xref: /openbmc/linux/include/drm/drm_mm.h (revision 32981ea5)
1 /**************************************************************************
2  *
3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
4  * All Rights Reserved.
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11  * permit persons to whom the Software is furnished to do so, subject to
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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/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 	DRM_MM_SEARCH_BELOW =		1 << 1,
51 };
52 
53 enum drm_mm_allocator_flags {
54 	DRM_MM_CREATE_DEFAULT =		0,
55 	DRM_MM_CREATE_TOP =		1 << 0,
56 };
57 
58 #define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
59 #define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP
60 
61 struct drm_mm_node {
62 	struct list_head node_list;
63 	struct list_head hole_stack;
64 	unsigned hole_follows : 1;
65 	unsigned scanned_block : 1;
66 	unsigned scanned_prev_free : 1;
67 	unsigned scanned_next_free : 1;
68 	unsigned scanned_preceeds_hole : 1;
69 	unsigned allocated : 1;
70 	unsigned long color;
71 	u64 start;
72 	u64 size;
73 	struct drm_mm *mm;
74 };
75 
76 struct drm_mm {
77 	/* List of all memory nodes that immediately precede a free hole. */
78 	struct list_head hole_stack;
79 	/* head_node.node_list is the list of all memory nodes, ordered
80 	 * according to the (increasing) start address of the memory node. */
81 	struct drm_mm_node head_node;
82 	unsigned int scan_check_range : 1;
83 	unsigned scan_alignment;
84 	unsigned long scan_color;
85 	u64 scan_size;
86 	u64 scan_hit_start;
87 	u64 scan_hit_end;
88 	unsigned scanned_blocks;
89 	u64 scan_start;
90 	u64 scan_end;
91 	struct drm_mm_node *prev_scanned_node;
92 
93 	void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
94 			     u64 *start, u64 *end);
95 };
96 
97 /**
98  * drm_mm_node_allocated - checks whether a node is allocated
99  * @node: drm_mm_node to check
100  *
101  * Drivers should use this helpers for proper encapusulation of drm_mm
102  * internals.
103  *
104  * Returns:
105  * True if the @node is allocated.
106  */
107 static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
108 {
109 	return node->allocated;
110 }
111 
112 /**
113  * drm_mm_initialized - checks whether an allocator is initialized
114  * @mm: drm_mm to check
115  *
116  * Drivers should use this helpers for proper encapusulation of drm_mm
117  * internals.
118  *
119  * Returns:
120  * True if the @mm is initialized.
121  */
122 static inline bool drm_mm_initialized(struct drm_mm *mm)
123 {
124 	return mm->hole_stack.next;
125 }
126 
127 static inline u64 __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
128 {
129 	return hole_node->start + hole_node->size;
130 }
131 
132 /**
133  * drm_mm_hole_node_start - computes the start of the hole following @node
134  * @hole_node: drm_mm_node which implicitly tracks the following hole
135  *
136  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
137  * inspect holes themselves. Drivers must check first whether a hole indeed
138  * follows by looking at node->hole_follows.
139  *
140  * Returns:
141  * Start of the subsequent hole.
142  */
143 static inline u64 drm_mm_hole_node_start(struct drm_mm_node *hole_node)
144 {
145 	BUG_ON(!hole_node->hole_follows);
146 	return __drm_mm_hole_node_start(hole_node);
147 }
148 
149 static inline u64 __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
150 {
151 	return list_next_entry(hole_node, node_list)->start;
152 }
153 
154 /**
155  * drm_mm_hole_node_end - computes the end of the hole following @node
156  * @hole_node: drm_mm_node which implicitly tracks the following hole
157  *
158  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
159  * inspect holes themselves. Drivers must check first whether a hole indeed
160  * follows by looking at node->hole_follows.
161  *
162  * Returns:
163  * End of the subsequent hole.
164  */
165 static inline u64 drm_mm_hole_node_end(struct drm_mm_node *hole_node)
166 {
167 	return __drm_mm_hole_node_end(hole_node);
168 }
169 
170 /**
171  * drm_mm_for_each_node - iterator to walk over all allocated nodes
172  * @entry: drm_mm_node structure to assign to in each iteration step
173  * @mm: drm_mm allocator to walk
174  *
175  * This iterator walks over all nodes in the range allocator. It is implemented
176  * with list_for_each, so not save against removal of elements.
