include/drm/drm_mm.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  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.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  *
  27  **************************************************************************/
  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