xref: /openbmc/linux/include/drm/drm_mm.h (revision e18c0412)
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2  *
3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
4  * All Rights Reserved.
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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/kernel.h>
41 #include <linux/list.h>
42 #include <linux/spinlock.h>
43 #ifdef CONFIG_DEBUG_FS
44 #include <linux/seq_file.h>
45 #endif
46 
47 enum drm_mm_search_flags {
48 	DRM_MM_SEARCH_DEFAULT =		0,
49 	DRM_MM_SEARCH_BEST =		1 << 0,
50 };
51 
52 struct drm_mm_node {
53 	struct list_head node_list;
54 	struct list_head hole_stack;
55 	unsigned hole_follows : 1;
56 	unsigned scanned_block : 1;
57 	unsigned scanned_prev_free : 1;
58 	unsigned scanned_next_free : 1;
59 	unsigned scanned_preceeds_hole : 1;
60 	unsigned allocated : 1;
61 	unsigned long color;
62 	unsigned long start;
63 	unsigned long size;
64 	struct drm_mm *mm;
65 };
66 
67 struct drm_mm {
68 	/* List of all memory nodes that immediately precede a free hole. */
69 	struct list_head hole_stack;
70 	/* head_node.node_list is the list of all memory nodes, ordered
71 	 * according to the (increasing) start address of the memory node. */
72 	struct drm_mm_node head_node;
73 	unsigned int scan_check_range : 1;
74 	unsigned scan_alignment;
75 	unsigned long scan_color;
76 	unsigned long scan_size;
77 	unsigned long scan_hit_start;
78 	unsigned long scan_hit_end;
79 	unsigned scanned_blocks;
80 	unsigned long scan_start;
81 	unsigned long scan_end;
82 	struct drm_mm_node *prev_scanned_node;
83 
84 	void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
85 			     unsigned long *start, unsigned long *end);
86 };
87 
88 /**
89  * drm_mm_node_allocated - checks whether a node is allocated
90  * @node: drm_mm_node to check
91  *
92  * Drivers should use this helpers for proper encapusulation of drm_mm
93  * internals.
94  *
95  * Returns:
96  * True if the @node is allocated.
97  */
98 static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
99 {
100 	return node->allocated;
101 }
102 
103 /**
104  * drm_mm_initialized - checks whether an allocator is initialized
105  * @mm: drm_mm to check
106  *
107  * Drivers should use this helpers for proper encapusulation of drm_mm
108  * internals.
109  *
110  * Returns:
111  * True if the @mm is initialized.
112  */
113 static inline bool drm_mm_initialized(struct drm_mm *mm)
114 {
115 	return mm->hole_stack.next;
116 }
117 
118 static inline unsigned long __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
119 {
120 	return hole_node->start + hole_node->size;
121 }
122 
123 /**
124  * drm_mm_hole_node_start - computes the start of the hole following @node
125  * @hole_node: drm_mm_node which implicitly tracks the following hole
126  *
127  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
128  * inspect holes themselves. Drivers must check first whether a hole indeed
129  * follows by looking at node->hole_follows.
130  *
131  * Returns:
132  * Start of the subsequent hole.
133  */
134 static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
135 {
136 	BUG_ON(!hole_node->hole_follows);
137 	return __drm_mm_hole_node_start(hole_node);
138 }
139 
140 static inline unsigned long __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
141 {
142 	return list_entry(hole_node->node_list.next,
143 			  struct drm_mm_node, node_list)->start;
144 }
145 
146 /**
147  * drm_mm_hole_node_end - computes the end of the hole following @node
148  * @hole_node: drm_mm_node which implicitly tracks the following hole
149  *
150  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
151  * inspect holes themselves. Drivers must check first whether a hole indeed
152  * follows by looking at node->hole_follows.
153  *
154  * Returns:
155  * End of the subsequent hole.
156  */
157 static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
158 {
159 	return __drm_mm_hole_node_end(hole_node);
160 }
161 
162 /**
163  * drm_mm_for_each_node - iterator to walk over all allocated nodes
164  * @entry: drm_mm_node structure to assign to in each iteration step
165  * @mm: drm_mm allocator to walk
166  *
167  * This iterator walks over all nodes in the range allocator. It is implemented
168  * with list_for_each, so not save against removal of elements.
