1 /**************************************************************************
2 *
3 * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
4 * Copyright 2016 Intel Corporation
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 *
28 **************************************************************************/
29 /*
30 * Authors:
31 * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
32 */
33
34 #ifndef _DRM_MM_H_
35 #define _DRM_MM_H_
36
37 /*
38 * Generic range manager structs
39 */
40 #include <linux/bug.h>
41 #include <linux/rbtree.h>
42 #include <linux/kernel.h>
43 #include <linux/mm_types.h>
44 #include <linux/list.h>
45 #include <linux/spinlock.h>
46 #ifdef CONFIG_DRM_DEBUG_MM
47 #include <linux/stackdepot.h>
48 #endif
49 #include <drm/drm_print.h>
50
51 #ifdef CONFIG_DRM_DEBUG_MM
52 #define DRM_MM_BUG_ON(expr) BUG_ON(expr)
53 #else
54 #define DRM_MM_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr)
55 #endif
56
57 /**
58 * enum drm_mm_insert_mode - control search and allocation behaviour
59 *
60 * The &struct drm_mm range manager supports finding a suitable modes using
61 * a number of search trees. These trees are oranised by size, by address and
62 * in most recent eviction order. This allows the user to find either the
63 * smallest hole to reuse, the lowest or highest address to reuse, or simply
64 * reuse the most recent eviction that fits. When allocating the &drm_mm_node
65 * from within the hole, the &drm_mm_insert_mode also dictate whether to
66 * allocate the lowest matching address or the highest.
67 */
68 enum drm_mm_insert_mode {
69 /**
70 * @DRM_MM_INSERT_BEST:
71 *
72 * Search for the smallest hole (within the search range) that fits
73 * the desired node.
74 *
75 * Allocates the node from the bottom of the found hole.
76 */
77 DRM_MM_INSERT_BEST = 0,
78
79 /**
80 * @DRM_MM_INSERT_LOW:
81 *
82 * Search for the lowest hole (address closest to 0, within the search
83 * range) that fits the desired node.
84 *
85 * Allocates the node from the bottom of the found hole.
86 */
87 DRM_MM_INSERT_LOW,
88
89 /**
90 * @DRM_MM_INSERT_HIGH:
91 *
92 * Search for the highest hole (address closest to U64_MAX, within the
93 * search range) that fits the desired node.
94 *
95 * Allocates the node from the *top* of the found hole. The specified
96 * alignment for the node is applied to the base of the node
97 * (&drm_mm_node.start).
98 */
99 DRM_MM_INSERT_HIGH,
100
101 /**
102 * @DRM_MM_INSERT_EVICT:
103 *
104 * Search for the most recently evicted hole (within the search range)
105 * that fits the desired node. This is appropriate for use immediately
106 * after performing an eviction scan (see drm_mm_scan_init()) and
107 * removing the selected nodes to form a hole.
108 *
109 * Allocates the node from the bottom of the found hole.
110 */
111 DRM_MM_INSERT_EVICT,
112
113 /**
114 * @DRM_MM_INSERT_ONCE:
115 *
116 * Only check the first hole for suitablity and report -ENOSPC
117 * immediately otherwise, rather than check every hole until a
118 * suitable one is found. Can only be used in conjunction with another
119 * search method such as DRM_MM_INSERT_HIGH or DRM_MM_INSERT_LOW.
120 */
121 DRM_MM_INSERT_ONCE = BIT(31),
122
123 /**
124 * @DRM_MM_INSERT_HIGHEST:
125 *
126 * Only check the highest hole (the hole with the largest address) and
127 * insert the node at the top of the hole or report -ENOSPC if
128 * unsuitable.
129 *
130 * Does not search all holes.
131 */
132 DRM_MM_INSERT_HIGHEST = DRM_MM_INSERT_HIGH | DRM_MM_INSERT_ONCE,
133
134 /**
135 * @DRM_MM_INSERT_LOWEST:
136 *
137 * Only check the lowest hole (the hole with the smallest address) and
138 * insert the node at the bottom of the hole or report -ENOSPC if
139 * unsuitable.
140 *
141 * Does not search all holes.
142 */
143 DRM_MM_INSERT_LOWEST = DRM_MM_INSERT_LOW | DRM_MM_INSERT_ONCE,
144 };
145
146 /**
147 * struct drm_mm_node - allocated block in the DRM allocator
148 *
149 * This represents an allocated block in a &drm_mm allocator. Except for
150 * pre-reserved nodes inserted using drm_mm_reserve_node() the structure is
151 * entirely opaque and should only be accessed through the provided funcions.
152 * Since allocation of these nodes is entirely handled by the driver they can be
153 * embedded.
