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 <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include "dev/drm/drmP.h"
33#include "dev/drm/drm.h"
34#include "dev/drm/i915_drm.h"
35#include "dev/drm/i915_drv.h"
36
37/* This memory manager is integrated into the global/local lru
38 * mechanisms used by the clients.  Specifically, it operates by
39 * setting the 'in_use' fields of the global LRU to indicate whether
40 * this region is privately allocated to a client.
41 *
42 * This does require the client to actually respect that field.
43 *
44 * Currently no effort is made to allocate 'private' memory in any
45 * clever way - the LRU information isn't used to determine which
46 * block to allocate, and the ring is drained prior to allocations --
47 * in other words allocation is expensive.
48 */
49static void mark_block(struct drm_device * dev, struct mem_block *p, int in_use)
50{
51	drm_i915_private_t *dev_priv = dev->dev_private;
52	drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
53	struct drm_tex_region *list;
54	unsigned shift, nr;
55	unsigned start;
56	unsigned end;
57	unsigned i;
58	int age;
59
60	shift = dev_priv->tex_lru_log_granularity;
61	nr = I915_NR_TEX_REGIONS;
62
63	start = p->start >> shift;
64	end = (p->start + p->size - 1) >> shift;
65
66	age = ++sarea_priv->texAge;
67	list = sarea_priv->texList;
68
69	/* Mark the regions with the new flag and update their age.  Move
70	 * them to head of list to preserve LRU semantics.
71	 */
72	for (i = start; i <= end; i++) {
73		list[i].in_use = in_use;
74		list[i].age = age;
75
76		/* remove_from_list(i)
77		 */
78		list[(unsigned)list[i].next].prev = list[i].prev;
79		list[(unsigned)list[i].prev].next = list[i].next;
80
81		/* insert_at_head(list, i)
82		 */
83		list[i].prev = nr;
84		list[i].next = list[nr].next;
85		list[(unsigned)list[nr].next].prev = i;
86		list[nr].next = i;
87	}
88}
89
90/* Very simple allocator for agp memory, working on a static range
91 * already mapped into each client's address space.
92 */
93
94static struct mem_block *split_block(struct mem_block *p, int start, int size,
95				     struct drm_file *file_priv)
96{
97	/* Maybe cut off the start of an existing block */
98	if (start > p->start) {
99		struct mem_block *newblock =
100		    drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
101		if (!newblock)
102			goto out;
103		newblock->start = start;
104		newblock->size = p->size - (start - p->start);
105		newblock->file_priv = NULL;
106		newblock->next = p->next;
107		newblock->prev = p;
108		p->next->prev = newblock;
109		p->next = newblock;
110		p->size -= newblock->size;
111		p = newblock;
112	}
113
114	/* Maybe cut off the end of an existing block */
115	if (size < p->size) {
116		struct mem_block *newblock =
117		    drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
118		if (!newblock)
119			goto out;
120		newblock->start = start + size;
121		newblock->size = p->size - size;
122		newblock->file_priv = NULL;
123		newblock->next = p->next;
124		newblock->prev = p;
125		p->next->prev = newblock;
126		p->next = newblock;
127		p->size = size;
128	}
129
130      out:
131	/* Our block is in the middle */
132	p->file_priv = file_priv;
133	return p;
134}
135
136static struct mem_block *alloc_block(struct mem_block *heap, int size,
137				     int align2, struct drm_file *file_priv)
138{
139	struct mem_block *p;
140	int mask = (1 << align2) - 1;
141
142	for (p = heap->next; p != heap; p = p->next) {
143		int start = (p->start + mask) & ~mask;
144		if (p->file_priv == NULL && start + size <= p->start + p->size)
145			return split_block(p, start, size, file_priv);
146	}
147
148	return NULL;
149}
150
151static struct mem_block *find_block(struct mem_block *heap, int start)
152{
153	struct mem_block *p;
154
155	for (p = heap->next; p != heap; p = p->next)
156		if (p->start == start)
157			return p;
158
159	return NULL;
160}
161
162static void free_block(struct mem_block *p)
163{
164	p->file_priv = NULL;
165
166	/* Assumes a single contiguous range.  Needs a special file_priv in
167	 * 'heap' to stop it being subsumed.
168	 */
169	if (p->next->file_priv == NULL) {
170		struct mem_block *q = p->next;
171		p->size += q->size;
172		p->next = q->next;
173		p->next->prev = p;
174		drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
175	}
176
177	if (p->prev->file_priv == NULL) {
178		struct mem_block *q = p->prev;
179		q->size += p->size;
180		q->next = p->next;
181		q->next->prev = q;
182		drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
183	}
184}
185
186/* Initialize.  How to check for an uninitialized heap?
