drivers/char/drm/i915_mem.c

   1 /* i915_mem.c -- Simple agp/fb memory manager for i915 -*- linux-c -*-
   2  */
   3 /**************************************************************************
   4  *
   5  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  21  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  23  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  24  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  25  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  26  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30 #include "drmP.h"
  31 #include "drm.h"
  32 #include "i915_drm.h"
  33 #include "i915_drv.h"
  34
  35 /* This memory manager is integrated into the global/local lru
  36  * mechanisms used by the clients.  Specifically, it operates by
  37  * setting the 'in_use' fields of the global LRU to indicate whether
  38  * this region is privately allocated to a client.
  39  *
  40  * This does require the client to actually respect that field.
  41  *
  42  * Currently no effort is made to allocate 'private' memory in any
  43  * clever way - the LRU information isn't used to determine which
  44  * block to allocate, and the ring is drained prior to allocations --
  45  * in other words allocation is expensive.
  46  */
  47 static void mark_block(drm_device_t * dev, struct mem_block *p, int in_use)
  48 {
  49         drm_i915_private_t *dev_priv = dev->dev_private;
  50         drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
  51         drm_tex_region_t *list;
  52         unsigned shift, nr;
  53         unsigned start;
  54         unsigned end;
  55         unsigned i;
  56         int age;
  57
  58         shift = dev_priv->tex_lru_log_granularity;
  59         nr = I915_NR_TEX_REGIONS;
  60
  61         start = p->start >> shift;
  62         end = (p->start + p->size - 1) >> shift;
  63
  64         age = ++sarea_priv->texAge;
  65         list = sarea_priv->texList;
  66
  67         /* Mark the regions with the new flag and update their age.  Move
  68          * them to head of list to preserve LRU semantics.
  69          */
  70         for (i = start; i <= end; i++) {
  71                 list[i].in_use = in_use;
  72                 list[i].age = age;
  73
  74                 /* remove_from_list(i)
  75                  */
  76                 list[(unsigned)list[i].next].prev = list[i].prev;
  77                 list[(unsigned)list[i].prev].next = list[i].next;
  78
  79                 /* insert_at_head(list, i)
  80                  */
  81                 list[i].prev = nr;
  82                 list[i].next = list[nr].next;
  83                 list[(unsigned)list[nr].next].prev = i;
  84                 list[nr].next = i;
  85         }
  86 }
  87
  88 /* Very simple allocator for agp memory, working on a static range
  89  * already mapped into each client's address space.
  90  */
  91
  92 static struct mem_block *split_block(struct mem_block *p, int start, int size,
  93                                      DRMFILE filp)
  94 {
  95         /* Maybe cut off the start of an existing block */
  96         if (start > p->start) {
  97                 struct mem_block *newblock =
  98                     drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
  99                 if (!newblock)
 100                         goto out;
 101                 newblock->start = start;
 102                 newblock->size = p->size - (start - p->start);
 103                 newblock->filp = NULL;
 104                 newblock->next = p->next;
 105                 newblock->prev = p;
 106                 p->next->prev = newblock;
 107                 p->next = newblock;
 108                 p->size -= newblock->size;
 109                 p = newblock;
 110         }
 111
 112         /* Maybe cut off the end of an existing block */
 113         if (size < p->size) {
 114                 struct mem_block *newblock =
 115                     drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
 116                 if (!newblock)
 117                         goto out;
 118                 newblock->start = start + size;
 119                 newblock->size = p->size - size;
 120                 newblock->filp = NULL;
 121                 newblock->next = p->next;
 122                 newblock->prev = p;
 123                 p->next->prev = newblock;
 124                 p->next = newblock;
 125                 p->size = size;
 126         }
 127
 128       out:
 129         /* Our block is in the middle */
 130         p->filp = filp;
 131         return p;
 132 }
 133
 134 static struct mem_block *alloc_block(struct mem_block *heap, int size,
 135                                      int align2, DRMFILE filp)
 136 {
 137         struct mem_block *p;
 138         int mask = (1 << align2) - 1;
 139
 140         for (p = heap->next; p != heap; p = p->next) {
 141                 int start = (p->start + mask) & ~mask;
 142                 if (p->filp == NULL && start + size <= p->start + p->size)
 143                         return split_block(p, start, size, filp);
 144         }
 145
 146         return NULL;
 147 }
 148
 149 static struct mem_block *find_block(struct mem_block *heap, int start)
 150 {
 151         struct mem_block *p;
 152
 153         for (p = heap->next; p != heap; p = p->next)
 154                 if (p->start == start)
 155                         return p;
 156
 157         return NULL;
 158 }
 159
 160 static void free_block(struct mem_block *p)
 161 {
 162         p->filp = NULL;
 163
 164         /* Assumes a single contiguous range.  Needs a special filp in
 165          * 'heap' to stop it being subsumed.
 166          */
 167         if (p->next->filp == NULL) {
 168                 struct mem_block *q = p->next;
 169                 p->size += q->size;
 170                 p->next = q->next;
 171                 p->next->prev = p;
 172                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 173         }
 174
 175         if (p->prev->filp == NULL) {
 176                 struct mem_block *q = p->prev;
 177                 q->size += p->size;
 178                 q->next = p->next;
 179                 q->next->prev = q;
 180                 drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
 181         }
 182 }
 183
 184 /* Initialize.  How to check for an uninitialized heap?