177  */
178 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
179 						&(mm)->head_node.node_list, \
180 						node_list)
181 
182 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
183 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
184 	     &entry->hole_stack != &(mm)->hole_stack ? \
185 	     hole_start = drm_mm_hole_node_start(entry), \
186 	     hole_end = drm_mm_hole_node_end(entry), \
187 	     1 : 0; \
188 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
189 
190 /**
191  * drm_mm_for_each_hole - iterator to walk over all holes
192  * @entry: drm_mm_node used internally to track progress
193  * @mm: drm_mm allocator to walk
194  * @hole_start: ulong variable to assign the hole start to on each iteration
195  * @hole_end: ulong variable to assign the hole end to on each iteration
196  *
197  * This iterator walks over all holes in the range allocator. It is implemented
198  * with list_for_each, so not save against removal of elements. @entry is used
199  * internally and will not reflect a real drm_mm_node for the very first hole.
200  * Hence users of this iterator may not access it.
201  *
202  * Implementation Note:
203  * We need to inline list_for_each_entry in order to be able to set hole_start
204  * and hole_end on each iteration while keeping the macro sane.
205  *
206  * The __drm_mm_for_each_hole version is similar, but with added support for
207  * going backwards.
208  */
209 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
210 	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)
211 
212 /*
213  * Basic range manager support (drm_mm.c)
214  */
215 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
216 
217 int drm_mm_insert_node_generic(struct drm_mm *mm,
218 			       struct drm_mm_node *node,
219 			       u64 size,
220 			       unsigned alignment,
221 			       unsigned long color,
222 			       enum drm_mm_search_flags sflags,
223 			       enum drm_mm_allocator_flags aflags);
224 /**
225  * drm_mm_insert_node - search for space and insert @node
226  * @mm: drm_mm to allocate from
227  * @node: preallocate node to insert
228  * @size: size of the allocation
229  * @alignment: alignment of the allocation
230  * @flags: flags to fine-tune the allocation
231  *
232  * This is a simplified version of drm_mm_insert_node_generic() with @color set
233  * to 0.
234  *
235  * The preallocated node must be cleared to 0.
236  *
237  * Returns:
238  * 0 on success, -ENOSPC if there's no suitable hole.
239  */
240 static inline int drm_mm_insert_node(struct drm_mm *mm,
241 				     struct drm_mm_node *node,
242 				     u64 size,
243 				     unsigned alignment,
244 				     enum drm_mm_search_flags flags)
245 {
246 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
247 					  DRM_MM_CREATE_DEFAULT);
248 }
249 
250 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
251 					struct drm_mm_node *node,
252 					u64 size,
253 					unsigned alignment,
254 					unsigned long color,
255 					u64 start,
256 					u64 end,
257 					enum drm_mm_search_flags sflags,
258 					enum drm_mm_allocator_flags aflags);
259 /**
260  * drm_mm_insert_node_in_range - ranged search for space and insert @node
261  * @mm: drm_mm to allocate from
262  * @node: preallocate node to insert
263  * @size: size of the allocation
264  * @alignment: alignment of the allocation
265  * @start: start of the allowed range for this node
266  * @end: end of the allowed range for this node
267  * @flags: flags to fine-tune the allocation
268  *
269  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
270  * @color set to 0.
271  *
272  * The preallocated node must be cleared to 0.
273  *
274  * Returns:
275  * 0 on success, -ENOSPC if there's no suitable hole.
276  */
277 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
278 					      struct drm_mm_node *node,
279 					      u64 size,
280 					      unsigned alignment,
281 					      u64 start,
282 					      u64 end,
283 					      enum drm_mm_search_flags flags)
284 {
285 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
286 						   0, start, end, flags,
287 						   DRM_MM_CREATE_DEFAULT);
288 }
289 
290 void drm_mm_remove_node(struct drm_mm_node *node);
291 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
292 void drm_mm_init(struct drm_mm *mm,
293 		 u64 start,
294 		 u64 size);
295 void drm_mm_takedown(struct drm_mm *mm);
296 bool drm_mm_clean(struct drm_mm *mm);
297 
298 void drm_mm_init_scan(struct drm_mm *mm,
299 		      u64 size,
300 		      unsigned alignment,
301 		      unsigned long color);
302 void drm_mm_init_scan_with_range(struct drm_mm *mm,
303 				 u64 size,
304 				 unsigned alignment,
305 				 unsigned long color,
306 				 u64 start,
307 				 u64 end);
308 bool drm_mm_scan_add_block(struct drm_mm_node *node);
309 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
310 
311 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
312 #ifdef CONFIG_DEBUG_FS
313 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
314 #endif
315 
316 #endif
317