sys/dev/drm/i915_mem.c

   1 /* i915_mem.c -- Simple agp/fb memory manager for i915 -*- linux-c -*-
   2  *
   3  * $FreeBSD$
   4  */
   5 /**************************************************************************
   6  *
   7  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   8  * All Rights Reserved.
   9  *
  10  **************************************************************************/
  11
  12 #include "drmP.h"
  13 #include "drm.h"
  14 #include "i915_drm.h"
  15 #include "i915_drv.h"
  16
  17 /* This memory manager is integrated into the global/local lru
  18  * mechanisms used by the clients.  Specifically, it operates by
  19  * setting the 'in_use' fields of the global LRU to indicate whether
  20  * this region is privately allocated to a client.
  21  *
  22  * This does require the client to actually respect that field.
  23  *
  24  * Currently no effort is made to allocate 'private' memory in any
  25  * clever way - the LRU information isn't used to determine which
  26  * block to allocate, and the ring is drained prior to allocations --
  27  * in other words allocation is expensive.
  28  */
  29 static void mark_block(drm_device_t * dev, struct mem_block *p, int in_use)
  30 {
  31         drm_i915_private_t *dev_priv = dev->dev_private;
  32         drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
  33         drm_tex_region_t *list;
  34         unsigned shift, nr;
  35         unsigned start;
  36         unsigned end;
  37         unsigned i;
  38         int age;
  39
  40         shift = dev_priv->tex_lru_log_granularity;
  41         nr = I915_NR_TEX_REGIONS;
  42
  43         start = p->start >> shift;
  44         end = (p->start + p->size - 1) >> shift;
  45
  46         age = ++sarea_priv->texAge;
  47         list = sarea_priv->texList;
  48
  49         /* Mark the regions with the new flag and update their age.  Move
  50          * them to head of list to preserve LRU semantics.
  51          */
  52         for (i = start; i <= end; i++) {
  53                 list[i].in_use = in_use;
  54                 list[i].age = age;
  55
  56                 /* remove_from_list(i)
  57                  */
  58                 list[(unsigned)list[i].next].prev = list[i].prev;
  59                 list[(unsigned)list[i].prev].next = list[i].next;
  60
  61                 /* insert_at_head(list, i)
  62                  */
  63                 list[i].prev = nr;
  64                 list[i].next = list[nr].next;
  65                 list[(unsigned)list[nr].next].prev = i;
  66                 list[nr].next = i;
  67         }
  68 }
  69
  70 /* Very simple allocator for agp memory, working on a static range
  71  * already mapped into each client's address space.
  72  */
  73
  74 static struct mem_block *split_block(struct mem_block *p, int start, int size,
  75                                      DRMFILE filp)
  76 {
  77         /* Maybe cut off the start of an existing block */
  78         if (start > p->start) {
  79                 struct mem_block *newblock =
  80                     drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
  81                 if (!newblock)
  82                         goto out;
  83                 newblock->start = start;
  84                 newblock->size = p->size - (start - p->start);
  85                 newblock->filp = NULL;
  86                 newblock->next = p->next;
  87                 newblock->prev = p;
  88                 p->next->prev = newblock;
  89                 p->next = newblock;
  90                 p->size -= newblock->size;
  91                 p = newblock;
  92         }
  93
  94         /* Maybe cut off the end of an existing block */
  95         if (size < p->size) {
  96                 struct mem_block *newblock =
  97                     drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
  98                 if (!newblock)
  99                         goto out;
 100                 newblock->start = start + size;
 101                 newblock->size = p->size - size;
 102                 newblock->filp = NULL;
 103                 newblock->next = p->next;
 104                 newblock->prev = p;
 105                 p->next->prev = newblock;
 106                 p->next = newblock;
 107                 p->size = size;
 108         }
 109
 110       out:
 111         /* Our block is in the middle */
 112         p->filp = filp;
 113         return p;
 114 }
 115
 116 static struct mem_block *alloc_block(struct mem_block *heap, int size,
 117                                      int align2, DRMFILE filp)
 118 {
 119         struct mem_block *p;
 120         int mask = (1 << align2) - 1;
 121
 122         for (p = heap->next; p != heap; p = p->next) {
 123                 int start = (p->start + mask) & ~mask;
 124                 if (p->filp == NULL && start + size <= p->start + p->size)
 125                         return split_block(p, start, size, filp);
 126         }
 127
 128         return NULL;
 129 }
 130
 131 static struct mem_block *find_block(struct mem_block *heap, int start)
 132 {
 133         struct mem_block *p;
 134
 135         for (p = heap->next; p != heap; p = p->next)
 136                 if (p->start == start)
 137                         return p;
 138
 139         return NULL;
 140 }
 141
 142 static void free_block(struct mem_block *p)
 143 {
 144         p->filp = NULL;
 145
 146         /* Assumes a single contiguous range.  Needs a special filp in
 147          * 'heap' to stop it being subsumed.
 148          */
 149         if (p->next->filp == NULL) {
 150                 struct mem_block *q = p->next;
 151                 p->size += q->size;
 152                 p->next = q->next;
 153                 p->next->prev = p;
 154                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 155         }
 156
 157         if (p->prev->filp == NULL) {
 158                 struct mem_block *q = p->prev;
 159                 q->size += p->size;
 160                 q->next = p->next;
 161                 q->next->prev = q;
 162                 drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
 163         }
 164 }
 165
 166 /* Initialize.  How to check for an uninitialized heap?
