include/drm/drm_mm.h

   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  *
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  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         unsigned long flags;
 172 #define DRM_MM_NODE_ALLOCATED_BIT       0
 173 #define DRM_MM_NODE_SCANNED_BIT         1
 174 #ifdef CONFIG_DRM_DEBUG_MM
 175         depot_stack_handle_t stack;
 176 #endif
 177 };
 178
 179 /**
 180  * struct drm_mm - DRM allocator
 181  *
 182  * DRM range allocator with a few special functions and features geared towards
 183  * managing GPU memory. Except for the @color_adjust callback the structure is
 184  * entirely opaque and should only be accessed through the provided functions
 185  * and macros. This structure can be embedded into larger driver structures.
 186  */
 187 struct drm_mm {
 188         /**
 189          * @color_adjust:
 190          *
 191          * Optional driver callback to further apply restrictions on a hole. The
 192          * node argument points at the node containing the hole from which the
 193          * block would be allocated (see drm_mm_hole_follows() and friends). The
 194          * other arguments are the size of the block to be allocated. The driver
 195          * can adjust the start and end as needed to e.g. insert guard pages.
 196          */
 197         void (*color_adjust)(const struct drm_mm_node *node,
 198                              unsigned long color,
 199                              u64 *start, u64 *end);
 200
 201         /* private: */
 202         /* List of all memory nodes that immediately precede a free hole. */
 203         struct list_head hole_stack;
 204         /* head_node.node_list is the list of all memory nodes, ordered
 205          * according to the (increasing) start address of the memory node. */
 206         struct drm_mm_node head_node;
 207         /* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */
 208         struct rb_root_cached interval_tree;
 209         struct rb_root_cached holes_size;
 210         struct rb_root holes_addr;
 211
 212         unsigned long scan_active;
 213 };
 214
 215 /**
 216  * struct drm_mm_scan - DRM allocator eviction roaster data
 217  *
 218  * This structure tracks data needed for the eviction roaster set up using
 219  * drm_mm_scan_init(), and used with drm_mm_scan_add_block() and
 220  * drm_mm_scan_remove_block(). The structure is entirely opaque and should only
 221  * be accessed through the provided functions and macros. It is meant to be
 222  * allocated temporarily by the driver on the stack.
 223  */
 224 struct drm_mm_scan {
 225         /* private: */
 226         struct drm_mm *mm;
 227
 228         u64 size;
 229         u64 alignment;
 230         u64 remainder_mask;
 231
 232         u64 range_start;
 233         u64 range_end;
 234
 235         u64 hit_start;
 236         u64 hit_end;
 237
 238         unsigned long color;
 239         enum drm_mm_insert_mode mode;
 240 };
 241
 242 /**
 243  * drm_mm_node_allocated - checks whether a node is allocated
 244  * @node: drm_mm_node to check
 245  *
 246  * Drivers are required to clear a node prior to using it with the
 247  * drm_mm range manager.
 248  *
 249  * Drivers should use this helper for proper encapsulation of drm_mm
 250  * internals.
 251  *
 252  * Returns:
 253  * True if the @node is allocated.
 254  */
 255 static inline bool drm_mm_node_allocated(const struct drm_mm_node *node)
 256 {
 257         return test_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
 258 }
 259
 260 /**
 261  * drm_mm_initialized - checks whether an allocator is initialized
 262  * @mm: drm_mm to check
 263  *
 264  * Drivers should clear the struct drm_mm prior to initialisation if they
 265  * want to use this function.
 266  *
 267  * Drivers should use this helper for proper encapsulation of drm_mm
 268  * internals.
 269  *
 270  * Returns:
 271  * True if the @mm is initialized.
 272  */
 273 static inline bool drm_mm_initialized(const struct drm_mm *mm)
 274 {
 275         return READ_ONCE(mm->hole_stack.next);
 276 }
 277
 278 /**
 279  * drm_mm_hole_follows - checks whether a hole follows this node
 280  * @node: drm_mm_node to check
 281  *
 282  * Holes are embedded into the drm_mm using the tail of a drm_mm_node.
 283  * If you wish to know whether a hole follows this particular node,
 284  * query this function. See also drm_mm_hole_node_start() and
 285  * drm_mm_hole_node_end().
 286  *
 287  * Returns:
 288  * True if a hole follows the @node.
 289  */
 290 static inline bool drm_mm_hole_follows(const struct drm_mm_node *node)
 291 {
 292         return node->hole_size;
 293 }
 294
 295 static inline u64 __drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
 296 {
 297         return hole_node->start + hole_node->size;
 298 }
 299
 300 /**
 301  * drm_mm_hole_node_start - computes the start of the hole following @node
 302  * @hole_node: drm_mm_node which implicitly tracks the following hole
 303  *
 304  * This is useful for driver-specific debug dumpers. Otherwise drivers should
 305  * not inspect holes themselves. Drivers must check first whether a hole indeed
 306  * follows by looking at drm_mm_hole_follows()
 307  *
 308  * Returns:
 309  * Start of the subsequent hole.
