xref: /openbmc/linux/include/drm/drm_mm.h (revision 18b40c58)
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2  *
3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
4  * All Rights Reserved.
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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/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_entry(hole_node->node_list.next,
152 			  struct drm_mm_node, node_list)->start;
153 }
154 
155 /**
156  * drm_mm_hole_node_end - computes the end of the hole following @node
157  * @hole_node: drm_mm_node which implicitly tracks the following hole
158  *
159  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
160  * inspect holes themselves. Drivers must check first whether a hole indeed
161  * follows by looking at node->hole_follows.
162  *
163  * Returns:
164  * End of the subsequent hole.
165  */
166 static inline u64 drm_mm_hole_node_end(struct drm_mm_node *hole_node)
167 {
168 	return __drm_mm_hole_node_end(hole_node);
169 }
170 
171 /**
172  * drm_mm_for_each_node - iterator to walk over all allocated nodes
173  * @entry: drm_mm_node structure to assign to in each iteration step
174  * @mm: drm_mm allocator to walk
175  *
176  * This iterator walks over all nodes in the range allocator. It is implemented
177  * with list_for_each, so not save against removal of elements.
178  */
179 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
180 						&(mm)->head_node.node_list, \
181 						node_list)
182 
183 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
184 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
185 	     &entry->hole_stack != &(mm)->hole_stack ? \
186 	     hole_start = drm_mm_hole_node_start(entry), \
187 	     hole_end = drm_mm_hole_node_end(entry), \
188 	     1 : 0; \
189 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
190 
191 /**
192  * drm_mm_for_each_hole - iterator to walk over all holes
193  * @entry: drm_mm_node used internally to track progress
194  * @mm: drm_mm allocator to walk
195  * @hole_start: ulong variable to assign the hole start to on each iteration
196  * @hole_end: ulong variable to assign the hole end to on each iteration
197  *
198  * This iterator walks over all holes in the range allocator. It is implemented
199  * with list_for_each, so not save against removal of elements. @entry is used
200  * internally and will not reflect a real drm_mm_node for the very first hole.
201  * Hence users of this iterator may not access it.
202  *
203  * Implementation Note:
204  * We need to inline list_for_each_entry in order to be able to set hole_start
205  * and hole_end on each iteration while keeping the macro sane.
206  *
207  * The __drm_mm_for_each_hole version is similar, but with added support for
208  * going backwards.
209  */
210 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
211 	__drm_mm_for_each_hole(entry, mm, hole_start, hole_end, 0)
212 
213 /*
214  * Basic range manager support (drm_mm.c)
215  */
216 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
217 
218 int drm_mm_insert_node_generic(struct drm_mm *mm,
219 			       struct drm_mm_node *node,
220 			       u64 size,
221 			       unsigned alignment,
222 			       unsigned long color,
223 			       enum drm_mm_search_flags sflags,
224 			       enum drm_mm_allocator_flags aflags);
225 /**
226  * drm_mm_insert_node - search for space and insert @node
227  * @mm: drm_mm to allocate from
228  * @node: preallocate node to insert
229  * @size: size of the allocation
230  * @alignment: alignment of the allocation
231  * @flags: flags to fine-tune the allocation
232  *
233  * This is a simplified version of drm_mm_insert_node_generic() with @color set
234  * to 0.
235  *
236  * The preallocated node must be cleared to 0.
237  *
238  * Returns:
239  * 0 on success, -ENOSPC if there's no suitable hole.
240  */
241 static inline int drm_mm_insert_node(struct drm_mm *mm,
242 				     struct drm_mm_node *node,
243 				     u64 size,
244 				     unsigned alignment,
245 				     enum drm_mm_search_flags flags)
246 {
247 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
248 					  DRM_MM_CREATE_DEFAULT);
249 }
250 
251 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
252 					struct drm_mm_node *node,
253 					u64 size,
254 					unsigned alignment,
255 					unsigned long color,
256 					u64 start,
257 					u64 end,
258 					enum drm_mm_search_flags sflags,
259 					enum drm_mm_allocator_flags aflags);
260 /**
261  * drm_mm_insert_node_in_range - ranged search for space and insert @node
262  * @mm: drm_mm to allocate from
263  * @node: preallocate node to insert
264  * @size: size of the allocation
265  * @alignment: alignment of the allocation
266  * @start: start of the allowed range for this node
267  * @end: end of the allowed range for this node
268  * @flags: flags to fine-tune the allocation
269  *
270  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
271  * @color set to 0.
272  *
273  * The preallocated node must be cleared to 0.
274  *
275  * Returns:
276  * 0 on success, -ENOSPC if there's no suitable hole.
277  */
278 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
279 					      struct drm_mm_node *node,
280 					      u64 size,
281 					      unsigned alignment,
282 					      u64 start,
283 					      u64 end,
284 					      enum drm_mm_search_flags flags)
285 {
286 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
287 						   0, start, end, flags,
288 						   DRM_MM_CREATE_DEFAULT);
289 }
290 
291 void drm_mm_remove_node(struct drm_mm_node *node);
292 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
293 void drm_mm_init(struct drm_mm *mm,
294 		 u64 start,
295 		 u64 size);
296 void drm_mm_takedown(struct drm_mm *mm);
297 bool drm_mm_clean(struct drm_mm *mm);
298 
299 void drm_mm_init_scan(struct drm_mm *mm,
300 		      u64 size,
301 		      unsigned alignment,
302 		      unsigned long color);
303 void drm_mm_init_scan_with_range(struct drm_mm *mm,
304 				 u64 size,
305 				 unsigned alignment,
306 				 unsigned long color,
307 				 u64 start,
308 				 u64 end);
309 bool drm_mm_scan_add_block(struct drm_mm_node *node);
310 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
311 
312 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
313 #ifdef CONFIG_DEBUG_FS
314 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
315 #endif
316 
317 #endif
318