struct address_space *file_mapping) 222 { 223 if (drm_mm_node_allocated(&node->vm_node)) 224 unmap_mapping_range(file_mapping, 225 drm_vma_node_offset_addr(node), 226 drm_vma_node_size(node) << PAGE_SHIFT, 1); 227 } 228 229 /** 230 * drm_vma_node_verify_access() - Access verification helper for TTM 231 * @node: Offset node 232 * @tag: Tag of file to check 233 * 234 * This checks whether @tag is granted access to @node. It is the same as 235 * drm_vma_node_is_allowed() but suitable as drop-in helper for TTM 236 * verify_access() callbacks. 237 * 238 * RETURNS: 239 * 0 if access is granted, -EACCES otherwise. 240 */ drm_vma_node_verify_access(struct drm_vma_offset_node * node,struct drm_file * tag)241 static inline int drm_vma_node_verify_access(struct drm_vma_offset_node *node, 242 struct drm_file *tag) 243 { 244 return drm_vma_node_is_allowed(node, tag) ? 0 : -EACCES; 245 } 246 247 #endif /* __DRM_VMA_MANAGER_H__ */ 248