xref: /openbmc/linux/include/drm/drm_mm.h (revision 45b186f1)
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3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
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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 #ifdef CONFIG_DRM_DEBUG_MM
48 #include <linux/stackdepot.h>
49 #endif
50 
51 enum drm_mm_search_flags {
52 	DRM_MM_SEARCH_DEFAULT =		0,
53 	DRM_MM_SEARCH_BEST =		1 << 0,
54 	DRM_MM_SEARCH_BELOW =		1 << 1,
55 };
56 
57 enum drm_mm_allocator_flags {
58 	DRM_MM_CREATE_DEFAULT =		0,
59 	DRM_MM_CREATE_TOP =		1 << 0,
60 };
61 
62 #define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
63 #define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP
64 
65 struct drm_mm_node {
66 	struct list_head node_list;
67 	struct list_head hole_stack;
68 	struct rb_node rb;
69 	unsigned hole_follows : 1;
70 	unsigned scanned_block : 1;
71 	unsigned scanned_prev_free : 1;
72 	unsigned scanned_next_free : 1;
73 	unsigned scanned_preceeds_hole : 1;
74 	unsigned allocated : 1;
75 	unsigned long color;
76 	u64 start;
77 	u64 size;
78 	u64 __subtree_last;
79 	struct drm_mm *mm;
80 #ifdef CONFIG_DRM_DEBUG_MM
81 	depot_stack_handle_t stack;
82 #endif
83 };
84 
85 struct drm_mm {
86 	/* List of all memory nodes that immediately precede a free hole. */
87 	struct list_head hole_stack;
88 	/* head_node.node_list is the list of all memory nodes, ordered
89 	 * according to the (increasing) start address of the memory node. */
90 	struct drm_mm_node head_node;
91 	/* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
92 	struct rb_root interval_tree;
93 
94 	unsigned int scan_check_range : 1;
95 	unsigned scan_alignment;
96 	unsigned long scan_color;
97 	u64 scan_size;
98 	u64 scan_hit_start;
99 	u64 scan_hit_end;
100 	unsigned scanned_blocks;
101 	u64 scan_start;
102 	u64 scan_end;
103 	struct drm_mm_node *prev_scanned_node;
104 
105 	void (*color_adjust)(const struct drm_mm_node *node,
106 			     unsigned long color,
107 			     u64 *start, u64 *end);
108 };
109 
110 /**
111  * drm_mm_node_allocated - checks whether a node is allocated
112  * @node: drm_mm_node to check
113  *
114  * Drivers should use this helpers for proper encapusulation of drm_mm
115  * internals.
116  *
117  * Returns:
118  * True if the @node is allocated.
119  */
120 static inline bool drm_mm_node_allocated(const struct drm_mm_node *node)
121 {
122 	return node->allocated;
123 }
124 
125 /**
126  * drm_mm_initialized - checks whether an allocator is initialized
127  * @mm: drm_mm to check
128  *
129  * Drivers should use this helpers for proper encapusulation of drm_mm
130  * internals.
131  *
132  * Returns:
133  * True if the @mm is initialized.
134  */
135 static inline bool drm_mm_initialized(const struct drm_mm *mm)
136 {
137 	return mm->hole_stack.next;
138 }
139 
140 static inline u64 __drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
141 {
142 	return hole_node->start + hole_node->size;
143 }
144 
145 /**
146  * drm_mm_hole_node_start - computes the start of the hole following @node
147  * @hole_node: drm_mm_node which implicitly tracks the following hole
148  *
149  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
150  * inspect holes themselves. Drivers must check first whether a hole indeed
151  * follows by looking at node->hole_follows.
152  *
153  * Returns:
154  * Start of the subsequent hole.
155  */
156 static inline u64 drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
157 {
158 	BUG_ON(!hole_node->hole_follows);
159 	return __drm_mm_hole_node_start(hole_node);
160 }
161 
162 static inline u64 __drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
163 {
164 	return list_next_entry(hole_node, node_list)->start;
165 }
166 
167 /**
168  * drm_mm_hole_node_end - computes the end of the hole following @node
169  * @hole_node: drm_mm_node which implicitly tracks the following hole
170  *
171  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
172  * inspect holes themselves. Drivers must check first whether a hole indeed
173  * follows by looking at node->hole_follows.
174  *
175  * Returns:
176  * End of the subsequent hole.
177  */
178 static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
179 {
180 	return __drm_mm_hole_node_end(hole_node);
181 }
182 
183 #define __drm_mm_nodes(mm) (&(mm)->head_node.node_list)
184 
185 /**
186  * drm_mm_for_each_node - iterator to walk over all allocated nodes
187  * @entry: drm_mm_node structure to assign to in each iteration step
188  * @mm: drm_mm allocator to walk
189  *
190  * This iterator walks over all nodes in the range allocator. It is implemented
191  * with list_for_each, so not save against removal of elements.
192  */
193 #define drm_mm_for_each_node(entry, mm) \
194 	list_for_each_entry(entry, __drm_mm_nodes(mm), node_list)
195 
196 /**
197  * drm_mm_for_each_node_safe - iterator to walk over all allocated nodes
198  * @entry: drm_mm_node structure to assign to in each iteration step
199  * @next: drm_mm_node structure to store the next step
200  * @mm: drm_mm allocator to walk
201  *
202  * This iterator walks over all nodes in the range allocator. It is implemented
203  * with list_for_each_safe, so save against removal of elements.
