xref: /linux/include/drm/drm_mm.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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2  *
3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
4  * All Rights Reserved.
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14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
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28 /*
29  * Authors:
30  * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
31  */
32 
33 #ifndef _DRM_MM_H_
34 #define _DRM_MM_H_
35 
36 /*
37  * Generic range manager structs
38  */
39 #include <linux/bug.h>
40 #include <linux/rbtree.h>
41 #include <linux/kernel.h>
42 #include <linux/list.h>
43 #include <linux/spinlock.h>
44 #ifdef CONFIG_DEBUG_FS
45 #include <linux/seq_file.h>
46 #endif
47 
48 enum drm_mm_search_flags {
49 	DRM_MM_SEARCH_DEFAULT =		0,
50 	DRM_MM_SEARCH_BEST =		1 << 0,
51 	DRM_MM_SEARCH_BELOW =		1 << 1,
52 };
53 
54 enum drm_mm_allocator_flags {
55 	DRM_MM_CREATE_DEFAULT =		0,
56 	DRM_MM_CREATE_TOP =		1 << 0,
57 };
58 
59 #define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
60 #define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP
61 
62 struct drm_mm_node {
63 	struct list_head node_list;
64 	struct list_head hole_stack;
65 	struct rb_node rb;
66 	unsigned hole_follows : 1;
67 	unsigned scanned_block : 1;
68 	unsigned scanned_prev_free : 1;
69 	unsigned scanned_next_free : 1;
70 	unsigned scanned_preceeds_hole : 1;
71 	unsigned allocated : 1;
72 	unsigned long color;
73 	u64 start;
74 	u64 size;
75 	u64 __subtree_last;
76 	struct drm_mm *mm;
77 };
78 
79 struct drm_mm {
80 	/* List of all memory nodes that immediately precede a free hole. */
81 	struct list_head hole_stack;
82 	/* head_node.node_list is the list of all memory nodes, ordered
83 	 * according to the (increasing) start address of the memory node. */
84 	struct drm_mm_node head_node;
85 	/* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
86 	struct rb_root interval_tree;
87 
88 	unsigned int scan_check_range : 1;
89 	unsigned scan_alignment;
90 	unsigned long scan_color;
91 	u64 scan_size;
92 	u64 scan_hit_start;
93 	u64 scan_hit_end;
94 	unsigned scanned_blocks;
95 	u64 scan_start;
96 	u64 scan_end;
97 	struct drm_mm_node *prev_scanned_node;
98 
99 	void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
100 			     u64 *start, u64 *end);
101 };
102 
103 /**
104  * drm_mm_node_allocated - checks whether a node is allocated
105  * @node: drm_mm_node to check
106  *
107  * Drivers should use this helpers for proper encapusulation of drm_mm
108  * internals.
109  *
110  * Returns:
111  * True if the @node is allocated.
112  */
113 static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
114 {
115 	return node->allocated;
116 }
117 
118 /**
119  * drm_mm_initialized - checks whether an allocator is initialized
120  * @mm: drm_mm to check
121  *
122  * Drivers should use this helpers for proper encapusulation of drm_mm
123  * internals.
124  *
125  * Returns:
126  * True if the @mm is initialized.
127  */
128 static inline bool drm_mm_initialized(struct drm_mm *mm)
129 {
130 	return mm->hole_stack.next;
131 }
132 
133 static inline u64 __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
134 {
135 	return hole_node->start + hole_node->size;
136 }
137 
138 /**
139  * drm_mm_hole_node_start - computes the start of the hole following @node
140  * @hole_node: drm_mm_node which implicitly tracks the following hole
141  *
142  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
143  * inspect holes themselves. Drivers must check first whether a hole indeed
144  * follows by looking at node->hole_follows.
145  *
146  * Returns:
147  * Start of the subsequent hole.
148  */
149 static inline u64 drm_mm_hole_node_start(struct drm_mm_node *hole_node)
150 {
151 	BUG_ON(!hole_node->hole_follows);
152 	return __drm_mm_hole_node_start(hole_node);
153 }
154 
155 static inline u64 __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
156 {
157 	return list_next_entry(hole_node, node_list)->start;
158 }
159 
160 /**
161  * drm_mm_hole_node_end - computes the end of the hole following @node
162  * @hole_node: drm_mm_node which implicitly tracks the following hole
163  *
164  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
165  * inspect holes themselves. Drivers must check first whether a hole indeed
166  * follows by looking at node->hole_follows.
167  *
168  * Returns:
169  * End of the subsequent hole.
170  */
171 static inline u64 drm_mm_hole_node_end(struct drm_mm_node *hole_node)
172 {
173 	return __drm_mm_hole_node_end(hole_node);
174 }
175 
176 /**
177  * drm_mm_for_each_node - iterator to walk over all allocated nodes
178  * @entry: drm_mm_node structure to assign to in each iteration step
179  * @mm: drm_mm allocator to walk
180  *
181  * This iterator walks over all nodes in the range allocator. It is implemented
182  * with list_for_each, so not save against removal of elements.