169  */
170 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
171 						&(mm)->head_node.node_list, \
172 						node_list)
173 
174 /**
175  * drm_mm_for_each_hole - iterator to walk over all holes
176  * @entry: drm_mm_node used internally to track progress
177  * @mm: drm_mm allocator to walk
178  * @hole_start: ulong variable to assign the hole start to on each iteration
179  * @hole_end: ulong variable to assign the hole end to on each iteration
180  *
181  * This iterator walks over all holes in the range allocator. It is implemented
182  * with list_for_each, so not save against removal of elements. @entry is used
183  * internally and will not reflect a real drm_mm_node for the very first hole.
184  * Hence users of this iterator may not access it.
185  *
186  * Implementation Note:
187  * We need to inline list_for_each_entry in order to be able to set hole_start
188  * and hole_end on each iteration while keeping the macro sane.
189  */
190 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
191 	for (entry = list_entry((mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
192 	     &entry->hole_stack != &(mm)->hole_stack ? \
193 	     hole_start = drm_mm_hole_node_start(entry), \
194 	     hole_end = drm_mm_hole_node_end(entry), \
195 	     1 : 0; \
196 	     entry = list_entry(entry->hole_stack.next, struct drm_mm_node, hole_stack))
197 
198 /*
199  * Basic range manager support (drm_mm.c)
200  */
201 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
202 
203 int drm_mm_insert_node_generic(struct drm_mm *mm,
204 			       struct drm_mm_node *node,
205 			       unsigned long size,
206 			       unsigned alignment,
207 			       unsigned long color,
208 			       enum drm_mm_search_flags flags);
209 /**
210  * drm_mm_insert_node - search for space and insert @node
211  * @mm: drm_mm to allocate from
212  * @node: preallocate node to insert
213  * @size: size of the allocation
214  * @alignment: alignment of the allocation
215  * @flags: flags to fine-tune the allocation
216  *
217  * This is a simplified version of drm_mm_insert_node_generic() with @color set
218  * to 0.
219  *
220  * The preallocated node must be cleared to 0.
221  *
222  * Returns:
223  * 0 on success, -ENOSPC if there's no suitable hole.
224  */
225 static inline int drm_mm_insert_node(struct drm_mm *mm,
226 				     struct drm_mm_node *node,
227 				     unsigned long size,
228 				     unsigned alignment,
229 				     enum drm_mm_search_flags flags)
230 {
231 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags);
232 }
233 
234 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
235 					struct drm_mm_node *node,
236 					unsigned long size,
237 					unsigned alignment,
238 					unsigned long color,
239 					unsigned long start,
240 					unsigned long end,
241 					enum drm_mm_search_flags flags);
242 /**
243  * drm_mm_insert_node_in_range - ranged search for space and insert @node
244  * @mm: drm_mm to allocate from
245  * @node: preallocate node to insert
246  * @size: size of the allocation
247  * @alignment: alignment of the allocation
248  * @start: start of the allowed range for this node
249  * @end: end of the allowed range for this node
250  * @flags: flags to fine-tune the allocation
251  *
252  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
253  * @color set to 0.
254  *
255  * The preallocated node must be cleared to 0.
256  *
257  * Returns:
258  * 0 on success, -ENOSPC if there's no suitable hole.
259  */
260 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
261 					      struct drm_mm_node *node,
262 					      unsigned long size,
263 					      unsigned alignment,
264 					      unsigned long start,
265 					      unsigned long end,
266 					      enum drm_mm_search_flags flags)
267 {
268 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
269 						   0, start, end, flags);
270 }
271 
272 void drm_mm_remove_node(struct drm_mm_node *node);
273 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
274 void drm_mm_init(struct drm_mm *mm,
275 		 unsigned long start,
276 		 unsigned long size);
277 void drm_mm_takedown(struct drm_mm *mm);
278 bool drm_mm_clean(struct drm_mm *mm);
279 
280 void drm_mm_init_scan(struct drm_mm *mm,
281 		      unsigned long size,
282 		      unsigned alignment,
283 		      unsigned long color);
284 void drm_mm_init_scan_with_range(struct drm_mm *mm,
285 				 unsigned long size,
286 				 unsigned alignment,
287 				 unsigned long color,
288 				 unsigned long start,
289 				 unsigned long end);
290 bool drm_mm_scan_add_block(struct drm_mm_node *node);
291 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
292 
293 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
294 #ifdef CONFIG_DEBUG_FS
295 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
296 #endif
297 
298 #endif
299