drm_vma_manager.h 8.1 KB

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