183  */
184 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
185 						&(mm)->head_node.node_list, \
186 						node_list)
187 
188 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
189 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
190 	     &entry->hole_stack != &(mm)->hole_stack ? \
191 	     hole_start = drm_mm_hole_node_start(entry), \
192 	     hole_end = drm_mm_hole_node_end(entry), \
193 	     1 : 0; \
194 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
195 
196 /**
197  * drm_mm_for_each_hole - iterator to walk over all holes
198  * @entry: drm_mm_node used internally to track progress
199  * @mm: drm_mm allocator to walk
200  * @hole_start: ulong variable to assign the hole start to on each iteration
201  * @hole_end: ulong variable to assign the hole end to on each iteration
202  *
203  * This iterator walks over all holes in the range allocator. It is implemented
204  * with list_for_each, so not save against removal of elements. @entry is used
205  * internally and will not reflect a real drm_mm_node for the very first hole.
206  * Hence users of this iterator may not access it.
207  *
208  * Implementation Note:
209  * We need to inline list_for_each_entry in order to be able to set hole_start
210  * and hole_end on each iteration while keeping the macro sane.
211  *
212  * The __drm_mm_for_each_hole version is similar, but with added support for
213  * going backwards.
214  */
215 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
216 	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)
217 
218 /*
219  * Basic range manager support (drm_mm.c)
220  */
221 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
222 
223 int drm_mm_insert_node_generic(struct drm_mm *mm,
224 			       struct drm_mm_node *node,
225 			       u64 size,
226 			       unsigned alignment,
227 			       unsigned long color,
228 			       enum drm_mm_search_flags sflags,
229 			       enum drm_mm_allocator_flags aflags);
230 /**
231  * drm_mm_insert_node - search for space and insert @node
232  * @mm: drm_mm to allocate from
233  * @node: preallocate node to insert
234  * @size: size of the allocation
235  * @alignment: alignment of the allocation
236  * @flags: flags to fine-tune the allocation
237  *
238  * This is a simplified version of drm_mm_insert_node_generic() with @color set
239  * to 0.
240  *
241  * The preallocated node must be cleared to 0.
242  *
243  * Returns:
244  * 0 on success, -ENOSPC if there's no suitable hole.
245  */
246 static inline int drm_mm_insert_node(struct drm_mm *mm,
247 				     struct drm_mm_node *node,
248 				     u64 size,
249 				     unsigned alignment,
250 				     enum drm_mm_search_flags flags)
251 {
252 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
253 					  DRM_MM_CREATE_DEFAULT);
254 }
255 
256 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
257 					struct drm_mm_node *node,
258 					u64 size,
259 					unsigned alignment,
260 					unsigned long color,
261 					u64 start,
262 					u64 end,
263 					enum drm_mm_search_flags sflags,
264 					enum drm_mm_allocator_flags aflags);
265 /**
266  * drm_mm_insert_node_in_range - ranged search for space and insert @node
267  * @mm: drm_mm to allocate from
268  * @node: preallocate node to insert
269  * @size: size of the allocation
270  * @alignment: alignment of the allocation
271  * @start: start of the allowed range for this node
272  * @end: end of the allowed range for this node
273  * @flags: flags to fine-tune the allocation
274  *
275  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
276  * @color set to 0.
277  *
278  * The preallocated node must be cleared to 0.
279  *
280  * Returns:
281  * 0 on success, -ENOSPC if there's no suitable hole.
282  */
283 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
284 					      struct drm_mm_node *node,
285 					      u64 size,
286 					      unsigned alignment,
287 					      u64 start,
288 					      u64 end,
289 					      enum drm_mm_search_flags flags)
290 {
291 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
292 						   0, start, end, flags,
293 						   DRM_MM_CREATE_DEFAULT);
294 }
295 
296 void drm_mm_remove_node(struct drm_mm_node *node);
297 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
298 void drm_mm_init(struct drm_mm *mm,
299 		 u64 start,
300 		 u64 size);
301 void drm_mm_takedown(struct drm_mm *mm);
302 bool drm_mm_clean(struct drm_mm *mm);
303 
304 struct drm_mm_node *
305 drm_mm_interval_first(struct drm_mm *mm, u64 start, u64 last);
306 
307 struct drm_mm_node *
308 drm_mm_interval_next(struct drm_mm_node *node, u64 start, u64 last);
309 
310 void drm_mm_init_scan(struct drm_mm *mm,
311 		      u64 size,
312 		      unsigned alignment,
313 		      unsigned long color);
314 void drm_mm_init_scan_with_range(struct drm_mm *mm,
315 				 u64 size,
316 				 unsigned alignment,
317 				 unsigned long color,
318 				 u64 start,
319 				 u64 end);
320 bool drm_mm_scan_add_block(struct drm_mm_node *node);
321 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
322 
323 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
324 #ifdef CONFIG_DEBUG_FS
325 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
326 #endif
327 
328 #endif
329