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 = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
  98                 if (!newblock)
  99                         goto out;
 100                 newblock->start = start;
 101                 newblock->size = p->size - (start - p->start);
 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 -= newblock->size;
 108                 p = newblock;
 109         }
 110
 111         /* Maybe cut off the end of an existing block */
 112         if (size < p->size) {
 113                 struct mem_block *newblock = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
 114                 if (!newblock)
 115                         goto out;
 116                 newblock->start = start + size;
 117                 newblock->size = p->size - size;
 118                 newblock->filp = NULL;
 119                 newblock->next = p->next;
 120                 newblock->prev = p;
 121                 p->next->prev = newblock;
 122                 p->next = newblock;
 123                 p->size = size;
 124         }
 125
 126       out:
 127         /* Our block is in the middle */
 128         p->filp = filp;
 129         return p;
 130 }
 131
 132 static struct mem_block *alloc_block(struct mem_block *heap, int size,
 133                                      int align2, DRMFILE filp)
 134 {
 135         struct mem_block *p;
 136         int mask = (1 << align2) - 1;
 137
 138         for (p = heap->next; p != heap; p = p->next) {
 139                 int start = (p->start + mask) & ~mask;
 140                 if (p->filp == NULL && start + size <= p->start + p->size)
 141                         return split_block(p, start, size, filp);
 142         }
 143
 144         return NULL;
 145 }
 146
 147 static struct mem_block *find_block(struct mem_block *heap, int start)
 148 {
 149         struct mem_block *p;
 150
 151         for (p = heap->next; p != heap; p = p->next)
 152                 if (p->start == start)
 153                         return p;
 154
 155         return NULL;
 156 }
 157
 158 static void free_block(struct mem_block *p)
 159 {
 160         p->filp = NULL;
 161
 162         /* Assumes a single contiguous range.  Needs a special filp in
 163          * 'heap' to stop it being subsumed.
 164          */
 165         if (p->next->filp == NULL) {
 166                 struct mem_block *q = p->next;
 167                 p->size += q->size;
 168                 p->next = q->next;
 169                 p->next->prev = p;
 170                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 171         }
 172
 173         if (p->prev->filp == NULL) {
 174                 struct mem_block *q = p->prev;
 175                 q->size += p->size;
 176                 q->next = p->next;
 177                 q->next->prev = q;
 178                 drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
 179         }
 180 }
 181
 182 /* Initialize.  How to check for an uninitialized heap?
 183  */
 184 static int init_heap(struct mem_block **heap, int start, int size)
 185 {
 186         struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
 187
 188         if (!blocks)
 189                 return -ENOMEM;
 190
 191         *heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
 192         if (!*heap) {
 193                 drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
 194                 return -ENOMEM;
 195         }
 196
 197         blocks->start = start;
 198         blocks->size = size;
 199         blocks->filp = NULL;
 200         blocks->next = blocks->prev = *heap;
 201
 202         memset(*heap, 0, sizeof(**heap));
 203         (*heap)->filp = (DRMFILE) - 1;
 204         (*heap)->next = (*heap)->prev = blocks;
 205         return 0;
 206 }
 207
 208 /* Free all blocks associated with the releasing file.
 209  */
 210 void i915_mem_release(drm_device_t * dev, DRMFILE filp, struct mem_block *heap)
 211 {
 212         struct mem_block *p;
 213
 214         if (!heap || !heap->next)
 215                 return;
 216
 217         for (p = heap->next; p != heap; p = p->next) {
 218                 if (p->filp == filp) {
 219                         p->filp = NULL;
 220                         mark_block(dev, p, 0);
 221                 }
 222         }
 223
 224         /* Assumes a single contiguous range.  Needs a special filp in
 225          * 'heap' to stop it being subsumed.
 226          */
 227         for (p = heap->next; p != heap; p = p->next) {
 228                 while (p->filp == NULL && p->next->filp == NULL) {
 229                         struct mem_block *q = p->next;
 230                         p->size += q->size;
 231                         p->next = q->next;
 232                         p->next->prev = p;
 233                         drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 234                 }
 235         }
 236 }
 237
 238 /* Shutdown.