 310  */
 311 static inline u64 drm_mm_hole_node_start(const struct drm_mm_node *hole_node)
 312 {
 313         DRM_MM_BUG_ON(!drm_mm_hole_follows(hole_node));
 314         return __drm_mm_hole_node_start(hole_node);
 315 }
 316
 317 static inline u64 __drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
 318 {
 319         return list_next_entry(hole_node, node_list)->start;
 320 }
 321
 322 /**
 323  * drm_mm_hole_node_end - computes the end of the hole following @node
 324  * @hole_node: drm_mm_node which implicitly tracks the following hole
 325  *
 326  * This is useful for driver-specific debug dumpers. Otherwise drivers should
 327  * not inspect holes themselves. Drivers must check first whether a hole indeed
 328  * follows by looking at drm_mm_hole_follows().
 329  *
 330  * Returns:
 331  * End of the subsequent hole.
 332  */
 333 static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node)
 334 {
 335         return __drm_mm_hole_node_end(hole_node);
 336 }
 337
 338 /**
 339  * drm_mm_nodes - list of nodes under the drm_mm range manager
 340  * @mm: the struct drm_mm range manger
 341  *
 342  * As the drm_mm range manager hides its node_list deep with its
 343  * structure, extracting it looks painful and repetitive. This is
 344  * not expected to be used outside of the drm_mm_for_each_node()
 345  * macros and similar internal functions.
 346  *
 347  * Returns:
 348  * The node list, may be empty.
 349  */
 350 #define drm_mm_nodes(mm) (&(mm)->head_node.node_list)
 351
 352 /**
 353  * drm_mm_for_each_node - iterator to walk over all allocated nodes
 354  * @entry: &struct drm_mm_node to assign to in each iteration step
 355  * @mm: &drm_mm allocator to walk
 356  *
 357  * This iterator walks over all nodes in the range allocator. It is implemented
 358  * with list_for_each(), so not save against removal of elements.
 359  */
 360 #define drm_mm_for_each_node(entry, mm) \
 361         list_for_each_entry(entry, drm_mm_nodes(mm), node_list)
 362
 363 /**
 364  * drm_mm_for_each_node_safe - iterator to walk over all allocated nodes
 365  * @entry: &struct drm_mm_node to assign to in each iteration step
 366  * @next: &struct drm_mm_node to store the next step
 367  * @mm: &drm_mm allocator to walk
 368  *
 369  * This iterator walks over all nodes in the range allocator. It is implemented
 370  * with list_for_each_safe(), so save against removal of elements.
 371  */
 372 #define drm_mm_for_each_node_safe(entry, next, mm) \
 373         list_for_each_entry_safe(entry, next, drm_mm_nodes(mm), node_list)
 374
 375 /**
 376  * drm_mm_for_each_hole - iterator to walk over all holes
 377  * @pos: &drm_mm_node used internally to track progress
 378  * @mm: &drm_mm allocator to walk
 379  * @hole_start: ulong variable to assign the hole start to on each iteration
 380  * @hole_end: ulong variable to assign the hole end to on each iteration
 381  *
 382  * This iterator walks over all holes in the range allocator. It is implemented
 383  * with list_for_each(), so not save against removal of elements. @entry is used
 384  * internally and will not reflect a real drm_mm_node for the very first hole.
 385  * Hence users of this iterator may not access it.
 386  *
 387  * Implementation Note:
 388  * We need to inline list_for_each_entry in order to be able to set hole_start
 389  * and hole_end on each iteration while keeping the macro sane.
 390  */
 391 #define drm_mm_for_each_hole(pos, mm, hole_start, hole_end) \
 392         for (pos = list_first_entry(&(mm)->hole_stack, \
 393                                     typeof(*pos), hole_stack); \
 394              &pos->hole_stack != &(mm)->hole_stack ? \
 395              hole_start = drm_mm_hole_node_start(pos), \
 396              hole_end = hole_start + pos->hole_size, \
 397              1 : 0; \
 398              pos = list_next_entry(pos, hole_stack))
 399
 400 /*
 401  * Basic range manager support (drm_mm.c)
 402  */
 403 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
 404 int drm_mm_insert_node_in_range(struct drm_mm *mm,
 405                                 struct drm_mm_node *node,
 406                                 u64 size,
 407                                 u64 alignment,
 408                                 unsigned long color,
 409                                 u64 start,
 410                                 u64 end,
 411                                 enum drm_mm_insert_mode mode);
 412
 413 /**
 414  * drm_mm_insert_node_generic - search for space and insert @node
 415  * @mm: drm_mm to allocate from
 416  * @node: preallocate node to insert
 417  * @size: size of the allocation
 418  * @alignment: alignment of the allocation
 419  * @color: opaque tag value to use for this node
 420  * @mode: fine-tune the allocation search and placement
 421  *
 422  * This is a simplified version of drm_mm_insert_node_in_range() with no
 423  * range restrictions applied.