154 */
155 struct drm_mm_node {
156 /** @color: Opaque driver-private tag. */
157 unsigned long color;
158 /** @start: Start address of the allocated block. */
159 u64 start;
160 /** @size: Size of the allocated block. */
161 u64 size;
162 /* private: */
163 struct drm_mm *mm;
164 struct list_head node_list;
165 struct list_head hole_stack;
166 struct rb_node rb;
167 struct rb_node rb_hole_size;
168 struct rb_node rb_hole_addr;
169 u64 __subtree_last;
170 u64 hole_size;
171 bool allocated : 1;
172 bool scanned_block : 1;
173 #ifdef CONFIG_DRM_DEBUG_MM
174 depot_stack_handle_t stack;
175 #endif
176 };
177
178 /**
179 * struct drm_mm - DRM allocator
180 *
181 * DRM range allocator with a few special functions and features geared towards
182 * managing GPU memory. Except for the @color_adjust callback the structure is
183 * entirely opaque and should only be accessed through the provided functions
184 * and macros. This structure can be embedded into larger driver structures.
185 */
186 struct drm_mm {
187 /**
188 * @color_adjust:
189 *
190 * Optional driver callback to further apply restrictions on a hole. The
191 * node argument points at the node containing the hole from which the
192 * block would be allocated (see drm_mm_hole_follows() and friends). The
193 * other arguments are the size of the block to be allocated. The driver
194 * can adjust the start and end as needed to e.g. insert guard pages.
195 */
196 void (*color_adjust)(const struct drm_mm_node *node,
197 unsigned long color,
198 u64 *start, u64 *end);
199
200 /* private: */
201 /* List of all memory nodes that immediately precede a free hole. */
202 struct list_head hole_stack;
203 /* head_node.node_list is the list of all memory nodes, ordered
204 * according to the (increasing) start address of the memory node. */
205 struct drm_mm_node head_node;
206 /* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
207 struct rb_root_cached interval_tree;
208 struct rb_root_cached holes_size;
209 struct rb_root holes_addr;
210
211 unsigned long scan_active;
212 };
213
214 /**
215 * struct drm_mm_scan - DRM allocator eviction roaster data
216 *
217 * This structure tracks data needed for the eviction roaster set up using
218 * drm_mm_scan_init(), and used with drm_mm_scan_add_block() and
219 * drm_mm_scan_remove_block(). The structure is entirely opaque and should only
220 * be accessed through the provided functions and macros. It is meant to be
221 * allocated temporarily by the driver on the stack.
222 */
223 struct drm_mm_scan {
224 /* private: */
225 struct drm_mm *mm;
226
227 u64 size;
228 u64 alignment;
229 u64 remainder_mask;
230
231 u64 range_start;
232 u64 range_end;
233
234 u64 hit_start;
235 u64 hit_end;
236
237 unsigned long color;
238 enum drm_mm_insert_mode mode;
239 };
240
241 /**
242 * drm_mm_node_allocated - checks whether a node is allocated
243 * @node: drm_mm_node to check
244 *
245 * Drivers are required to clear a node prior to using it with the
246 * drm_mm range manager.
247 *
248 * Drivers should use this helper for proper encapsulation of drm_mm
249 * internals.
250 *
251 * Returns:
252 * True if the @node is allocated.
253 */
254 static inline bool drm_mm_node_allocated(const struct drm_mm_node *node)
255 {
256 return node->allocated;
257 }
258
259 /**
260 * drm_mm_initialized - checks whether an allocator is initialized
261 * @mm: drm_mm to check
262 *
263 * Drivers should clear the struct drm_mm prior to initialisation if they
264 * want to use this function.
265 *
266 * Drivers should use this helper for proper encapsulation of drm_mm
267 * internals.
268 *
269 * Returns:
270 * True if the @mm is initialized.
271 */
272 static inline bool drm_mm_initialized(const struct drm_mm *mm)
273 {
274 return mm->hole_stack.next;
275 }
276
277 /**
278 * drm_mm_hole_follows - checks whether a hole follows this node
279 * @node: drm_mm_node to check
280 *
281 * Holes are embedded into the drm_mm using the tail of a drm_mm_node.
282 * If you wish to know whether a hole follows this particular node,
283 * query this function. See also drm_mm_hole_node_start() and
284 * drm_mm_hole_node_end().
285 *
286 * Returns:
287 * True if a hole follows the @node.