187 */
188static int init_heap(struct mem_block **heap, int start, int size)
189{
190	struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
191
192	if (!blocks)
193		return -ENOMEM;
194
195	*heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
196	if (!*heap) {
197		drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
198		return -ENOMEM;
199	}
200
201	blocks->start = start;
202	blocks->size = size;
203	blocks->file_priv = NULL;
204	blocks->next = blocks->prev = *heap;
205
206	memset(*heap, 0, sizeof(**heap));
207	(*heap)->file_priv = (struct drm_file *) - 1;
208	(*heap)->next = (*heap)->prev = blocks;
209	return 0;
210}
211
212/* Free all blocks associated with the releasing file.
213 */
214void i915_mem_release(struct drm_device * dev, struct drm_file *file_priv,
215		      struct mem_block *heap)
216{
217	struct mem_block *p;
218
219	if (!heap || !heap->next)
220		return;
221
222	for (p = heap->next; p != heap; p = p->next) {
223		if (p->file_priv == file_priv) {
224			p->file_priv = NULL;
225			mark_block(dev, p, 0);
226		}
227	}
228
229	/* Assumes a single contiguous range.  Needs a special file_priv in
230	 * 'heap' to stop it being subsumed.
231	 */
232	for (p = heap->next; p != heap; p = p->next) {
233		while (p->file_priv == NULL && p->next->file_priv == NULL) {
234			struct mem_block *q = p->next;
235			p->size += q->size;
236			p->next = q->next;
237			p->next->prev = p;
238			drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
239		}
240	}
241}
242
243/* Shutdown.
244 */
245void i915_mem_takedown(struct mem_block **heap)
246{
247	struct mem_block *p;
248
249	if (!*heap)
250		return;
251
252	for (p = (*heap)->next; p != *heap;) {
253		struct mem_block *q = p;
254		p = p->next;
255		drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
256	}
257
258	drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
259	*heap = NULL;
260}
261
262static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
263{
264	switch (region) {
265	case I915_MEM_REGION_AGP:
266		return &dev_priv->agp_heap;
267	default:
268		return NULL;
269	}
270}
271
272/* IOCTL HANDLERS */
273
274int i915_mem_alloc(struct drm_device *dev, void *data,
275		   struct drm_file *file_priv)
276{
277	drm_i915_private_t *dev_priv = dev->dev_private;
278	drm_i915_mem_alloc_t *alloc = data;
279	struct mem_block *block, **heap;
280
281	if (!dev_priv) {
282		DRM_ERROR("called with no initialization\n");
283		return -EINVAL;
284	}
285
286	heap = get_heap(dev_priv, alloc->region);
287	if (!heap || !*heap)
288		return -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, file_priv);
297
298	if (!block)
299		return -ENOMEM;
300
301	mark_block(dev, block, 1);
302
303	if (DRM_COPY_TO_USER(alloc->region_offset, &block->start,
304			     sizeof(int))) {
305		DRM_ERROR("copy_to_user\n");
306		return -EFAULT;
307	}
308
309	return 0;
310}
311
312int i915_mem_free(struct drm_device *dev, void *data,
313		  struct drm_file *file_priv)
314{
315	drm_i915_private_t *dev_priv = dev->dev_private;
316	drm_i915_mem_free_t *memfree = data;
317	struct mem_block *block, **heap;
318
319	if (!dev_priv) {
320		DRM_ERROR("called with no initialization\n");
321		return -EINVAL;
322	}
323
324	heap = get_heap(dev_priv, memfree->region);
325	if (!heap || !*heap)
326		return -EFAULT;
327
328	block = find_block(*heap, memfree->region_offset);
329	if (!block)
330		return -EFAULT;
331
332	if (block->file_priv != file_priv)
333		return -EPERM;
334
335	mark_block(dev, block, 0);
336	free_block(block);
337	return 0;
338}
339
340int i915_mem_init_heap(struct drm_device *dev, void *data,
341		       struct drm_file *file_priv)
342{
343	drm_i915_private_t *dev_priv = dev->dev_private;
344	drm_i915_mem_init_heap_t *initheap = data;
345	struct mem_block **heap;
346
347	if (!dev_priv) {
348		DRM_ERROR("called with no initialization\n");
349		return -EINVAL;
350	}
351
352	heap = get_heap(dev_priv, initheap->region);
353	if (!heap)
354		return -EFAULT;
355
356	if (*heap) {
357		DRM_ERROR("heap already initialized?");
358		return -EFAULT;
359	}
360
361	return init_heap(heap, initheap->start, initheap->size);
362}
363
364int i915_mem_destroy_heap( struct drm_device *dev, void *data,
365			   struct drm_file *file_priv )
366{
367	drm_i915_private_t *dev_priv = dev->dev_private;
368	drm_i915_mem_destroy_heap_t *destroyheap = data;
369	struct mem_block **heap;
370
371	if ( !dev_priv ) {
372		DRM_ERROR( "called with no initialization\n" );
373		return -EINVAL;
374	}
375
376	heap = get_heap( dev_priv, destroyheap->region );
377	if (!heap) {
378		DRM_ERROR("get_heap failed");
379		return -EFAULT;
380	}
381
382	if (!*heap) {
383		DRM_ERROR("heap not initialized?");
384		return -EFAULT;
385	}
386
387	i915_mem_takedown( heap );
388	return 0;
389}
390