 424  *
 425  * The preallocated node must be cleared to 0.
 426  *
 427  * Returns:
 428  * 0 on success, -ENOSPC if there's no suitable hole.
 429  */
 430 static inline int
 431 drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
 432                            u64 size, u64 alignment,
 433                            unsigned long color,
 434                            enum drm_mm_insert_mode mode)
 435 {
 436         return drm_mm_insert_node_in_range(mm, node,
 437                                            size, alignment, color,
 438                                            0, U64_MAX, mode);
 439 }
 440
 441 /**
 442  * drm_mm_insert_node - search for space and insert @node
 443  * @mm: drm_mm to allocate from
 444  * @node: preallocate node to insert
 445  * @size: size of the allocation
 446  *
 447  * This is a simplified version of drm_mm_insert_node_generic() with @color set
 448  * to 0.
 449  *
 450  * The preallocated node must be cleared to 0.
 451  *
 452  * Returns:
 453  * 0 on success, -ENOSPC if there's no suitable hole.
 454  */
 455 static inline int drm_mm_insert_node(struct drm_mm *mm,
 456                                      struct drm_mm_node *node,
 457                                      u64 size)
 458 {
 459         return drm_mm_insert_node_generic(mm, node, size, 0, 0, 0);
 460 }
 461
 462 void drm_mm_remove_node(struct drm_mm_node *node);
 463 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
 464 void drm_mm_init(struct drm_mm *mm, u64 start, u64 size);
 465 void drm_mm_takedown(struct drm_mm *mm);
 466
 467 /**
 468  * drm_mm_clean - checks whether an allocator is clean
 469  * @mm: drm_mm allocator to check
 470  *
 471  * Returns:
 472  * True if the allocator is completely free, false if there's still a node
 473  * allocated in it.
 474  */
 475 static inline bool drm_mm_clean(const struct drm_mm *mm)
 476 {
 477         return list_empty(drm_mm_nodes(mm));
 478 }
 479
 480 struct drm_mm_node *
 481 __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
 482
 483 /**
 484  * drm_mm_for_each_node_in_range - iterator to walk over a range of
 485  * allocated nodes
 486  * @node__: drm_mm_node structure to assign to in each iteration step
 487  * @mm__: drm_mm allocator to walk
 488  * @start__: starting offset, the first node will overlap this
 489  * @end__: ending offset, the last node will start before this (but may overlap)
 490  *
 491  * This iterator walks over all nodes in the range allocator that lie
 492  * between @start and @end. It is implemented similarly to list_for_each(),
 493  * but using the internal interval tree to accelerate the search for the
 494  * starting node, and so not safe against removal of elements. It assumes
 495  * that @end is within (or is the upper limit of) the drm_mm allocator.
 496  * If [@start, @end] are beyond the range of the drm_mm, the iterator may walk
 497  * over the special _unallocated_ &drm_mm.head_node, and may even continue
 498  * indefinitely.
 499  */
 500 #define drm_mm_for_each_node_in_range(node__, mm__, start__, end__)     \
 501         for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \
 502              node__->start < (end__);                                   \
 503              node__ = list_next_entry(node__, node_list))
 504
 505 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 506                                  struct drm_mm *mm,
 507                                  u64 size, u64 alignment, unsigned long color,
 508                                  u64 start, u64 end,
 509                                  enum drm_mm_insert_mode mode);
 510
 511 /**
 512  * drm_mm_scan_init - initialize lru scanning
 513  * @scan: scan state
 514  * @mm: drm_mm to scan
 515  * @size: size of the allocation
 516  * @alignment: alignment of the allocation
 517  * @color: opaque tag value to use for the allocation
 518  * @mode: fine-tune the allocation search and placement
 519  *
 520  * This is a simplified version of drm_mm_scan_init_with_range() with no range
 521  * restrictions applied.
 522  *
 523  * This simply sets up the scanning routines with the parameters for the desired
 524  * hole.
 525  *
 526  * Warning:
 527  * As long as the scan list is non-empty, no other operations than
 528  * adding/removing nodes to/from the scan list are allowed.
 529  */
 530 static inline void drm_mm_scan_init(struct drm_mm_scan *scan,
 531                                     struct drm_mm *mm,
 532                                     u64 size,
 533                                     u64 alignment,
 534                                     unsigned long color,
 535                                     enum drm_mm_insert_mode mode)
 536 {
 537         drm_mm_scan_init_with_range(scan, mm,
 538                                     size, alignment, color,
 539                                     0, U64_MAX, mode);
 540 }
 541
 542 bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
 543                            struct drm_mm_node *node);
 544 bool drm_mm_scan_remove_block(struct drm_mm_scan *scan,
 545                               struct drm_mm_node *node);
 546 struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan);
 547
 548 void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p);
 549
 550 #endif