 167  */
 168 static int init_heap(struct mem_block **heap, int start, int size)
 169 {
 170         struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
 171
 172         if (!blocks)
 173                 return -ENOMEM;
 174
 175         *heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
 176         if (!*heap) {
 177                 drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
 178                 return -ENOMEM;
 179         }
 180
 181         blocks->start = start;
 182         blocks->size = size;
 183         blocks->filp = NULL;
 184         blocks->next = blocks->prev = *heap;
 185
 186         memset(*heap, 0, sizeof(**heap));
 187         (*heap)->filp = (DRMFILE) - 1;
 188         (*heap)->next = (*heap)->prev = blocks;
 189         return 0;
 190 }
 191
 192 /* Free all blocks associated with the releasing file.
 193  */
 194 void i915_mem_release(drm_device_t * dev, DRMFILE filp, struct mem_block *heap)
 195 {
 196         struct mem_block *p;
 197
 198         if (!heap || !heap->next)
 199                 return;
 200
 201         for (p = heap->next; p != heap; p = p->next) {
 202                 if (p->filp == filp) {
 203                         p->filp = NULL;
 204                         mark_block(dev, p, 0);
 205                 }
 206         }
 207
 208         /* Assumes a single contiguous range.  Needs a special filp in
 209          * 'heap' to stop it being subsumed.
 210          */
 211         for (p = heap->next; p != heap; p = p->next) {
 212                 while (p->filp == NULL && p->next->filp == NULL) {
 213                         struct mem_block *q = p->next;
 214                         p->size += q->size;
 215                         p->next = q->next;
 216                         p->next->prev = p;
 217                         drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 218                 }
 219         }
 220 }
 221
 222 /* Shutdown.
 223  */
 224 void i915_mem_takedown(struct mem_block **heap)
 225 {
 226         struct mem_block *p;
 227
 228         if (!*heap)
 229                 return;
 230
 231         for (p = (*heap)->next; p != *heap;) {
 232                 struct mem_block *q = p;
 233                 p = p->next;
 234                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 235         }
 236
 237         drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
 238         *heap = NULL;
 239 }
 240
 241 static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
 242 {
 243         switch (region) {
 244         case I915_MEM_REGION_AGP:
 245                 return &dev_priv->agp_heap;
 246         default:
 247                 return NULL;
 248         }
 249 }
 250
 251 /* IOCTL HANDLERS */
 252
 253 int i915_mem_alloc(DRM_IOCTL_ARGS)
 254 {
 255         DRM_DEVICE;
 256         drm_i915_private_t *dev_priv = dev->dev_private;
 257         drm_i915_mem_alloc_t alloc;
 258         struct mem_block *block, **heap;
 259
 260         if (!dev_priv) {
 261                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 262                 return DRM_ERR(EINVAL);
 263         }
 264
 265         DRM_COPY_FROM_USER_IOCTL(alloc, (drm_i915_mem_alloc_t __user *) data,
 266                                  sizeof(alloc));
 267
 268         heap = get_heap(dev_priv, alloc.region);
 269         if (!heap || !*heap)
 270                 return DRM_ERR(EFAULT);
 271
 272         /* Make things easier on ourselves: all allocations at least
 273          * 4k aligned.
 274          */
 275         if (alloc.alignment < 12)
 276                 alloc.alignment = 12;
 277
 278         block = alloc_block(*heap, alloc.size, alloc.alignment, filp);
 279
 280         if (!block)
 281                 return DRM_ERR(ENOMEM);
 282
 283         mark_block(dev, block, 1);
 284
 285         if (DRM_COPY_TO_USER(alloc.region_offset, &block->start, sizeof(int))) {
 286                 DRM_ERROR("copy_to_user\n");
 287                 return DRM_ERR(EFAULT);
 288         }
 289
 290         return 0;
 291 }
 292
 293 int i915_mem_free(DRM_IOCTL_ARGS)
 294 {
 295         DRM_DEVICE;
 296         drm_i915_private_t *dev_priv = dev->dev_private;
 297         drm_i915_mem_free_t memfree;
 298         struct mem_block *block, **heap;
 299
 300         if (!dev_priv) {
 301                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 302                 return DRM_ERR(EINVAL);
 303         }
 304
 305         DRM_COPY_FROM_USER_IOCTL(memfree, (drm_i915_mem_free_t __user *) data,
 306                                  sizeof(memfree));
 307
 308         heap = get_heap(dev_priv, memfree.region);
 309         if (!heap || !*heap)
 310                 return DRM_ERR(EFAULT);
 311
 312         block = find_block(*heap, memfree.region_offset);
 313         if (!block)
 314                 return DRM_ERR(EFAULT);
 315
 316         if (block->filp != filp)
 317                 return DRM_ERR(EPERM);
 318
 319         mark_block(dev, block, 0);
 320         free_block(block);
 321         return 0;
 322 }
 323
 324 int i915_mem_init_heap(DRM_IOCTL_ARGS)
 325 {
 326         DRM_DEVICE;
 327         drm_i915_private_t *dev_priv = dev->dev_private;
 328         drm_i915_mem_init_heap_t initheap;
 329         struct mem_block **heap;
 330
 331         if (!dev_priv) {
 332                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 333                 return DRM_ERR(EINVAL);
 334         }
 335
 336         DRM_COPY_FROM_USER_IOCTL(initheap,
 337                                  (drm_i915_mem_init_heap_t __user *) data,
 338                                  sizeof(initheap));
 339
 340         heap = get_heap(dev_priv, initheap.region);
 341         if (!heap)
 342                 return DRM_ERR(EFAULT);
 343
 344         if (*heap) {
 345                 DRM_ERROR("heap already initialized?");
 346                 return DRM_ERR(EFAULT);
 347         }
 348
 349         return init_heap(heap, initheap.start, initheap.size);
 350 }