 239  */
 240 void i915_mem_takedown(struct mem_block **heap)
 241 {
 242         struct mem_block *p;
 243
 244         if (!*heap)
 245                 return;
 246
 247         for (p = (*heap)->next; p != *heap;) {
 248                 struct mem_block *q = p;
 249                 p = p->next;
 250                 drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
 251         }
 252
 253         drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
 254         *heap = NULL;
 255 }
 256
 257 static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
 258 {
 259         switch (region) {
 260         case I915_MEM_REGION_AGP:
 261                 return &dev_priv->agp_heap;
 262         default:
 263                 return NULL;
 264         }
 265 }
 266
 267 /* IOCTL HANDLERS */
 268
 269 int i915_mem_alloc(DRM_IOCTL_ARGS)
 270 {
 271         DRM_DEVICE;
 272         drm_i915_private_t *dev_priv = dev->dev_private;
 273         drm_i915_mem_alloc_t alloc;
 274         struct mem_block *block, **heap;
 275
 276         if (!dev_priv) {
 277                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 278                 return DRM_ERR(EINVAL);
 279         }
 280
 281         DRM_COPY_FROM_USER_IOCTL(alloc, (drm_i915_mem_alloc_t __user *) data,
 282                                  sizeof(alloc));
 283
 284         heap = get_heap(dev_priv, alloc.region);
 285         if (!heap || !*heap)
 286                 return DRM_ERR(EFAULT);
 287
 288         /* Make things easier on ourselves: all allocations at least
 289          * 4k aligned.
 290          */
 291         if (alloc.alignment < 12)
 292                 alloc.alignment = 12;
 293
 294         block = alloc_block(*heap, alloc.size, alloc.alignment, filp);
 295
 296         if (!block)
 297                 return DRM_ERR(ENOMEM);
 298
 299         mark_block(dev, block, 1);
 300
 301         if (DRM_COPY_TO_USER(alloc.region_offset, &block->start, sizeof(int))) {
 302                 DRM_ERROR("copy_to_user\n");
 303                 return DRM_ERR(EFAULT);
 304         }
 305
 306         return 0;
 307 }
 308
 309 int i915_mem_free(DRM_IOCTL_ARGS)
 310 {
 311         DRM_DEVICE;
 312         drm_i915_private_t *dev_priv = dev->dev_private;
 313         drm_i915_mem_free_t memfree;
 314         struct mem_block *block, **heap;
 315
 316         if (!dev_priv) {
 317                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 318                 return DRM_ERR(EINVAL);
 319         }
 320
 321         DRM_COPY_FROM_USER_IOCTL(memfree, (drm_i915_mem_free_t __user *) data,
 322                                  sizeof(memfree));
 323
 324         heap = get_heap(dev_priv, memfree.region);
 325         if (!heap || !*heap)
 326                 return DRM_ERR(EFAULT);
 327
 328         block = find_block(*heap, memfree.region_offset);
 329         if (!block)
 330                 return DRM_ERR(EFAULT);
 331
 332         if (block->filp != filp)
 333                 return DRM_ERR(EPERM);
 334
 335         mark_block(dev, block, 0);
 336         free_block(block);
 337         return 0;
 338 }
 339
 340 int i915_mem_init_heap(DRM_IOCTL_ARGS)
 341 {
 342         DRM_DEVICE;
 343         drm_i915_private_t *dev_priv = dev->dev_private;
 344         drm_i915_mem_init_heap_t initheap;
 345         struct mem_block **heap;
 346
 347         if (!dev_priv) {
 348                 DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
 349                 return DRM_ERR(EINVAL);
 350         }
 351
 352         DRM_COPY_FROM_USER_IOCTL(initheap,
 353                                  (drm_i915_mem_init_heap_t __user *) data,
 354                                  sizeof(initheap));
 355
 356         heap = get_heap(dev_priv, initheap.region);
 357         if (!heap)
 358                 return DRM_ERR(EFAULT);
 359
 360         if (*heap) {
 361                 DRM_ERROR("heap already initialized?");
 362                 return DRM_ERR(EFAULT);
 363         }
 364
 365         return init_heap(heap, initheap.start, initheap.size);
 366 }