1 /* i915_mem.c -- Simple agp/fb memory manager for i915 -*- linux-c -*-
2  */
3 /*
4  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
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
20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
22  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26  *
27  */
28 
29 #include "drmP.h"
30 #include "drm.h"
31 #include "i915_drm.h"
32 #include "i915_drv.h"
33 
34 /* This memory manager is integrated into the global/local lru
35  * mechanisms used by the clients.  Specifically, it operates by
36  * setting the 'in_use' fields of the global LRU to indicate whether
37  * this region is privately allocated to a client.
38  *
39  * This does require the client to actually respect that field.
40  *
41  * Currently no effort is made to allocate 'private' memory in any
42  * clever way - the LRU information isn't used to determine which
43  * block to allocate, and the ring is drained prior to allocations --
44  * in other words allocation is expensive.
45  */
mark_block(struct drm_device * dev,struct mem_block * p,int in_use)46 static void mark_block(struct drm_device * dev, struct mem_block *p, int in_use)
47 {
48           drm_i915_private_t *dev_priv = dev->dev_private;
49           drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
50           struct drm_tex_region *list;
51           unsigned shift, nr;
52           unsigned start;
53           unsigned end;
54           unsigned i;
55           int age;
56 
57           shift = dev_priv->tex_lru_log_granularity;
58           nr = I915_NR_TEX_REGIONS;
59 
60           start = p->start >> shift;
61           end = (p->start + p->size - 1) >> shift;
62 
63           age = ++sarea_priv->texAge;
64           list = sarea_priv->texList;
65 
66           /* Mark the regions with the new flag and update their age.  Move
67            * them to head of list to preserve LRU semantics.
68            */
69           for (i = start; i <= end; i++) {
70                     list[i].in_use = in_use;
71                     list[i].age = age;
72 
73                     /* remove_from_list(i)
74                      */
75                     list[(unsigned)list[i].next].prev = list[i].prev;
76                     list[(unsigned)list[i].prev].next = list[i].next;
77 
78                     /* insert_at_head(list, i)
79                      */
80                     list[i].prev = nr;
81                     list[i].next = list[nr].next;
82                     list[(unsigned)list[nr].next].prev = i;
83                     list[nr].next = i;
84           }
85 }
86 
87 /* Very simple allocator for agp memory, working on a static range
88  * already mapped into each client's address space.
89  */
90 
split_block(struct mem_block * p,int start,int size,struct drm_file * file_priv)91 static struct mem_block *split_block(struct mem_block *p, int start, int size,
92                                              struct drm_file *file_priv)
93 {
94           /* Maybe cut off the start of an existing block */
95           if (start > p->start) {
96                     struct mem_block *newblock =
97                         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->file_priv = 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 =
114                         drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
115                     if (!newblock)
116                               goto out;
117                     newblock->start = start + size;
118                     newblock->size = p->size - size;
119                     newblock->file_priv = NULL;
120                     newblock->next = p->next;
121                     newblock->prev = p;
122                     p->next->prev = newblock;
123                     p->next = newblock;
124                     p->size = size;
125           }
126 
127       out:
128           /* Our block is in the middle */
129           p->file_priv = file_priv;
130           return p;
131 }
132 
alloc_block(struct mem_block * heap,int size,int align2,struct drm_file * file_priv)133 static struct mem_block *alloc_block(struct mem_block *heap, int size,
134                                              int align2, struct drm_file *file_priv)
135 {
136           struct mem_block *p;
137           int mask = (1 << align2) - 1;
138 
139           for (p = heap->next; p != heap; p = p->next) {
140                     int start = (p->start + mask) & ~mask;
141                     if (p->file_priv == NULL && start + size <= p->start + p->size)
142                               return split_block(p, start, size, file_priv);
143           }
144 
145           return NULL;
146 }
147 
find_block(struct mem_block * heap,int start)148 static struct mem_block *find_block(struct mem_block *heap, int start)
149 {
150           struct mem_block *p;
151 
152           for (p = heap->next; p != heap; p = p->next)
153                     if (p->start == start)
154                               return p;
155 
156           return NULL;
157 }
158 
free_block(struct mem_block * p)159 static void free_block(struct mem_block *p)
160 {
161           p->file_priv = NULL;
162 
163           /* Assumes a single contiguous range.  Needs a special file_priv in
164            * 'heap' to stop it being subsumed.
165            */
166           if (p->next->file_priv == NULL) {
167                     struct mem_block *q = p->next;
168                     p->size += q->size;
169                     p->next = q->next;
170                     p->next->prev = p;
171                     drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
172           }
173 
174           if (p->prev->file_priv == NULL) {
175                     struct mem_block *q = p->prev;
176                     q->size += p->size;
177                     q->next = p->next;
178                     q->next->prev = q;
179                     drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
180           }
181 }
182 
183 /* Initialize.  How to check for an uninitialized heap?
