summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/i915_gem_stolen.c
blob: f21ae17e298ffe9e6995aad80512a6e529c8ee1a (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
/*
 * Copyright © 2008-2012 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"

/*
 * The BIOS typically reserves some of the system's memory for the exclusive
 * use of the integrated graphics. This memory is no longer available for
 * use by the OS and so the user finds that his system has less memory
 * available than he put in. We refer to this memory as stolen.
 *
 * The BIOS will allocate its framebuffer from the stolen memory. Our
 * goal is try to reuse that object for our own fbcon which must always
 * be available for panics. Anything else we can reuse the stolen memory
 * for is a boon.
 */

static unsigned long i915_stolen_to_physical(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct pci_dev *pdev = dev_priv->bridge_dev;
	u32 base;

	/* On the machines I have tested the Graphics Base of Stolen Memory
	 * is unreliable, so on those compute the base by subtracting the
	 * stolen memory from the Top of Low Usable DRAM which is where the
	 * BIOS places the graphics stolen memory.
	 *
	 * On gen2, the layout is slightly different with the Graphics Segment
	 * immediately following Top of Memory (or Top of Usable DRAM). Note
	 * it appears that TOUD is only reported by 865g, so we just use the
	 * top of memory as determined by the e820 probe.
	 *
	 * XXX gen2 requires an unavailable symbol and 945gm fails with
	 * its value of TOLUD.
	 */
	base = 0;
	if (INTEL_INFO(dev)->gen >= 6) {
		/* Read Base Data of Stolen Memory Register (BDSM) directly.
		 * Note that there is also a MCHBAR miror at 0x1080c0 or
		 * we could use device 2:0x5c instead.
		*/
		pci_read_config_dword(pdev, 0xB0, &base);
		base &= ~4095; /* lower bits used for locking register */
	} else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
		/* Read Graphics Base of Stolen Memory directly */
		pci_read_config_dword(pdev, 0xA4, &base);
#if 0
	} else if (IS_GEN3(dev)) {
		u8 val;
		/* Stolen is immediately below Top of Low Usable DRAM */
		pci_read_config_byte(pdev, 0x9c, &val);
		base = val >> 3 << 27;
		base -= dev_priv->mm.gtt->stolen_size;
	} else {
		/* Stolen is immediately above Top of Memory */
		base = max_low_pfn_mapped << PAGE_SHIFT;
#endif
	}

	return base;
}

static int i915_setup_compression(struct drm_device *dev, int size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);

	/* Try to over-allocate to reduce reallocations and fragmentation */
	compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
					   size <<= 1, 4096, 0);
	if (!compressed_fb)
		compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
						   size >>= 1, 4096, 0);
	if (compressed_fb)
		compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
	if (!compressed_fb)
		goto err;

	if (HAS_PCH_SPLIT(dev))
		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
	else if (IS_GM45(dev)) {
		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
	} else {
		compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
						    4096, 4096, 0);
		if (compressed_llb)
			compressed_llb = drm_mm_get_block(compressed_llb,
							  4096, 4096);
		if (!compressed_llb)
			goto err_fb;

		dev_priv->compressed_llb = compressed_llb;

		I915_WRITE(FBC_CFB_BASE,
			   dev_priv->mm.stolen_base + compressed_fb->start);
		I915_WRITE(FBC_LL_BASE,
			   dev_priv->mm.stolen_base + compressed_llb->start);
	}

	dev_priv->compressed_fb = compressed_fb;
	dev_priv->cfb_size = size;

	DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
		      size);

	return 0;

err_fb:
	drm_mm_put_block(compressed_fb);
err:
	return -ENOSPC;
}

int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (dev_priv->mm.stolen_base == 0)
		return -ENODEV;

	if (size < dev_priv->cfb_size)
		return 0;

	/* Release any current block */
	i915_gem_stolen_cleanup_compression(dev);

	return i915_setup_compression(dev, size);
}

void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (dev_priv->cfb_size == 0)
		return;

	if (dev_priv->compressed_fb)
		drm_mm_put_block(dev_priv->compressed_fb);

	if (dev_priv->compressed_llb)
		drm_mm_put_block(dev_priv->compressed_llb);

	dev_priv->cfb_size = 0;
}

void i915_gem_cleanup_stolen(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	i915_gem_stolen_cleanup_compression(dev);
	drm_mm_takedown(&dev_priv->mm.stolen);
}

int i915_gem_init_stolen(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
	if (dev_priv->mm.stolen_base == 0)
		return 0;

	DRM_DEBUG_KMS("found %d bytes of stolen memory at %08lx\n",
		      dev_priv->mm.gtt->stolen_size, dev_priv->mm.stolen_base);

	/* Basic memrange allocator for stolen space */
	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->mm.gtt->stolen_size);

	return 0;
}

static struct sg_table *
i915_pages_create_for_stolen(struct drm_device *dev,
			     u32 offset, u32 size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct sg_table *st;
	struct scatterlist *sg;

	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
	BUG_ON(offset > dev_priv->mm.gtt->stolen_size - size);

	/* We hide that we have no struct page backing our stolen object
	 * by wrapping the contiguous physical allocation with a fake
	 * dma mapping in a single scatterlist.
	 */

	st = kmalloc(sizeof(*st), GFP_KERNEL);
	if (st == NULL)
		return NULL;

	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
		kfree(st);
		return NULL;
	}

	sg = st->sgl;
	sg->offset = offset;
	sg->length = size;

	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
	sg_dma_len(sg) = size;

	return st;
}

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
{
	BUG();
	return -EINVAL;
}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
{
	/* Should only be called during free */
	sg_free_table(obj->pages);
	kfree(obj->pages);
}

static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
	.get_pages = i915_gem_object_get_pages_stolen,
	.put_pages = i915_gem_object_put_pages_stolen,
};

static struct drm_i915_gem_object *
_i915_gem_object_create_stolen(struct drm_device *dev,
			       struct drm_mm_node *stolen)
{
	struct drm_i915_gem_object *obj;

	obj = i915_gem_object_alloc(dev);
	if (obj == NULL)
		return NULL;

	if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
		goto cleanup;

	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);

	obj->pages = i915_pages_create_for_stolen(dev,
						  stolen->start, stolen->size);
	if (obj->pages == NULL)
		goto cleanup;

	obj->has_dma_mapping = true;
	obj->pages_pin_count = 1;
	obj->stolen = stolen;

	obj->base.write_domain = I915_GEM_DOMAIN_GTT;
	obj->base.read_domains = I915_GEM_DOMAIN_GTT;
	obj->cache_level = I915_CACHE_NONE;

	return obj;

cleanup:
	i915_gem_object_free(obj);
	return NULL;
}

struct drm_i915_gem_object *
i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_i915_gem_object *obj;
	struct drm_mm_node *stolen;

	if (dev_priv->mm.stolen_base == 0)
		return NULL;

	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
	if (size == 0)
		return NULL;

	stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
	if (stolen)
		stolen = drm_mm_get_block(stolen, size, 4096);
	if (stolen == NULL)
		return NULL;

	obj = _i915_gem_object_create_stolen(dev, stolen);
	if (obj)
		return obj;

	drm_mm_put_block(stolen);
	return NULL;
}

void
i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
{
	if (obj->stolen) {
		drm_mm_put_block(obj->stolen);
		obj->stolen = NULL;
	}
}