288 */
289 static inline bool drm_mm_hole_follows(const struct drm_mm_node *node)
290 {
291 return node->hole_size;
292 }
293
294 static inline u64 __drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
295 {
296 return hole_node->start + hole_node->size;
297 }
298
299 /**
300 * drm_mm_hole_node_start - computes the start of the hole following @node
301 * @hole_node: drm_mm_node which implicitly tracks the following hole
302 *
303 * This is useful for driver-specific debug dumpers. Otherwise drivers should
304 * not inspect holes themselves. Drivers must check first whether a hole indeed
305 * follows by looking at drm_mm_hole_follows()
306 *
307 * Returns:
308 * Start of the subsequent hole.
309 */
310 static inline u64 drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
311 {
312 DRM_MM_BUG_ON(!drm_mm_hole_follows(hole_node));
313 return __drm_mm_hole_node_start(hole_node);
314 }
315
316 static inline u64 __drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
317 {
318 return list_next_entry(hole_node, node_list)->start;
319 }
320
321 /**
322 * drm_mm_hole_node_end - computes the end of the hole following @node
323 * @hole_node: drm_mm_node which implicitly tracks the following hole
324 *
325 * This is useful for driver-specific debug dumpers. Otherwise drivers should
326 * not inspect holes themselves. Drivers must check first whether a hole indeed
327 * follows by looking at drm_mm_hole_follows().
328 *
329 * Returns:
330 * End of the subsequent hole.
331 */
332 static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
333 {
334 return __drm_mm_hole_node_end(hole_node);
335 }
336
337 /**
338 * drm_mm_nodes - list of nodes under the drm_mm range manager
339 * @mm: the struct drm_mm range manger
340 *
341 * As the drm_mm range manager hides its node_list deep with its
342 * structure, extracting it looks painful and repetitive. This is
343 * not expected to be used outside of the drm_mm_for_each_node()
344 * macros and similar internal functions.
345 *
346 * Returns:
347 * The node list, may be empty.
348 */
349 #define drm_mm_nodes(mm) (&(mm)->head_node.node_list)
350
351 /**
352 * drm_mm_for_each_node - iterator to walk over all allocated nodes
353 * @entry: &struct drm_mm_node to assign to in each iteration step
354 * @mm: &drm_mm allocator to walk
355 *
356 * This iterator walks over all nodes in the range allocator. It is implemented
357 * with list_for_each(), so not save against removal of elements.
358 */
359 #define drm_mm_for_each_node(entry, mm) \
360 list_for_each_entry(entry, drm_mm_nodes(mm), node_list)
361
362 /**
363 * drm_mm_for_each_node_safe - iterator to walk over all allocated nodes
364 * @entry: &struct drm_mm_node to assign to in each iteration step
365 * @next: &struct drm_mm_node to store the next step
366 * @mm: &drm_mm allocator to walk
367 *
368 * This iterator walks over all nodes in the range allocator. It is implemented
369 * with list_for_each_safe(), so save against removal of elements.
370 */
371 #define drm_mm_for_each_node_safe(entry, next, mm) \
372 list_for_each_entry_safe(entry, next, drm_mm_nodes(mm), node_list)
373
374 /**
375 * drm_mm_for_each_hole - iterator to walk over all holes
376 * @pos: &drm_mm_node used internally to track progress
377 * @mm: &drm_mm allocator to walk
378 * @hole_start: ulong variable to assign the hole start to on each iteration
379 * @hole_end: ulong variable to assign the hole end to on each iteration
380 *
381 * This iterator walks over all holes in the range allocator. It is implemented
382 * with list_for_each(), so not save against removal of elements. @entry is used
383 * internally and will not reflect a real drm_mm_node for the very first hole.
384 * Hence users of this iterator may not access it.
385 *
386 * Implementation Note:
387 * We need to inline list_for_each_entry in order to be able to set hole_start
388 * and hole_end on each iteration while keeping the macro sane.
389 */
390 #define drm_mm_for_each_hole(pos, mm, hole_start, hole_end) \
391 for (pos = list_first_entry(&(mm)->hole_stack, \
392 typeof(*pos), hole_stack); \
393 &pos->hole_stack != &(mm)->hole_stack ? \
394 hole_start = drm_mm_hole_node_start(pos), \
395 hole_end = hole_start + pos->hole_size, \
396 1 : 0; \
397 pos = list_next_entry(pos, hole_stack))
398
399 /*
400 * Basic range manager support (drm_mm.c)
401 */
402 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
403 int drm_mm_insert_node_in_range(struct drm_mm *mm,
404 struct drm_mm_node *node,
405 u64 size,
406 u64 alignment,
407 unsigned long color,
408 u64 start,
409 u64 end,
410 enum drm_mm_insert_mode mode);
411
412 /**
413 * drm_mm_insert_node_generic - search for space and insert @node
414 * @mm: drm_mm to allocate from
415 * @node: preallocate node to insert
416 * @size: size of the allocation
417 * @alignment: alignment of the allocation
418 * @color: opaque tag value to use for this node
419 * @mode: fine-tune the allocation search and placement
420 *
421 * This is a simplified version of drm_mm_insert_node_in_range() with no
422 * range restrictions applied.