184  */
init_heap(struct mem_block ** heap,int start,int size)185 static int init_heap(struct mem_block **heap, int start, int size)
186 {
187           struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
188 
189           if (!blocks)
190                     return -ENOMEM;
191 
192           *heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
193           if (!*heap) {
194                     drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
195                     return -ENOMEM;
196           }
197 
198           blocks->start = start;
199           blocks->size = size;
200           blocks->file_priv = NULL;
201           blocks->next = blocks->prev = *heap;
202 
203           memset(*heap, 0, sizeof(**heap));
204           (*heap)->file_priv = (struct drm_file *) - 1;
205           (*heap)->next = (*heap)->prev = blocks;
206           return 0;
207 }
208 
209 /* Free all blocks associated with the releasing file.
210  */
i915_mem_release(struct drm_device * dev,struct drm_file * file_priv,struct mem_block * heap)211 void i915_mem_release(struct drm_device * dev, struct drm_file *file_priv,
212                           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->file_priv == file_priv) {
221                               p->file_priv = NULL;
222                               mark_block(dev, p, 0);
223                     }
224           }
225 
226           /* Assumes a single contiguous range.  Needs a special file_priv in
227            * 'heap' to stop it being subsumed.
228            */
229           for (p = heap->next; p != heap; p = p->next) {
230                     while (p->file_priv == NULL && p->next->file_priv == 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  */
i915_mem_takedown(struct mem_block ** heap)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 
get_heap(drm_i915_private_t * dev_priv,int region)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 
i915_mem_alloc(struct drm_device * dev,void * data,struct drm_file * file_priv)271 int i915_mem_alloc(struct drm_device *dev, void *data,
272                        struct drm_file *file_priv)
273 {
274           drm_i915_private_t *dev_priv = dev->dev_private;
275           drm_i915_mem_alloc_t *alloc = data;
276           struct mem_block *block, **heap;
277 
278           if (!dev_priv) {
279                     DRM_ERROR("called with no initialization\n");
280                     return -EINVAL;
281           }
282 
283           heap = get_heap(dev_priv, alloc->region);
284           if (!heap || !*heap)
285                     return -EFAULT;
286 
287           /* Make things easier on ourselves: all allocations at least
288            * 4k aligned.
289            */
290           if (alloc->alignment < 12)
291                     alloc->alignment = 12;
292 
293           block = alloc_block(*heap, alloc->size, alloc->alignment, file_priv);
294 
295           if (!block)
296                     return -ENOMEM;
297 
298           mark_block(dev, block, 1);
299 
300           if (DRM_COPY_TO_USER(alloc->region_offset, &block->start,
301                                    sizeof(int))) {
302                     DRM_ERROR("copy_to_user\n");
303                     return -EFAULT;
304           }
305 
306           return 0;
307 }
308 
i915_mem_free(struct drm_device * dev,void * data,struct drm_file * file_priv)309 int i915_mem_free(struct drm_device *dev, void *data,
310                       struct drm_file *file_priv)
311 {
312           drm_i915_private_t *dev_priv = dev->dev_private;
313           drm_i915_mem_free_t *memfree = data;
314           struct mem_block *block, **heap;
315 
316           if (!dev_priv) {
317                     DRM_ERROR("called with no initialization\n");
318                     return -EINVAL;
319           }
320 
321           heap = get_heap(dev_priv, memfree->region);
322           if (!heap || !*heap)
323                     return -EFAULT;
324 
325           block = find_block(*heap, memfree->region_offset);
326           if (!block)
327                     return -EFAULT;
328 
329           if (block->file_priv != file_priv)
330                     return -EPERM;
331 
332           mark_block(dev, block, 0);
333           free_block(block);
334           return 0;
335 }
336 
i915_mem_init_heap(struct drm_device * dev,void * data,struct drm_file * file_priv)337 int i915_mem_init_heap(struct drm_device *dev, void *data,
338                            struct drm_file *file_priv)
339 {
340           drm_i915_private_t *dev_priv = dev->dev_private;
341           drm_i915_mem_init_heap_t *initheap = data;
342           struct mem_block **heap;
343 
344           if (!dev_priv) {
345                     DRM_ERROR("called with no initialization\n");
346                     return -EINVAL;
347           }
348 
349           heap = get_heap(dev_priv, initheap->region);
350           if (!heap)
351                     return -EFAULT;
352 
353           if (*heap) {
354                     DRM_ERROR("heap already initialized?");
355                     return -EFAULT;
356           }
357 
358           return init_heap(heap, initheap->start, initheap->size);
359 }
360 
i915_mem_destroy_heap(struct drm_device * dev,void * data,struct drm_file * file_priv)361 int i915_mem_destroy_heap( struct drm_device *dev, void *data,
362                                  struct drm_file *file_priv )
363 {
364           drm_i915_private_t *dev_priv = dev->dev_private;
365           drm_i915_mem_destroy_heap_t *destroyheap = data;
366           struct mem_block **heap;
367 
368           if ( !dev_priv ) {
369                     DRM_ERROR( "called with no initialization\n" );
370                     return -EINVAL;
371           }
372 
373           heap = get_heap( dev_priv, destroyheap->region );
374           if (!heap) {
375                     DRM_ERROR("get_heap failed");
376                     return -EFAULT;
377           }
378 
379           if (!*heap) {
380                     DRM_ERROR("heap not initialized?");
381                     return -EFAULT;
382           }
383 
384           i915_mem_takedown( heap );
385           return 0;
386 }
387