summaryrefslogtreecommitdiffstats
path: root/drivers/char/drm/i915_mem.c
blob: d54a3005946b724a8b3deb1a5f8dbf9188cb8b76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
/* i915_mem.c -- Simple agp/fb memory manager for i915 -*- linux-c -*-
 */
/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 **************************************************************************/

#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"

/* This memory manager is integrated into the global/local lru
 * mechanisms used by the clients.  Specifically, it operates by
 * setting the 'in_use' fields of the global LRU to indicate whether
 * this region is privately allocated to a client.
 *
 * This does require the client to actually respect that field.
 *
 * Currently no effort is made to allocate 'private' memory in any
 * clever way - the LRU information isn't used to determine which
 * block to allocate, and the ring is drained prior to allocations --
 * in other words allocation is expensive.
 */
static void mark_block(drm_device_t * dev, struct mem_block *p, int in_use)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
	drm_tex_region_t *list;
	unsigned shift, nr;
	unsigned start;
	unsigned end;
	unsigned i;
	int age;

	shift = dev_priv->tex_lru_log_granularity;
	nr = I915_NR_TEX_REGIONS;

	start = p->start >> shift;
	end = (p->start + p->size - 1) >> shift;

	age = ++sarea_priv->texAge;
	list = sarea_priv->texList;

	/* Mark the regions with the new flag and update their age.  Move
	 * them to head of list to preserve LRU semantics.
	 */
	for (i = start; i <= end; i++) {
		list[i].in_use = in_use;
		list[i].age = age;

		/* remove_from_list(i)
		 */
		list[(unsigned)list[i].next].prev = list[i].prev;
		list[(unsigned)list[i].prev].next = list[i].next;

		/* insert_at_head(list, i)
		 */
		list[i].prev = nr;
		list[i].next = list[nr].next;
		list[(unsigned)list[nr].next].prev = i;
		list[nr].next = i;
	}
}

/* Very simple allocator for agp memory, working on a static range
 * already mapped into each client's address space.  
 */

static struct mem_block *split_block(struct mem_block *p, int start, int size,
				     DRMFILE filp)
{
	/* Maybe cut off the start of an existing block */
	if (start > p->start) {
		struct mem_block *newblock = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
		if (!newblock)
			goto out;
		newblock->start = start;
		newblock->size = p->size - (start - p->start);
		newblock->filp = NULL;
		newblock->next = p->next;
		newblock->prev = p;
		p->next->prev = newblock;
		p->next = newblock;
		p->size -= newblock->size;
		p = newblock;
	}

	/* Maybe cut off the end of an existing block */
	if (size < p->size) {
		struct mem_block *newblock = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
		if (!newblock)
			goto out;
		newblock->start = start + size;
		newblock->size = p->size - size;
		newblock->filp = NULL;
		newblock->next = p->next;
		newblock->prev = p;
		p->next->prev = newblock;
		p->next = newblock;
		p->size = size;
	}

      out:
	/* Our block is in the middle */
	p->filp = filp;
	return p;
}

static struct mem_block *alloc_block(struct mem_block *heap, int size,
				     int align2, DRMFILE filp)
{
	struct mem_block *p;
	int mask = (1 << align2) - 1;

	for (p = heap->next; p != heap; p = p->next) {
		int start = (p->start + mask) & ~mask;
		if (p->filp == NULL && start + size <= p->start + p->size)
			return split_block(p, start, size, filp);
	}

	return NULL;
}

static struct mem_block *find_block(struct mem_block *heap, int start)
{
	struct mem_block *p;

	for (p = heap->next; p != heap; p = p->next)
		if (p->start == start)
			return p;

	return NULL;
}

static void free_block(struct mem_block *p)
{
	p->filp = NULL;

	/* Assumes a single contiguous range.  Needs a special filp in
	 * 'heap' to stop it being subsumed.
	 */
	if (p->next->filp == NULL) {
		struct mem_block *q = p->next;
		p->size += q->size;
		p->next = q->next;
		p->next->prev = p;
		drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
	}

	if (p->prev->filp == NULL) {
		struct mem_block *q = p->prev;
		q->size += p->size;
		q->next = p->next;
		q->next->prev = q;
		drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
	}
}