423 *
424 * The preallocated node must be cleared to 0.
425 *
426 * Returns:
427 * 0 on success, -ENOSPC if there's no suitable hole.
428 */
429 static inline int
430 drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
431 u64 size, u64 alignment,
432 unsigned long color,
433 enum drm_mm_insert_mode mode)
434 {
435 return drm_mm_insert_node_in_range(mm, node,
436 size, alignment, color,
437 0, U64_MAX, mode);
438 }
439
440 /**
441 * drm_mm_insert_node - search for space and insert @node
442 * @mm: drm_mm to allocate from
443 * @node: preallocate node to insert
444 * @size: size of the allocation
445 *
446 * This is a simplified version of drm_mm_insert_node_generic() with @color set
447 * to 0.
448 *
449 * The preallocated node must be cleared to 0.
450 *
451 * Returns:
452 * 0 on success, -ENOSPC if there's no suitable hole.
453 */
454 static inline int drm_mm_insert_node(struct drm_mm *mm,
455 struct drm_mm_node *node,
456 u64 size)
457 {
458 return drm_mm_insert_node_generic(mm, node, size, 0, 0, 0);
459 }
460
461 void drm_mm_remove_node(struct drm_mm_node *node);
462 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
463 void drm_mm_init(struct drm_mm *mm, u64 start, u64 size);
464 void drm_mm_takedown(struct drm_mm *mm);
465
466 /**
467 * drm_mm_clean - checks whether an allocator is clean
468 * @mm: drm_mm allocator to check
469 *
470 * Returns:
471 * True if the allocator is completely free, false if there's still a node
472 * allocated in it.
473 */
474 static inline bool drm_mm_clean(const struct drm_mm *mm)
475 {
476 return list_empty(drm_mm_nodes(mm));
477 }
478
479 struct drm_mm_node *
480 __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
481
482 /**
483 * drm_mm_for_each_node_in_range - iterator to walk over a range of
484 * allocated nodes
485 * @node__: drm_mm_node structure to assign to in each iteration step
486 * @mm__: drm_mm allocator to walk
487 * @start__: starting offset, the first node will overlap this
488 * @end__: ending offset, the last node will start before this (but may overlap)
489 *
490 * This iterator walks over all nodes in the range allocator that lie
491 * between @start and @end. It is implemented similarly to list_for_each(),
492 * but using the internal interval tree to accelerate the search for the
493 * starting node, and so not safe against removal of elements. It assumes
494 * that @end is within (or is the upper limit of) the drm_mm allocator.
495 * If [@start, @end] are beyond the range of the drm_mm, the iterator may walk
496 * over the special _unallocated_ &drm_mm.head_node, and may even continue
497 * indefinitely.
498 */
499 #define drm_mm_for_each_node_in_range(node__, mm__, start__, end__) \
500 for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
501 node__->start < (end__); \
502 node__ = list_next_entry(node__, node_list))
503
504 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
505 struct drm_mm *mm,
506 u64 size, u64 alignment, unsigned long color,
507 u64 start, u64 end,
508 enum drm_mm_insert_mode mode);
509
510 /**
511 * drm_mm_scan_init - initialize lru scanning
512 * @scan: scan state
513 * @mm: drm_mm to scan
514 * @size: size of the allocation
515 * @alignment: alignment of the allocation
516 * @color: opaque tag value to use for the allocation
517 * @mode: fine-tune the allocation search and placement
518 *
519 * This is a simplified version of drm_mm_scan_init_with_range() with no range
520 * restrictions applied.
521 *
522 * This simply sets up the scanning routines with the parameters for the desired
523 * hole.
524 *
525 * Warning:
526 * As long as the scan list is non-empty, no other operations than
527 * adding/removing nodes to/from the scan list are allowed.
528 */
529 static inline void drm_mm_scan_init(struct drm_mm_scan *scan,
530 struct drm_mm *mm,
531 u64 size,
532 u64 alignment,
533 unsigned long color,
534 enum drm_mm_insert_mode mode)
535 {
536 drm_mm_scan_init_with_range(scan, mm,
537 size, alignment, color,
538 0, U64_MAX, mode);
539 }
540
541 bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
542 struct drm_mm_node *node);
543 bool drm_mm_scan_remove_block(struct drm_mm_scan *scan,
544 struct drm_mm_node *node);
545 struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan);
546
547 void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p);
548
549 #endif