 185  */
 186 static int init_heap(struct mem_block **heap, int start, int size)
 187 {
 188         struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
 189
 190         if (!blocks)
 191                 return -ENOMEM;
 192
 193         *heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
 194         if (!*heap) {
 195                 drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
 196                 return -ENOMEM;
 197         }
 198
 199         blocks->start = start;
 200         blocks->size = size;
 201         blocks->filp = NULL;
 202         blocks->next = blocks->prev = *heap;
 203
 204         memset(*heap, 0, sizeof(**heap));
 205         (*heap)->filp = (DRMFILE) - 1;
 206         (*heap)->next = (*heap)->prev = blocks;
 207         return 0;
 208 }
 209
 210 /* Free all blocks associated with the releasing file.
 211  */
 212 void i915_mem_release(drm_device_t * dev, DRMFILE filp, struct mem_block *heap)
 213 {
 214         struct mem_block *p;
 215
 216         if (!heap || !heap->next)
 217                 return;
 218
 219         for (p = heap->next; p != heap; p = p->next) {
 220                 if (p->filp == filp) {
 221                         p->filp = NULL;
 222                         mark_block(dev, p, 0);
 223                 }
 224         }
 225
 226         /* Assumes a single contiguous range.  Needs a special filp in
 227          * 'heap' to stop it being subsumed.
 228          */
 229         for (p = heap->next; p != heap; p = p->next) {
 230                 while (p->filp == NULL && p->next->filp == NULL) {
 231                         struct mem_block *q = p->next;
 232                         p->size += q->size;
 233                         p->next = q->next;
 234                         p->next->prev = p;
 235                         drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 236                 }
 237         }
 238 }
 239
 240 /* Shutdown.
 241  */
 242 void i915_mem_takedown(struct mem_block **heap)
 243 {
 244         struct mem_block *p;
 245
 246         if (!*heap)
 247                 return;
 248
 249         for (p = (*heap)->next; p != *heap;) {
 250                 struct mem_block *q = p;
 251                 p = p->next;
 252                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 253         }
 254
 255         drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
 256         *heap = NULL;
 257 }
 258
 259 static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
 260 {
 261         switch (region) {
 262         case I915_MEM_REGION_AGP:
 263                 return &dev_priv->agp_heap;
 264         default:
 265                 return NULL;
 266         }
 267 }
 268
 269 /* IOCTL HANDLERS */
 270
 271 int i915_mem_alloc(DRM_IOCTL_ARGS)
 272 {
 273         DRM_DEVICE;
 274         drm_i915_private_t *dev_priv = dev->dev_private;
 275         drm_i915_mem_alloc_t alloc;
 276         struct mem_block *block, **heap;
 277
 278         if (!dev_priv) {
 279                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 280                 return DRM_ERR(EINVAL);
 281         }
 282
 283         DRM_COPY_FROM_USER_IOCTL(alloc, (drm_i915_mem_alloc_t __user *) data,
 284                                  sizeof(alloc));
 285
 286         heap = get_heap(dev_priv, alloc.region);
 287         if (!heap || !*heap)
 288                 return DRM_ERR(EFAULT);
 289
 290         /* Make things easier on ourselves: all allocations at least
 291          * 4k aligned.
 292          */
 293         if (alloc.alignment < 12)
 294                 alloc.alignment = 12;
 295
 296         block = alloc_block(*heap, alloc.size, alloc.alignment, filp);
 297
 298         if (!block)
 299                 return DRM_ERR(ENOMEM);
 300
 301         mark_block(dev, block, 1);
 302
 303         if (DRM_COPY_TO_USER(alloc.region_offset, &block->start, sizeof(int))) {
 304                 DRM_ERROR("copy_to_user\n");
 305                 return DRM_ERR(EFAULT);
 306         }
 307
 308         return 0;
 309 }
 310
 311 int i915_mem_free(DRM_IOCTL_ARGS)
 312 {
 313         DRM_DEVICE;
 314         drm_i915_private_t *dev_priv = dev->dev_private;
 315         drm_i915_mem_free_t memfree;
 316         struct mem_block *block, **heap;
 317
 318         if (!dev_priv) {
 319                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 320                 return DRM_ERR(EINVAL);
 321         }
 322
 323         DRM_COPY_FROM_USER_IOCTL(memfree, (drm_i915_mem_free_t __user *) data,
 324                                  sizeof(memfree));
 325
 326         heap = get_heap(dev_priv, memfree.region);
 327         if (!heap || !*heap)
 328                 return DRM_ERR(EFAULT);
 329
 330         block = find_block(*heap, memfree.region_offset);
 331         if (!block)
 332                 return DRM_ERR(EFAULT);
 333
 334         if (block->filp != filp)
 335                 return DRM_ERR(EPERM);
 336
 337         mark_block(dev, block, 0);
 338         free_block(block);
 339         return 0;
 340 }
 341
 342 int i915_mem_init_heap(DRM_IOCTL_ARGS)
 343 {
 344         DRM_DEVICE;
 345         drm_i915_private_t *dev_priv = dev->dev_private;
 346         drm_i915_mem_init_heap_t initheap;
 347         struct mem_block **heap;
 348
 349         if (!dev_priv) {
 350                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 351                 return DRM_ERR(EINVAL);
 352         }
 353
 354         DRM_COPY_FROM_USER_IOCTL(initheap,
 355                                  (drm_i915_mem_init_heap_t __user *) data,
 356                                  sizeof(initheap));
 357
 358         heap = get_heap(dev_priv, initheap.region);
 359         if (!heap)
 360                 return DRM_ERR(EFAULT);
 361
 362         if (*heap) {
 363                 DRM_ERROR("heap already initialized?");
 364                 return DRM_ERR(EFAULT);
 365         }
 366
 367         return init_heap(heap, initheap.start, initheap.size);
 368 }