/* Initialize.  How to check for an uninitialized heap?
 */
static int init_heap(struct mem_block **heap, int start, int size)
{
	struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);

	if (!blocks)
		return -ENOMEM;

	*heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
	if (!*heap) {
		drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
		return -ENOMEM;
	}

	blocks->start = start;
	blocks->size = size;
	blocks->filp = NULL;
	blocks->next = blocks->prev = *heap;

	memset(*heap, 0, sizeof(**heap));
	(*heap)->filp = (DRMFILE) - 1;
	(*heap)->next = (*heap)->prev = blocks;
	return 0;
}

/* Free all blocks associated with the releasing file.
 */
void i915_mem_release(drm_device_t * dev, DRMFILE filp, struct mem_block *heap)
{
	struct mem_block *p;

	if (!heap || !heap->next)
		return;

	for (p = heap->next; p != heap; p = p->next) {
		if (p->filp == filp) {
			p->filp = NULL;
			mark_block(dev, p, 0);
		}
	}

	/* Assumes a single contiguous range.  Needs a special filp in
	 * 'heap' to stop it being subsumed.
	 */
	for (p = heap->next; p != heap; p = p->next) {
		while (p->filp == NULL && p->next->filp == NULL) {
			struct mem_block *q = p->next;
			p->size += q->size;
			p->next = q->next;
			p->next->prev = p;
			drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
		}
	}
}

/* Shutdown.
 */
void i915_mem_takedown(struct mem_block **heap)
{
	struct mem_block *p;

	if (!*heap)
		return;

	for (p = (*heap)->next; p != *heap;) {
		struct mem_block *q = p;
		p = p->next;
		drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
	}

	drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
	*heap = NULL;
}

static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
{
	switch (region) {
	case I915_MEM_REGION_AGP:
		return &dev_priv->agp_heap;
	default:
		return NULL;
	}
}

/* IOCTL HANDLERS */

int i915_mem_alloc(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_mem_alloc_t alloc;
	struct mem_block *block, **heap;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(alloc, (drm_i915_mem_alloc_t __user *) data,
				 sizeof(alloc));

	heap = get_heap(dev_priv, alloc.region);
	if (!heap || !*heap)
		return DRM_ERR(EFAULT);

	/* Make things easier on ourselves: all allocations at least
	 * 4k aligned.
	 */
	if (alloc.alignment < 12)
		alloc.alignment = 12;

	block = alloc_block(*heap, alloc.size, alloc.alignment, filp);

	if (!block)
		return DRM_ERR(ENOMEM);

	mark_block(dev, block, 1);

	if (DRM_COPY_TO_USER(alloc.region_offset, &block->start, sizeof(int))) {
		DRM_ERROR("copy_to_user\n");
		return DRM_ERR(EFAULT);
	}

	return 0;
}

int i915_mem_free(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_mem_free_t memfree;
	struct mem_block *block, **heap;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(memfree, (drm_i915_mem_free_t __user *) data,
				 sizeof(memfree));

	heap = get_heap(dev_priv, memfree.region);
	if (!heap || !*heap)
		return DRM_ERR(EFAULT);

	block = find_block(*heap, memfree.region_offset);
	if (!block)
		return DRM_ERR(EFAULT);

	if (block->filp != filp)
		return DRM_ERR(EPERM);

	mark_block(dev, block, 0);
	free_block(block);
	return 0;
}

int i915_mem_init_heap(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_mem_init_heap_t initheap;
	struct mem_block **heap;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(initheap,
				 (drm_i915_mem_init_heap_t __user *) data,
				 sizeof(initheap));

	heap = get_heap(dev_priv, initheap.region);
	if (!heap)
		return DRM_ERR(EFAULT);

	if (*heap) {
		DRM_ERROR("heap already initialized?");
		return DRM_ERR(EFAULT);
	}

	return init_heap(heap, initheap.start, initheap.size);
}