204  */
205 #define drm_mm_for_each_node_safe(entry, next, mm) \
206 	list_for_each_entry_safe(entry, next, __drm_mm_nodes(mm), node_list)
207 
208 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
209 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
210 	     &entry->hole_stack != &(mm)->hole_stack ? \
211 	     hole_start = drm_mm_hole_node_start(entry), \
212 	     hole_end = drm_mm_hole_node_end(entry), \
213 	     1 : 0; \
214 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
215 
216 /**
217  * drm_mm_for_each_hole - iterator to walk over all holes
218  * @entry: drm_mm_node used internally to track progress
219  * @mm: drm_mm allocator to walk
220  * @hole_start: ulong variable to assign the hole start to on each iteration
221  * @hole_end: ulong variable to assign the hole end to on each iteration
222  *
223  * This iterator walks over all holes in the range allocator. It is implemented
224  * with list_for_each, so not save against removal of elements. @entry is used
225  * internally and will not reflect a real drm_mm_node for the very first hole.
226  * Hence users of this iterator may not access it.
227  *
228  * Implementation Note:
229  * We need to inline list_for_each_entry in order to be able to set hole_start
230  * and hole_end on each iteration while keeping the macro sane.
231  *
232  * The __drm_mm_for_each_hole version is similar, but with added support for
233  * going backwards.
234  */
235 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
236 	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)
237 
238 /*
239  * Basic range manager support (drm_mm.c)
240  */
241 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
242 
243 int drm_mm_insert_node_generic(struct drm_mm *mm,
244 			       struct drm_mm_node *node,
245 			       u64 size,
246 			       unsigned alignment,
247 			       unsigned long color,
248 			       enum drm_mm_search_flags sflags,
249 			       enum drm_mm_allocator_flags aflags);
250 /**
251  * drm_mm_insert_node - search for space and insert @node
252  * @mm: drm_mm to allocate from
253  * @node: preallocate node to insert
254  * @size: size of the allocation
255  * @alignment: alignment of the allocation
256  * @flags: flags to fine-tune the allocation
257  *
258  * This is a simplified version of drm_mm_insert_node_generic() with @color set
259  * to 0.
260  *
261  * The preallocated node must be cleared to 0.
262  *
263  * Returns:
264  * 0 on success, -ENOSPC if there's no suitable hole.
265  */
266 static inline int drm_mm_insert_node(struct drm_mm *mm,
267 				     struct drm_mm_node *node,
268 				     u64 size,
269 				     unsigned alignment,
270 				     enum drm_mm_search_flags flags)
271 {
272 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
273 					  DRM_MM_CREATE_DEFAULT);
274 }
275 
276 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
277 					struct drm_mm_node *node,
278 					u64 size,
279 					unsigned alignment,
280 					unsigned long color,
281 					u64 start,
282 					u64 end,
283 					enum drm_mm_search_flags sflags,
284 					enum drm_mm_allocator_flags aflags);
285 /**
286  * drm_mm_insert_node_in_range - ranged search for space and insert @node
287  * @mm: drm_mm to allocate from
288  * @node: preallocate node to insert
289  * @size: size of the allocation
290  * @alignment: alignment of the allocation
291  * @start: start of the allowed range for this node
292  * @end: end of the allowed range for this node
293  * @flags: flags to fine-tune the allocation
294  *
295  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
296  * @color set to 0.
297  *
298  * The preallocated node must be cleared to 0.
299  *
300  * Returns:
301  * 0 on success, -ENOSPC if there's no suitable hole.
302  */
303 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
304 					      struct drm_mm_node *node,
305 					      u64 size,
306 					      unsigned alignment,
307 					      u64 start,
308 					      u64 end,
309 					      enum drm_mm_search_flags flags)
310 {
311 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
312 						   0, start, end, flags,
313 						   DRM_MM_CREATE_DEFAULT);
314 }
315 
316 void drm_mm_remove_node(struct drm_mm_node *node);
317 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
318 void drm_mm_init(struct drm_mm *mm, u64 start, u64 size);
319 void drm_mm_takedown(struct drm_mm *mm);
320 bool drm_mm_clean(const struct drm_mm *mm);
321 
322 struct drm_mm_node *
323 __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
324 
325 /**
326  * drm_mm_for_each_node_in_range - iterator to walk over a range of
327  * allocated nodes
328  * @node__: drm_mm_node structure to assign to in each iteration step
329  * @mm__: drm_mm allocator to walk
330  * @start__: starting offset, the first node will overlap this
331  * @end__: ending offset, the last node will start before this (but may overlap)
332  *
333  * This iterator walks over all nodes in the range allocator that lie
334  * between @start and @end. It is implemented similarly to list_for_each(),
335  * but using the internal interval tree to accelerate the search for the
336  * starting node, and so not safe against removal of elements. It assumes
337  * that @end is within (or is the upper limit of) the drm_mm allocator.
338  */
339 #define drm_mm_for_each_node_in_range(node__, mm__, start__, end__)	\
340 	for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
341 	     node__ && node__->start < (end__);				\
342 	     node__ = list_next_entry(node__, node_list))
343 
344 void drm_mm_init_scan(struct drm_mm *mm,
345 		      u64 size,
346 		      unsigned alignment,
347 		      unsigned long color);
348 void drm_mm_init_scan_with_range(struct drm_mm *mm,
349 				 u64 size,
350 				 unsigned alignment,
351 				 unsigned long color,
352 				 u64 start,
353 				 u64 end);
354 bool drm_mm_scan_add_block(struct drm_mm_node *node);
355 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
356 
357 void drm_mm_debug_table(const struct drm_mm *mm, const char *prefix);
358 #ifdef CONFIG_DEBUG_FS
359 int drm_mm_dump_table(struct seq_file *m, const struct drm_mm *mm);
360 #endif
361 
362 #endif
363